Culture‐dependent and culture‐independent characterization of potentially functional biphenyl‐degrading bacterial community in response to extracellular organic matter from Micrococcus luteus

• Published in: Microbial biotechnology Vol. 8; no. 3; pp. 569 - 578
• Main Authors: Su, Xiao‐Mei, Liu, Yin‐Dong, Hashmi, Muhammad Zaffar, Ding, Lin‐Xian, Shen, Chao‐Feng
• Format: Journal Article
• Language: English
• Published: United States BlackWell Publishing Ltd 01.05.2015
• Subjects: Actinobacteria; Bacteria - classification; Bacteria - isolation & purification; Bacteria - metabolism; Biotransformation; Cluster Analysis; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; DNA, Ribosomal - chemistry; DNA, Ribosomal - genetics; Environmental Microbiology; Microbial Consortia - drug effects; Micrococcus luteus; Micrococcus luteus - chemistry; Molecular Sequence Data; Organic Chemicals - isolation & purification; Phylogeny; Polychlorinated Biphenyls - metabolism; Proteobacteria; Pseudomonas; Rhodococcus; RNA, Ribosomal, 16S - genetics; Sequence Analysis, DNA
• ISSN: 1751-7915; 1751-7915
• DOI: 10.1111/1751-7915.12266

Summary Biphenyl (BP)‐degrading bacteria were identified to degrade various polychlorinated BP (PCB) congers in long‐term PCB‐contaminated sites. Exploring BP‐degrading capability of potentially useful bacteria was performed for enhancing PCB bioremediation. In the present study, the bacterial composition of the PCB‐contaminated sediment sample was first investigated. Then extracellular organic matter (EOM) from Micrococcus luteus was used to enhance BP biodegradation. The effect of the EOM on the composition of bacterial community was investigated by combining with culture‐dependent and culture‐independent methods. The obtained results indicate that Proteobacteria and Actinobacteria were predominant community in the PCB‐contaminated sediment. EOM from M. luteus could stimulate the activity of some potentially difficult‐to‐culture BP degraders, which contribute to significant enhancement of BP biodegradation. The potentially difficult‐to‐culture bacteria in response to EOM addition were mainly Rhodococcus and Pseudomonas belonging to Gammaproteobacteria and Actinobacteria respectively. This study provides new insights into exploration of functional difficult‐to‐culture bacteria with EOM addition and points out broader BP/PCB degrading, which could be employed for enhancing PCB‐bioremediation processes. This research paper highlights the application of an innovative method based on extracellular organic matter (EOM) from Micrococcus luteus for enhancing biphenyl‐degrading capability in PCB‐contaminated sediment. It also investigates the effects of EOM on the bacterial composition of the PCB‐contaminated sediment, and explains how the bacterial composition is correlated to biphenyl biodegradation capability. Results suggest that EOM significantly enhanced the biphenyl biodegradation capability, which could be attributed to enrichment of some potentially difficult‐to‐culture biphenyl/PCB‐degraders. Given the worldwide concerns about PCB contamination, EOM from M. luteus as an additive holds great potential for the efficient bioremediation of PCB‐contaminated environment.