RESUMO
India has emerged as a key player with a high potential to develop a biomass and biobased economy due to its large geographic size and the massive amounts of agricultural and non agricultural biomass produced. India has joined hands with Europe to synchronize its efforts to create and facilitate the development of a biobased economy in this country. This paper aims to examine common research and development actions between the European Union (EU) and India to facilitate the development of these biobased economies. As a base, a thorough study has been performed considering the biomass potential and current status of the bioeconomy in both the EU and India based on the distillation of a series of 80 potential recommendations. The recommendations were grouped into four major categories: (1) biomass production, (2) by-products/waste, (3) biorefineries and (4) policy, market, and value-added products. A questionnaire was designed and distributed to key stakeholders belonging to: academia, industry, and policymakers in both India and the EU. A total of 231 responses were received and analyzed, based on the key recommendations made for the essential research and development topics that are of prime importance to develop biobased economies in both the EU and India. The findings of this study suggest recognizing the value-added contributions made by biobased products such as: food, feed, valuable materials and chemicals in both regions. It is important to reduce the overall process costs and minimize the environmental impacts of such a biobased economy.
Assuntos
Biotecnologia , Biomassa , Biotecnologia/economia , Biotecnologia/organização & administração , Biotecnologia/tendências , Europa (Continente) , Humanos , ÍndiaRESUMO
Background: The intestinal microbiota, through complex interactions with the gut mucosa, play a key role in the pathogenesis of colon carcinoma and inflammatory bowel disease (IBD). The disease condition and dietary habits both influence gut microbial diversity. Objective: The aim of this study was to assess the gut microbial profile of healthy subjects and patients with colon carcinoma and IBD. Healthy subjects included 'Indian vegetarians/lactovegetarians', who eat plant produce, milk and milk products, and 'Indian non-vegetarians', who eat plant produce, milk and milk products, certain meats and fish, and the eggs of certain birds and fish. 'Indian vegetarians' are different from 'vegans', who do not eat any foods derived wholly or partly from animals, including milk products. Design: Stool samples were collected from healthy Indian vegetarians/lactovegetarians and non-vegetarians, and colon cancer and IBD patients. Clonal libraries of 16S ribosomal DNA (rDNA) of bacteria were created from each sample. Clones were sequenced from one representative sample of each group. Approximately 500 white colonies were picked at random from each sample and 100 colonies were sequenced after amplified rDNA restriction analysis. Results: The dominant phylum from the healthy vegetarian was Firmicutes (34%), followed by Bacteroidetes (15%). The balance was reversed in the healthy non-vegetarian (Bacteroidetes 84%, Firmicutes 4%; ratio 21:1). The colon cancer and IBD patients had higher percentages of Bacteroidetes (55% in both) than Firmicutes (26% and 12%, respectively) but lower Bacteroidetes:Firmicutes ratios (3.8:1 and 2.4:1, respectively) than the healthy non-vegetarian. Bacterial phyla of Verrucomicrobiota and Actinobacteria were detected in 23% and 5% of IBD and colon patients, respectively. Conclusions: Ribosomal Database Project profiling of gut flora in this study population showed remarkable differences, with unique diversity attributed to different diets and disease conditions.
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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. This case involves multiple electrode reactions in series in the cathode compartment. The model structure captures interactions between important system variables based on first principles and provides a platform for the dynamic description of METs involving electrode reactions both in parallel and in series and in both MFC and MEC configurations. Such a theoretical modelling approach, largely based on first principles, appears promising in the development and testing of MET control and optimization strategies.
