Bacillus Amyloliquefaciens

Efecto de las PGPB sobre el crecimiento Pennisetum clandestinum bajo condiciones de estrés salino PGPB effect on the growth Pennisetum clandestinum under salt stress Resumen Esta investigación tuvo como objetivo el aislamiento y caracterización de bacterias con potencial para promover el crecimiento del pasto Pennisetum clandestinum en suelos salinos simulados. De muestras de suelo rizosférico de P. clandestinum se aislaron 92 bacterias Gram positivas, diez aislados crecieron en agar nutritivo suplementado con NaCl (2,578 M). Los aislados se evaluaron bajo condiciones de invernadero; las cepas identificadas como KISA 34 y KISA 71 fueron seleccionadas como las mejores con base a la prueba estadística de Dunnet (p≤ 0,05) y fueron identificadas molecularmente como Bacillus amyloliquefaciens KISA 34 y Bacillus subtilis KISA 71. Estas cepas tienen la capacidad de producir; amonio, exopolisacáridos y celulosa, y tanto en presencia como ausencia de NaCl, produjeron índoles totales y solubilización de fósforo. La evaluación de las cepas en invernadero evidenció que el T6-KISA 34 + KISA 71+ 25 % (Roca Fosfórica RF) con respecto al T2-testigo químico completo incrementaron de manera significativa la biomasa y el desarrollo de la planta (p≤ 0.05). Los resultados de esta investigación demostraron que las cepas aisladas tienen la capacidad de crecer en suelos salinos conservando sus características como promotoras de crecimiento vegetal con efectos positivos sobre P. clandestinum. Abstract This research aims the isolation and characterization of bacteria with potential to promote the growth of grass Pennisetum clandestinum in simulated saline soils. 92 Gram positive bacterias were isolated from Rhizosphere soil samples of P. clandestinum. Ten isolated bacteria grew on nutrient agar supplemented with NaCl (2.578 M). Isolates were evaluated under greenhouse conditions; the strains identified as KISA 34 and KISA 71 were selected as the best based on the statistical test of Dunnet (p ≤ 0.05) and were identified Bacillus amyloliquefaciens KISA 34 and Bacillus subtilis KISA 71. These strains have the ability to produce ammonium, exopolysaccharides and cellulose, both in absence and presence of NaCl. The strains produced indoles and

Alpha amylase (E.C. 3.2.1.1) is one of the most important starch-degrading enzymes and widely applied in pharmaceutical, food, feed, detergent, textile and bio refinery industries. The present work was focused on optimization of -amylase production using the bacteria strain Bacillus amyloliquefaciens in submerged cultivation system. The results showed that, the optimal soluble starch concentration for maximal enzyme production of 1950 kat.L-1 was 20 g.L-1. Compared to shake flask, bioreactor batch cultivation yielded higher volumetric enzyme production of 4125 kat.L-1 (about 1.84-folds higher than the value obtained in shake flask). In addition, fed-batch cultivation with two feeding strategies (constant feeding and increased feeding) was also designed to improve the production process. The maximal volumetric enzyme production of 8160 kat.L-1 was obtained in increased feeding strategy after 36 hours of cultivation. This value was almost 98 and 18% higher than the enzyme produced in batch and constant feeding fed-batch cultivations, respectively.

Background: The use of auxin-producing rhizosphere bacteria as agricultural products promises increased root production and therefore greater phosphate (Pi) uptake. Whilst such bacteria promote root production in vitro, the nature of the bacteria-plant interaction in live soil, particularly concerning any effects on nutrient uptake, are not known. This study uses Bacillus amyloliquefaciens FZB42, an auxin-producing rhizobacterium, as a dressing on Triticum aestivum seeds. It then examines the effects on root production, Pi uptake, Pi-related gene expression and organic carbon (C) exudation.
Results: Seed treatment with B. amyloliquefaciens FZB42 increased root production at low environmental Pi concentrations, but significantly repressed root Pi uptake. This coincided with an auxin-mediated reduction in expression of the Pi transporters TaPHT1.8 and TaPHT1.10. Applied exogenous auxin also triggered an increase in root C exudation. At high external Pi concentrations, root production was promoted by B. amyloliquefaciens FZB42, but Pi uptake was unaffected.
Conclusions: We conclude that, alongside promoting root production, auxin biosynthesis by B. amyloliquefaciens FZB42 both remodels Pi transporter expression and elevates organic C exudation. This shows the potential importance of rhizobacterial-derived auxin following colonisation of root surfaces, and the nature of this bacteria-plant interaction in soil.

