Bar-Coded Pyrosequencing Reveals the Responses of PBDE-Degrading Microbial Communities to Electron Donor Amendments

Abstract

Polybrominated diphenyl ethers (PBDEs) can be reductively degraded by microorganisms under anaerobic conditions. However, little is known about the effect of electron donors on microbial communities involved in PBDEs degradation. Here we employed 454 Titanium pyrosequencing to examine the phylogenetic diversity, composition, structure and dynamics of microbial communities from microcosms under the conditions of different electron donor amendments. The community structures in each of the five alternate electron donor enrichments were significantly shifted in comparison with those of the control microcosm. Commonly existing OTUs between the treatment and control consortia increased from 5 to 17 and more than 50% of OTUs increased around 13.7 to 186 times at least in one of the microcosms after 90-days enrichment. Although the microbial communities at different taxonomic levels were significantly changed by different environmental variable groups in redundancy analysis, significant correlations were observed between the microbial communities and PBDE congener profiles. The lesser-brominated PBDE congeners, tri-BDE congener (BDE-32) and hexa-BDE, were identified as the key factors shaping the microbial community structures at OTU level. Some rare populations, including the known dechlorinating bacterium, Dehalobacter, showed significant positive-correlation with the amounts of PBDE congeners in the consortia. The same results were also observed on some unclassified bacteria. These results suggest that PBDEs-degrading microbial communities can be successfully enriched, and their structures and compositions can be manipulated through adjusting the environmental parameters.

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

“…Although it was not possible to correlate the use of ethanol by Sedimentibacter, Tissierela and Fusibacter, Vishnivetskaya et al (2010) affirmed that Firmicutes generally use ethanol for acetogenesis, which was consistent with the elevated concentrations of acetic acid found in the PCBs-spiked reactors. Moreover, Xu et al (2012) observed that Firmicutes was the dominant phylum in microcosms that were enriched with ethanol and were operated to degrade polybrominated diphenyl ethers under anaerobic conditions. Hou and Dutta (2000) performed a phylogenetic characterization of PCB-degrading anaerobic consortia from Lake Medinah (USA) based on 16S ribosomal DNA analysis and found that PCB degradation was most efficiently achieved by using a multispecies consortium of Clostridium (Firmicutes) and Sedimentibacter hydroxybenzoicus was formerly classified as C. hydroxybenzoicum (Breitenstein et al 2002).…”

“…Although anaerobic process occur naturally in several aquatic sediments, their reduced yields relative to laboratory conditions indicate that novel processes that apply local anaerobic consortia to reduce costs and improve dechlorination should be studied (Zanaroli et al 2012). Thus, 454 pyrosequencing is an interesting approach for studying complex communities (Xu et al 2012;Zhang et al 2012). However, only a few studies have determined the microbial diversity of anaerobic consortia after PCB exposure using high-throughput sequencing (Leigh et al 2007).…”

Microbial communities associated with anaerobic degradation of polybrominated diphenyl ethers in river sediment

“…The pyrosequencing of 16S ribosomal RNA (rRNA) genes has been developed as a high-throughput metagenomic technology for profiling microbial communities in a resolution at the genus level. 7,8 We aimed to assess the anaerobic degradation of highand low-brominated PBDEs with zero-valent iron in sediment from the Erren River, considered one of the most heavily contaminated rivers in Taiwan. We used pyrosequencing to examine the phylogenetic diversity, composition, and structure of the microbial community associated with PBDE degradation.…”

Genotypic responses of bacterial community structure to a mixture of wastewater-borne PAHs and PBDEs in constructed mangrove microcosms

“…It would be interesting to know the exact numbers of the dominant bacteria within the total microbial community, which can be obtained by surveys based on either high-throughput sequencing or construction of clone library of the whole bacterial community [17]. However, whether the dominant species were important for pollutant degradation or just for fundamental energy flow and nutrient cycling is still unknown.…”