Assuntos
Fontes de Energia Bioelétrica/microbiologia , Técnicas Eletroquímicas , Biodegradação Ambiental , Butanóis/análise , Butanóis/metabolismo , Simulação por Computador , Eletrodos , Eletrólise , Etanol/análise , Etanol/metabolismo , Ácidos Graxos/análise , Ácidos Graxos/metabolismo , Modelos Biológicos , Oxirredução , Percloratos/isolamento & purificação , Percloratos/metabolismoRESUMO
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. Key considerations associated with these approaches for efficient treatment of PW are also discussed. After a thorough assessment of the salient features of these treatment platforms, we propose a new strategy of uniquely integrating bioelectrochemical processes with biological system for more effective PW treatment and management.
Assuntos
Eletroquímica/métodos , Hidrocarbonetos/química , Sulfatos/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Água/química , Carvão Mineral , Eletrodos , Gases , Geografia , Química Verde , Membranas Artificiais , Metano/química , Gás Natural , Osmose , Petróleo , Salinidade , Águas ResiduáriasRESUMO
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 76.60% respectively, along with the reduction in TDS during BES operation under 400mV of cathode potential. There was also a reduction in concentration of sulfates, however, it was not significant at, since oxidative conditions are being maintained at anode. Improved oxidation of PPW at anode also resulted in good power output (-20.47mA) and also depicted improved fuel cell behaviour. The electrochemical analysis in terms of cyclic/linear sweep voltammetry also showed well correlation with the observed treatment efficiencies. The microbial dynamics of the BES after loading real field wastewater showed the dominance of species that are reported to be effective for petroleum crude oil degradation.
Assuntos
Fontes de Energia Bioelétrica , Campos de Petróleo e Gás , Águas Residuárias/análise , Purificação da Água/métodos , Catálise , Técnicas Eletroquímicas/métodos , Eletrodos , Resíduos Industriais , Consórcios Microbianos , Oxirredução , Petróleo , Sulfatos , ÁguaRESUMO
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. The developed mass culture strategy led to achieve the reduction in surface tension (26dynescm(-1) from 69 dynescm(-1)) and degradation of 67% in bench scale experiments. The total crude oil degradation of 96% was achieved in 4000l of natural seawater after 28days without adding any nutrients. The survival of the augmented co-culture was maintained (10(9)cellsml(-1)) in contaminated marine environment. The mass culture protocol devised for the bioaugmentation was a key breakthrough that was subsequently used for pilot scale studies with 100l and 4000l of natural seawater for potential application in marine oil spills.
Assuntos
Biodegradação Ambiental , Reatores Biológicos/microbiologia , Petróleo/metabolismo , Bacillus/metabolismo , Candida/metabolismo , Técnicas de Cocultura , Hidrocarbonetos/metabolismo , Índia , Consórcios Microbianos , Poluição por Petróleo , Água do Mar/microbiologiaRESUMO
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. EDX analysis was done to confirm the presence of Ni in the spent catalyst after roasting it to decoke its surface. The optimum temperature for A. thiooxidans DSM-11478 growth was found to be 32 degrees C. The enhanced recovery of nickel at very low pH was attributed to the higher acidic strength of sulfuric acid produced in the culture medium by the bacterium. During the bioleaching process, 89% of the Ni present in the catalyst waste could be successfully recovered in optimized conditions. This environment friendly bioleaching process proved efficient than the chemical method. Taking leads from the lab scale results, bioleaching in larger volumes (1, 5 and 10 L) was also performed to provide guidelines for taking up this technology for in situ industrial waste management.
Assuntos
Acidithiobacillus thiooxidans/metabolismo , Poluentes Ambientais/análise , Resíduos Industriais/análise , Níquel/química , Petróleo , Biodegradação Ambiental , Poluentes Ambientais/química , Poluentes Ambientais/metabolismo , Concentração de Íons de Hidrogênio , Níquel/análise , Níquel/metabolismo , TemperaturaRESUMO
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. A synthetic PPW was designed for the study using response surface methodology. During the first step, sulfate present in PPW was reduced to sulfide by anaerobic fermentation with 80% efficiency. In the second step, more than 70% of the accumulated sulfide was electrochemically oxidized. This integrated approach successfully removed sulfate from the synthetic wastewater indicating its applicability in the treatment of PPW and its subsequent applications in other oil field operations.
