Diversity of anoxygenic phototrophic bacteria in anaerobic lagoons and facultative stabilization pond used in treatment of sewage

The objective of this study was to identify the anoxygenic phototrophic bacteria in the anaerobic lagoons and facultative stabilization pond of the Vale do Ribeira, Cajati, Sí£o Paulo, Brazil, and their correlation with physical and chemical parameters of the ponds' water. The samples were collected seasonally (spring, summer, autumn and winter) in the sub-surface, intermediate layer and sediment-water interface. We used the PCR/DGGE with pufM 557FGC and pufM 750R primers specific to the reaction center of the photosynthetic phototrophic bacteria for their identification. The amplification products were separated by electrophoresis on denaturing gradient gel. From the bands cut out and sequenced from DGGE, the identified bacteria were Rhodopseudomonas palustris (99% similarity), Chromatium sp. (92%), Thiocapsa sp. (90%), Rhodospirillum sp. (95%), Roseobacter sp. (93%) and other uncultured bacteria

Produção de biossurfactante por Lysinibacillus sp. e Bacillus sp. a partir de diferentes óleos como fonte de carbono

Biossurfactantes são moléculas multifuncionais produzidas por microrganismos e podem apresentar vantagens em relação aos surfactantes sintéticos, como baixa toxicidade, alta biodegradabilidade, maior redução da tensão superficial e alta diversidade química. No entanto, a produção em escala comercial ainda é escassa devido ao elevado custo dos substratos utilizados. Portanto, no presente trabalho foi avaliada a produção de biossurfactantes utilizando diferentes óleos como fonte de carbono, como óleo de soja, óleo de fritura, óleo diesel, óleo lubrificante novo e usado, a partir de dois gêneros de bactérias isoladas de lodo indústria de cosméticos e solo contaminado com óleo diesel, Lysinibacillus sp. e Bacillus sp. respectivamente. Estas foram identificadas por sequenciamento do fragmento do gene RNAr 16S e mantidas sob refrigeração a 4 ºC em tubos de ensaio, com ágar triptona de soja. Os ensaios de produção foram realizados sob agitação de 200 rpm a 30 °C com duração de 7 dias. A produção de biossurfactante foi analisada pela atividade emulsificante, índice emulsificação e por colapso da gota. As bactérias utilizadas produziram biossurfactante em todos os tipos de óleos testados. O óleo de soja mostrou-se o melhor substrato para produção de biossurfactante a partir do Lysinibacillus sp. e Bacillus sp. com índice de emulsificação de 50 % e 46,63 %, respectivamente. Palavras-chave: emulsificantes; bactérias; fontes alternativas; fermentação.

Microbiological characterization of the removal and degradation of linear alkylbenzene (LAS) in anaerobic reactors with biofim and planctonics cells

