论文部分内容阅读
采用平板涂布法和MPN法测定了虾池底质下 0到 30cm深度范围内 3类主要细菌类群的垂直分布情况。结果表明 ,底泥中细菌主要集中于 0到 5cm的表层范围内 ,随深度增加 ,数量急剧减少 ,至 30cm深处所测到菌量已很少。底泥中的总菌量随养殖时间推移 ,逐渐增加 ,到养殖中后期 ,表层菌量增加至 10 6CFU/g ,表层以下 10～2 0cm的总异养菌量和硝酸盐还原菌数量也增加至 10 5CFU/ g以上。弧菌仍集中于表层。细菌的垂直分布主要受各层有机物和溶解氧含量的影响
The vertical distribution of three major bacterial groups in the depth of 0 to 30 cm under the sediment of shrimp ponds was determined by the plate coating method and the MPN method. The results showed that the bacteria in the sediments mainly concentrated in the surface layer of 0 to 5 cm. With the increase of the depth, the number decreased drastically, and the amount of bacteria was detected to the depth of 30 cm. The total amount of bacteria in the sediment gradually increased with the passage of time, reaching to 10 6CFU / g in the middle and late stages of culture. The total heterotrophic bacteria and the number of nitrate-reducing bacteria increased from 10 to 20 cm below the surface To 10 5 CFU / g or more. Vibrio is still focused on the surface. The vertical distribution of bacteria is mainly affected by the organic matter and dissolved oxygen content of each layer