Assuntos
Técnicas Eletroquímicas/métodos , Petróleo/análise , Sulfatos/análise , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Poluentes Químicos da Água/química , Técnicas Eletroquímicas/instrumentação , Oxirredução , Eliminação de Resíduos Líquidos/instrumentaçãoRESUMO
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 optimized value of operational parameters i.e. initial media pH, incubation temperature, initial syngas pressure, and agitation speed were 6.0±0.1, 37°C, 2kgcm(-2) and 100rpm respectively. Under these conditions ethanol and acetic acid production by the selected mixed culture were 1.54gL(-1) and 0.8gL(-1) respectively. Furthermore, up-scaling studies in semi-continuous fermentation mode further enhanced ethanol and acetic acid production up to 2.2gL(-1) and 0.9gL(-1) respectively. Mixed culture TERI SA1 was efficient for ethanol production by syngas fermentation.
Assuntos
Bactérias/metabolismo , Biotecnologia/métodos , Etanol/metabolismo , Gases/metabolismo , Ácido Acético/metabolismo , Anaerobiose , Bactérias/crescimento & desenvolvimento , Biomassa , Técnicas de Cultura de Células , Fermentação , Concentração de Íons de Hidrogênio , Pressão , TemperaturaRESUMO
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. Total petroleum hydrocarbon mass was effectively reduced by 53.3 (±5.75)% to 147,000 (±21,000) mg l(-1) within 27 weeks. 16S rDNA bacterial community profiling using Denaturant Gradient Gel Electrophoresis revealed that cyanobacteria and Proteobacteria dominated the microbial community. Aquatic toxicity assessment was conducted by ecotoxicity assays using brine shrimp hatchability, Microtox and Phaeodactylum tricornutum. This study revealed the importance of combining ecotoxicity assays with oil chemistry analysis to ensure safe remediation methods are developed.
Assuntos
Biodegradação Ambiental , Poluição por Petróleo , Petróleo/metabolismo , Poluentes Químicos da Água/química , Animais , Artemia , Bioensaio , Cianobactérias/metabolismo , Petróleo/análise , Proteobactérias/metabolismo , Água do Mar/microbiologia , Poluentes Químicos da Água/toxicidadeRESUMO
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 (3.5M KCl). A range of chemicals were bioelectrosynthesized, however the gases present in headspace environment of the bioelectrochemical reactor governed the product profile. Succinate, ethanol, hydrogen, glycerol and propionate were observed to be the predominant products when the reactor was hermetically sealed. On the other hand, acetone, propionate, isopropanol, propanol, isobutyrate, isovalerate and heptanoate were the predominant products when the reactor was continuously sparged with nitrogen. This study highlights the importance of head space composition in order to manoeuvre the final product profile desired during a microbial electro-synthesis operation and the need for simultaneously developing effective separation and recovery strategies from an economical and practical standpoint.
Assuntos
Bactérias/metabolismo , Sulfatos/metabolismo , Reatores Biológicos/microbiologia , Técnicas Eletroquímicas , Eletrodos , Hidrogênio/metabolismo , Concentração de Íons de HidrogênioRESUMO
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 23.11 mW/m(2)) and threefolds increase in current density (from 75 to 250 mA/m(2)). Enhanced redox currents and lower Tafel slopes observed from cyclic voltammograms of ACF with SS mesh indicated the positive role of uniform electron collecting points. Differential pulse voltammetry technique was employed as an additional tool to assess the redox carriers involved in bioelectrochemical reactions. SRB biocathode was also tested for reduction of volatile fatty acids (VFA) present in the fermentation effluent stream and the results indicated the possibility of integration of this system with anaerobic fermentation for efficient product recovery.
