Qi Huizhou, Chen Hong, Ao Jingqun, Zhou Hongbo, Chen Xinhua
Laboratory of Marine Biogenetic Resources of State Oceanic Administration, Third Institute of Oceanography, Fujian, People's Republic of China.
J Gen Appl Microbiol. 2010 Oct;56(5):389-97. doi: 10.2323/jgam.56.389.
Sulfobacillus sp. TPY is a moderately thermophilic and acidophilic bacterium found in hydrothermal vents in the Pacific Ocean. This bacterium can oxidize ferrous sulfate (Fe(2+)) and elemental sulfur (S(0)) under separate conditions. We used random arbitrarily primed polymerase chain reaction (RAP-PCR) to screen and identify differentially expressed genes from bacteria grown on Fe(2+) or S(0) as the energy source. Fifty-five differential cDNA fragments were isolated and subjected to single-pass sequencing. Thirty-five fragments were identified as orthologs of known genes in the GenBank databases, of which 19 were confirmed to be differentially expressed at the transcriptional level by Northern blot analysis. Among these 19 genes, 14 genes, including isocitrate dehydrogenase, formyltetrahydrofolate deformylase, 3-hydroxybutyryl-CoA dehydrogenase, and GTP-binding protein, were upregulated in TPY grown on Fe(2+) or downregulated in TPY grown on S(0), while five genes such as the outer membrane adhesion-like protein, phosphomannomutase, and cysteine desulfurase sufS were upregulated in TPY strain grown on S(0) or downregulated in TPY grown on Fe(2+). These altered genes are involved in metabolism, osmotic stress, cell membrane alterations, oxidative stress, and the regulatory adaptive response. These results will aid our understanding of the molecular basis of Fe(2+) or S(0) oxidation by the moderately thermophilic and acidophilic bacteria.
嗜热硫化芽孢杆菌TPY是在太平洋热液喷口发现的一种嗜热嗜酸细菌。这种细菌能够在不同条件下氧化硫酸亚铁（Fe(2+)）和元素硫（S(0)）。我们使用随机任意引物聚合酶链反应（RAP-PCR）从以Fe(2+)或S(0)作为能源生长的细菌中筛选并鉴定差异表达基因。分离出55个差异cDNA片段并进行单通道测序。35个片段被鉴定为GenBank数据库中已知基因的直系同源物，其中19个通过Northern印迹分析在转录水平被确认为差异表达。在这19个基因中，包括异柠檬酸脱氢酶、甲酰四氢叶酸脱甲酰酶、3-羟基丁酰辅酶A脱氢酶和GTP结合蛋白在内的14个基因在以Fe(2+)生长的TPY中上调或在以S(0)生长的TPY中下调，而诸如外膜黏附样蛋白、磷酸甘露糖变位酶和半胱氨酸脱硫酶sufS等5个基因在以S(0)生长的TPY菌株中上调或在以Fe(2+)生长的TPY中下调。这些变化的基因参与代谢、渗透胁迫、细胞膜改变、氧化应激和调节适应性反应。这些结果将有助于我们理解嗜热嗜酸细菌氧化Fe(2+)或S(0)的分子基础。
