Chien Chihching, Kuo Yumei, Chen Changchieh, Hung Chunwei, Yeh Chihwei, Yeh Weijen
Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Chung-Li, Taiwan 320, China.
J Environ Sci (China). 2008;20(3):359-63. doi: 10.1016/s1001-0742(08)60056-x.
In this study we evaluated the bacterial diversity in a soil sample from a site next to a chemical industrial factory previously contaminated with heavy metals. Analysis of 16S rDNA sequences amplified from DNA directly extracted from the soil revealed 17 different bacterial types (genera and/or species). They included Polyangium spp., Sphingomonas spp., Variovorax spp., Hafina spp., Clostridia, Acidobacteria, the enterics and some uncultured strains. Microbes able to tolerate high concentrations of cadmium (500 micromol/L and above) were also isolated from the soil. These isolates included strains of Acinetobacter (strain CD06), Enterobacter sp. (strains CD01, CD03, CD04 and CD08) (similar strains also identified in culture-independent approach) and a strain of Stenotrophomonas sp. The results indicated that the species identified from direct analysis of 16S rDNA of the soil can be quite different from those strains obtained from enrichment cultures and the microbial activities for heavy metal resistance might be more appropriately addressed by the actual isolates.
在本研究中，我们评估了来自一家曾受重金属污染的化学工业工厂旁某地点的土壤样本中的细菌多样性。对直接从土壤中提取的DNA扩增得到的16S rDNA序列进行分析，发现了17种不同的细菌类型（属和/或种）。它们包括多囊菌属、鞘氨醇单胞菌属、贪铜菌属、哈夫尼亚菌属、梭菌纲、酸杆菌门、肠道菌以及一些未培养菌株。还从土壤中分离出了能够耐受高浓度镉（500微摩尔/升及以上）的微生物。这些分离株包括不动杆菌属菌株（CD06菌株）、肠杆菌属（CD01、CD03、CD04和CD08菌株）（在非培养方法中也鉴定出了类似菌株）以及一株嗜麦芽窄食单胞菌。结果表明，直接分析土壤16S rDNA鉴定出的物种可能与从富集培养物中获得的菌株有很大不同，而重金属抗性的微生物活性可能更适合通过实际分离株来研究。
