Rashmi Rathour
Jawaharlal Nehru University, School of Environmental Sciences, Department Member
- Research work focused on the study of culture-dependent and independent approaches to investigate the role of bacteri... moreResearch work focused on the study of culture-dependent and independent approaches to investigate the role of bacterial diversity in biodegradation and bio-valorization of pollutants to solve the increasing toxic waste burden at the contaminated sites.edit
Fast growth of bamboo species make them a suitable candidate for eco-restoration, while its lignocellulosic substrate could be used for production of high-value green products such as biofuels, chemicals, and biomaterials. Within these... more
Fast growth of bamboo species make them a suitable candidate for eco-restoration, while its lignocellulosic substrate could be used for production of high-value green products such as biofuels, chemicals, and biomaterials. Within these frameworks, this review comprehensively explored the thermochemical and biological conversion of bamboo biomass to value-added fuels and chemicals. Additionally, this review stretches an indepth understanding of bamboo biomass lignin extraction technologies and bioengineered methodologies, as well as their biorefinery conversion strategies. Additionally, bamboo biomass often utilized in biorefineries are mostly constituted of cellulose, hemicellulose, and lignin, along with proteins, lipids, and a few micronutrients which are not utilized efficientely by current bioengineered techniques. The results indicates that the potential for producing high-value products from bamboo biomass has not been adequately explored. However, enormous potential is still available to make bamboo biorefinery technologies cost-effective, and environmentally sustainable, which are discussed in the current review comprehensively. Furthermore, processes such as pretreatment, enzymatic hydrolysis, and fermentation are essential to obtain final high-value bio-based products from bamboo biomass, therefore, this review critically designed to explore the current state of the art of these technologies. Overall, the current review establishes a zero-waste sustainable approach for the reformation of bamboo biomass into chemicals, biofuels, and value-added products.
Research Interests:
Research Interests:
Research Interests:
Increasing population, industrialization, and economic growth cause several adverse impacts on the existing environment and living being. Therefore, rising pollutants load and their mitigation strategies, as well as achieving energy... more
Increasing population, industrialization, and economic growth cause several adverse impacts on the existing environment and living being. Therefore, rising pollutants load and their mitigation strategies, as well as achieving energy requirements while reducing reliance on fossil fuels are the key areas, which needs significant consideration for sustainable environment. Since India has considerable biomass resources, bioenergy is a significant part of the country's energy policy. However, the selection of feedstock is a crucial step in bioenergy production that could produce raw material without compromising food reserve along with the sustainable environment. Higher growth capacity of bamboo species makes them a suitable lignocellulosic substrate for the production of high-value greener products such as fuels, chemicals, and biomaterials as well as an appropriate candidate for eco-restoration of degraded land. In that context, the current review discusses the multidimensional applications of bamboo species in India. The bioenergy potency of bamboo and probability of aligning its production, cultivation, and operation with economic and social development agendas are also addressed, making it an exceptional crop in India. Additionally, its fast growth, perennial root systems, and capability to restore degraded land make it an essential part of ecological restoration. Furthermore, this review explores additional benefits of bamboo plantation on the environment, economy, and society along with future research prospects.
Research Interests:
Research Interests:
Globally, there are concerning trends of waste generation as we progress towards a more developed society. India, the second most populous country, is on the edge of being the fifth largest economy in the world. In the last five decades,... more
Globally, there are concerning trends of waste generation as we progress towards a more developed society. India, the second most populous country, is on the edge of being the fifth largest economy in the world. In the last five decades, its metropolitanization has increased by approximately 10% and would further rise to 20% by 2026. The increasing urbanization and evolving lifestyles, food habits, and standards prompt such exponential expansion of robust waste. It is basically answerable for the introduction of a waste era posing various threats to health and causing ecological deformities. In 1996, the urban number created around 114,576 tonnes of municipal solid waste (MSW) per day, which is predicted to be 440,460 tonnes per day−1 by 2026. A large section of the waste is handled using the concept of 3Rs (reduce, reuse, and recycle), but the biological microbial potential is still underestimated. Less than 1% of the microbial community is culturable due to which the conservative ...
Research Interests:
Polycyclic aromatic hydrocarbons (PAHs) such as pyrene are universal contaminants existing in the environment which have known cancer-causing and mutagenic characteristics. A psychrophilic bacterial strain Shewanella sp. ISTPL2 was... more
Polycyclic aromatic hydrocarbons (PAHs) such as pyrene are universal contaminants existing in the environment which have known cancer-causing and mutagenic characteristics. A psychrophilic bacterial strain Shewanella sp. ISTPL2 was isolated from the sediment sample collected from the Pangong lake, Jammu & Kashmir, India. In our previous study, the pyrene degradation potential of the ISTPL2 strain was studied in both mineral salt media as well as in soil artificially spiked with different concentrations of pyrene. Whole-genome sequencing of ISTPL2 strain in the current study highlighted the key genes of pyrene metabolism, including alcohol dehydrogenase and ring hydroxylating dioxygenase alpha-subunit. Pyrene cytotoxicity was evaluated on HepG2, a human hepato-carcinoma cell line. The cytotoxicity of the organic extract decreased with the increasing duration of bacterial treatment. To develop a more sustainable biodegradation approach, the potential impacts were evaluated for human health and ecosystem using life-cycle assessment (LCA) following the ReCiPe methodology for the considered PAH. The results implemented that global warming potential (GWP) had the highest impact, whereas both ecotoxicity and human toxicity had least from this study.