Assuntos
Bactérias/metabolismo , Carvão Vegetal/farmacologia , Aço Inoxidável/farmacologia , Sulfatos/metabolismo , Têxteis , Bactérias/efeitos dos fármacos , Fontes de Energia Bioelétrica/microbiologia , Reatores Biológicos/microbiologia , Catálise , Eletricidade , Técnicas Eletroquímicas , Eletrodos , Ácidos Graxos Voláteis/análise , Concentração de Íons de Hidrogênio , Oxirredução/efeitos dos fármacosRESUMO
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).
Assuntos
Acetatos/metabolismo , Acetona/metabolismo , Álcoois/metabolismo , Bactérias/metabolismo , Butiratos/metabolismo , Biocatálise , Técnicas Eletroquímicas , Transporte de Elétrons , OxirreduçãoRESUMO
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. Here, we used a tank mesocosm system (50 l) to follow the degradation of weathered oil (10 g l(-1)) using a bacterial consortium mobilised onto different carrier materials (alginate or shell grit). GCMS analysis demonstrated that the extent of hydrocarbon degradation was dependent upon the carrier material. Augmentation of shell grit with nutrients and exogenous hydrocarbon degraders resulted in 75±14% removal of >C32 hydrocarbons after 12 weeks compared to 20±14% for the alginate carrier. This study demonstrated the effectiveness of a biostimulated and bioaugmented carrier material to degrade marine weathered oil.
Assuntos
Alginatos/farmacologia , Exoesqueleto/química , Bactérias/metabolismo , Óleos/isolamento & purificação , Água do Mar/microbiologia , Poluentes Químicos da Água/isolamento & purificação , Poluição da Água/análise , Animais , Bactérias/efeitos dos fármacos , Biodegradação Ambiental/efeitos dos fármacos , Reatores Biológicos/microbiologia , Cromatografia Gasosa , Ecotoxicologia , Ácido Glucurônico/farmacologia , Ácidos Hexurônicos/farmacologia , Hidrocarbonetos/análise , Luminescência , Viabilidade Microbiana , Filogenia , RNA Ribossômico 16S/genéticaRESUMO
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 30.90 %, 18.80 %, 25.90 % and 29.90 % respectively, after 360 days of treatment with microbial consortia was reduced to 0.97 %, 1.0 %, 1.0 %, and 1.1 % respectively. Whereas, only 5 % degradation was observed in the control plot after 365 days (microbial consortium not applied).
Assuntos
Bactérias/metabolismo , Consórcios Microbianos , Poluição por Petróleo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Cromatografia Gasosa , Hexanos/metabolismo , Hidrocarbonetos/metabolismo , Petróleo/metabolismo , Tolueno/metabolismoRESUMO
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. TERIG02 showed 42% viscosity reduction when asphalt along with molasses was used as a sole carbon source compared to only asphalt (37%). The viscosity reduction by asphaltene degradation has been structurally characterized by Fourier transform infrared spectroscopy (FTIR). This strain also shows an additional preference to degrade toxic asphalt and aromatics compounds first unlike the other known strains. All these characteristics makes TERIG02 a potential candidate for enhanced oil recovery and a solution to degrading toxic aromatic compounds.
Assuntos
Eubacterium/metabolismo , Hidrocarbonetos/metabolismo , Petróleo , Microbiologia da Água , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Eubacterium/genética , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Água do Mar/microbiologia , Espectroscopia de Infravermelho com Transformada de Fourier , ViscosidadeRESUMO
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. synthase. The corresponding gene was expressed in Pseudomonas putida KT2440 ΔphaC1 which is impaired in PHA production. The gene conferred the recombinant strain PpKT-40N22 with the ability to produce copolymers with up to 21% in medium-chain-length content. Thus, 37% and 45% of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate-co-3-hydroxyoctanoate), respectively were obtained when using sodium heptanoate and oleic acid as carbon sources. These 3-hydroxybutyrate-(3HB)-based polymers are of interest since they incorporate the properties of medium chain length polymers and thus increase the range of applications of PHAs.
