A metilamina ('CH IND.3'NH IND.2') é um composto orgânico usado na produção de inseticidas, herbicidas, fungicidas, surfactantes, combustíveis fósseis, explosivos, produtos farmacêuticos, químicos fotográficos, tintas, tecidos, solventes, borrachas e anti-corrosivos. Estudos sobre tratamento de águas residuárias contendo metilamina são escassos e se restringem aos trabalhos envolvendo pesticidas carbamatados. Visando contribuir com os estudos acerca da degradação anaeróbia da metilamina, esta pesquisa estudou a comunidade microbiana e a atividade metanogênica específica em reatores anaeróbios em batelada, inoculados com lodo granular oriundo de reator UASB usado no tratamento de água residuária de abatedouro de aves, sob diferentes condições nutricionais: controle – sem metilamina, 5 mM, 10 mM, 20 mM, 30 mM, 50 mM, 75 mM e 90 mM de metilamina. Os reatores foram incubados sob temperatura de 30°C e agitação de 150 rpm. Desses reatores foram obtidas amostras para a determinação da atividade metanogênica específica (AME), sólidos suspensos voláteis (SVT), nitrogênio amoniacal e exames microscópicos. Ao final do experimento, foram realizados exames da biomassa por meio da técnica do número mais provável (NMP) e análise da diversidade microbiana por PCR/DGGE e seqüenciamento. O aumento da AME foi proporcional ao aumento das concentrações de metilamina, com inibição de produção de metano apenas nos reatores alimentados com 90 mM de metilamina. Os reatores alimentados com 50 mM e 75 mM de metilamina apresentaram os melhores resultados, com valores médios de AME de 0,0804 mmol 'CH IND.4'/g SVT.h e 0,0825 mmol 'CH IND.4'/g SVT.h respectivamente. Nos exames microscópicos foi verificado semelhança de morfologias microbianas em todas as concentrações de metilamina estudadas. Os organismos presentes nos reatores foram Methanosarcina sp., Methanosaeta sp., bacilos, coco-bacilos, filamentos e cocos. Em relação à análise de DGGE, não houve variação significativa nos padrões de bandas, tanto para o domínio Archaea quanto para o domínio Bacteria. Com os resultados da técnica de número mais provável (NMP) observou-se a predominância de arquéias metanogênicas dentre as bactérias anaeróbias totais. / The methylamine ('CH IND.3'NH IND.2') is an organic compound used in the production of insecticides, herbicides, fungicides, surfactants, fossil fuels, explosives, pharmaceuticals, photographic chemicals, paints, textiles, dyes, rubber and anticorrosive chemicals. Some studies about the treatment of wastewater containing methylamine are scarce and limited to works involving carbamate pesticides. This research aimed to study the anaerobic degradation of methylamine, the microbial community and the specific methanogenic activity in anaerobic battled reactors. The reactors were inoculated with granular sludge from a UASB reactor treating poultry wastes. Different nutritional conditions were adopted in the operation of the reactors: control (without methylamine), 5 mM, 10 mM, 20 mM, 30 mM, 50 mM, 75 mM and 90 mM of methylamine. The reactors were incubated under standard conditions: 30ºC and 150 rpm. Samples had been removed from the reactors to determine the specific methanogenic activity, the concentration of volatile suspended solids and ammoniacal nitrogen and the microscopic analysis. At the end of the experiment, the biomass was studied by the most probable number (MPN) technique and by the microbial diversity analysis with PCR and DGGE techniques. The increase of the specific methanogenic activity was proportional to the increase of methylamine concentration. The methane production was inhibited only in the reactor that was fed with 90 mM of methylamine. The reactors that were fed with 50 mM and 75 mM of methylamine showed the best results, with medium values of specific methanogenic activity equal to 0,0804 mmol 'CH IND.4'/g SVT.h and 0,0825 mmol 'CH IND.4'/g SVT.h, respectively. The microscopic analysis showed similarity between the microbial morphologies in all of the reactors. The observed microorganisms were Methanosarcina sp., Methanosaeta sp., rods, cocci and filaments. The DGGE analysis did not show significant variation in the standard profile of the Archaea and Bacteria domains. The results of the MPN technique revealed the predominance of the methanogenic archaea among the total anaerobic bacteria.

