斑节对虾养殖池塘藻-菌关系初探

Preliminary research on relationship between algae and bacteria in culture ponds of black giant tiger shrimp Penaeus monodon

本研究通过对斑节对虾养殖系统中的异养细菌、浮游微藻进行为期3个月的监测,发现浮游微藻和异养细菌的总量都表现为养殖后期高于养殖前期,其中浮游微藻增加了2个数量级,异养细菌增加了1个数量级,施放有益芽孢杆菌群对池塘菌群和藻群的变动有明显的影响.施放有益芽孢杆菌群的池塘,异养细菌总数略低,弧菌数量维持在103 CFU/mL以下,浮游微藻平稳增长,蓝藻占20%以下;对照池异养细菌的总数略高,弧菌数量达到104 CFU/mL,浮游微藻数量波动,养殖后期蓝藻占60%,为绝对优势种群.表明有益芽孢杆菌群有促进浮游微藻平稳繁殖的作用,但对浮游蓝藻和弧菌的繁殖起抑制作用,浮游蓝藻与弧菌之间具有一定的繁殖相关性.

The experiment period was three months. Three ponds in an aquaculture farm along the east coast of southeast Guangdong Province were used and the stock density of juvenile shrimp Penaeus monodon was at 52 ind/ m2. The Bacillus spp. mixture solution (20×108 CFU/g) were added into two of the ponds at 1. 5 mg/L four days before the stocking and after that the bacteria solution was added at 0. 75 mg/L in the intervals of 15 d until the experiment finished. At the late period the amounts of phytoplankton and heterotrophic bacteria were higher than those at the early period in all the three ponds, but in the two Bacillus -added ponds, the mutualism appeared obviously between the phytoplankton and the bacteria, while in the control (no Bacillus ) , the amount of the heterotrophic bacteria was very high comparing to the beginning, and the total amount of phytoplankton decreased. Furthermore, during the whole period of the experiment, the amounts of Cynophyta and vibrio in the Bacillus-added ponds maintained at very low levels, while in the control the amount of Cynophyta and vibrio increased dramatically at the end.