University of Hong Kong , China

Prof. Zhang is a Professor in Environmental Biotechnology Laboratory in Department of Civil Engineering, The University of Hong Kong ...

... His researches include biodegradation of emerging pollutants, environmental bioinformatics, omics technologies, anaerobic digestion and bioenergy from wastes/wastewater, biological wastewater treatment (N removal and P recovery), antibiotic and antibiotic resistance genes, etc. He has published over 200 peer-reviewed papers on the above topics, and got more than 12, 500 citations (Google Scholar). He has a H index of 63 and is Top 1% researcher (Essential Science Indicators) for the past 9 years from 2009 to 2017. He is associate editors of Microbiome, and Applied Microbiology and Biotechnology, and had served as an advisor for BGI (Beijing Genomics Institute) on Environmental Microbiology and Biotechnology from 2011 to 2014. He was Yi Xing Chair Professor of Nanjing University from 2013 to 2016, and currently a distinguished visiting professor of Southern University of Science and Technology.

 

Abstract


Microbial Partnership in Aerobic Degradation of Sulfadiazine Revealed by Metagenomics Analysis and Isolation

Tong Zhang1, * and Yu Deng1

1 Environmental Biotechnology Laboratory, Department of Civil Engineering, The University of Hong Kong

In this study, metagenomic analyses were combined with cultivation-based techniques as a nested approach to identify functionally significant bacteria for sulfadiazine biodegradation within enrichment communities. Two aerobic sulfadiazine (SDZ) degrading bacterial strains, D2 and D4, affiliated with the genus Arthrobacter, were isolated from SDZ-enriched activated sludge. The degradation of SDZ by the two isolates followed first-order decay kinetics. The half-life time of complete SDZ degradation was 11.3 h for strain D2 and 46.4 h for strain D4. Both isolates could degrade SDZ into 12 biodegradation products via 3 parallel pathways, of which 2-amino-4-hydroxypyrimidine was detected as the principal intermediate product toward the pyrimidine ring cleavage. The metagenomic investigations indicated that Arthrobacter sp. D2 and another Pimelobacter bacterium concomitantly occurred as most abundant members in the community of an enrichment culture that performed complete sulfadiazine mineralization for over two years. Responses of the enriched populations to sole carbon source alternation further suggested the ability of this Pimelobacter member to grow on 2-aminopyrimidine, the most prominent intermediate metabolite of sulfadiazine. Taking advantage of this propensity, additional cultivation procedures have enabled the successful isolation of Pimelobacter sp. LG209, whose genomic sequences exactly matched that of the dominant Pimelobacter bacterium in the sulfadiazine enrichment culture. Integration of metagenomic investigations with the physiological characteristics of the isolates conclusively demonstrated that the sulfadiazine mineralization in a long-running enrichment culture was prominently mediated by primary sulfadiazine-degrading specialist strain Arthrobacter sp. D2 in association with the 2-aminopyrimidine-degrading partner strain Pimelobacter sp. LG209. Here, we provided the first mechanistic insight into microbial interactions in steady sulfadiazine mineralization processes, which will help develop appropriate bioremediation strategies for sulfadiazine-contaminated hotspot sites.


 

  1. Deng Y, Wang Y, Mao Y, Zhang T. 2018. Partnership of Arthrobacter and Pimelobacter in aerobic degradation of sulfadiazine revealed by metagenomics analysis and isolation. Environmental Science & Technology. 52(5), 2963-72.
  2. Deng Y, Mao YP, Li B, Yang C, Zhang T. 2016. Aerobic degradation of sulfadiazine by Arthrobacter spp.: kinetics, pathways, and genomic characterization. Environmental Science and Technology. 50(17), 9566–9575.