Research Interests:
The current study demonstrates the enhanced production capability of strain Cupriavidus sp. ISTL7 for polyhydroxyalkanoates (PHA) using acetate and glucose (4.93 ± 0.4571 g L-1) which was characterised analytically by GC-MS, FTIR and NMR... more
The current study demonstrates the enhanced production capability of strain Cupriavidus sp. ISTL7 for polyhydroxyalkanoates (PHA) using acetate and glucose (4.93 ± 0.4571 g L-1) which was characterised analytically by GC-MS, FTIR and NMR analysis. Whole genome sequencing of strain ISTL7 unveiled an array of PHA metabolism genes which included phaA, phaB and phaC. Life cycle assessment of the protocol established that the production was most sustainable with the carbon source acetate. + Glucose as compared to acetate/glucose alone. It also concluded that solvent extraction of PHA and energy consumption during the process requires optimization to sustain the production on ecological fronts. Additionally, acetoacetyl-CoA reductase (phaB) gene was molecularly cloned, expressed and purified (27 KDa, 2.63 mg/ml). Conclusively, Cupriavidus sp. ISTL7 is a potential strain for PHA production with a scope of improvement on energy fronts which would transform the production environmentally and economically appealing.
Research Interests:
The present study discusses the genomic analysis of Bacillus sp. ISTL8 along with the production of EPS (Extracellular polymeric substances) using carbofuran, a toxic carbamate pesticide. Bacillus strain was isolated from landfill soil... more
The present study discusses the genomic analysis of Bacillus sp. ISTL8 along with the production of EPS (Extracellular polymeric substances) using carbofuran, a toxic carbamate pesticide. Bacillus strain was isolated from landfill soil and evaluated for high growth rates and EPS production. One strain, renamed ISTL8 grew on a broad range of carbon sources, including toxic carbofuran, while producing copious EPS. Growth assays verified the strain to be thermophilic, low salt tolerant, and with a preference for neutral pH. SEM (Scanning Electron Microscopy) was used for morphological characterization of the EPS while the monomeric composition, bonding patterns and functional groups were deduced by GC-MS (Gas Chromatography-Mass Spectrometry), 1H and 13C NMR (Nuclear Magnetic Resonance) and FTIR (Fourier Transform Infrared Spectroscopy). The production of EPS using carbofuran (carbamate pesticide) as a carbon source was found to be 6.20 ± 0.29 g L-1 containing 61.17% w/w carbohydrates, 29.72% w/w proteins and 6.11% w/w lipids (of dry EPS). The potential cytotoxicity of EPS was evaluated with 3- (4,5-dimethyl thiazol-2-Yl) -2,5-diphenyl tetrazolium bromide (MTT) assay and found non-toxic (2.25%). WGS (Whole genome sequencing) was performed for the strain Bacillus sp. ISTL8 producing EPS; an array of genes putatively involved in the EPS production were identified in several different genomic locations, guiding potential genetic manipulation studies in the future. The results highlight the potency of a bacterial isolate Bacillus sp. ISTL8 to produce non-cytotoxic EPS using carbofuran that can be further harnessed for environmental and commercial applications. Additionally, WGS revealed an array of EPS specific genes which can be effectively engineered for much enhanced production.
Research Interests:
A psychrophilic and halophilic bacterial isolate, Shewanella sp. ISTPL2, procured from the pristine Pangong Lake, Ladakh, Jammu and Kashmir, India, was used for the production and characterization of the psychrophilic and alkalophilic... more
A psychrophilic and halophilic bacterial isolate, Shewanella sp. ISTPL2, procured from the pristine Pangong Lake, Ladakh, Jammu and Kashmir, India, was used for the production and characterization of the psychrophilic and alkalophilic α-amylase enzyme. The α-amylase is a critical enzyme that catalyses the hydrolysis of α-1,4-glycosidic bonds of starch molecules and is predominately utilized in biotechnological applications. The highest enzyme activity of partially purified extracellular α-amylase was 10,064.20 U/mL after 12 h of incubation in a shake flask at pH 6.9 and 10 °C. Moreover, the maximum intracellular α-amylase enzyme activity (259.62 U/mL) was also observed at 6 h of incubation. The extracellular α-amylase was refined to the homogeneity with the specific enzyme activity of 36,690.47 U/mg protein corresponding to 6.87-fold purification. The optimized pH and temperature for the α-amylase were found to be pH 8 and 4 °C, respectively, suggesting its stability at alkaline con...
Research Interests:
Abstract The increasing load on the ecosystem with activities, such as deforestation, exploited land use, industrialization, and excess waste generation, leads to a global climate shift, which is one of the leading environmental issues of... more
Abstract The increasing load on the ecosystem with activities, such as deforestation, exploited land use, industrialization, and excess waste generation, leads to a global climate shift, which is one of the leading environmental issues of the world today. The basic biomolecules for the production of biofuel include fatty acids, alcohols, and alkanes. Biodiesel is composed of monoalkyl esters of higher chain of fatty acids, produced though the transesterification reaction by alcohol in the presence of a catalyst. Hydrocarbons are the metabolic by-product of many bacterial sp. and generally produced from fatty acids and triacylglycerol (TAG). Bacterial lipids and TAG are the precursor material for improved biofuel production, because of their wide application in the production of different chain length hydrocarbons. The advance science of genetic engineering can help in modification of the conventional approaches of production in order to achieve a higher yield of such biological materials. Therefore by employing a joint strategy of natural and altered synthetic (fatty acid biosynthesis) pathways in bacteria, the production of valuable chemicals and fuels is expected to be enhanced in future.
