近海养虾场底泥中产芽孢细菌的生态特征

ECOLOGICAL CHARACTERIZATION OF BACILLI IN SEDIMENT FROM A NEAR-SHORE MARINE HORTICULTRTAL REGION

通过对近海养虾场底泥中的细菌数量和类群的调查 ,发现有超过 5 0 %的细菌生物量是产芽孢细菌 ,因此对底泥中的产芽孢细菌进行了分离和纯化 ,通过对细胞形态、生理生化等特征的研究和对部分菌株的 16SrRNA基因的ARDRA分型、序列分析等 ,鉴定了 6 7株产芽孢细菌 ,其中 6 2株属于芽孢杆菌属 ,5株属于短芽孢杆菌属 .进一步对 6 2株芽孢杆菌属的细菌在底泥不同深度的分布进行研究 ,结果表明 ,巨大芽孢杆菌主要分布在底泥深度 0～ 6cm左右的区域 ,海洋芽孢杆菌、短小芽孢杆菌和蜡状芽孢杆菌主要分布于底泥 6cm以下的区域 ,与坚强芽孢杆菌性状相近的菌分布在底泥 2～ 8cm深度 ;与耐碱芽孢杆菌性状相近的芽孢菌广泛分布在 0～ 12cm区域 .讨论认为 ,应用这些产芽孢细菌资源在修复海洋环境和开发海水养殖微生态制剂方面具有一定可能性 .图 3表 3参

A survey on microbial populations in the sediment from a near-shore mariculture region revealed that over 50% (by cells) of the biomass was spore-producing bacteria. Totally 67 strains of spore-producing bacteria were obtained and were identified by their cellular morphology, physiological and biochemical features. 12 of the 67 strains were further characterized by cloning their 16S rRNA genes. Results indicate that 62 out of the 67 spore-producing bacterial strains belong to the genus Bacillus and 5 strains belong to Brevibacillus. Among the 62 strains of Bacillus, B. megaterium, B. marinus, B. pumilus, B. cereus, B. thuringensis, B. sphaericus and B. firmus were identified, while other 28 strains could not be taxonomically identified and need further studies. The strains of B. megaterium mainly distributed in the zone above 6 cm of the sediments, and B. pumilus and B. cereus were dominant species in the sediment under depth of 6 cm. The unidentified bacilli distributed through out the entire zone (0～12 cm) of the sediment. The possibility of applying these bacilli for bioremediation of the polluted marine environments or for developing ecological preparations for horticultural is discussed. Fig 3, Tab 3, Ref 15