As cianobactérias atuam no tratamento de águas residuárias em lagoas de estabilização. Seu estudo torna-se importante tanto pela atuação no referido tratamento como na possível produção de toxinas e seus efeitos nos sistemas aquáticos e saúde da população. Protocolos moleculares para culturas axênicas ou naturais foram testados e adaptados para as amostras analisadas. Este trabalho teve como objetivo avaliar o método molecular de eletroforese em gel de gradiente desnaturante nas espécies de Microcystis (cianobactérias) em um sistema de lagoas de estabilização. Foram utilizadas as técnicas de Reação de Polimerização em Cadeia (PCR) e Eletroforese em Gel de Gradiente Desnaturante (DGGE) do gene RNAr 16S como marcador molecular na análise de cianobactérias no sistema de lagoas de estabilização de São Lourenço da Serra - SP. Este sistema é composto por tratamento primário (caixa de areia), fossa séptica seguida de um sistema australiano (lagoa anaeróbia seguida por uma lagoa facultativa) e na saída do sistema de lagoas um tanque de cloração. Na amostra ambiental realizada na lagoa facultativa obteve-se, através de exame microscópico, o predomínio das espécies Microcystis aeruginosa e Microcystis flos-aquae. Através da técnica molecular de DGGE foi obtido um padrão de aproximadamente 18 bandas com a amostra ambiental. / Cyanobacteria are active in wastewater treatment in stabilization ponds. The study of these microrganisms is of a great importance considering their role in the referred wastewater treatments as well as their potential to produce toxins and their effects in aquatic systems and public health. Molecular protocols for pure or natural cultures were tested and adapted for the collected environmental samples. This work had as objective to evaluate the molecular method of denatuirng gradient gel electrophoresis in the Microcystis species (cyanobacteria) in a system of stabilization ponds. The techniques Polimerase Chain Reaction (PCR) and Denaturing Gradient Gel Electrophoresis (DGGE) of the gene 16S rRNA as molecular marker were used in the cyanobacteria analysis in the system of stabilization ponds of São Lourenço da Serra - SP. This system is composed by primary treatment (box of sand), septic tank followed by an Australian system (anaerobic pond proceeded by an facultative pond) and in the exit of the system a clorine tank. In environmental sample accomplished in the facultative pond it was obtained, as microscopic result, the prevalence of the species Microcystis aeruginosa and Microcystis flos-aquae. Through molecular techniques a pattern of approximately 18 bands with these environmental sample was obtained.

Neste trabalho foi realizada a caracterização microbiana, por meio de técnicas de biologia molecular, do lodo granulado de reator anaeróbio de fluxo ascendente e manta de lodo (UASB - Upflow Anaerobic Sludge Blanket Reactor) operado sob condições mesofílicas (30 \'+ OU -\' 2ºC) e sulfetogênicas, com (TDH) de 12 h, na presença de 3,0 \'+ OU -\' 0,7 mg/L de oxigênio dissolvido. Essa caracterização foi realizada no lodo granulado proveniente da manta inferior (P1) e superior (P2) do UASB. O reator UASB de 10,5 L foi alimentado com meio basal Zinder acrescido de solução de vitaminas, metais traços e bicarbonato de sódio (10%). O meio foi preparado diariamente com água de abastecimento público, pH 7-8. Etanol e sulfato de sódio foram utilizados como fonte orgânica e de enxofre, respectivamente. Nestas condições, foram estudadas três diferentes relações de demanda química de oxigênio (DQO)/sulfato (3,0, 1,6 e 2,0). A análise de hibridação in situ fluorescente (FISH) demonstrou que houve predomínio de arquéias metanogênicas, detectadas com a sonda ARC915, em todas as condições operacionais, com médias iguais a 75,9, 77,1 e 85,4% em P1 e 78,6, 73,4 e 83,1% em P2, respectivamente. Methanosaeta sp. foi a arquéia metanogênica acetoclástica predominante confirmada também por seqüenciamento da banda recortada do gel de DGGE (eletroforese em gel de cadeia desnaturante), com similaridade