A Multiple Reaction Modelling Framework for Microbial Electrochemical Technologies.

A mathematical model for the theoretical evaluation of microbial electrochemical technologies (METs) is presented that incorporates a detailed physico-chemical framework, includes multiple reactions (both at the electrodes and in the bulk phase) and involves a variety of microbial functional groups. The model is applied to two theoretical case studies: (i) A microbial electrolysis cell (MEC) for continuous anodic volatile fatty acids (VFA) oxidation and cathodic VFA reduction to alcohols, for which the theoretical system response to changes in applied voltage and VFA feed ratio (anode-to-cathode) as well as membrane type are investigated. This case involves multiple parallel electrode reactions in both anode and cathode compartments; (ii) A microbial fuel cell (MFC) for cathodic perchlorate reduction, in which the theoretical impact of feed flow rates and concentrations on the overall system performance are investigated.

Bioelectrochemical approaches for removal of sulfate, hydrocarbon and salinity from produced water.

Produced water (PW) is the largest liquid waste stream generated during the exploration and drilling process of both the conventional hydrocarbon based resources like crude oil and natural gas, as well as the new fossil resources like shale gas and coal bed methane. Resource management, efficient utilization of the water resources, and water purification protocols are the conventionally used treatment methods applied to either treat or utilize the generated PW. This review provides a comprehensive overview of these conventional PW treatment strategies with special emphasises on electrochemical treatment.

Bio-electro catalytic treatment of petroleum produced water: Influence of cathode potential upliftment.

Treatment of petroleum produced water (PPW) was studied using bioelectrochemical system (BES) under uplifted cathode potential. The treatment efficiency in terms of COD and hydrocarbon removal was observed at 91.25% and 76.

Mass culture strategy for bacterial yeast co-culture for degradation of petroleum hydrocarbons in marine environment.

In the present study a metabolically versatile co-culture with two Bacilli and one yeast strain was developed using enrichment culture techniques. The developed co-culture had affinity to degrade both aliphatic and aromatic fractions of petroleum crude oil. Degradation kinetics was established for designing the fermentation protocol of the co-culture.

Electrochemical removal of sulfate from petroleum produced water.

Petroleum produced water (PPW) is a waste-stream that entails huge cost on the petroleum industry. Along with other suspended and dissolved solids, it contains sulfate, which is a major hurdle for its alternative use intended toward enhanced oil recovery. This study proposes a two-step process for sulfate removal from PPW.

Bioleaching of nickel from spent petroleum catalyst using Acidithiobacillus thiooxidans DSM- 11478.

The present work deals with optimization of culture conditions and process parameters for bioleaching of spent petroleum catalyst collected from a petroleum refinery. The efficacy of Ni bioleaching from spent petroleum catalyst was determined using pure culture of Acidithiobacillus thiooxidans DSM- 11478. The culture conditions of pH, temperature and headspace volume to media volume ratio were optimized.

Enrichment and optimization of anaerobic bacterial mixed culture for conversion of syngas to ethanol.

The main aim of the present study was to enrich anaerobic mixed bacterial culture capable of producing ethanol from synthesis gas fermentation. Screening of thirteen anaerobic strains together with enrichment protocol helped to develop an efficient mixed culture capable of utilizing syngas for ethanol production. Physiological and operational parameters were optimized for enhanced ethanol production.

The application of a carrier-based bioremediation strategy for marine oil spills.

The application of recycled marine materials to develop sustainable remediation technologies in marine environment was assessed. The remediation strategy consisted of a shell carrier mounted bacterial consortium composed of hydrocarbonoclastic strains enriched with nutrients (Bioaug SC). Pilot scale studies (5000 l) were used to examine the ability of Bioaug-SC to degrade weathered crude oil (10 g l(-1); initially 315,000±44,000 mg l(-1)) and assess the impacts of the introduction and biodegradation of oil.

Influence of headspace composition on product diversity by sulphate reducing bacteria biocathode.

Mixed culture of sulphate reducing bacteria named TERI-MS-003 was used for development of biocathode on activated carbon fabric fastened to stainless steel mesh for conversion of volatile fatty acids to reduced organic compounds under chronoamperometric conditions of -0.85V vs. Ag/AgCl (3.

Enhanced performance of sulfate reducing bacteria based biocathode using stainless steel mesh on activated carbon fabric electrode.

An anoxic biocathode was developed using sulfate-reducing bacteria (SRB) consortium on activated carbon fabric (ACF) and the effect of stainless steel (SS) mesh as additional current collector was investigated. Improved performance of biocathode was observed with SS mesh leading to nearly five folds increase in power density (from 4.79 to 23.

Bioelectrocatalyzed reduction of acetic and butyric acids via direct electron transfer using a mixed culture of sulfate-reducers drives electrosynthesis of alcohols and acetone.

Sulfate-reducing bacteria (SRB) developed biocathodes efficient for reduction of acetic and butyric acids to alcohols and acetone via direct electron transfer reaching current densities of 160-210 A m(-2).

Carrier mounted bacterial consortium facilitates oil remediation in the marine environment.

Marine oil pollution can result in the persistent presence of weathered oil. Currently, removal of weathered oil is reliant on chemical dispersants and physical removal, causing further disruption. In contrast few studies have examined the potential of an environmentally sustainable method using a hydrocarbon degrading microbial community attached to a carrier.

