Extremophiles

psychrophiles, halophiles, thermophiles and to compare the Cellulase activity from samples
collected from different geographical regions of India.
Place and Duration of Study: Bharathiar University, Department of Biotechnology,
Molecular Microbiology Lab, Coimbatore, Tamilnadu, India, between January to April 2011.
Methodology: Cellulase-producing extremophilic bacteria viz., psychrophiles, halophiles,
and thermophiles have been isolated from soil samples. According to morphology and
pigmentation, 138 distinct bacteria were isolated and screened for cellulase activity by
Gram’s iodine–carboxymethylcellulose plate (CMC) assay. On the basis of the cellulase
activity, six potent cellulase-producing isolates from each cluster viz., P14, P36, H6, H13,
T2 and T3 were selected for 16S rRNA gene based identification. The strains were
optimized for maximum cellulase activity at various temperature and pH range.
Results: The phylogenetic relationship revealed that P14 and P36 psychrophilic isolates
possessed maximum identity with Bacillus simplex (100%) and Arthrobactercitreus (99%),
with a cellulase activity of 14.10± 1.73 and 18.27± 0.71 UmL-1 respectively. Likewise, among halophiles, H6 and H13 were identified as Bacillus subtilis and Bacillus
endophyticus (99%), with a cellulase activity of 14.87 ± 0.55 and 16.83 ± 0.44 U mL-1,
correspondingly. In thermophiles, T2 and T3 showed close proximity with Bacillus
amyloliquefaciens and Bacillus megaterium (99%), with a cellulase activity of 21.53 ± 1.30
and 19.93 ± 0.38 U mL-1 respectively.
Conclusion: In the present study, the thermophilic isolates showed promising Cellulase
activity compared to psychrophiles and halophiles.

Evidence is reviewed which supports the hypothesis that prokaryotes and eukaryotes may have colonized Mars. One source of Martian life, is Earth. A variety of species remain viable after long term exposure to the radiation intense environment of space, and may survive ejection from Earth following meteor strikes, ejection from the stratosphere and mesosphere via solar winds, and sterilization of Mars-bound spacecraft; whereas simulations studies have shown that prokaryotes, fungi and lichens survive in simulated Martian environments-findings which support the hypothesis life may have been repeatedly transferred from Earth to Mars. Four independent investigators have reported what appears to be fungi and lichens on the Martian surface, whereas a fifth investigator reported what may be cyanobacteria. In another study, a statistically significant majority of 70 experts, after examining Martian specimens photographed by NASA, identified and agreed fungi, basidiomycota ("puffballs"), and lichens may have colonized Mars. Fifteen specimens resembling and identified as "puffballs" were photographed emerging from the ground over a three day period. It is possible these latter specimens are hematite and what appears to be "growth" is due to a strong wind which uncovered these specimens-an explanation which cannot account for before and after photos of what appears to be masses of fungi growing atop and within the Mars rovers. Terrestrial hematite is in part fashioned and cemented together by prokaryotes and fungi, and thus Martian hematite may also be evidence of biology. Three independent research teams have identified sediments on Mars resembling stromatolites and outcroppings having micro meso and macro characteristics typical of terrestrial microbialites constructed by cyanobacteria. Quantitative morphological analysis determined these latter specimens are statistically and physically similar to terrestrial stromatolites. Reports of water, biological residue discovered in Martian meteor ALH84001, the seasonal waning and waxing of atmospheric and ground level Martian methane which on Earth is 90% due to biology and plant growth and decay, and results from the 1976 Mars Viking Labeled Release Experiments indicating biological activity, also support the hypothesis that Mars was, and is, a living planet. Nevertheless, much of the evidence remains circumstantial and unverified, and the possibility of life on Mars remains an open question.

Soil bacteria are very important in biogeochemical cycles and have been used for crop production for decades. Plant-bacterial interactions in the rhizosphere are the determinants of plant health and soil fertility. Free-living soil bacteria beneficial to plant growth, usually referred to as plant growth promoting rhizobacteria (PGPR), are capable of promoting plant growth by colonizing the plant root. PGPR are also termed plant health promoting rhizobacteria (PHPR) or nodule promoting rhizobacteria (NPR). These are associated with the rhizosphere, which is an important soil ecological environment for plant–microbe interactions. Symbiotic nitrogen-fixing bacteria include the cyanobacteria of the genera Rhizobium, Bradyrhizobium, Azorhizobium, Allorhizobium, Sinorhizobium and Mesorhizobium. Free-living nitrogen-fixing bacteria or associative nitrogen fixers, for example bacteria belonging to the species Azospirillum, Enterobacter, Klebsiella and Pseudomonas, have been shown to attach to the root and efficiently colonize root surfaces. PGPR have the potential to contribute to sustainable plant growth promotion. Generally, PGPR function in three different ways: synthesizing particular compounds for the plants, facilitating the uptake of certain nutrients from the soil, and lessening or preventing the plants from diseases. Plant growth promotion and development can be facilitated both directly and indirectly. Indirect plant growth promotion includes the prevention of the deleterious effects of phytopathogenic organisms. This can be achieved by the production of siderophores, i.e. small metal-binding molecules. Biological control of soil-borne plant pathogens and the synthesis of antibiotics have also been reported in several bacterial species. Another mechanism by which PGPR can inhibit phytopathogens is the production of hydrogen cyanide (HCN) and/or fungal cell wall degrading enzymes, e.g., chitinase and ß-1,3-glucanase. Direct plant growth promotion includes symbiotic and non-symbiotic PGPR which function through production of plant hormones such as auxins, cytokinins, gibberellins, ethylene and abscisic acid. Production of indole-3-ethanol or indole-3-acetic acid (IAA), the compounds belonging to auxins, have been reported for several bacterial genera. Some PGPR function as a sink for 1-aminocyclopropane-1-carboxylate (ACC), the immediate precursor of ethylene in higher plants, by hydrolyzing it into α-ketobutyrate and ammonia, and in this way promote root growth by lowering indigenous ethylene levels in the micro-rhizo environment. PGPR also help in solubilization of mineral phosphates and other nutrients, enhance resistance to stress, stabilize soil aggregates, and improve soil structure and organic matter content. PGPR retain more soil organic N, and other nutrients in the plant–soil system, thus reducing the need for fertilizer N and P and enhancing release of the nutrients.

