Analysis of a microbial community associated with polychlorinated biphenyl degradation in anaerobic batch reactors

Abstract

The degradation of polychlorinated biphenyls (PCBs) was investigated under fermentative-methanogenic conditions for up to 60 days in the presence of anaerobic biomass from a full-scale UASB reactor. The low methane yields in the PCBs-spiked batch reactors suggested that the biomass had an inhibitory effect on the methanogenic community. Reactors containing PCBs and co-substrates (ethanol/sodium formate) exhibited substantial PCB reductions from 0.7 to 0.2 mg mL(-1). For the Bacteria domain, the PCBs-spiked reactors were grouped with the PCB-free reactors with a similarity of 55 %, which suggested the selection of a specific population in the presence of PCBs. Three genera of bacteria were found exclusively in the PCB-spiked reactors and were identified using pyrosequencing analysis, Sedimentibacter, Tissierela and Fusibacter. Interestingly, the Sedimentibacter, which was previously correlated with the reductive dechlorination of PCBs, had the highest relative abundance in the RCS-PCB (7.4 %) and RCS-PCB-PF (12.4 %) reactors. Thus, the anaerobic sludge from the UASB reactor contains bacteria from the Firmicutes phylum that are capable of degrading PCBs.

Microbial diversity of a full‐scale UASB reactor applied to poultry slaughterhouse wastewater treatment: integration of 16S rRNA gene amplicon and shotgun metagenomic sequencing

“…The high microbial diversity observed (Delforno et al., ) represents a high genetic diversity and, consequently, a broad metabolic potential for several bioprocesses. Therefore, a wide application of granular sludge for nitrogen (Moura, Damianovic, & Foresti, ) and sulfide removal (Camiloti et al., ), hydrogen production (Penteado et al., ), anionic surfactant degradation (Okada et al., ), polychlorinated biphenyl (PCB) degradation (Gomes et al., ), and veterinary antimicrobial removal (Oliveira, Santos‐Neto, & Zaiat, ) has been observed.…”

Response of microbial communities to bioturbation by artificially introducing macrobenthos to mudflat sediments for in situ bioremediation in a typical semi-enclosed bay, southeast China

“…As shown in Fig. 5, the abundance of a few ecologically important genera increased, such as the Fusobacteria Propionigenium, which are able to ferment succinate and organics to propionate (Martin et al, 2006); the Firmicutes Fusibacter, which were involved in biodegradation of polychlorinated biphenyls (PCBs) (Gomes et al, 2014), alkanes and aromatics (Hasegawa et al, 2014); and the free-living saccharolytic Spirochaeta of Spirochaetes (Martin et al, 2006). Some bacteria are associated with nitrite oxidization, such as the Nitrospirae LCP-6, and sulfate reduction, such as the Deltaproteobacteria Desulfococcus (Ravenschlag et al, 2000;Llobet-Brossa et al, 2002;Musat et al, 2006).…”

Análise dos parâmetros que interferem no metabolismo da microbiota anaeróbia e anóxica na remoção de bifenilas policloradas

“…Deste modo, metodologias mais eficientes e rápidas na identificação de organismos que possam ser responsáveis pela desalogenação do PCB tornam-se ferramentas potencialmente eficazes. No entanto, poucos estudos tiveram como objetivo determinar a diversidade microbiana de consórcios anaeróbios após a exposição PCB utilizando sequenciamento massivo de alto rendimento (LEIGH et al, 2007a;GOMES et al, 2014).…”

“…Cerca de 12% e 22% de remoção de PCB 118 foram atingidos proporcionalmente às suas concentrações iniciais de 1 mg.L -1 e 20 mg.L -1 , respectivamente. Gomes et al (2014) avaliaram a degradação de seis congêneres de PCB (PCB 10,28,52,132,153,180) em reatores em batelada sob condições metanogênicas. Os reatores foram inoculados com lodo proveniente de reator anaeróbio de fluxo ascendente (UASB).…”

“…Em trabalhos anteriores a remoção de cloro de PCB por bactérias anaeróbias não foram evidenciadas em menos de quatro meses com consórcio não-adaptado (CHANG; CHOU; YUAN, 1999). Entretanto, Gomes et al (2014) evidenciaram para consócio fermentativo-metanogênico não-adaptado capacidade de degradação de PCB (PCB 10,28,52,138, 153 e 180) com taxa de remoção de 0,7 a 0,2 mg.mL -1 para concentração inicial de 0,7 mg.L -1 em reatores em batelada por 60 dias. Desse modo, a aplicação de consórcios fermentivo-metanogênico em reatores anaeróbios e a identificação das concentrações inibitórias de PCB podem elucidar lacunas referentes a remoção desse composto.…”