de 96%. As bactérias (sonda EUB338) variaram de 9,6 a 36,2% e de 15,5 a 37,4% em P1 e P2, respectivamente. As bactérias redutoras de sulfato (BRS), detectadas com a sonda SRB385, variaram de 7,9 a 10,8% e de 8,7 a 19,8% em P1 e P2, respectivamente. Outros microrganismos identificados foram Shewanella sp. e Desulfitobacterium hafniense Y51, e a bactéria redutora de sulfato Desulfovibrio vulgaris subsp. vulgaris DP4. A distribuição do tamanho dos grânulos não sofreu mudança significativa no decorrer dos ensaios. Grânulos de 2 a 3 mm, que geralmente representam biomassa ativa no reator, contou com média de 76% do total quantificado; enquanto, grânulos de 1 a 2 mm, os quais sugerem que novos grânulos estavam sendo formados representaram 17% no reator UASB. As concentrações médias de metano e sulfeto no biogás foram iguais a 33 e 1,5 \'mü\'mol/ mL, respectivamente. Os resultados obtidos neste trabalho demonstraram que a presença de oxigênio, na concentração aplicada, não afetou severamente o metabolismo dos microrganismos comumente considerados estritamente anaeróbios. Esse fato foi evidenciado também pelo valor do potencial redox obtido que se manteve aproximadamente constante em -208 mV, mesmo na presença de oxigênio. As eficiências de remoção de matéria orgânica (DQO) e redução de sulfato também alcançaram resultados favoráveis, com médias superiores a 74%. / A microbial characterization of granular sludge from an upflow anaerobic sludge blanket reactor (UASB) was carried out by molecular biology techniques. The reactor with 1,5 L of volume was operated with HRT of 12 h under mesophilic (30 \'+ OR -\' 2ºC) and sulfidogenic conditions, in the presence of 3.0 \'+ OR -\' 0.7 mg \'O IND.2\'/L. The granular sludge samples were withdrawn from the bottom (P1) and upper (P2) parts of the reactor. The synthetic substrate used in the reactor feeding was composed by Zinder basal medium in addition with a solution of vitamins, trace metal and sodium bicarbonate (10%). The Zinder basal medium was prepared daily with tap water with pH value varying from 7 to 8. Concentrations of ethanol and sodium sulfate were applied as organic and sulfur sources, respectively. Three different COD/sulfate ratios (3,0, 1,6 and 2,0) were evaluated in these conditions. The fluorescent in situ hibridization (FISH) analysis demonstrated the predominance of methanogenic archaea, detected by ARC915 specific probe, in all the operational conditions, with mean values of 75.9%, 77.1% and 85.4% in P1 and 78.6%, 73.4% and 83.1% in P2. The sequencing of the excised band of DGGE (denaturing gradient gel electrophoresis) showed similarity of 96% with the acetoclastic archaea Methanosaeta sp. The bacterial community (EUB338 probe) varied from 9.6% to 36.2% in P1 and from 15.5% to 37.4% in P2. Sulfate-reducing bacteria (SRB), detected by SRB385 probe, varied from 7.9% to 10.8% and from 8.7% to 19.8% in P1 and P2, respectively. Other identified microorganisms were Shewanella sp. and Desulfitobacterium hafniense Y51 bacteria, and the sulfate-reducing Desulfovibrio vulgaris subsp. vulgaris DP4. Granule-size distribution did not significantly change during the assays. Granules of size varying from 2 mm to 3 mm, that generally represent the active biomass inside the reactor, accounted for 76% of the total quantified percentage; while, granules of size varying from 1 mm to 2 mm, that suggest the formation of new granules in the reactor, presented mean percentage of 17% of the total. The mean produced concentrations of methane and sulfide in the reactor were equal to 33 \'mü\'mol/mL and 1.5 \'mü\'mol/mL of biogas, respectively. The obtained results indicated that the applied oxygen concentration did not severely affect the metabolism of the strictly anaerobic microorganisms. This fact was evidenced by the obtained result of the oxidation-reduction potential that remained equal to -208 mV, even in the presence of oxygen. The mean removal efficiencies of organic matter (COD) and sulfate also achieved favourable results with values higher than 74%.