Research Interests:
Research Interests:
Research Interests:
We report the soil microbial diversity and functional aspects related to degradation of recalcitrant compounds, determined using a metagenomic approach, in a landfill lysimeter prepared with soil from Ghazipur landfill site, New Delhi,... more
We report the soil microbial diversity and functional aspects related to degradation of recalcitrant compounds, determined using a metagenomic approach, in a landfill lysimeter prepared with soil from Ghazipur landfill site, New Delhi, India. Metagenomic analysis revealed the presence and functional diversity of complex microbial communities responsible for waste degradation.
Research Interests:
Pangong is a brackish water lake having environmental conditions that are hostile to supporting life. This is the first report unveiling the microbial diversity of sediment from Pangong Lake, Ladakh, India, using a high-throughput... more
Pangong is a brackish water lake having environmental conditions that are hostile to supporting life. This is the first report unveiling the microbial diversity of sediment from Pangong Lake, Ladakh, India, using a high-throughput metagenomic approach. Metagenomic data analysis revealed a community structure of microbes in which functional genetic diversity facilitates their survival.
Research Interests: Biology and Metagenomics
An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas sp. ISTPL3 isolated from Pangong lake. Lipase was purified by sequential methods of ammonium sulphate precipitation, dialysis,... more
An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas sp. ISTPL3 isolated from Pangong lake. Lipase was purified by sequential methods of ammonium sulphate precipitation, dialysis, DEAE-cellulose ion exchange chromatography and Sephadex G-100 gel filtration chromatography, resulting in a purification fold of 6.53 and yield of 5.45%. The molecular weight was approximately 31kDa. The purified lipase was used for transesterification of lipids produced by oleaginous chemolithotrophic bacterium Serratia sp. ISTD04 for production of biodiesel. Upon biochemical characterization, lipase was found to be alkalophilc, thermostable, active in organic polar solvents and sensitive to detergents. Further, lipase was immobilized on activated biochar to assess its transesterification efficiency during biodiesel production. Immobilized lipase gave the highest yield of fatty acid methyl esters (FAMEs) (92.23%)>unimmobilized lipase>NaOH. The immobilized...
Research Interests:
An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas sp. ISTPL3 isolated from Pangong lake. Lipase was purified by sequential methods of ammonium sulphate precipitation, dialysis,... more
An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas sp. ISTPL3 isolated from Pangong lake. Lipase was purified by sequential methods of ammonium sulphate precipitation, dialysis, DEAE-cellulose ion exchange chromatography and Sephadex G-100 gel filtration chromatography, resulting in a purification fold of 6.53 and yield of 5.45%. The molecular weight was approximately 31kDa. The purified lipase was used for transesterification of lipids produced by oleaginous chemolithotrophic bacterium Serratia sp. ISTD04 for production of biodiesel. Upon biochemical characterization, lipase was found to be alkalophilc, thermostable, active in organic polar solvents and sensitive to detergents. Further, lipase was immobilized on activated biochar to assess its transesterification efficiency during biodiesel production. Immobilized lipase gave the highest yield of fatty acid methyl esters (FAMEs) (92.23%)>unimmobilized lipase>NaOH. The immobilized...
Research Interests:
Polycyclic aromatic hydrocarbons (PAHs) are universal environmental contaminants of great concern with regard to their potential exposure and deleterious effect on human health. The current study is the first report of phenanthrene... more
Polycyclic aromatic hydrocarbons (PAHs) are universal environmental contaminants of great concern with regard to their potential exposure and deleterious effect on human health. The current study is the first report of phenanthrene degradation by a psychrotolerant (15 °C), halophilic (5% NaCl), and alkalophilic (pH 8) bacterial strain Zhihengliuella sp. ISTPL4, isolated from the sediment sample of the Pangong Lake, Ladakh, Jammu and Kashmir, India. Degradation studies revealed that the optimum specific growth rate was observed at 250 ppm of phenanthrene with 81% and 87% removal of phenanthrene in 72 h and 168 h, respectively. During the degradation of phenanthrene; 9,10-dihydrophenanthrene; 1-phenanthrenecarboxylic acid; and phthalic acid were detected as intermediates. Whole-genome sequencing of strain ISTPL4 has predicted phenanthrene; 9,10-monooxygense; and epoxide hydrolase B that are involved in the phenanthrene metabolism. Phenanthrene cytotoxicity was evaluated with human hepatic carcinoma cell line (HepG2) and it was observed that the cytotoxicity decreased with increased duration of bacterial incubation and maximum cell viability was observed at 168 h (89.92%). Our results suggest, Zhihengliuella sp. ISTPL4 may promise a great potential for environmental remediation applications.