O objetivo desse trabalho foi avaliar a degradação de alquilbenzeno linear sulfonado (LAS) em condições anaeróbias. Os primeiros experimentos foram realizados em reatores em batelada alimentados com diferentes substratos e concentrações de LAS. Apesar do surfactante ficar adsorvido no lodo, não foram observadas interferências no metabolismo de microrganismos anaeróbios, pois dessa forma o LAS tornou-se indisponível para a degradação celular. Reatores anaeróbios horizontais de leito fixo (RAHLF) foram avaliados quanto à remoção de LAS e inoculados com lodos anaeróbios provenientes de reatores UASB usados respectivamente no tratamento de esgoto sanitário (R1) e tratamento de dejetos suinocultura (R2) imobilizados em espuma de poliuretano. A adição de LAS não influenciou na estabilidade do reator. O LAS começou a ser degradado após 108 dias da sua adição no afluente dos reatores. Porcentagens de remoção, considerando adsorção e degradação de LAS, com 313 dias de operação foram iguais a 50% e 91% para o R1 e R2, respectivamente, quando foram alimentados com esgoto sintético e 14 mg/L de LAS (reator - R1) e somente LAS a 14 mg/L (reator - R2). Em relação ao balanço de massa de LAS, os reatores apresentaram degradações muito semelhantes, sendo 35% para o reator R1 e 34% para o reator - R2. A diversidade microbiana referente aos domínios Bacteria e Archaea e ao grupo BRS foi avaliada utilizando a técnica de PCR/DGGE. Para o domínio Archaea, foram observadas diferenças significativas nas populações quando os reatores foram alimentados com LAS. Diferenças foram observadas no domínio Bactéria e grupo das BRS, para concentrações de LAS de 14 mg/L. A alteração na diversidade microbiana pode ter ocorrido devido à seleção dos microrganismos pela presença do surfactante. A biomassa presente no final da operação foi submetida à técnica de clonagem e seqüenciamento do fragmento do RNAr 16S para o domínio Bacteria. Observou-se que os reatores que apresentaram maior número de clones relacionados ao filo Firmicutes, classe Clostridia, ordem Clostridiales. Provavelmente os microrganismos pertencentes a esse grupo estejam envolvidos com a degradação do LASThe objective of this work was to evaluate the degradation of linear alkylbenzene sulfonate (LAS) in anaerobic conditions. The first experiments were accomplished in reactors in batch fed with different substrates and concentration of LAS. In spite of the surfactant to be adsorbed in the sludge interferences was not observed in the metabolism of anaerobic microorganisms, because in that way LAS became unavailable for the cellular degradation. Horizontal anaerobic immobilized biomass (HAIB) reactors were appraised as for the removal of LAS and inoculated with coming anaerobic slugde of reactors UASB used respectively in the treatment of sanitary sewage (R1) and treatment of wastewater swine (R2) immobilized polyurethane foam. The addition of LAS didnt influence in the stability of the reactor. LAS began to be degraded after 108 days of its addition in the tributary of the reactors. Removal percentages, considering adsorption and degradation of LAS, with 313 days of operation was same to 50% and 91% for R1 and R2, respectively, when they were fed with synthetic sewage and 14 mg/L of LAS (reactor R1) and only LAS to 14 mg/L (reactor R2). In relation to the balance of mass of LAS, the reactors presented very similar degradations, being 35% for the reactor R1 and 34% for the reactor R2. The microbial diversity regarding the Bacteria and Archaea domain and to the group BRS was evaluated using the technique of PCR/DGGE. The alteration in the microbial diversity might have happened due to the selection of the microorganisms for the presence of the surfactant. The biomass present in the end of the operation was submitted the cloning technique and sequencing of the fragment of 16S rRNA for the bacteria domain. It was observed that the reactors presented larger number of clones related to the phylum Firmicutes, Clostridia, Clostridiales. Probably the microorganisms belonging to that group are involved with the degradation of LA

Influence of support material on the immobilization of biomass for the degradation of linear alkylbenzene sulfonate in anaerobic reactors

Two horizontal-flow anaerobic immobilized biomass reactors (HAIB) were used to study the degradation of the LAS surfactant: one filled with charcoal (HAIB1) and the other with a mixed bed of expanded clay and polyurethane foam (HAIB2). The reactors were fed with synthetic substrate supplemented with 14 mg l(-1) of LAS, kept at 30 +/- 2 degrees C and operated with a hydraulic retention time (HRT) of 12 h. The surfactant was quantified by HPLC. Spatial variation analyses were done to quantify organic matter and LAS consumption along the reactor length. The presence of the surfactant in the load did not affect the removal of organic matter (COD), which was close to 90% in both reactors for an influent COD of 550 ring l(-1). The results of a mass balance indicated that 28% of all LAS added to HAIB1 was removed by degradation. HAIB2 presented 27% degradation. Molecular biology techniques revealed microorgan isms belonging the uncultured Holophaga sp., uncultured delta Proteobacterium, uncultured Verrucomicrobium sp., Bacteroides sp. and uncultured gamma Proteobacterium sp. The reactor with biomass immobilized on charcoal presented lower adsorption and a higher kinetic degradation coefficient. So, it was the most suitable support for LAS anaerobic treatment. (c) 2008 Elsevier Ltd. All rights reserved

A Comparison of Microbial Communities of Mango and Orange Residues for Bioprospecting of Biosurfactant Producers

