Characterization of Burkholderia sp. strain CJ1, a newly isolated berberine-degrading bacterium from rhizosphere of Coptis japonica

2020 ◽  
Vol 84 (6) ◽  
pp. 1299-1302
Author(s):  
Hinaka Yoshida ◽  
Hisashi Takeda ◽  
Daigo Wakana ◽  
Tomoo Hosoe
2019 ◽  
Vol 51 (2) ◽  
pp. 170-178
Author(s):  
Tao Peng ◽  
Qing-Kun Chen ◽  
Jing-Sheng Lun ◽  
Amit Pratush ◽  
Guang-Ming Xiong ◽  
...  

2005 ◽  
Vol 251 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Li Yang ◽  
Yu-hua Zhao ◽  
Bing-xin Zhang ◽  
Ching-Hong Yang ◽  
Xin Zhang

Author(s):  
Lingling Zhao ◽  
Zhenyang Zhao ◽  
Kaiyun Zhang ◽  
Xuan Zhang ◽  
Siqiong Xu ◽  
...  

Cotinine is a stable toxic contaminant, produced as a byproduct of smoking. It is of emerging concern due to its global distribution in aquatic environments. Microorganisms have the potential to degrade cotinine, however, the genetic mechanisms of this process are unknown. Nocardioides sp. strain JQ2195 is a pure culture strain that has been reported to degrade cotinine at micropollutant concentrations. This strain utilizes cotinine as its sole carbon and nitrogen source. In this study, a 50 kb gene cluster (designated as cot ) involved in cotinine degradation, was predicted based on genomic and transcriptomic analyses. A novel three-component cotinine hydroxylase gene (designated as cotA1A2A3 ), which initiated cotinine catabolism was identified and characterized. CotA from Shinella sp. HZN7 was heterologously expressed and purified, and shown to convert cotinine into 6-hydroxycotinine. H 2 18 O-labelling and ESI-MS analysis confirmed that the hydroxyl group incorporated into 6-hydroxycotinine was derived from water. This study provides new molecular insights into the microbial metabolism of heterocyclic chemical pollutants. IMPORTANCE In the human body, cotinine is the major metabolite of nicotine, and 10–15% of generated cotinine is excreted in urine. Cotinine is a structural analogue of nicotine and is much more stable than nicotine. Increased tobacco consumption has led to high environmental concentrations of cotinine, which may have detrimental effects on aquatic ecosystems and human health. Nocardioides sp. strain JQ2195 is a unique cotinine-degrading bacterium. However, the underlying genetic and biochemical foundations of cotinine degradation are still unknown. In this study, a 50 kb gene cluster (designated cot ) was identified by genomic and transcriptomic analyses as being involved in the degradation of cotinine. A novel three-component cotinine hydroxylase gene (designated cotA1A2A3 ) catalyzed cotinine to 6-hydroxy-cotinine. This study provides new molecular insights into the microbial degradation and enzymatic transformation of cotinine.


Author(s):  
Y. Murtala ◽  
B. C. Nwanguma ◽  
L. U. S. Ezeanyika

Background: Despite the banned on the use of dichlorodiphenyltrichloroethane (DDT) and other Persistent Organic Pollutants (POPs) by the Stockholm Convention for their toxicity, emerging shreds of evidence have indicated that DDT is, however, still in use in developing countries. This might increase the global burden of DDT contamination and its hazardous effects. Aim: This study focused on the isolation and characterization of p,p’-DDT-degrading bacterium from a tropical agricultural soil. Methodology: Standard isolation procedure was used for the screening and isolation of the strain. The 16S rRNA and phylogenetic analyses were used to identify the isolate and established protocols were followed to characterize the strain. Results: A new strain belonging to the genus Aeromonas was isolated from agricultural soil using minimal salt-p,p’-DDT enrichment medium. The 16S rRNA sequencing was used to identify the strain and the partial sequence was deposited in the NCBI GenBank as Aeromonas sp. Strain MY1. This mesophilic isolate was capable of utilizing up to 50 mgL-1 of p,p’-DDT as the sole carbon source at an optimum pH of 7.5 and optimum temperature of 35 °C within 120 h under aerobic conditions. Fe2+ (0.2 mgL-1) demonstrated a stimulatory effect on the p,p’-DDT degradation capacity by the strain MY1. However, Zn, Cu, Pb, Hg, Ag and Cr ions have demonstrated various patterns of inhibitory effect on the p,p’-DDT degradation capacity of the isolate at 0.2 mgL-1. The strain MY1 could be a promising candidate for the bioremediation of p,p’-DDT contaminant. Conclusion: Aeromonas sp. strain MY1 was capable of utilizing p,p’-DDT as a sole carbon source under aerobic conditions. The utilization capacity of the strain was influenced by some heavy metals. Fe was found to enhance the p,p’-DDT utilization capacity of the isolate at a lower concentration. While Zn, Cu, Pb, Hg, Ag and Cr showed various patterns of inhibitory effect.


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