海洋光合细菌的分离鉴定及其生长条件的研究

ISOLATION AND IDENTIFICATION OF MARINE PHOTOSYNTHETIC BACTERIA AND THEIR GROWTH CONDITIONS

用红色硫细菌培养基从青岛沿海潮间带海泥中分离出8株光合细菌,经鉴定菌株HD_1属最小着色菌(Chromatium minutissimum),HD_2、HD_4为细着色菌(Chromatium gracile);菌株SL_1、SL_1x、PL_1和PL_2为嗜酸红假单胞菌(Rhodopseudomonas acidophila),菌株HCx为沼泽红假单胞菌(Rhodopseudomonaspalustris)。分离菌株均具运动性,不需生长因子。菌株HD_1、HD_2和HD_4在厌氧光照条件下利用硫化物,且在细胞内贮存硫粒。菌株HD_1、HD_2的最适盐度为4.0％,最适pH为7.0,8.0。当培养基中硫化物含量为0.01—0.04％时,菌株HD_1、HD_4生长良好。菌株PL_2在初始pH为6时生长最好。酵母膏对菌株HCx具有明显的促生长作用。

Eight strains of marine photosynthetic bacteria were isolated from the sediments of the tidal zone of Qingdao coast. They were identified as Chromatium minutissimum (strain HD_1), Chromatium gracile (strain HD_2 and HD_4). Rhodopseudomonas acidophila (strain SL_1, SL_(1x), PL_1, and PL_2) and Rhodopseudomonas palustris (strain HC_x). All bacteria were motile. They grew well without growth factors. When growing anaerobically in the light using sulfide as electron donor, strain HD_1, HD_2 and HD_4 deposited sulfur granules in the cells. The optimum pH for strain HD_1 and HD_2 were 7.0 and 8.0, respectively. The optimum salinity for these two strains was 4.0%. Strain HD_1 and HD_4 grew well when the concentration of sulfide was 0.01-0.04% in the medium. Strain PL_2 grew best when the initial pH in the medium was 6.0. Yeast extract could promote the growth of strain HCx.