Research Interests:
Livestock manure (LSM) is a profitable waste if handled sensibly, but simultaneously it imposes several environmental and health impacts if managed improperly. Several approaches have been adopted globally to cartel the problem associated... more
Livestock manure (LSM) is a profitable waste if handled sensibly, but simultaneously it imposes several environmental and health impacts if managed improperly. Several approaches have been adopted globally to cartel the problem associated with LSM management and recovery of value-added products, still, technological innovation needs further upgradation in consideration with the environment, energy, and economy. This review delivered a vibrant portrait of manure management, which includes, bioenergy generation and resource recovery strategies, their current scenario, opportunities, challenges, and prospects for future researches along with global regulations and policies. Several bioenergy generation and nutrient recoveries technologies have been discussed in details, still, the major glitches allied with these technologies are its high establishment costs, operational costs, manure assortment, and digestate handling. This review also discussed the techno-economic assessment (TEA) and life cycle assessment (LCA) of LSM management operation in the context of their economical and environmental sustainability. Still, extensive researches needed to build an efficient manure management framework to advance the integrated bioenergy production, nutrients recycling, and digestate utilization with least environmental impacts and maximal economical gain, which has critically discussed in the current review.
Research Interests:
Increasing population, industrialization, and economic growth cause several adverse impacts on the existing environment and living being. Therefore, rising pollutants load and their mitigation strategies, as well as achieving energy... more
Increasing population, industrialization, and economic growth cause several adverse impacts on the existing environment and living being. Therefore, rising pollutants load and their mitigation strategies, as well as achieving energy requirements while reducing reliance on fossil fuels are the key areas, which needs significant consideration for sustainable environment. Since India has considerable biomass resources, bioenergy is a significant part of the country's energy policy. However, the selection of feedstock is a crucial step in bioenergy production that could produce raw material without compromising food reserve along with the sustainable environment. Higher growth capacity of bamboo species makes them a suitable lignocellulosic substrate for the production of high-value greener products such as fuels, chemicals, and biomaterials as well as an appropriate candidate for eco-restoration of degraded land. In that context, the current review discusses the multidimensional applications of bamboo species in India. The bioenergy potency of bamboo and probability of aligning its production, cultivation, and operation with economic and social development agendas are also addressed, making it an exceptional crop in India. Additionally, its fast growth, perennial root systems, and capability to restore degraded land make it an essential part of ecological restoration. Furthermore, this review explores additional benefits of bamboo plantation on the environment, economy, and society along with future research prospects.
Research Interests:
Livestock manure (LSM) is a profitable waste if handled sensibly, but simultaneously it imposes several environmental and health impacts if managed improperly. Several approaches have been adopted globally to cartel the problem associated... more
Livestock manure (LSM) is a profitable waste if handled sensibly, but simultaneously it imposes several environmental and health impacts if managed improperly. Several approaches have been adopted globally to cartel the problem associated with LSM management and recovery of value-added products, still, technological innovation needs further upgradation in consideration with the environment, energy, and economy. This review delivered a vibrant portrait of manure management, which includes, bioenergy generation and resource recovery strategies, their current scenario, opportunities, challenges, and prospects for future researches along with global regulations and policies. Several bioenergy generation and nutrient recoveries technologies have been discussed in details, still, the major glitches allied with these technologies are its high establishment costs, operational costs, manure assortment, and digestate handling. This review also discussed the techno-economic assessment (TEA) and life cycle assessment (LCA) of LSM management operation in the context of their economical and environmental sustainability. Still, extensive researches needed to build an efficient manure management framework to advance the integrated bioenergy production, nutrients recycling, and digestate utilization with least environmental impacts and maximal economical gain, which has critically discussed in the current review.
Research Interests:
Lignocellulosic biomass is an abundant resource with untapped potential for biofuel, enzymes, and chemical production. Its complex recalcitrant structure obstructs its bioconversion into biofuels and other value-added products. For... more
Lignocellulosic biomass is an abundant resource with untapped potential for biofuel, enzymes, and chemical production.
Its complex recalcitrant structure obstructs its bioconversion into biofuels and other value-added products. For
improving its bioconversion efficiency, it is important to deconstruct its complex structure. In natural systems like
rumen, diverse microbial communities carry out hydrolysis, acidogenesis, acetogenesis, and methanogenesis of lignocellulosic
biomass through physical penetration, synergistic and enzymatic actions enhancing lignocellulose degradation
activity. This review article aims to discuss comprehensively the rumen microbial ecosystem, their interactions,
enzyme production, and applications for efficient bioconversion of lignocellulosic waste to biofuels. Furthermore,
meta ‘omics’ approaches to elucidate the structure and functions of rumen microorganisms, fermentation mechanisms,
microbe-microbe interactions, and host-microbe interactions have been discussed thoroughly. Additionally, feed additives'
role in improving ruminal fermentation efficiency and reducing environmental nitrogen losses has been discussed.
Finally, the current status of rumen microbiota applications and future perspectives for the development of
rumen mimic bioreactors for efficient bioconversion of lignocellulosic wastes to biofuels and chemicals have been
highlighted.
