硝化细菌对罗非鱼苗培育环境及抗病力的影响

Effects of Nitrifying Bacteria on Culture Environment and Anti-Disease Ability of Larval Tilapia

于罗非鱼鱼苗培育水体中引入不同浓度的硝化细菌,检测主要水质因子,测定罗非鱼与抗病力有关的酶的活力,研究微生态调控对水质和对罗非鱼抗病力的影响。结果显示,硝化细菌浓度为100/L时,氨氮含量相对于对照组降低25.05%,亚硝酸氮含量降低45.16%,COD值降低12.33%,差异显著(P<0.05);鱼苗培育成活率相对于对照组高7.58%,体长增加22.18%,体重增加46.15%;幼鱼的抗菌酶、碱性磷酸酶(AKP)和超氧化物歧化酶(SOD)活力相对于对照组分别提高18.60%、59.19%和49.89%,差异显著(P<0.05),组织过氧化物酶(POD)活力差异不显著。表明不同浓度的硝化细菌可显著改善罗非鱼苗培育环境的水质,增强罗非鱼苗的抗病力。

The main water quality factors, anti-disease ability and survival rate of larval hybrid tilapia （ Oreochromis aureus ♂× Oreochromis niloticus ♀ ） in the culture system added different density of nitrifying bacteria were determined. The comparison of test results between treatment and control groups showed that nitrifying bacteria in appropriate density （100 cfu/L） could significantly （P〈0.05） improve the water quality and anti-disease ability of larval tilapia： the concentration of TAN, NO2-N and COD of the treated groups decreased by 25.05%, 45.16% and 12.33% respectively; the livahility, body length and body weight of larval tilapia of the treatment groups increased by 7.58%, 22.18% and 46.15% respectively; and the activity of antibacterial enzyme, alkaline phosphatase （AKP） and superoxide dismutase （SOD） of larval tilapia increased by 18.60%, 59.19% and 49.89% respectively. However, the activity of peroxidase （ POD ） has no significant difference（P 〉0.05）.