A utilização de técnicas moleculares têm facilitado o estudo de comunidades bacterianas complexas no ambiente. O presente trabalho teve como objetivo utilizar a técnica DGGE para avaliação dos efeitos do aumento da temperatura, causado pela queima de um canavial, na estrutura da comunidade bacteriana de solo, com ênfase ao grupo dos actinomicetos. Foram coletadas amostras de solo em diferentes profundidades, antes e depois da queima, e dados físico-químicos e climáticos associados. O DNA da comunidade bacteriana foi amplificado utilizando conjunto de primers específicos para o Domínio Bacteria e para o grupo de actinomicetos, e os produtos de amplificação analisados por DGGE. Resultados obtidos para as populações de actinomicetos não foram conclusivos. Apesar da variação dos parâmetros físico-químicos do solo provocadas pela queima, os padrões de bandas obtidos com os primers para o Domínio Bacteria, apresentaram-se uniformes. Sendo assim, nas condições de estudo deste trabalho, os resultados obtidos não revelaram alterações na estrutura da comunidade bacteriana do solo de canavial depois da queima. / The utilization of molecular techniques has facilitated the study of complex bacterial communities in the environment. The present study aimed at using DGGE technique to evaluate the effect of temperature variation, caused by sugar-cane plantation burn, in the soil bacterial community structure emphasizing the actinomycete group. Soil samples from different depths, were collected before and after the bum, as well as physical-chemical and climatic associated data. The bacterial community DNA was amplified using a specific primer set and the amplification products analyzed by DGGE. The results obtained for the actinomycete populations were not conclusive. Despite the variation of the soil parameters caused by the burn, the band patterns obtained used in this study were uniform. Therefore, under the conditions used in this study, the results obtained did not show any alteration in the structure of soil bacterial community associated with sugar-cane plantation after the burn.

O presente trabalho busca entender a dinâmica de comunidades bacterianas cultiváveis e não cultiváveis do ecossistema do manguezal e prospectar nesse ambiente ainda inexplorado, um possível potencial biotecnológico. As amostras de sedimentos foram retiradas de duas profundidades no inverno e no verão. Bactérias caracterizadas por meio da técnica de ARDRA pertencem as ordens Vibrionales, Bacillales e Actinomycetales. As espécies bacterianas cultiváveis e as não cultiváveis foram também avaliadas por meio da técnica de PCR-DGGE, onde utilizou-se iniciadores seletivos para Actinobacterias, a e b Proteobacteria, Pseudomonas spp. e Paenibacillus spp., além do universal para bacteria. A análise multivariada de redundância (RDA) permitiu verificar a relação dos perfis obtidos das amostras com os fatores ambientais. Verificou-se uma diferente distribuição dos grupos de a e b Proteobacteria em relação à sazonalidade, enquanto que a profundidade de amostragem mostrou ser essencial no perfil das comunidades totais, a e b-Proteobacteria e Actinobacterias. / The objective of the present work is the understanding of culturable and non-culturable bacterial community dynamic present in the mangrove ecosystem also to explore the biotechnological potential of bacteria present in this environmental. Sediment samples were obtained from two depths winter and summer seasons and further analyzed. The Bacteria were characterized by ARDRA and identified the orders Vibrionales, Bacillales e Actinomycetales. Culturable and non-culturable bacteria were also assessed by PCR-DGGE using specific primers for Actinobacteria, a-Proteobacteria, b-proteobacteria, Pseudomonas spp., Paenibacillus spp. and bacteria universal primers. Multivariate redundancy analysis allowed the verification of main factors determining the bacterial communities patterns found on samples. It was verified a seasonal distribution of a and b-Proteobacteria groups, while the sampled depth was determinant for the total bacterial community composition, and also influenced the a and b-Proteobacteria and Actinobacteria profiles.

The rhizosphere is characterized by the presence of high microbial activities which are influenced by plant root exudates. This study examined bacterial diversity and physiological functions plants rhizosphere using both culture-dependent and culture-independent techniques of seven cultivated. Physico-chemical properties of soil samples revealed that the rhizobacteria adapted well to pH ranging from 7.5 to 9.1. Macronutrients (carbon, nitrogen, calcium, magnesium, phosphorous, potassium, sodium and iron) had a wide range of concentration between 0 to 4380.1 mg/kg. Concentrations of metal elements (cadmium, cobalt, chromium, copper and zinc) from all rhizosphere samples were below the amount of 3.1 mg/kg, indicating that the samples were free from metal contaminations. Sole carbon substrates utilization of bacteria in rhizosphere samples were measured as Average Well Colour Development (A WCD) and Group-wise Average Well Colour Development (AWCDg) patterns. At seventy two hours, there was no significant difference in AWCD patterns between bacteria in all samples and there was a significant difference in AWCDg patterns. Biochemical tests showed majority of isolates had similar physiological properties to members of Bacillus genus. All the bacterial isolates exhibited positive antifungal trait, fifteen solubilized phosphate and three had cyanide production traits during in vitro plant growth promotion assays. In vitro plant growth revealed that bacterial