凡纳滨对虾低盐度高产虾池环境微生物生态研究

对广东珠三角地区,凡纳滨对虾低盐度高产虾池环境微生物调查结果,养殖水体异养菌平均数量为5.15×10⁴cfu·mL^-1,致病性弧菌为5.00×10³cfu·mL^-1,池底泥浆中异养细菌平均数量为2.41×10⁶cfu·mL^-1,致病性弧菌为1.45×10⁵cfu·mL^-1。不同虾池异养细菌的数量差别小而稳定,致病性弧菌的数量差别及波动大。淤泥较深的老化虾池,水体和泥浆中异养细菌平均分别为6.10×10⁴cfu·mL^-1和2.89×10⁶cfu·mL^-1,致病性弧菌为6.00×10³cfu·mL^-1和2.14×10⁵cfu·mL^-1;无淤泥虾池水体和泥浆中异养细菌平均分别为4.53×10⁴cfu·mL^-1和2.08×10⁶cfu·mL^-1,致病性弧菌为4.34×10³cfu·mL^-1和9.86×10⁴cfu·mL^-1。老化虾池底泥致病性弧菌明显偏高,成为老化虾池易爆发虾病的重要原因。低盐度虾池水体异养菌和致病性弧菌的数量变化,表现为养殖前期高,中后期低而稳定;池底泥浆中异养菌和致病性弧菌的数量变化,呈不规则波动。高的养殖水温对养殖环境异养菌和致病性弧菌表现抑制作用,养殖环境微生物与水体浮游藻类也有一定的关系。

Environmental bacteria in Litopenaeus Vannamei low salinity intensive stocking ponds

Environmental bacteria investigations were conducted in Litopenaeus vannamei low salinity intensive stocking ponds in the area of Pearl River Delta, Guangdong Province.The results showed that the mean of heterotrophic bacteria were 5.15×10⁴cfu·mL^-1 and pathogenic Vibrio were 5.00×10³cfu·mL^-1 in water column, but it were 2.41×10⁶cfu·mL^-1 and 1.45×10⁵cfu·mL^-1 in the ponds sediment, respectively.There was a less difference to heterotrophic bacteria whereas larger to pathogenic Vibrio in water and sediment in different ponds.In old shrimp ponds with a depth of sediment, the evenness of heterotrophic bacteria were 6.10×10⁴cfu·mL^-1 in water and 2.89×10⁶cfu·mL^-1 in sediment, and pathogenic Vibrio were 6.00×10³cfu·mL^-1 and 2.14×10⁵cfu·mL^-1, respectively.But in ponds of bottom renovated with little sediment, heterotrophic bacteria average were 4.53×10⁴cfu·mL^-1 in water and 2.08×10⁶cfu·mL^-1 in sediment, 4.34×10³cfu·mL^-1 of pathogenic Vibrio in water and 9.86×10⁴cfu·mL^-1 in sediment.The pathogenic Vibrio were higher obviously in sediment of old shrimp ponds, it would be the cause of diseases outbreak in old ones.Heterotrophic bacteria and pathogenic Vibrio was higher in early period of stocking, lower and stable in middle and final term in water column, but a fluctuation was found to them in the sediment throughout the low salinity stocking.High water temperature indicated an inhibiting to heterotrophic bacteria and pathogenic Vibrio in low salinity stocking ponds, moreover, the environmental bacteria were also impacted by phytoplankton.