title: Insights into the pH up-shift responsive mechanism of Acidithiobacillus ferrooxidans by microarray transcriptome profiling.
abstract: To define the molecular response of Acidithiobacillus ferrooxidans under pH up-shift, temporal gene expression profiles were examined by using whole-genome DNA microarrays for A. ferrooxidans. Approximately 30% of the 3,132 genes represented on the microarray were significantly upregulated over a 160-min period, while about 14% were significantly downregulated. Our results revealed that A. ferrooxidans showed potential self-protection and self-regulation performance in response to pH up-shift stress. Many genes involved in regulation of membrane components were differentially expressed under the pH up-shift stress. Likewise, most of genes involved in phosphate metabolism, sulfur assimilation, and CO(2) fixation were obviously induced. Conversely, the transcription of a polyphosphate kinase gene (AFE1210) associated with phosphate storage was significantly repressed, which probably stemmed from the depletion of polyphosphate. Besides, most of the genes involved in hydrogen uptake were significantly induced, whereas many genes involved in nitrogen fixation were obviously repressed, which suggested that hydrogen uptake and nitrogen fixation could contribute to cytoplasmic pH homeostasis.
authors: School of Minerals Processing and Bioengineering, Central South University, Changsha, China.
authors: Qian
authors: Q
authors: Li
authors: Youhua
authors: Y
authors: Ren
authors: Guanzhou
authors: G
authors: Qiu
authors: Nuo
authors: N
authors: Li
authors: Hongwei
authors: H
authors: Liu
authors: Zhimin
authors: Z
authors: Dai
authors: Xian
authors: X
authors: Fu
authors: Li
authors: L
authors: Shen
authors: Yili
authors: Y
authors: Liang
authors: Huaqun
authors: H
authors: Yin
authors: Xueduan
authors: X
authors: Liu
mesh_terms: D042763:Acidithiobacillus / Q000235:genetics / Q000378:metabolism*; D002245:Carbon Dioxide / Q000378:metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D005798:Genes, Bacterial; D016680:Genome, Bacterial; D006859:Hydrogen / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology / Q000379:methods*; D009586:Nitrogen Fixation / Q000235:genetics; D020411:Oligonucleotide Array Sequence Analysis; D010710:Phosphates / Q000378:metabolism; D040901:Proteomics / Q000379:methods*; D013312:Stress, Physiological; D013455:Sulfur / Q000378:metabolism
chemical_list: D010710:Phosphates; D002245:Carbon Dioxide; D013455:Sulfur; D006859:Hydrogen