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Polychlorinated biphenyls (PCBs) are the typical persistent organic pollutants (POPs) in the environment. As a ubiquitous attenuation course of chlorinated organic compounds in anoxic environment, the microorganism-mediated reductive dechlorination process plays an important role in PCBs transformation, especially the transformation of higher chlorinated PCBs. The higher chlorinated PCBs can be dechlorinated in anaerobic condition, and thus, their persistence and toxicity can be decreased. The resultant lower chlorinated PCBs from the dechlorination can be further degraded and completely mineralized in aerobic condition. This paper summarized the research advances of PCBs microbial reductive dechlorination, introduced the mechanisms and characteristics of the dechlorination and the related specific microorganisms, and approached the affecting factors of PCBs bio-dechlorination, as well as the significances of anaerobic dechlorination coupling with aerobic degradation. The future research directions, including the complex metabolic networks of dechlorinating microbial populations, the screening of novel specific dechlorinators and their practical applications in the remediation of PCBs contaminated sites were also prospected.

Persistent organic pollutants have increasingly become a critical environmental concern, while thermophiles have the high potential of degrading various kinds of environmental organic pollutants. At high temperatures, thermophiles have higher metabolic activity, and the competition by mesophiles is reduced, meanwhile, the solubility and bioavailability of some persistent organic pollutants are greatly increased, and thus, the degradation of the pollutants by thermophiles is more rapid and complete. Therefore, thermophils are of great significance for the bio-treatment of organic wastewater and the bioremediation of organic pollutants-contaminated sites. This paper introduced the research progress on the degradation of organic pollutants by thermophiles in terms of the characteristics of thermophiles in degrading organic pollutants, the effects of temperature on the degradation, the degradation pathways, the degradation enzymes, their coding genes, and practical engineering applications. The future research directions including the degradation mechanisms of thermophiles, their resources reserve, related technology strategies and their applications were also prospected.

A pot experiment was conducted to study the microbial activity and community structure in a lead-polluted paddy soil under effects of amendment with different concentration sodium thiosulfate. The amendment of the sulfur-containing substrate increased the soil oxidation-reduction potential and respiration rate, promoted the growth of soil sulfur-oxidizing bacteria, and induced some changes in soil microbial community structure. The clone sequencing indicated that the specific bands of soil microbes in sodium thiosulfate treatments had very high similarity to Bateroidetes, Thiobacillus, beta-proteobacteria, and Acidobacteria. Significant changes were observed in the contents of soil carbonate- and Fe/Mn oxide- bound Pb after the amendment of sodium thiosulfate.