Assuntos
Aciltransferases/metabolismo , Variação Genética , Metagenômica/métodos , Poliésteres/metabolismo , Pseudomonas putida/enzimologia , Pseudomonas putida/genética , Recombinação Genética/genética , Sequência de Bases , Carbono/farmacologia , Meios de Cultura/farmacologia , Genes Bacterianos/genética , Testes Genéticos , Variação Genética/efeitos dos fármacos , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , Pseudomonas putida/efeitos dos fármacos , Análise de Sequência de DNA , Especificidade por Substrato/efeitos dos fármacosRESUMO
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. Sulfide production was the lowest with cow urine (0.08 mmol/L), followed by tetrakishydroxymethyl phosphonium sulfonate 0.72 mmol/L. On day 90 of treatment, Fe(II) production was also found to be the lowest with cow urine. The scanning electron microscopic studies indicated that the biofilm bacteria were killed by cow urine. These results demonstrate the cow urine mediated control of microbially induced corrosion, and this is indicative of its potential as a viable substitute of toxic biocides. To the best of our knowledge, this seems to be the first report which screens possible biocidal activity by cow urine as compared to the most common biocides which oil industry is currently using.
Assuntos
Corrosão , Desulfovibrio gigas/efeitos dos fármacos , Desulfovibrio vulgaris/efeitos dos fármacos , Desinfetantes/farmacologia , Biofilmes/efeitos dos fármacosRESUMO
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. The time course degradation experiment detected several intermediate products and the metabolites were identified by gas chromatography mass spectrometry analysis. Metabolite I was the detected on the 5th day and was identified as 1-hydroxypyrene and was detected till 10th day. Metabolite II which was detected on 10th day was identified as 1,2-phenanthrenedicarboxylic acid. Metabolite III and Metabolite IV were identified as 2-carboxy benzaldehyde and ortho-phthalic acid, respectively and were detected in the culture broth on 10th and 15th day. 1,2-benzene diol (catechol) was the fifth metabolite detected in the culture extracts on the 15th day and was subsequently reduced on day 20. Identification of Metabolite I as 1-hydroxypyrene was further investigated as this intermediate was not previously reported as a ring oxidation product for degradation of pyrene by bacterial strains. Purification by preparative high performance liquid chromatography and nuclear magnetic resonance spectroscopy, confirmed the identification of Metabolite I as 1-hydroxypyrene. L. adecarboxylata PS4040 could also use 1-hydroxypyrene as a sole source of carbon and energy. Thus a probable pathway for degradation of pyrene by enteric bacterium is proposed in this study, with 1-hydroxypyrene as initial ring oxidation product.
Assuntos
Enterobacteriaceae/metabolismo , Pirenos/metabolismo , Biodegradação Ambiental , Enterobacteriaceae/química , Enterobacteriaceae/isolamento & purificação , Pirenos/química , Esgotos/microbiologiaRESUMO
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. MATERIALS AND METHODS: One hundred and sixty-six patients (96 DU and 70 functional dyspepsia) were included in this study. In addition, sequence diversity of dupA gene of H. pylori found in these patients was analyzed by sequencing the PCR products jhp0917 and jhp0918 on both strands with appropriate primers. RESULTS: PCR and hybridization analyses indicated that dupA gene was present in 37.5% (36/96) of H. pylori strains isolated from DU patients and 22.86% (16/70) of functional dyspepsia patients (p < or = .05). Of these, 35 patients with DU (97.2%) and 14 patients with functional dyspepsia (81.25%) were infected by H. pylori positive for cagA genotype. Furthermore, the presence of dupA was significantly associated with the cagA-positive genotype (p < or = .02). CONCLUSION: Results of our study have shown that significant association of dupA gene with DU in this population. The dupA gene can be considered as a novel virulent marker for DU in this population.