杭州西湖水体中异养细菌生长的限制因子

Factors restricting growth of heterotrophic bacteria in the water body of West Lake, Hangzhou

通过添加不同营养盐类的纯种和自然培养试验 ,对异养细菌生长的限制因子进行了研究 .结果表明 ,生物可利用的有机碳是主要的限制性营养因子 ,而氮源和磷源的影响相对较小 ;湖水的高 pH、丰富的藻类和浮游动物生物量也制约了异养细菌的生长 .此外还发现 ,在自然水体中添加 0 .5 %葡萄糖后 ,一些自生固氮细菌得到富集 ;添加C +N +P后 ,有大量霉菌生长 ,添加 0 .0 1 %牛肉膏后 ,假单胞菌属 (Pseu domonas)细菌由原来的 30 %提高到 57% ;湖水进行实验室培养时细菌的最大生长量可达 1 0 5个·ml- 1 .

Restricting factors of bacteria growth were studied by pure culture and natural culture test. The results showed that organic carbon source available for bacteria was more important than (NH 4) 2SO 4 and KH 2PO 4, while higher pH, and rich biomass of phytoplanktons and zooplanktons in the water restrained the growth of heterotrophic bacteria. Under natural culture experiment, Azotobacter increased after 0.5% glucose was added, and a lot of mildew grew after adding 0.5% glucose with 0.1%(NH 4) 2SO 4 and 0.1% KH 2PO 4, while Pseudomonas enriched 30～57% after adding 0.01% beef extract. It was also showed that bacteria growth potentiality in natural water could reach to 10 5 cfu·ml -1 .