Biodegradation of N,N-dimethylacetamide by Rhodococcus sp. strain B83 isolated from the rhizosphere of pagoda tree
Xingdu Chen
,
Chengjian Yang
,
Weiwei Wang
,
Bizhou Ge
,
Jun Zhang
,
Yucan Liu
,
Yaping Nan
DOI:10.1016/j.jes.2016.05.013
Received December 16, 2015,Revised May 05, 2016, Accepted May 10, 2016, Available online June 09, 2016
Volume 29,2017,Pages 88-98
The biodegradation characteristic and potential metabolic pathway for removal of environmental N,N-dimethylacetamide (DMAC) by Rhodococcus sp. strain B83 was studied. Rhodococcus sp. strain B83 was isolated from the rhizosphere of a pagoda tree and proved capable of utilizing DMAC as sole source of carbon and nitrogen. Batch culture studies showed that strain B83 could tolerate up to 25 g/L DMAC and showed distinct growth on possible catabolic intermediates except for acetate. The nitrogen balance analysis revealed that approximately 71% of the initial nitrogen was converted to organic nitrogen. DMAC degradation has led to accumulation of acetate and organic nitrogen, meanwhile traces of nitrate and ammonia was build-up but without nitrite. The growth of strain B83 could be inhibited by adding exogenous acetate. By means of the assay of enzymatic degradation of DMAC, several catabolic intermediates at different intervals were observed and identified. Based on the results obtained from culture solution and enzymatic degradation assay, a detailed pathway is proposed for DMAC biodegradation.
