Preeti Arora

Development of a microbial process for the recovery of petroleum oil from depleted reservoirs at 91–96 °C

A consortium of bacteria growing at 91°C and above (optimally at 96°C) was developed for the recovery of crude oil from declining/depleted oil reservoirs having temperature of more than 91°C. PCR-DGGE-Sequencing analysis of 16S rRNA gene fragments of NJS-4 consortium revealed the presence of four strains identified as members of the genus Clostridium. The metabolites produced by NJS-4 consortium included volatile fatty acids, organic acids, surfactants, exopolysaccarides and CO2, which reduced viscosity, emulsified crude oil and increased the pressure that facilitated displacement of emulsified oil towards the surface. NJS-4 enhanced oil recovery by 26.7% and 10.1% in sand pack trials and core flood studies respectively in optimized nutrient medium comprised of sucrose and sodium acetate as carbon/energy source and urea as nitrogen source (pH 7-9, 96°C, and 4% salinity). Nutrient medium for MEOR was constituted using commercial grade cheap nutrients to improve the economic viability of MEOR process.

Metagenome changes in the biogas producing community during anaerobic digestion of rice straw.

The present investigation was undertaken to study the microbial community succession in a sour and healthy digester. Ion torrent next-generation sequencing (NGS)-based metagenomic approach indicated abundance of hydrolytic bacteria and exclusion of methanogens and syntrophic bacteria in sour digester. Functional gene analysis revealed higher abundance of enzymes involved in acidogenesis and lower abundance of enzymes associated with methanogenesis like Methyl coenzyme M-reductase, F420 dependent reductase and Formylmethanofuran dehydrogenase in sour digester. Increased abundance of methanogens (Methanomicrobia) and genes involved in methanogenesis was observed in the restored/healthy digester highlighting revival of pH sensitive methanogenic community.

Draft genome of Cryobacterium sp. MLB-32, an obligate psychrophile from glacier cryoconite holes of high Arctic.

Obligate psychrophilic, Cryobacterium sp. MLB-32, was isolated from cryoconite holes of high Arctic glaciers. Here, we report the first draft genome sequence of the putative novel species of the genus Cryobacterium, providing opportunities for biotechnological and agricultural exploitation of its genome features.

Genome Characteristics of a Novel Type I Methanotroph (Sn10-6) Isolated from a Flooded Indian Rice Field

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.

Draft Genome Sequence of Geobacillus sp. Strain FW23, Isolated from a Formation Water Sample

ABSTRACT The thermophilic Geobacillus sp. strain FW23 was isolated from the Mehsana oil wells in Gujrat, India, during a screening for oil-degrading bacteria. Here, we report the draft genome sequence of Geobacillus sp. FW23, which may help reveal the genomic differences between this strain and the earlier reported species of the genus Geobacillus.

Draft genome of Elstera litoralis, a freshwater epilithic biofilm associated bacterium from littoral zone of Lake Constance.

Elstera litoralis, is a Rhodospirillaceae member which was isolated from the littoral zone of Lake Constance from a stone biofilm using diatom extracellular polymeric substances (EPS) as C source. We present here the draft genome of E. litoralis which has a genome size of 3.83 Mb and 61.2% G+C content. Genome analysis indicated utilization of multiple C substrates explaining its heterotrophic lifestyle as a bacterium present in natural biofilms. Further comparative genome analysis of Elstera with other members of Rhodospirillaceae would be helpful to understand the evolutionary relationships and divergence of hydrobacteria from terrabacteria.

Cultivable bacterial flora of Indian oil reservoir: isolation, identification and characterization of the biotechnological potential

Abstract ‘Produced water’ is a term used in oil industry to describe water produced along with oil and gas from oil reservoir. Microorganisms have been frequently isolated from produced water/oil reservoirs; however, there is paucity of information regarding the diversity and characterization of bacterial flora from Indian oil reservoirs. The present investigation was undertaken to study bacterial diversity associated with Indian oil reservoirs and to investigate their potential as a source of industrially valuable enzymes. A total of 103 strains were isolated from five oil reservoirs. PCR-based DNA fingerprinting grouped these strains into 72 genovars. These isolates were identified using morphological, phenotypical and phylogenetic analyses. Most of these isolates were thermophiles (growing at 45◦C or higher), halotolerant (growth at 5% salinity) and were distributed through a variety of genera including but not limited to Bacillus, Chelatococcus, Paenibacillus and Pseudomonas species. The 16S rRNA gene sequence of several strains shared less than 97% homology with the reference sequences in the GenBank database indicating taxonomic novelty of these strains. Assessment of the biotechnological potential of 72 genovars revealed that majority of strains produce one or many of the valuable enzymes including amylase, cellulase, xylanase, pectinase, inulinase, protease, alcohol dehydrogenase and urease. Most of the isolates also degraded crude oil or petroleum hydrocarbons. The vast pool of phenotypic, genetic and functional diversity of the strains retrieved in this study suggested oil reservoirs as yet largely untapped and potent source of taxonomically novel and biotechnologically valuable microorganisms.

Draft genome sequence of Methanoculleus sp. MH98A, a novel methanogen isolated from sub-seafloor methane hydrate deposits in Krishna Godavari basin

Members of the genus Methanoculleus are among the most prevalent methanogens in biomethanation processes especially in marine and brackish environments. A methanogen, identified as a novel species of the genus Methanoculleus, was isolated from deep sub-seafloor sediment obtained from the Krishna Godavari Basin off the eastern coast of India. This methanogen is thought to be the supplier of the methane in the submarine methane hydrate deposits. Further study of this microorganism could possibly help to revolutionize the energy industry. The draft genome of Methanoculleus sp. MH98A is presented.

Draft genome sequence of Clostridium sulfidigenes 113A isolated from sub-seafloor sediments associated with methane hydrate deposits.

Clostridium sulfidigenes 113A is a strictly anaerobic, rod shaped, gram positive bacterium isolated from sub-seafloor sediments associated with methane hydrates. Here, we report the first draft genome of C. sulfidigenes strain 113A, which comprises 3,717,420 bp in 96 contigs with the G+C content of 30.1%. A total of 3148 protein coding sequences were predicted. The genome annotation revealed that 113A could play an important role in biogeochemical cycles and have potential biotechnological applications such as production of organic acids and butanol.

Draft genome sequence of Clostridium celerecrescens 152B isolated from sub-seafloor methane hydrate deposits.

Clostridium celerecrescens 152B is an obligate anaerobic, Gram positive rod shaped bacterium isolated from sub-seafloor methane hydrate sediments of Krishna Godavari basin, India. Here, we report the first draft genome sequence of C. celerecrescens 152B, which comprises 5,050,495bp in 92 contigs with the G+C content of 43.5%. The whole genome of C. celerecrescens 152B was sequenced for further biotechnological exploitation of its genome features especially regarding the production of secondary metabolites as well as for environmental bioremediation and production of industrially valuable enzymes.