Plants and their derivatives, such as fruits, can be inhabited by different bacteria. However, this microbiota is still poorly studied. Among the wide variety of metabolites that bacteria produce, biosurfactants have been identified as potential molecules in the development of bioprocesses for various industrial sectors. In this work, we analyzed and compared the microbiota of fruit residues (mango and orange), in order to compare two possible sources of bioprospecting. For this, a bioinformatics approach was used to perform the taxonomic analysis and the prediction of the functional profile of the microbiota present in the samples. The results showed that the microbiota present in both fruit residues have the potential in biotechnological applications to produce biosurfactants, as these microbiota have genes related to the biosynthesis of these compounds. The common core of the microbiota present in the samples—Stenotrophomonas, Klebsiella, Serratia and Citrobacter—proved, according to the literature, to be composed of biosurfactant producers, showing the biosurfactant potential of the bacteria isolated from orange and mango residues

A Comparison of Microbial Communities of Mango and Orange Residues for Bioprospecting of Biosurfactant Producers

Plants and their derivatives, such as fruits, can be inhabited by different bacteria. However, this microbiota is still poorly studied. Among the wide variety of metabolites that bacteria produce, biosurfactants have been identified as potential molecules in the development of bioprocesses for various industrial sectors. In this work, we analyzed and compared the microbiota of fruit residues (mango and orange), in order to compare two possible sources of bioprospecting. For this, a bioinformatics approach was used to perform the taxonomic analysis and the prediction of the functional profile of the microbiota present in the samples. The results showed that the microbiota present in both fruit residues have the potential in biotechnological applications to produce biosurfactants, as these microbiota have genes related to the biosynthesis of these compounds. The common core of the microbiota present in the samples—Stenotrophomonas, Klebsiella, Serratia and Citrobacter—proved, according to the literature, to be composed of biosurfactant producers, showing the biosurfactant potential of the bacteria isolated from orange and mango residues

Anaerobic degradation of anionic surfactants by indigenous microorganisms from sediments of a tropical polluted river in Brazil

The aim of this study was to evaluate the ability of the microorganisms present in the sediment of the Tietê river to degrade anionic surfactant – linear alkylbenzene sulphonate (LAS)  in the reactor operated in batch sequences under denitrifying conditions.  The reactor was fed with synthetic substrate consisting of yeast extract, soluble starch, sodium bicarbonate and sucrose; LAS was added at different stages in concentration of 15 mg/l after 30 mg/L. Reduction in the concentration of co-substrates were evaluated in order to optimize the degradation of surfactant. The results showed that the efficiency of degradation of LAS is directly related to the population of denitrifying bacteria and that the Tietê River sediment can be used as inoculum for the treatment of LAS.  These bacteria were able to degrade LAS regardless of additional carbon source.  The removal of LAS and nitrate can be achieved simultaneously in wastewater with low organic load.The aim of this study was to evaluate the ability of the microorganisms present in the sediment of the Tietê river to degrade anionic surfactant – linear alkylbenzene sulphonate (LAS)  in the reactor operated in batch sequences under denitrifying conditions.  The reactor was fed with synthetic substrate consisting of yeast extract, soluble starch, sodium bicarbonate and sucrose; LAS was added at different stages in concentration of 15 mg/l after 30 mg/L. Reduction in the concentration of co-substrates were evaluated in order to optimize the degradation of surfactant. The results showed that the efficiency of degradation of LAS is directly related to the population of denitrifying bacteria and that the Tietê River sediment can be used as inoculum for the treatment of LAS.  These bacteria were able to degrade LAS regardless of additional carbon source.  The removal of LAS and nitrate can be achieved simultaneously in wastewater with low organic load

Screening design of nutritional and physicochemical parameters on bio-hydrogen and volatile fatty acids production from Citrus Peel Waste in batch reactors

International audienceDifferent nutritional and physicochemical conditions to obtain H2 from Citrus Peel Waste (CPW) were evaluated. For this, a screening design was carried out using Plackett and Burman design, in order to verify the main significant conditions of this process. The variables studied were pH (5.5–8.5), temperature (30–44 °C), autochthonous inoculum (0.75–2.25 gTVS.L−1), allochthonous inoculum (1–3 gTVS.L−1) and substrate (5–15 g.L−1), headspace (40–60%) and nutritional medium components, such as yeast extract (0–1 g.L−1), CaCO3, NaCl and peptone (0–5 g.L−1). The most significant operational variables were pH (8.5), allochthonous inoculum (3 gTVS.L−1) and substrate concentration (15 g CPW.L−1), conditions that favored the highest H2 (13.29 mmol.L−1) and acetic acid productions (1340 mg.L−1). Escherichia (34.5%) and Clostridium (29.93%) were the main genera identified under these conditions