Microbial community structure of crude petroleum oil (CP)- and refined petroleum oil (RP)-contaminated soil was investigated. The taxonomical and functional diversity of such soils can be a great ...source of information about microbial community and genes involved in petroleum hydrocarbon (PHC) degradation. In this study, microbial diversity of soils contaminated by RP from urban biome of Pune, India, and CP from agricultural biome of Gujarat, India, were assessed by 16S rRNA amplicon sequencing on Illumina MiSeq platform. Association between the soil microbial community and the physicochemical parameters were investigated for their potential role. In RP- and CP-contaminated soils, the microbiome analysis showed Proteobacteria as most dominant phylum followed by Actinobacteria. Interestingly, Firmicutes were most prevailing 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 in RP as compared to CP soils. Further prediction of metagenome using PICRUSt revealed that the RP and CP soils contain microbial communities with excellent metabolic potential for PHC degradation. Microbial community contributing to genes essential for soil health improvement and plant growth promotion was also gauged. Our analysis showed promising results for future bioaugmentation assisted phytoremediation (BAP) strategies for treating such soils.
Phylogenetic diversity of culturable actinobacteria isolated from the intertidal regions of west coast of Maharashtra, India was studied using 16S rRNA gene sequencing. Total of 140 actinobacterial ...isolates were obtained, which belonged to 14 genera, 10 families and 65 putative species with
Streptomyces
being the most dominant (63%) genus followed by
Nocardiopsis
and
Micromonospora
. Isolates were screened for production of extracellular protease inhibitors (PI) against three pure proteases viz. chymotrypsin, trypsin, subtilisin and a crude extracellular protease from
Pseudomonas aeruginosa
. Eighty percent of the isolates showed PI activity against at least one of the four proteases, majority of these belonged to genus
Streptomyces
. Actinobacterial diversity from two sites Ade (17° 52′ N, 73° 04′ E) and Harnai (17° 48′ N, 73° 05′ E) with varying anthropological pressure showed that more putative species diversity was obtained from site with lower human intervention i.e. Ade (Shannon’s H 3.45) than from Harnai (Shannon’s H 2.83), a site with more human intervention. However, in Ade, percentage of isolates not showing PI activity against any of the proteases was close to 21% and that in Harnai was close to 9%. In other words, percentage of PI producers was lower at a site with lesser human intervention.
Aims: Dental biofilms are complex, multi-species microorganism communities that inhabit the oral cavity in the form of dental plaque which causes dental caries and periodontal diseases. The present ...study aims to explore the potential of Lemon Grass Essential Oil (LGEO) extracted from Cymbopogon citratus as antimicrobial and antibiofilm agent against the microorganisms responsible for dental plaque.
Study Design: Observational and comparison study.
Place and Duration of Study: Research centre, Department of Microbiology, Abasaheb Garware college, Pune, India, between Dec 2012 to Jan 2017.
Methodology: Three bacterial species primarily responsible for the biofilm formation were isolated from dental plaque and identified using 16S ribosomal RNA sequences. Five most primary colonizer of dental plaque organisms were acquired from the Microbial Type Culture Collection cultures. Antimicrobial as well as antibiofilm activity of LGEO, was determined against these eight biofilm forming microorganism. The antibiofilm activity of LGEO was evaluated against oral flora individually, as well as in consortium.
Results: LGEO displayed excellent antimicrobial activity against eight test organisms associated with dental plaque, representing four genera namely Streptococcus, Staphylococcus, Lactobacillus and Candida. MIC of LGEO for all test organisms was determined as 1.5% (v/v). The LGEO was found to exhibit as high as 76% biofilm inhibitory activity even in the consortium, where the biofilm formation sometimes has been noted to be comparatively more than that of the individual organism, making LGEO a very promising antibiofilm agent.
Conclusion: LGEO present in rampantly grown plant, Cymbopogon citratus, has remarkable antimicrobial and antibiofilm activity against the dental plaque organism and thus can be the economical, convenient, natural and nontoxic herbal material to effectively control the oral microflora associated with dental plaque.