In this paper, we report the presence of sedimentary microbial ecosystems in wetlands of the Salar de Atacama. These laminated systems, which bind, trap and precipitate mineral include: microbial mats at Laguna Tebenquiche and Laguna La Brava, gypsum domes at Tebenquiche and carbonate microbialites at La Brava. Microbial diversity and key biogeochemical characteristics of both lakes (La Brava and Tebenquiche) and their various microbial ecosystems (non-lithifying mats, flat and domal microbialites) were determined. The composition and abundance of minerals ranged from trapped and bound halite in organic-rich non-lithifying mats to aragonite-dominated lithified flat microbialites and gypsum in lithified domal structures. Pyrosequencing of the V4 region of the 16s rDNA gene showed that Proteobacteria comprised a major phylum in all of the microbial ecosystems studied, with a marked lower abundance in the non-lithifying mats. A higher proportion of Bacteroidetes was present in Tebenquiche sediments compared to La Brava samples. The concentration of pigments, particularly that of Chlorophyll a, was higher in the Tebenquiche than in La Brava. Pigments typically associated with anoxygenic phototrophic bacteria were present in lower amounts. Organic-rich, non-lithifying microbial mats frequently formed snake-like, bulbous structures due to gas accumulation underneath the mat. We hypothesize that the lithified microbialites might have developed from these snake-like microbial mats following mineral precipitation in the surface layer, producing domes with endoevaporitic communities in Tebenquiche and carbonate platforms in La Brava. Whereas the potential role of microbes in carbonate platforms is well established, the contribution of endoevaporitic microbes to formation of gypsum domes needs further investigation.

In this experimental study, cells of the radiation-resistant bacterium Deinococcus radiodurans were exposed to several different sources of radiation chosen to replicate the charged particles found in the solar wind. Naked cells or cells mixed with dust grains (basalt or sandstone) differing in elemental composition were exposed to electrons, protons, and ions to determine the probability of cell survival after irradiation. Doses necessary to reduce the viability of cell population to 10% (LD10) were determined under different experimental conditions. The results of this study indicate that low-energy particle radiation (2–4keV), typically present in the slow component of the solar wind, had no effect on dehydrated cells, even if exposed at fluences only reached in more than 1000 years at Sun-Earth distance (1 AU). Higher-energy ions (200 keV) found in solar flares would inac- tivate 90% of exposed cells after several events in less than 1 year at 1 AU. When mixed with dust grains, LD10 increases about 10-fold. These results show that, compared to the highly deleterious effects of UV radiation, solar wind charged particles are relatively benign, and organisms protected under grains from UV radiation would also be protected from the charged particles considered in this study.

Antioxidants  are  molecules  involved  in  defense  mechanisms  against  the  deleterious  effects  of  free
radicals in most organisms. A number of methods arecurrently being used for the evaluation of the antioxidant
and  free-radical  scavenging  properties  of  natural  and  synthetic  antioxidants,  including  the  DPPH  method.
Numerous  speculations  about  the  stability  of  DPPH  solution  over  a  long  period of  time,  at  normal  ambient
temperature  have  been  observed  in  previous  studies  but  no  definite  information  exists  in  literature  in this
regard. Using established protocols, the free-radical capability of DPPH methanolic solution (stored in dark at
ambient  temperature)  was  assessed  using  ascorbic  acid  as  the  antioxidant.  Results  revealed  that  DPPH
methanolic solution gave comparable free-radical activity 24 hours post preparation compared with the  freshly
prepared solution. After 24 hours, activity was greatly reduced. We therefore recommend that freshly prepared
DPPH solution should be used at all times; however for prolonged experimental schedules, the DPPH solution
should be used within 24 hours post preparation, soas to give comparable results with the freshly prepared
solution and avoid ambiguity in results interpretation

The M'Diq beach has seen a successive outbreak's of starting in 2011. During the summer season, which is also Pelagia noctiluca known as the blooming and stranding's jellyfish season has severe impacts on regional activities. For this reason, this research aimed at documenting the mean causes of outbreaks on our coastline. As a result, the simple linear tests shows that outbreaks P. noctiluca P. noctiluca have a very significant linear relationship and are positively correlated to sea surface temperature with P= 0.0079 with y = 3.5254x-59.616, R² = 0.2062, sea salinity P= 0.0029 with y =14.741x-507.54, R² = 0.2517 and waves high P= 0.000000002 with y = 20.473x-4.4583, R² = 0.6893. Moreover, the blooms of jellyfish along with the production of Pelagic fish and whitefish were respectively and share a strong correlation with P= 0.000001936, with y =-0.0079x + 40.881, R² = 0.5063 for Pelagic fish and y =-0.0323x + 55.431, R² = 0.3008 for whitefish production.