Its complex recalcitrant structure obstructs its bioconversion into biofuels and other value-added products. For
improving its bioconversion efficiency, it is important to deconstruct its complex structure. In natural systems like
rumen, diverse microbial communities carry out hydrolysis, acidogenesis, acetogenesis, and methanogenesis of lignocellulosic
biomass through physical penetration, synergistic and enzymatic actions enhancing lignocellulose degradation
activity. This review article aims to discuss comprehensively the rumen microbial ecosystem, their interactions,
enzyme production, and applications for efficient bioconversion of lignocellulosic waste to biofuels. Furthermore,
meta ‘omics’ approaches to elucidate the structure and functions of rumen microorganisms, fermentation mechanisms,
microbe-microbe interactions, and host-microbe interactions have been discussed thoroughly. Additionally, feed additives'
role in improving ruminal fermentation efficiency and reducing environmental nitrogen losses has been discussed.
Finally, the current status of rumen microbiota applications and future perspectives for the development of
rumen mimic bioreactors for efficient bioconversion of lignocellulosic wastes to biofuels and chemicals have been
highlighted.
Research Interests:
Research Interests:
The present study demonstrates EPS production by Cupriavidus sp. ISTL7 along with its capability to remediate a toxic carbamate pesticide, carbofuran. The strain ISTL7 efficiently degraded approximately 98% of carbofuran (400 ppm) within... more
The present study demonstrates EPS production by Cupriavidus sp. ISTL7 along with its capability to remediate a toxic carbamate pesticide, carbofuran. The strain ISTL7 efficiently degraded approximately 98% of carbofuran (400 ppm) within 96 h. GC-MS analysis showed catabolic metabolites of degradation which included carbofuran-7-phenol, methylamine, 2-hydroxy-3-(3-methylpropan-2-ol)benzene-N-methyl-carbamate etc. EPS production from the mineral medium supplemented with carbofuran was observed to be 3.112 ± 0.3682 g L-1. FTIR confirmed its carbohydrate composition and the monomeric sugars: glucose, xylose, sorbitol and fructose were identified by GC-MS analysis. The toxic potential of degradation experiment and the produced EPS was evaluated on HepG2 (mammalian liver cell line). The cytotoxicity of carbofuran was reduced upon bacterial degradation and the formed EPS was found to be non-toxic as inferred from percentage cell viability. The present research can possibly influence the d...
• The metagenome of the Pangong lake performed using Illumina NextSeq500 platform. • Proteobacteria and Methylophaga were most prominent at the phylum and genus levels, respectively. • The Pangong lake metagenome compared with three... more
• The metagenome of the Pangong lake performed using Illumina NextSeq500 platform. • Proteobacteria and Methylophaga were most prominent at the phylum and genus levels, respectively. • The Pangong lake metagenome compared with three different aquatic habitats. • Microbial community of the Pangong lake contains six unique genera. The environment of a high altitude brackish water lake presents an unprecedented reservoir for the microbial community with adaptability towards surviving stressful conditions. Pangong lake is a high altitude brackish water lake of the Himalayas situated in the eastern part of Ladakh (Indian Tibet), at the height of 4250 m above the sea level. Shotgun metagenomics sequencing of Pangong Lake sediments was performed to examine the taxonomic diversity and functional adaptations of the resident psychrophilic and psychrotolerant microbial communities of the lake (September; a temperature of ±10°C). Proteobacteria was the most prominent phylum, and Methylophaga, Halomonas, and Marinobacter were mainly abundant at the genus level. Enzyme pathways responsible for methane metabolism, nitrogen metabolism, sulfur reduction, benzoate, and xylene degradation appeared to be complete in the metagenomic dataset. Stress response genes responsible for adaption to pH, cold, salt tolerance, osmotic stress, and oxidative stress were also found in abundance in the metagenome. We compared the Pangong lake metagenome sample to sediments and water samples from three different aquatic habitats, namely saline lake, freshwater lakes and marine ecosystem using MG-RAST server against RefSeq and Subsystem databases. The Pangong lake microbial community contains six unique genera. Regression analysis using metagenome samples suggested that Pangong lake was most closely related to the Trophic South Pacific Ocean (R 2 = 0.971) and Socompa lake ecosystem (R 2 = 0.991) at phylum and functional level II, respectively. Our study signifies that the functional metabolic potentiality of Pangong lake is strongly influenced by the taxonomic structure and environmental conditions. We are reporting the metagenome of the sediment sample of the Pangong lake, which unveils the microbial diversity and their functional potential.
Research Interests:
A psychrophilic and halophilic bacterial isolate, Shewanella sp. ISTPL2, procured from the pristine Pangong Lake, Ladakh, Jammu and Kashmir, India, was used for the production and characterization of the psychrophilic and alkalophilic... more
A psychrophilic and halophilic bacterial isolate, Shewanella sp. ISTPL2, procured from the pristine Pangong Lake, Ladakh, Jammu and Kashmir, India, was used for the production and characterization of the psychrophilic and alkalophilic α-amylase enzyme. The α-amylase is a critical enzyme that catalyses the hydrolysis of α-1,4-glycosidic bonds of starch molecules and is predominately utilized in biotechnological applications. The highest enzyme activity of partially purified extracellular α-amylase was 10,064.20 U/mL after 12 h of incubation in a shake flask at pH 6.9 and 10 °C. Moreover, the maximum intracellular α-amylase enzyme activity (259.62 U/mL) was also observed at 6 h of incubation. The extracellular α-amylase was refined to the homogeneity with the specific enzyme activity of 36,690.47 U/mg protein corresponding to 6.87fold purification. The optimized pH and temperature for the α-amylase were found to be pH 8 and 4 °C, respectively, suggesting its stability at alkaline conditions and low or higher temperatures. The amylase activity was highly activated by Cu 2+ , Fe 2+ and Ca 2+ , while inhibited by Cd 2+ , Co 2+ and Na 2+. As per our knowledge, the current study reports the highest activity of a psychrophilic α-amylase enzyme providing prominent biotechnological potential.
