Applied Microbiology: Open Access
Open Access

Interplay between expression of sulfur assimilation pathway genes and metal (Cd, Zn, Pb) stress in Acidithiobacillus ferrooxidans

4^th World Congress and Expo on Applied Microbiology

September 19-21, 2016 Las Vegas, USA

Chunli Zheng, Minjie Chen, Dan Wang, Li Zhang, JianYing Wang and Xuefeng Zhang

Inner Mongolia University of Science and Technology, China
Bayan Obo Multi-Metal Resources, China

Posters & Accepted Abstracts: Appli Micro Open Access

Abstract :

Acidithiobacillus ferrooxidans plays a critical role in metal solubilization in the biomining industry, and occupies an ecological niche characterized by high acidity and high concentrations of toxic heavy metal ions. In this paper, we investigated the interplay between metal resistance, SAP gene expression and thiol-containing metabolite levels. Cells grown in the presence of metal (Cd, Zn, Pb) had effected activities for the following enzymes: adenosyl phosphosulfate reductase (APR), serine acetyl transferase (SAT) and O-acetylserine (thiol) lyase (OAS-T). We investigated the concentrations of mRNA transcripts of the genes encoding these enzymes in cells grown in the presence of metal transcripts for 4 SAP genes- ATPS (ATP sulfurylase), APR, SiR (sulfite reductase), SAT and OAS-TL; each showed more than three-fold concentration increase. At the metabolite level, concentrations of intracellular cysteine and glutathione (GSH) were nearly doubled. These results suggested that Cd and Zn induced SAP pathway gene transcription, while Pb inhibited SAP gene expression and enzyme activities compared to the pathway in most organisms. Since the detoxification function of thiol pool, the results also suggested that the high resistance of A. ferrooxidans to Cd, Zn may also be due to regulation of GSH and the cysteine synthesis pathway.

Biography :

Email: zhengchunli1979@163.com