Snow ecosystems represent a large part of the Earth's biosphere and harbour diverse microbial communities. Despite our increased knowledge of snow microbial communities, the question remains as to their functional potential, particularly with respect to their role in adapting to and modifying the specific snow environment. In this work, we investigated the diversity and functional capabilities of microorganisms from 3 regions of East Antarctica, with respect to compounds present in snow and tested whether their functional signature reflected the snow environment. A diverse assemblage of bacteria (Proteobacteria, Actinobacteria, Firmicutes, Bacteroidetes, Deinococcus-Thermus, Planctomycetes, Verrucomicrobia), archaea (Euryarchaeota), and eukarya (Basidiomycota, Ascomycota, Cryptomycota and Rhizaria) were detected through culture-dependent and -independent methods. Although microbial communities observed in the three snow samples were distinctly different, all isolates tested produced one or more of the following enzymes: lipase, protease, amylase, β-galactosidase, cellulase, and/or lignin modifying enzyme. This indicates that the snow pack microbes have the capacity to degrade organic compounds found in Antarctic snow (proteins, lipids, carbohydrates, lignin), thus highlighting their potential to be involved in snow chemistry.
Spore forming Bacillus species are widely used as probiotics for human dietary supplements and in animal feeds. However, information on genetic basis of their probiotic action is obscure. Therefore, the present investigation was undertaken to elucidate probiotic traits of B. coagulans HS243 through its genome analysis. Genome mining revealed the presence of an arsenal of marker genes attributed to genuine probiotic traits. In silico analysis of HS243 genome revealed the presence of multi subunit ATPases, ADI pathway genes, chologlycine hydrolase, adhesion proteins for surviving and colonizing harsh gastric transit. HS243 genome harbored vitamin and essential amino acid biosynthetic genes, suggesting the use of HS243 as a nutrient supplement. Bacteriocin producing genes highlighted the disease preventing potential of HS243. Thus, this work established that HS243 possessed the genetic repertoire required for surviving harsh gastric transit and conferring health benefits to the host which were further validated by wet lab evidences.
Methanotrophs play a crucial role in filtering out methane from habitats, such as flooded rice fields. India has the largest area under rice cultivation in the world; however, to the best of our knowledge, methanotrophs have not been isolated and characterized from Indian rice fields. A cultivation strategy composing of a modified medium, longer incubation time, and serial dilutions in microtiter plates was used to cultivate methanotrophs from a rice rhizosphere sample from a flooded rice field in Western India. We compared the cultured members with the uncultured community as revealed by three culture-independent methods. A novel type Ia methanotroph (Sn10-6), at the rank of a genus, and a putative novel species of a type II methanotroph (Sn-Cys) were cultivated from the terminal positive dilution (10(-6)). From lower dilution (10(-4)), a strain of Methylomonas spp. was cultivated. All the three culture-independent analyses, i.e., pmoA clone library, terminal restriction fragment length polymorphism (T-RFLP), and metagenomics approach, revealed the dominance of type I methanotrophs. Only metagenomic analysis showed significant presence of type II methanotrophs, albeit in lower proportion (37 %). All the three isolates showed relevance to the methanotrophic community as depicted by uncultured methods; however, the cultivated members might not be the most dominant ones. In conclusion, a combined cultivation and cultivation-independent strategy yielded us a broader picture of the methanotrophic community from rice rhizospheres of a flooded rice field in India.
Flooded rice fields are important sources of atmospheric methane. Aerobic methanotrophs living in the vicinity of rice roots oxidize methane and act as environmental filters. Here, we present genome characteristics of a gammaproteobacterial methanotroph, isolate Sn10-6, which was isolated from a rice rhizosphere of a flooded field in India. Sn10-6 has been identified as a member of a putative novel genus and species within the family Methylococcaceae (Type I methanotrophs). The draft genome of Sn10-6 showed pathways for the following: methane oxidation, formaldehyde assimilation (RuMP), nitrogen fixation, conversion of nitrite to nitrous oxide, and other interesting genes including the ones responsible for survival in the rhizosphere environment. The majority of genes found in this genome were most similar to Methylovulum miyakonese which is a forest isolate. This draft genome provided insight into the physiology, ecology, and phylogeny of this gammaproteobacterial methanotroph.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.