Bacillus amyloliquefaciens QST713 and B. firmus I-1582 are bacterial strains which are used as active ingredients of commercially-available soil application and seed treatment products Serenade® and VOTiVO®, respectively. These bacteria colonize plant roots promoting plant growth and offering protection against pathogens/pests. The objective of this study was to develop a qPCR protocol to quantitate the dynamics of root colonization by these two strains under field conditions. Primers and TaqMan® probes were designed based on genome comparisons of the two strains with publicly-available and unpublished bacterial genomes of the same species. An optimized qPCR protocol was developed to quantify bacterial colonization of corn roots after seed treatment. Treated corn seeds were planted in non-sterile soil in the greenhouse and grown for 28 days. Specific detection of bacteria was quantified weekly, and showed stable colonization between ~104-105 CFU/g during the experimental period for ...

The genomes of three potential biocontrol bacterial isolates, <i>Bacillus</i><b> </b><i>amyloliquefaciens </i>(BTLK6A), <i>B. subtilis</i> (BTS-3), and <i>B.</i><b> </b><i>amyloliquefaciens </i>(BTS-4) were analysed to gain insights into the underlying molecular basis of their inhibitory activities against the wheat blast fungus <i>Magnaporthe oryzae Triticum</i> (MoT) pathotype.<br>

The commercially available inoculant Bacillus amyloliquefaciens FZB42 is able to considerably reduce lettuce bottom rot caused by Rhizoctonia solani. To understand the interaction between FZB42 and R. solani in the rhizosphere of lettuce, we used an axenic system with lettuce bacterized with FZB42 and inoculated with R. solani. Confocal laser scanning microscopy showed that FZB42 could delay the initial establishment of R. solani on the plants. To show which secondary metabolites of FZB42 are produced under these in-situ conditions, we developed an ultra-high performance liquid chromatography coupled to time of flight mass spectrometry–based method and identified surfactin, fengycin, and bacillomycin D in the lettuce rhizosphere. We hypothesized that lipopeptides and polyketides play a role in enhancing the plant defense responses in addition to the direct antagonistic effect toward R. solani and used a quantitative real-time polymerase chain reaction–based assay for marker genes in...

Increasing population and urbanization has led to an exponential increase in organic waste. This waste if not treated properly may lead to pollution and health hazards. So, a study was conducted to develop an efficient bacterial consortium for the degradation of organic kitchen waste. Different bacterial strains were obtained from MTCC, initially grown on specific media and were screened for their enzymatic activities. Eight bacterial strains viz. Bacillus subtilus (MTCC 441), B. amyloliquefaciens (MTCC 7913), B. megaterium (MTCC 8510), Lactobacillus delbrueckii (MTCC 2365), L. plantarum (MTCC 1407), L. rhamnosus (MTCC 1423), Pseudomonas aeruginosa (MTCC 4673) and Staphylococcus aureus (MTCC 740) were tested for the production of lipase, amylase, protease and cellulase. All the bacterial strains exhibited enzyme activities except B. megaterium. So, combinations of these strains were used to make consortia on basis of pathogenicity. Two different microbial consortiums were prepared w...

