Microbiome and imputed metagenome study of crude and refined petroleum-oil-contaminated soils: Potential for hydrocarbon degradation and plant-growth promotion

Microbial community structure of crude petroleum oil (CP)- and refined petroleum oil (RP)-contaminated soil wasinvestigated. The taxonomical and functional diversity of such soils can be a great source of information about microbialcommunity and genes involved in petroleum hydrocarbon (PHC) degradation. In this study, microbial diversity of soilscontaminated by RP from urban biome of Pune, India, and CP from agricultural biome of Gujarat, India, were assessed by16S rRNA amplicon sequencing on Illumina MiSeq platform. Association between the soil microbial community and thephysicochemical parameters were investigated for their potential role. In RP- and CP-contaminated soils, the microbiomeanalysis showed Proteobacteria as most dominant phylum followed by Actinobacteria. Interestingly, Firmicutes were mostprevailing in a CP-contaminated sample while they were least prevailing in RP-contaminated soils. Soil moisture content,total organic carbon and organic nitrogen content influenced the taxa diversity in these soils. Species richness was more inRP as compared to CP soils. Further prediction of metagenome using PICRUSt revealed that the RP and CP soils containmicrobial communities with excellent metabolic potential for PHC degradation. Microbial community contributing to genesessential for soil health improvement and plant growth promotion was also gauged. Our analysis showed promising resultsfor future bioaugmentation assisted phytoremediation (BAP) strategies for treating such soils.

Transcriptome analysis of Anopheles stephensi embryo using expressed sequence tags.

Germ band retraction (GBR) stage is one of the important stages during insect development. It is associated with an extensive epithelial morphogenesis and may also be pivotal in generation of morphological diversity in insects. Despite its importance, only a handful of studies report the transcriptome repertoire of this stage in insects. Here, we report generation, annotation and analysis of ESTs from the embryonic stage (16–22 h post fertilization) of laboratoryreared Anopheles stephensi mosquitoes. A total of 1002 contigs were obtained upon clustering of 1140 high-quality ESTs, which demonstrates an astonishingly low transcript redundancy (12.1%). Putative functions were assigned only to 213 contigs (21%), comprising mainly of transcripts encoding protein synthesis machinery. Approximately 78% of the transcripts remain uncharacterized, illustrating a lack of sequence information about the genes expressed in the embryonic stages of mosquitoes. This study highlights several novel transcripts, which apart from insect development, may significantly contribute to the essential biological complexity underlying insect viability in adverse environments. Nonetheless, the generated sequence information from this work provides a comprehensive resource for genome annotation, microarray development, phylogenetic analysis and other molecular biology applications in entomology.

Molecular analysis of gut microbiota in obesity among Indian individuals.

Obesity is a consequence of a complex interplay between the host genome and the prevalent obesogenic factors among the modern communities. The role of gut microbiota in the pathogenesis of the disorder was recently discovered; however, 16S-rRNA-based surveys revealed compelling but community-specific data. Considering this, despite unique diets, dietary habits and an uprising trend in obesity, the Indian counterparts are poorly studied. Here, we report a comparative analysis and quantification of dominant gut microbiota of lean, normal, obese and surgically treated obese individuals of Indian origin. Representative gut microbial diversity was assessed by sequencing fecal 16S rRNA libraries for each group (n=5) with a total of over 3000 sequences. We detected no evident trend in the distribution of the predominant bacterial phyla, Bacteroidetes and Firmicutes. At the genus level, the bacteria of genus Bacteroides were prominent among the obese individuals, which was further confirmed by qPCR (P<0.05). In addition, a remarkably high archaeal density with elevated fecal SCFA levels was also noted in the obese group. On the contrary, the treated-obese individuals exhibited comparatively reduced Bacteroides and archaeal counts along with reduced fecal SCFAs. In conclusion, the study successfully identified a representative microbial diversity in the Indian subjects and demonstrated the prominence of certain bacterial groups in obese individuals; nevertheless, further studies are essential to understand their role in obesity.