Research Interests:
The current study demonstrates the enhanced production capability of strain Cupriavidus sp. ISTL7 for polyhydroxyalkanoates (PHA) using acetate and glucose (4.93 ± 0.4571 g L-1) which was characterised analytically by GC–MS, FTIR and NMR... more
The current study demonstrates the enhanced production capability of strain Cupriavidus sp. ISTL7 for polyhydroxyalkanoates (PHA) using acetate and glucose (4.93 ± 0.4571 g L-1) which was characterised analytically by GC–MS, FTIR and NMR analysis. Whole genome sequencing of strain ISTL7 unveiled an array of PHA metabolism genes which included phaA, phaB and phaC. Life cycle assessment of the protocol established that the production was most sustainable with the carbon source acetate. Glucose as compared to acetate/glucose alone. It also concluded that solvent extraction of PHA and energy consumption during the process requires optimization to sustain the production on ecological fronts. Additionally, acetoacetyl-CoA reductase (phaB) gene was molecularly cloned, expressed and purified (27 KDa, 2.63 mg/ml). Conclusively, Cupriavidus sp. ISTL7 is a potential strain for PHA production with a scope of improvement on energy fronts which would transform the production environmentally and economically appealing.
Research Interests:
Polycyclic aromatic hydrocarbons (PAHs) such as pyrene are universal contaminants existing in the environment which have known cancer-causing and mutagenic characteristics. A psychrophilic bacterial strain Shewanella sp. ISTPL2 was... more
Polycyclic aromatic hydrocarbons (PAHs) such as pyrene are universal contaminants existing in the environment which have known cancer-causing and mutagenic characteristics. A psychrophilic bacterial strain Shewanella sp. ISTPL2 was isolated from the sediment sample collected from the Pangong lake, Jammu & Kashmir, India. In our previous study, the pyrene degradation potential of the ISTPL2 strain was studied in both mineral salt media as well as in soil artificially spiked with different concentrations of pyrene. Whole-genome sequencing of ISTPL2 strain in the current study highlighted the key genes of pyrene metabolism, including alcohol dehydrogenase and ring hydroxylating dioxygenase alpha-subunit. Pyrene cytotoxicity was evaluated on HepG2, a human hepato-carcinoma cell line. The cytotoxicity of the organic extract decreased with the increasing duration of bacterial treatment. To develop a more sustainable biodegradation approach, the potential impacts were evaluated for human health and ecosystem using life-cycle assessment (LCA) following the ReCiPe methodology for the considered PAH. The results implemented that global warming potential (GWP) had the highest impact, whereas both ecotoxicity and human toxicity had least from this study.
Research Interests:
• The metagenome of the Pangong lake performed using Illumina NextSeq500 platform. • Proteobacteria and Methylophaga were most prominent at the phylum and genus levels, respectively. • The Pangong lake metagenome compared with three... more
• The metagenome of the Pangong lake performed using Illumina NextSeq500 platform. • Proteobacteria and Methylophaga were most prominent at the phylum and genus levels, respectively. • The Pangong lake metagenome compared with three different aquatic habitats. • Microbial community of the Pangong lake contains six unique genera. The environment of a high altitude brackish water lake presents an unprecedented reservoir for the microbial community with adaptability towards surviving stressful conditions. Pangong lake is a high altitude brackish water lake of the Himalayas situated in the eastern part of Ladakh (Indian Tibet), at the height of 4250 m above the sea level. Shotgun metagenomics sequencing of Pangong Lake sediments was performed to examine the taxonomic diversity and functional adaptations of the resident psychrophilic and psychrotolerant microbial communities of the lake (September; a temperature of ±10°C). Proteobacteria was the most prominent phylum, and Methylophaga, Halomonas, and Marinobacter were mainly abundant at the genus level. Enzyme pathways responsible for methane metabolism, nitrogen metabolism, sulfur reduction, benzoate, and xylene degradation appeared to be complete in the metagenomic dataset. Stress response genes responsible for adaption to pH, cold, salt tolerance, osmotic stress, and oxidative stress were also found in abundance in the metagenome. We compared the Pangong lake metagenome sample to sediments and water samples from three different aquatic habitats, namely saline lake, freshwater lakes and marine ecosystem using MG-RAST server against RefSeq and Subsystem databases. The Pangong lake microbial community contains six unique genera. Regression analysis using metagenome samples suggested that Pangong lake was most closely related to the Trophic South Pacific Ocean (R 2 = 0.971) and Socompa lake ecosystem (R 2 = 0.991) at phylum and functional level II, respectively. Our study signifies that the functional metabolic potentiality of Pangong lake is strongly influenced by the taxonomic structure and environmental conditions. We are reporting the metagenome of the sediment sample of the Pangong lake, which unveils the microbial diversity and their functional potential.
Research Interests:
Excessive utilization of synthetic plastics has led to a major detrimental impact on the environment. Plastic pollution and accumulation in water bodies have threatened the survival of marine life. Plastic pollution can be prevented by... more
Excessive utilization of synthetic plastics has led to a major detrimental impact on the environment.