Bacterial wilt complex disease of tomato (Solanum lycopersicum L.) was incited jointly by bacterial wilt pathogen Ralstonia solanacearum and Meloidogyne incognita worldwide. Bio-efficacy of bacterial antagonists i.e. B. amyloliquefaciens DSBA-11 and P. fluorescens DTPF-3 was studied against the wilt disease complex in tomato at National Phytotran facility Indian Agricultural Research Institute (IARI), New Delhi, at 26 ± 2 °C. Minimum wilt disease incidence (26.00%) with the highest bio-control efficacy (64.15%), less juvenile population (19.33 J 2 /g of soil) of M. incognita was recorded in the combined application of DTPF-3 + DSBA-11 after 30 d of inoculation under glasshouse conditions. In a field study, minimum bacterial wilt disease incidences 19.0% and 20.4% were recorded in the bleaching powder treatment followed by mixed application of DSBA-11 + DTPF-3, 19.6% and 21.2% wilt incidence in 2014 and 2015 respectively. However, a reduction of root-knot gall index was recorded a maximum of 59.76% and 69.62% in DSBA-11 + DTPF-3 treated plants followed by 54.88% and 60.13% over control in DTPF-3 treatment in 2014 and 2015 respectively. The yield of tomato fruit was increased over control by 17.48% and 16.97% in 2014 and 2015 respectively under field conditions. A combination of P. fluorescens DTPF-3 + B. amyloliquefaciens DSBA-11 suppressed bacterial wilt and root-knot diseases and also increased the yield of the tomato fruit significantly (p < 0.05) under field conditions.

Biosurfactants are important in many areas; however, costs impede large-scale production. This work aimed to develop a global sustainable strategy for the production of biosurfactants by a novel strain of Bacillus amyloliquefaciens. Initially, Bacillus sp. strain 0G was renamed B. amyloliquefaciens subsp. plantarum (syn. Bacillus velezensis) after analysis of the gyrA and gyrB DNA sequences. Growth in modified Landy’s medium produced 3 main recoverable metabolites: surfactin, fengycin, and acetoin, which promote plant growth. Cultivation was studied in the presence of renewable carbon (as glycerol) and nitrogen (as arginine) sources. While diverse kinetics of acetoin production were observed in different media, similar yields (6–8 g·L–1) were obtained after 72 h of growth. Glycerol increased surfactin-specific production, while arginine increased the yields of surfactin and fengycin and increased biomass significantly. The specific production of fengycin increased ∼10 times, possibl...

Despite successful use of Plant Growth Promoting Rhizobacteria (PGPR) in agriculture, little is known about specific mechanisms of gene regulation facilitating the effective communication between bacteria and plants during plant colonization. Active PGPR strain B. atrophaeus UCMB-5137 was studied in this research. RNA sequencing profiles were generated in experiments where root exudate stimulations were used to mimic interactions between bacteria and plants. It was found that the gene regulation in B. atrophaeus UCMB-5137 in response to the root exudate stimuli differed from the reported gene regulation at similar conditions in B. amyloliquefaciens FZB42, which was considered as a paradigm PGPR. This difference was explained by hypersensitivity of UCMB-5137 to the root exudate stimuli impelling it to a sessile root colonization behavior through the CcpA-CodY-AbrB regulation. It was found that the transcriptional factor DegU also could play an important role in gene regulations durin...

Metal containing engineered nanomaterials (ENMs) are now commonly used in various industrial and commercial applications. Many of these materials can be transformed during waste water treatment and ultimately enter terrestrial ecosystems via agriculturally applied biosolids. It is unclear how agriculturally important soil microbes will be affected by exposure to environmentally relevant, sublethal concentrations of ENMs and their transformation products (i.e., ions, aggregates, etc.). A method was developed, which puts O2 consumption responses in terms of viability, and tested by examining the toxic effects of Ag(+), Zn(2+), and Ni(2+) ions on the plant growth promoting rhizobacterium (PGPR) Bacillus amyloliquefaciens GB03. The method was then used to examine the toxicity of Ag(+), as-synthesized polyvinylpyrrolidone-coated silver ENM (PVP-AgENMs), and 100% sulfidized AgENM on B. amyloliquefaciens GB03, and two additional PGPRs Sinorhizobium meliloti 2011, and Pseudomonas putida UW4...