生物絮团在罗氏沼虾育苗中的应用

Bio-flocs technology application in breeding of Macrobrachium rosenbergii

对罗氏沼虾育苗水体连续添加不同浓度的葡萄糖和定量的枯草芽孢杆菌培育生物絮团,自1日龄幼体培育至仔虾,连续监测水体的氨氮、亚硝酸氮、溶解氧、COD、葡萄糖和生物絮团等浓度;通过变性梯度凝胶电泳(DGGE)分析生物絮团中微生物组成,测定出苗率及育成仔虾个体大小。通过27 d室内罗氏沼虾育苗试验发现:各组生物絮团含量无显著差异,应用生物絮团后,葡萄糖终浓度为20 mg/L组的氨态氮和亚硝酸氮明显低于对照组(P<0.05),溶解氧和COD浓度在试验组与对照组之间不存在显著差异。DGGE分析结果和序列测定结果显示,添加葡萄糖和枯草芽孢杆菌制剂产生的生物絮团,条件致病菌气单胞菌属细菌(Aeromonas sp.)显著少于自然产生的生物絮团,并促进水产有益菌芽孢杆菌属细菌(Bacillus sp.)的生长。出苗率及生长测定表明,对照组出苗率为32.60%,20 mg/L试验组为60.60%,比对照组高85.90%。对照组仔虾体长平均值为8.193 mm,20 mg/L试验组体长平均值为10.488 mm,比对照组高28.00%。添加一定浓度葡萄糖和枯草芽孢杆菌产生的生物絮团能有效地控制水质和减少有害细菌的生长。

An experiment was conducted to investigate the role of bioflocs technology for maintaining good water quality and inhibiting potential pathogen in the breeding systems of Macrobrachium rosenbergii.Glucose was added to the breeding system of Macrobrachium rosenbergii with different concentration to stimulate the formation of bioflocs everyday.The ammonia nitrogen,nitrite-N,dissolved oxygen,chemical oxygen demand（COD）,the concentration of glucose and bio-flocs were continuously monitored.The composition of the microorganism of bioflocs and length of Macrobrachium rosenbergii of postlarval stage were systematically investigated respectively.The results indicated that ammonia-N and nitrite-N concentrations of water in the 20 mg/L glucose group were significantly lower than the control group（P0.05）.The content of bioflocs,dissolved oxygen,COD and concentration of glucose showed no significant differences.By comparing the microbial diversity of bioflocs in control and treatment groups,Aeromonas sp.was probably inhibited in bioflocs treatment groups.The survival rates of post larval in bioflocs group（20 mg/L） and control group were 32.60% and 60.60%,and was 85.90% higher than control group.The average length of Macrobrachium rosenbergii of postlarval stage of control group and bioflocs groups（20 mg/L） were 8.193 mm and 10.488 mm.Bioflocs group（20 mg/L） was 28.00% longer than control.