isolate RL1 (Bacillus licheniformis) produced the highest concentration of indole acetic acid (IAA) at 25 mg/ml. Bacterial isolate RG3 (Bacillus pumilus) had the highest amino cyclopropane carboxylase (ACC) deaminase activity indicated by the high production of α-ketobutyrate produced at 4.8 mg/ml. There were significant differences in shoot length at P ≤ 5% level of significance and there was no significant difference in the number of leaves across all three inoculated plants at P ≥ 5% level of significance. Sequence and phylogenetic analysis of identified culture-dependent bacteria revealed a homologous similarity of 94 to 100% between isolates sequences and GenBank sequences. From this, 81% of the sequences were closely related to Firmicutes, 13% to Actinobacteria and 6% to Proteobacteria. From cultureindependent method, only 8 PCR-DGGE bands were detected, the 200 bp sequences in the 16S rRNA fragment showed 91 to 100% homologous similarity to GenBank sequences. Their 16S rRNA sequences was closely related to 50% uncultured bacterium clones, 25% Firmicutes, 13% Proteobacteria and 12% Bacteroidetes sequences. Both culture-dependent and cultureindependent techniques were precise in the identification and description of bacterial community in rhizosphere. / Thesis (M.Sc) North-West University, Mafikeng Campus, 2014

Made available in DSpace on 2014-06-12T17:39:25Z (GMT). No. of bitstreams: 2 arquivo2665_1.pdf: 3125066 bytes, checksum: 315b558f101ff9ca6e9a3c9c14e2db28 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O aproveitramento energético do biogás já é uma realidade em grandes aterros sanitários. No entanto, aterros pequenos, antigos ou lixões podem emitir biogás consideravelmente, porém em quantidades que inviabilizam economicamente o aproveitamento energético ou a queima de flares . Mesmo em aterros com extração forçada de gases, uma grande quantidade de biogás escapa para a atmosfera através da cobertura. Recentemente têm-se estuddado camadas de cobertura não convencionais visando atuar como elemento redutor da emissão de Gases Estufa. A degradação microbiana pode ser utilizada como alternativa na redução do biogás emitido através dessas camadas em aterros sanitários . O objetivo deste trabalho foi estudar os materiais usados em camadas de coberturas de aterros sanitários do tipo convencional e em sistemas de biocamada oxidativa, como suporte para crescimento de micro-organismos metanotróficos, tentando relacionar as emissões de metano de cada camada e com suas características geotécnicas e microbiológicas. Para tanto, duas diferentes camadas de cobertura(solo compactado e mistura de solo composto) foram simuladas em caixas de fluxo. Também foram analisadas camadas de cobertura construídas e em funcionamento em uma célula de resíduos sólidos experimental, em cada piloto, construída para o aproveitamento energético do biogás, no Aterro da Muribeca- PE. A estrutura da comunidade foi avaliada através da técnica de semi-nested PCR/DGGE, com a utilização de iniciadores funcionais para as bactérias do grupo I e II de metanotróficas. Os resultados apresentaram uma diminuição da concentração volumétrica do metano e simultâneo aumento da concentração volumétrica de gás carbônico, o que indicou estar ocorrendo a oxidação biológica. A utilização da mistura de solo argiloso com composto orgânico mostrou-se viável como material suporte para a atividade metanotrófica, por manter uma umidade e porosidade adequadas, para que haja fluxo de metano necessário ao desenvolvimento desse grupo de bactérias. A técnica de DGGE foi capaz de indicar diferenças na estrutura dominante da comunidade bacteriana diferenciando a camada convencional da biocamada oxidativa. Além disso, foi possível verificar diferenças na estrutura de comunidade em profundidade em cada tipo de camada de cobertura

On sait que les sols et les populations bactériennes indigènes ont une influence sur la mobilité des métaux, donc sur leur toxicité. Cette étude a été menée sur des sols uranifères et contrôles collectés dans le Limousin (régions naturellement riches en uranium ). une analyse physico-chimique et minéralogique des échantillons de sol a été réalisée. La structure des communautés bactériennes a été étudiée par électrophorèse en gradient de dénaturant (DGGE). La structure des communautés est remarquablement stable dans les sols uranifères, ce qui indique que l'uranium exerce une forte pression de sélection. D'autre part, une collection de bactéries cultivables à été réalisée à partir des sols, puis criblée pour la résistance à l'uranium, dans le but d'étudier les interactions entre bactéries et uranium. Des observations en Microscopie Électronique à Balayage ont mis en évidence différents mécanismes de chélation de l'uranium à la surface cellulaire / It is well known that soils play a key role in controlling the mobility of toxic metals and this property is greatly influenced by indigeous bacterial communities. This study has been conducted on radioactive and controls soils, collected in natural uraniferous areas (Limousin). A physico-chemical and mineralogical analysis of soils samples was carried out.The structure of bacterial communities was etimated by Denaturing Gradient Gel Electrophoresis (DGGE). The community structure is remarkably more stable in the uranium-rich soils than in the control ones, indicating that uranium exerts a high selection from the soils was constructed and screened for uranium resistance in order to study basteria-uranium interactions. Scanning electron microscopy revealed that a phylogenetically diverse set of uranium-resistant species ware able to chelate uranium at the cell surface.