While the debate on the existence of 'directed', 'Cairnsian', 'adaptive' or 'post-selection' mutations still continues, the suggestion that such a feature will be strongly advantageous seems to be ...uncritically accepted. We modelled competition in a chemostat with the substrate alternating between a 'normal' and an 'alternative' nutrient. Simulations involving genotypes (1) with inducible operon for alternative substrate, (2) without any gene for the alternative substrate, (3) with a cryptic gene for the alternative substrate and the ability to bring about a directed mutation and (4) with a cryptic gene having mutational hotspot showed that a directed mutation conferred little selective advantage. The widely held belief is thus challenged and we need to look into the directed-mutation controversy with a new insight.
We present optical and X-ray properties for the first confirmed galaxy cluster sample selected by the Sunyaev-Zel'dovich effect (SZE) from 148 GHz maps over 455 deg2 of sky made with the Atacama ...Cosmology Telescope (ACT). These maps, coupled with multi-band imaging on 4 m class optical telescopes, have yielded a sample of 23 galaxy clusters with redshifts between 0.118 and 1.066. Of these 23 clusters, 10 are newly discovered. The selection of this sample is approximately mass limited and essentially independent of redshift. We provide optical positions, images, redshifts, and X-ray fluxes and luminosities for the full sample, and X-ray temperatures of an important subset. The mass limit of the full sample is around 8.0 X 1014 M , with a number distribution that peaks around a redshift of 0.4. For the 10 highest significance SZE-selected cluster candidates, all of which are optically confirmed, the mass threshold is 1 X 1015 M and the redshift range is 0.167-1.066. Archival observations from Chandra, XMM-Newton, and ROSAT provide X-ray luminosities and temperatures that are broadly consistent with this mass threshold. Our optical follow-up procedure also allowed us to assess the purity of the ACT cluster sample. Eighty (one hundred) percent of the 148 GHz candidates with signal-to-noise ratios greater than 5.1 (5.7) are confirmed as massive clusters. The reported sample represents one of the largest SZE-selected sample of massive clusters over all redshifts within a cosmologically significant survey volume, which will enable cosmological studies as well as future studies on the evolution, morphology, and stellar populations in the most massive clusters in the universe.
This is a summary of the beyond the Standard Model (including model building) working group of the WHEPP-X workshop held at Chennai from January 3 to 15, 2008.
We present optical and X-ray properties for the first confirmed galaxy cluster sample selected by the Sunyaev-Zel'dovich Effect from 148 GHz maps over 455 square degrees of sky made with the Atacama ...Cosmology Telescope. These maps, coupled with multi-band imaging on 4-meter-class optical telescopes, have yielded a sample of 23 galaxy clusters with redshifts between 0.118 and 1.066. Of these 23 clusters, 10 are newly discovered. The selection of this sample is approximately mass limited and essentially independent of redshift. We provide optical positions, images, redshifts and X-ray fluxes and luminosities for the full sample, and X-ray temperatures of an important subset. The mass limit of the full sample is around 8e14 Msun, with a number distribution that peaks around a redshift of 0.4. For the 10 highest significance SZE-selected cluster candidates, all of which are optically confirmed, the mass threshold is 1e15 Msun and the redshift range is 0.167 to 1.066. Archival observations from Chandra, XMM-Newton, and ROSAT provide X-ray luminosities and temperatures that are broadly consistent with this mass threshold. Our optical follow-up procedure also allowed us to assess the purity of the ACT cluster sample. Eighty (one hundred) percent of the 148 GHz candidates with signal-to-noise ratios greater than 5.1 (5.7) are confirmed as massive clusters. The reported sample represents one of the largest SZE-selected sample of massive clusters over all redshifts within a cosmologically-significant survey volume, which will enable cosmological studies as well as future studies on the evolution, morphology, and stellar populations in the most massive clusters in the Universe.
PDF