Biodegradation of oil spill by petroleum refineries using consortia of novel bacterial strains.

Feasibility study carried out at the site prior to the full scale study showed that the introduced bacterial consortium effectively adapted to the local environment of the soil at bioremediation site. The soil samples were collected from the contaminated fields after treatment with bacterial consortium at different time intervals and analyzed by gas chromatography after extraction with hexane and toluene. At time zero (just before initiation of bioremediation), the concentration of total petroleum hydrocarbons in the soil (25-cm horizon) of plot A, B, C and D was 30.

Efficacy of natural biocide on control of microbial induced corrosion in oil pipelines mediated by Desulfovibrio vulgaris and Desulfovibrio gigas.

We compared the efficacy of a natural biocide with four chemical tetrakishydroxymethyl phosphonium sulfonate, benzyl trimethyl ammonium chloride, and formaldehyde, glutaraldehyde, to control microbial induced corrosion in oil pipelines. The efficacy of biocides were monitored against Desulfovibrio vulgaris and Desulfovibrio gigas in experimental pipes by measuring cell counts, H2S production, Fe(II) production, production of extracellular polymeric substances and structure of biofilm. The treatment with cow urine had minimum planktonic cell counts of 3 x 10(2) CFU/mL as well as biofilm cell counts of 9 x 10(1) CFU/mL as compared with tetrakishydroxyl methyl phosphonium sulfonate, benzyl trimethyl ammonium chloride, formaldehyde and glutaraldehyde.

Exploiting metagenomic diversity for novel polyhydroxyalkanoate synthases: production of a terpolymer poly(3-hydroxybutyrate-co-3-hydroxyhexanoate-co-3-hydroxyoctanoate) with a recombinant Pseudomonas putida strain.

A metagenomic library of 2.1×10(6) clones was constructed using oil-contaminated soil from Gujarat (India). One of the fosmid clones, 40N22, encodes a polyhydroxyalkanoate synthase showing 76% identity with an Alcaligenes sp.

Biodegradation of asphalt by Garciaella petrolearia TERIG02 for viscosity reduction of heavy oil.

Petroleum hydrocarbon is an important energy resource, but it is difficult to exploit due to the presence of dominated heavy constituents such as asphaltenes. In this study, viscosity reduction of Jodhpur heavy oil (2,637 cP at 50°C) has been carried out by the biodegradation of asphalt using a bacterial strain TERIG02. TERIG02 was isolated from sea buried oil pipeline known as Mumbai Uran trunk line (MUT) located on western coast of India and identified as Garciaella petrolearia by 16S rRNA full gene sequencing.

Degradation of pyrene by an enteric bacterium, Leclercia adecarboxylata PS4040.

A newly discovered enteric bacterium Leclercia adecarboxylata PS4040, isolated from oily sludge contaminated soil sample was reported for degradation of polycyclic aromatic hydrocarbons (Appl Environ Microbiol 70:3163-3166, 2004a). This strain could degrade 61.5% of pyrene within 20 days when used as sole source of carbon and energy.

Prevalence of duodenal ulcer-promoting gene (dupA) of Helicobacter pylori in patients with duodenal ulcer in North Indian population.

Background: The duodenal ulcer (DU)-promoting gene (dupA) of Helicobacter pylori has been identified as a novel virulent marker associated with an increased risk for DU. The presence or absence of dupA gene of H. pylori present in patients with DU and functional dyspepsia in North Indian population was studied by polymerase chain reaction (PCR) and hybridization analysis.

Assessment of intra-species diversity among strains of Acinetobacter baumannii isolated from sites contaminated with petroleum hydrocarbons.

A total of 96 crude oil-degrading bacterial strains were isolated from 5 geographically diverse sites in India that were contaminated with different types of petroleum hydrocarbons. The strains were identified by sequencing the genes that encode for 16S rRNA. Out of the 96 isolates, 25 strains were identified as Acinetobacter baumannii and selected for the study.

Crude oil degradation efficiency of a recombinant Acinetobacter baumannii strain and its survival in crude oil-contaminated soil microcosm.

A hydrocarbon degrading Acinetobacter baumannii S30 strain, isolated from crude oil-contaminated soil, was inserted with the lux gene from the luciferase gene cassette luxCDABE. Soil microcosms were designed to study the degradation efficacy for total petroleum hydrocarbon (TPH) of crude oil by lux-tagged A. baumannii S30 pJES.

Degradation of polycyclic aromatic hydrocarbons by a newly discovered enteric bacterium, Leclercia adecarboxylata.

A bacterial strain, PS4040, capable of degrading polycyclic aromatic hydrocarbons for use as the sole carbon source was isolated from oily-sludge-contaminated soil. The 16S rRNA gene showed 98.8% homology to that of Leclercia adecarboxylata.

Evaluation of genetic diversity among Pseudomonas citronellolis strains isolated from oily sludge-contaminated sites.

The diversity among a set of bacterial strains that have the capacity to degrade total petroleum hydrocarbons (TPH) in soil contaminated with oily sludge (hazardous hydrocarbon waste from oil refineries) was determined. TPH is composed of alkane, aromatics, nitrogen-, sulfur-, and oxygen-containing compound, and asphaltene fractions of crude oil. The 150 bacterial isolates which could degrade TPH were isolated from soil samples obtained from diverse geoclimatic regions of India.