Plastic pollution and accumulation in water bodies have threatened the survival of marine life. Plastic
pollution can be prevented by using biopolymers that are eco-friendly and can be naturally produced by
certain living organisms. The biopolymers have environmental advantages over synthetic plastics, such
as biodegradability and biocompatibility. In comparison to plants and other microbial systems, bacteria
can accumulate a high amount of polyhydroxyalkanoates (PHAs). However, the major stumbling block in
the production of bacterial PHAs is its low cost-effectiveness due to costs associated with fermentaion
and down-stream processing. In consideration with the above properties, opportunities and challeges
associated with bacterial PHAs, this review focuses on structural diversity of PHAs, biosynthesis mechanism
in bacteria, biodegradation, life cycle analysis, and environmental impact of bioplastic production.
It further enumerates the advanced tools and techniques for bacterial PHA production, along with
various factors affecting the commercialization of bioplastics. Extraction methods, down-stream processing,
and biomedical applications of PHAs are also discussed. The opportunities and challenges in the
commercialization of bacterial PHAs along with future scenario and environmental sustainability are
presented for the purpose of fostering sustainable development.
Plastic pollution and accumulation in water bodies have threatened the survival of marine life. Plastic
pollution can be prevented by using biopolymers that are eco-friendly and can be naturally produced by
certain living organisms. The biopolymers have environmental advantages over synthetic plastics, such
as biodegradability and biocompatibility. In comparison to plants and other microbial systems, bacteria
can accumulate a high amount of polyhydroxyalkanoates (PHAs). However, the major stumbling block in
the production of bacterial PHAs is its low cost-effectiveness due to costs associated with fermentaion
and down-stream processing. In consideration with the above properties, opportunities and challeges
associated with bacterial PHAs, this review focuses on structural diversity of PHAs, biosynthesis mechanism
in bacteria, biodegradation, life cycle analysis, and environmental impact of bioplastic production.
It further enumerates the advanced tools and techniques for bacterial PHA production, along with
various factors affecting the commercialization of bioplastics. Extraction methods, down-stream processing,
and biomedical applications of PHAs are also discussed. The opportunities and challenges in the
commercialization of bacterial PHAs along with future scenario and environmental sustainability are
presented for the purpose of fostering sustainable development.
Research Interests:
The current review explores the potential application of algal biomass for the production of biofuels and biobased products. The variety of processes and pathways through which bio-valorization of algal biomass can be performed are... more
The current review explores the potential application of algal biomass for the production of biofuels and biobased
products. The variety of processes and pathways through which bio-valorization of algal biomass can be
performed are described in this review. Various lipid extraction techniques from algal biomass along with
transesterification reactions for biodiesel production are briefly discussed. Processes such as the pretreatment
and saccharification of algal biomass, fermentation, gasification, pyrolysis, hydrothermal liquefaction, and anaerobic
digestion for the production of biohydrogen, bio-oils, biomethane, biochar (BC), and various bio-based products
are reviewed in detail. The biorefinery model and its collaborative approach with various processes are
highlighted for the production of eco-friendly, sustainable, and cost-effective biofuels and value-added products.
The authors also discuss opportunities and challenges related to bio-valorization of algal biomass and use their
own perspective regarding the processes involved in production and the feasibility to make algal research a reality
for the production of biofuels and bio-based products in a sustainable manner.
products. The variety of processes and pathways through which bio-valorization of algal biomass can be
performed are described in this review. Various lipid extraction techniques from algal biomass along with
transesterification reactions for biodiesel production are briefly discussed. Processes such as the pretreatment
and saccharification of algal biomass, fermentation, gasification, pyrolysis, hydrothermal liquefaction, and anaerobic
digestion for the production of biohydrogen, bio-oils, biomethane, biochar (BC), and various bio-based products
are reviewed in detail. The biorefinery model and its collaborative approach with various processes are
highlighted for the production of eco-friendly, sustainable, and cost-effective biofuels and value-added products.
The authors also discuss opportunities and challenges related to bio-valorization of algal biomass and use their
own perspective regarding the processes involved in production and the feasibility to make algal research a reality
for the production of biofuels and bio-based products in a sustainable manner.
Research Interests:
The present study demonstrates EPS production by Cupriavidus sp. ISTL7 along with its capability to remediate a toxic carbamate pesticide, carbofuran. The strain ISTL7 efficiently degraded approximately 98% of carbofuran (400 ppm) within... more
The present study demonstrates EPS production by Cupriavidus sp. ISTL7 along with its capability to remediate a toxic carbamate pesticide, carbofuran. The strain ISTL7 efficiently degraded approximately 98% of carbofuran (400 ppm) within 96 h. GC-MS analysis showed catabolic metabolites of degradation which included carbo-furan-7-phenol, methylamine, 2-hydroxy-3-(3-methylpropan-2-ol)benzene-N-methyl-carbamate etc. EPS production from the mineral medium supplemented with carbofuran was observed to be 3.112 ± 0.3682 g L −1. FTIR confirmed its carbohydrate composition and the monomeric sugars: glucose, xylose, sorbitol and fructose were identified by GC-MS analysis. The toxic potential of degradation experiment and the produced EPS was evaluated on HepG2 (mammalian liver cell line). The cytotoxicity of carbofuran was reduced upon bacterial degradation and the formed EPS was found to be non-toxic as inferred from percentage cell viability. The present research can possibly influence the development strategies of biological remediation.
