Yazdani Mahnaz, Naderi-Manesh Hossein, Khajeh Khosro, Soudi Mohammad Reza, Asghari S Mohsen, Sharifzadeh Marziyeh
Department of Biochemistry, Faculty of Science, Tarbiat Modares University, Tehran, Iran.
J Basic Microbiol. 2009 Feb;49(1):119-27. doi: 10.1002/jobm.200800177.
30 pure colonies with various colors and shapes were isolated from the samples of water and mud which were collected from the Abe-Siah hot springs in Ramsar, a city in north of Iran, with high-level of radiation (up to 4 Gy). Colonies were irradiated by 22 KGy radiations and only one of them survived. The survived bacterium with an optimum growth of 30 to 37 degrees C, pH 6 to 7, and at minimum of 5% NaCl concentration showed promising characteristics. This strain is aerobic, mesophilic, white colony, with catalase-positive, oxidase-negative, non motile, spore forming, rod-shape and finally Gram positive. Strain Bacillus sp. WHO represented a strain of genus Bacillus megaterium according to a phylogenetic analysis of the 16S rDNA and biochemical features. Its radio-resistancy was compared with E. coli and B. megaterium which were inactivated in 2 KGy and 5.9 KGy respectively. In order to reveal the mechanisms of this extreme radio-resistancy and WHO DNA repair system we examined its proteomic map, following gamma-irradiation, using two-dimensional polyacrylamide gel electrophoresis and silver-staining. The expression levels of majority number of protein spots showed significant changes under radiation stress.
从伊朗北部城市拉姆萨尔的阿贝-西亚赫温泉采集的水和泥浆样本中分离出30个具有不同颜色和形状的纯菌落，该温泉辐射水平较高（高达4戈瑞）。对这些菌落进行22千戈瑞的辐射，只有其中一个存活下来。存活的细菌在30至37摄氏度、pH值6至7以及至少5%氯化钠浓度的条件下生长最佳，显示出良好的特性。该菌株为需氧、嗜温、白色菌落，过氧化氢酶阳性、氧化酶阴性、不运动、形成芽孢、杆状，最终革兰氏阳性。根据16S rDNA的系统发育分析和生化特征，菌株芽孢杆菌属WHO代表巨大芽孢杆菌属的一个菌株。将其抗辐射能力与分别在2千戈瑞和5.9千戈瑞下失活的大肠杆菌和巨大芽孢杆菌进行了比较。为了揭示这种极端抗辐射能力和WHO DNA修复系统的机制，我们在γ辐射后，使用二维聚丙烯酰胺凝胶电泳和银染技术检测了其蛋白质组图谱。在辐射应激下，大多数蛋白质斑点的表达水平发生了显著变化。
