Comparative analysis of microbiome inhabiting oxygenated and deoxygenated habitats using V3 and V6 metabarcoding of 16S rRNA gene.

We examine how oxygen levels and the choice of 16S ribosomal RNA (rRNA) tags impact marine bacterial communities using Next-Generation amplicon sequencing. Analyzing V3 and V6 regions, we assess microbial composition in both Oxygen minimum zones (OMZ) and non-OMZ (NOMZ) areas in the Arabian Sea (AS) and the Central Indian Ocean basin (CIOB) respectively. Operational taxonomic units (OTUs) at 97% similarity showed slightly higher richness and diversity with V6 compared to V3.

Diversity and Quantitative Detection of Clade I Type nosZ Denitrifiers in the Arabian Sea Oxygen Minimum Zone.

A significant amount of nitrous oxide (NO) is effluxed into the atmosphere as a result of marine denitrification in the Arabian Sea (AS) oxygen minimum zone (OMZ). An assessment of temporal variations in the diversity and abundance of nosZ denitrifiers was performed to establish the relative importance of these bacteria in denitrification. Sampling was conducted at the Arabian Sea Time Series (ASTS) location and a quantitative PCR (qPCR) ana-lysis was performed.

Chromate detoxification potential of Staphylococcus sp. isolates from an estuary.

Chromium (Cr) pollution is an emerging environmental problem. The present study was carried out to isolate Cr-resistant bacteria and characterize their Cr detoxification and resistance ability. Bacteria screened by exposure to chromate (Cr) were isolated from Mandovi estuary Goa, India.

Response to chromate challenge by marine sp. NIOMR8 evaluated by differential protein expression.

Liquid Chromatography-Mass Spectrometry-Quadrupole Time of Flight (LC/MS QToF) protein profiling of marine-derived NIOMR8 was carried out to evaluate proteins conferring chromate (Cr) resistance and possible metabolic pathways that were altered as a result. Expressional (up or down-regulation) responses to varying Cr (0, 50, 100, 150, and 200 µg mL) concentrations varied, with as many as 346 proteins identified. Most number of proteins-their numbers in parentheses-were up-regulated when grown in medium with 50 µg mL (162) and, down-regulated in medium with 100 (281) or 200 µg mL Cr (280).

Improved Sprouting and Growth of Mung Plants in Chromate Contaminated Soils Treated with Marine Strains of Species.

Marine bacteria possess a wide variety of bioremediation potential which is beneficial environmentally and economically. In this study, bacterial isolates from marine waters were screened for tolerance and growth in high concentrations of chromate (Cr). Two isolates, capable of tolerating Cr concentrations 300 µg mL or higher, and found to completely reduce 20 µg mL Cr were grown in Cr (50 and 100 mg kg) spiked garden soil.

Efficient bioremediation of tannery wastewater by monostrains and consortium of marine Chlorella sp. and Phormidium sp.

This study evaluated the bioremediation potential of two marine microalgae Chlorella sp. and Phormidium sp., both individually and in consortium, to reduce various pollutants in tannery wastewater (TW).

Plant growth promoting potential and phylogenetic characteristics of a lichenized nitrogen fixing bacterium, Enterobacter cloacae.

Lichens are complex symbiotic association of mycobionts, photobionts, and bacteriobionts, including chemolithotropic bacteria. In the present study, 46 lichenized bacteria were isolated by conventional and enrichment culture methods on nitrogen-free bromothymol blue (NFb) medium. Only 11 of the 46 isolates fixed nitrogen on NFb and had reduced acetylene.

Response of bacterioplankton to iron fertilization of the Southern Ocean, Antarctica.

Ocean iron fertilization is an approach to increase CO2 sequestration. The Indo-German iron fertilization experiment "LOHAFEX" was carried out in the Southern Ocean surrounding Antarctica in 2009 to monitor changes in bacterial community structure following iron fertilization-induced phytoplankton bloom of the seawater from different depths. 16S rRNA gene libraries were constructed using metagenomic DNA from seawater prior to and after iron fertilization and the clones were sequenced for identification of the major bacterial groups present and for phylogenetic analyses.

PCR detection of ansA from marine bacteria and its sequence characteristics from Bacillus tequilensis NIOS4.

As many as 71 marine bacterial DNA extracts were PCR screened for L-asparaginase (ansA), a key gene in anti-cancer molecular-searches. Over 62% (44) of them were positive for ansA gene. The positive cultures were from genera Bacillus and Staphylococcus.

Microbial community response during the iron fertilization experiment LOHAFEX.

Iron fertilization experiments in high-nutrient, low-chlorophyll areas are known to induce phytoplankton blooms. However, little is known about the response of the microbial community upon iron fertilization. As part of the LOHAFEX experiment in the southern Atlantic Ocean, Bacteria and Archaea were monitored within and outside an induced bloom, dominated by Phaeocystis-like nanoplankton, during the 38 days of the experiment.

Denaturing gradient gel electrophoresis profiling of bacterial communities composition in Arabian Sea.

Denaturing gradient gel electrophoresis (DGGE) was used to elucidate spatial and temporal variations in bacterial community composition (BCC) from four locations along the central west coast of India. DNA extracts from 36 water samples collected from surface, mid-depth (-10 m) and dose to bottom (-20 m) during premonsoon, postmonsoon, monsoon were analyzed by PCRfor amplifying variable region of 16S rRNAgene and subsequently through DGGE. Prominent bands were excised, cloned and sequenced indicated the preponderance of gammaproteobacteria, bacteroidetes and cyanobacteria.

Phylogenetic diversity of archaeal 16S rRNA and ammonia monooxygenase genes from tropical estuarine sediments on the central west coast of India.

Phylogenetic diversity analyses of archaeal 16S rRNA and ammonia monooxygenase subunit A (AamoA) genes were carried out on sediment samples from the Mandovi and Zuari estuaries on the central west coast of India. The 16S rRNA gene libraries revealed quite high diversity of archaea in these sediments compared to previous reports from tropical and temperate estuarine sediments. Uncultured members of Crenarchaeota accounted for approximately 78% of 433 archaeal 16S rRNA gene clones from both of the estuaries.

Detection of luciferase gene sequences in nonluminescent bacteria from the Chesapeake Bay.

A 745-bp luxA fragment was amplified from Vibrio harveyi (UM 1503), radiolabeled, and used as a probe to detect and quantify luxA genotypes in culturable bacterial populations from the Chesapeake Bay. DNA samples from 53 reference strains were also examined for this gene. The luxA-positive bacteria comprised from 0-6% of the culturable heterotrophic bacterial community in samples from the Bay.