The goal of this study was to use molecular biology techniques to access and monitor the efficacy of bioremediation on a trichloroethene (TCE) polluted site. We added emulsified hydrogen releasing materials to stimulate onsite microbial growth and the biodegradation of TCE. This process was known as enhanced bioremediation. In this study, there were two bioremediation sites had been treated anaerobically. Groundwater samples were taken periodically for microbial analysis. Denaturing gradient gel electrophoresis (DGGE) was used to evaluate the variations in microbial community structures during the in situ groundwater remediation. The DGGE DNA bandings were sequenced to determine the 16S rRNA gene sequences and identify the dominate bacterial species. In addition, we used Dehalococcoides spp. 16S rRNA genes as the targets to do real-time PCR. Results show that the emulsified hydrogen releasing materials could enhance anaerobic reductive dechlorination. After addition of emulsified hydrogen releasing materials, we found that the volatile organic compounds concentrations (i.e., TCE, 1, 1-DCE and VC) were decreased. In microbial analysis, the diversities of the microbial community were increased after nutrient supplement. According to the DNA sequencing results, there were 31 bacterial species had been found that related to TCE degradation (i.e., Acidovorax sp., Burkholderiales, Pseudomonas sp., £]-proteobacterium, Comamonadaceae, Iron-reducing bacterium, Hydrogenophilaceae, Clostridium sp., Geobacter sp., Rhodoferax ferrireducens, Dehalospirillum multivorans and Dehalococcoides spp.). Dehalococcoides spp. can be used as a biomarker to evaluate the efficacy of anaerobic bioremediation on a TCE contaminated site. Therefore, we quantified Dehalococcoides populations to explain the capacity of bioremediation after addition of emulsified hydrogen releasing materials to groundwater. Results reveal that Dehalococcoides cell numbers of site A were 4.47¡Ñ103-8.26¡Ñ104 CFU/liter, site B were 4.60¡Ñ102-9.31¡Ñ107 CFU/liter. This data indicated that the addition of emulsified substrate would increase the growth of total Dehalococcoides population under anaerobic conditions. Overall, results from this study demonstrated that the microbial analysis and quantities of Dehalococcoides at different time points can provide useful information to proceed with bioremediation methods.

1,2-dichloroethane (1,2-DCA) is a popular industrial chlorinated organic chemical. Because 1,2-DCA is a dense non-aqueous phase liquid and easily accumulated in deep soil and water, it is difficult to be removed from the contaminated sites. In this study, aerobic and anaerobic microcosm batch experiments were performed to evaluate the feasibility of biodegradation of 1,2-DCA by adding different growth substrates. The aerobic microcosm results show that approximately 90% of 1,2-DCA removal was observed in the natural degradation group (A1) and the aerobic sludge addition group (A3) after 7 days of incubation. Up to 95% of 1,2-DCA removal could be observed in the substrate supplement group in after 14 days of incubation. In the anaerobic microcosm studies, 50% of 1,2-DCA removal could be obtained in all groups after 10 days except for the natural degradation group (B1). Moreover, the degradation efficiency for the anaerobic sludge group (B3) reached 80% of 1,2-DCA removal in 5 days. The DGGE profiles show that the microbial diversity varied with time and the sugar supplement groups (A2, B2) exhibited the most microbial diversity. Bacterial clones results revealed that the 1,2-DCA biodegradable microbial strains were presented in the microcosms, such as Klebsiella, Pseudomonas, Rhodoferax and Xanthobactor. The real-time PCR results indicated that the Dehalococcoides spp. was the major bacterium that was responsible for the degradation of 1,2-DCA in the anaerobic substrate supplement group (B2). Desulfitobacterium spp. could be the dominant 1,2-DCA degrading bacterium for the aerobic substrate supplement group (A2) and all of the anaerobic groups (B1, B2, B3, B4).