Research Interests:
A B S T R A C T An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas sp. ISTPL3 isolated from Pangong lake. Lipase was purified by sequential methods of ammonium sulphate precipitation,... more
A B S T R A C T An extracellular lipase was purified and characterized from psychrotolerant bacterium Pseudomonas sp. ISTPL3 isolated from Pangong lake. Lipase was purified by sequential methods of ammonium sulphate precipitation, dialysis, DEAE-cellulose ion exchange chromatography and Sephadex G-100 gel filtration chromatography, resulting in a purification fold of 6.53 and yield of 5.45%. The molecular weight was approximately 31 kDa. The purified lipase was used for transesterification of lipids produced by oleaginous chemolithotrophic bacterium Serratia sp. ISTD04 for production of biodiesel. Upon biochemical characterization, lipase was found to be al-kalophilc, thermostable, active in organic polar solvents and sensitive to detergents. Further, lipase was immobilized on activated biochar to assess its transesterification efficiency during biodiesel production. Immobilized lipase gave the highest yield of fatty acid methyl esters (FAMEs) (92.23%) > unimmobilized lipase > NaOH. The immobilized lipase was assessed for its reusability and retained 75.11% of its activity after 3 cycles of biodiesel production.
We report the soil microbial diversity and functional aspects related to degradation of recalcitrant compounds, determined using a metagenomic approach, in a landfill lysimeter prepared with soil from Ghazipur landfill site, New Delhi,... more
We report the soil microbial diversity and functional aspects related to degradation of recalcitrant compounds, determined using a metagenomic approach, in a landfill lysimeter prepared with soil from Ghazipur landfill site, New Delhi, India. Metagenomic analysis revealed the presence and functional diversity of complex microbial communities responsible for waste degradation.
A B S T R A C T The present study demonstrates pyrene degradation by a pshychrophilic bacterial strain, Shewanella sp. ISTPL2 isolated from Pangong lake, Ladakh, India. The ISTPL2 strain showed highest specific growth rate at 500 ppm with... more
A B S T R A C T The present study demonstrates pyrene degradation by a pshychrophilic bacterial strain, Shewanella sp. ISTPL2 isolated from Pangong lake, Ladakh, India. The ISTPL2 strain showed highest specific growth rate at 500 ppm with 93% extent of degradation. Pyrene metabolic pathway was confirmed from metabolites such as 4,5-dihy-droxypyrene, 2-carboxybenzalpyruvate, phthalic acid and salicylic acid obtained from pyrene degradation. Soil microcosm was set up with different concentration of pyrene and investigated using GC–MS to uncover the arrangement of intermediary metabolites. The results indicated that 75.11%, 95.39%, 94.32% and 93.11% of pyrene was degraded within 90 days in the soil spiked with 50, 350, 500 and 1000 ppm pyrene respectively. Strain ISTPL2 is a potent candidate for pyrene degradation as it can survive under high pyrene load.
Increasing population load and an altered lifestyle attitude are exerting extra pressure on the production market, to satisfy the demands and desire of society. The recently developed production and consumption models largely rely on... more
Increasing population load and an altered lifestyle attitude are exerting extra pressure
on the production market, to satisfy the demands and desire of society. The
recently developed production and consumption models largely rely on fossil-based
resources, which are affecting the environment and natural resources adversely. The
cost-effective production of biological materials is an emerging sector with remarkable
future prospects and provides many business opportunities. With time the
research endeavors are gradually shifting toward bacterial lipids-derived biofuel
production, which is more suitable and compatible for an industrial application. The
major challenge in the overall process of the production of lipids-derived fuels from
microbes is the involved carbon source as it contributes to more than half of the
production cost. Therefore the production of lipids and biodiesel from bacteria
using different waste materials as carbon source involving the application of
advanced biotechnological tools, and modified transesterification reactions will
make the biodiesel production cost effective.
on the production market, to satisfy the demands and desire of society. The
recently developed production and consumption models largely rely on fossil-based
resources, which are affecting the environment and natural resources adversely. The
cost-effective production of biological materials is an emerging sector with remarkable
future prospects and provides many business opportunities. With time the
research endeavors are gradually shifting toward bacterial lipids-derived biofuel
production, which is more suitable and compatible for an industrial application. The
major challenge in the overall process of the production of lipids-derived fuels from
microbes is the involved carbon source as it contributes to more than half of the
production cost. Therefore the production of lipids and biodiesel from bacteria
using different waste materials as carbon source involving the application of
advanced biotechnological tools, and modified transesterification reactions will
make the biodiesel production cost effective.
Globally, there are concerning trends of waste generation as we progress towards a more developed society. India, the second most populous country, is on the edge of being the fifth largest economy in the world. In the last five decades,... more
Globally, there are concerning trends of waste generation as we progress towards a more developed society. India, the second most populous country, is on the edge of being the fifth largest economy in the world. In the last five decades, its metropolitanization has increased by approximately 10% and would further rise to 20% by 2026. The increasing urbanization and evolving lifestyles, food habits, and standards prompt such exponential expansion of robust waste.