工厂化养殖方斑东风螺消化道及养殖环境中细菌数量变动与理化因子的关系

Physical-chemical factors associated with the dynamic change of bacterial quantity of alimentary tract and environment in Babylonia areolate industrial aquaculture

为掌握秋冬季方斑东风螺养殖系统细菌数量变动情况及其与理化因子的关系,试验采用TCBS培养法分别检测方斑东风螺(Babylonia areolate)消化道及其养殖水体、底沙弧菌数量(Sediment Vibrio,SV),用营养琼脂培养法检测螺消化道异养菌数量(Heterotrophic Bacteria of Alimentarytract,AHB),用荧光显微镜法检测水体总细菌数量(Water Total Bacteria,WTB),并对养殖理化因子(水温(T)、盐度(S)、pH、溶解氧(DO)、氨氮(AN)、亚硝酸盐氮(Nitrite))及底质营养盐(总氮(TN)、总磷(TP))进行监测。结果显示,消化道异养菌数量为4.3×104~5.9×106CFU/g,弧菌(Alimentarytract Vibrio,AV)为2.0×102~7.5×105CFU/g;水体总细菌、水体弧菌(Water Vibrio,WV)数量分别为4.8×104~3.8×105cells/m L、2.1×102~1.2×104CFU/m L;底沙弧菌数量为6.0×104~1.9×106CFU/g。消化道内异养菌及弧菌分别与亚硝酸盐氮呈极显著正相关(P<0.01),与pH、盐度均呈显著负相关(P<0.05);水体中总细菌数量与溶解氧呈显著负相关(P<0.05),弧菌与总磷呈显著负相关(P<0.05);底沙中弧菌数量与各理化因子无明显相关性。主成分分析(Principal component analysis,PCA)结果显示,东风螺消化道细菌、养殖水体总细菌及弧菌、底沙弧菌数量在秋季主要受温度、氨氮、亚硝酸盐氮的影响,而冬季受水体溶解氧的影响更多,在整个养殖期间,需加强对盐度及pH的监控。

With the aims to master the dynamic change of bacteria quantity of alimentary tract and aquaculture environment in Babyloniaareolate,TCBS and nutrient AGAR cultivation method was applied to detection vibrio and heterotrophic bacteria quantity respectively,fluorescence microscopy was applied to detection water total bacteria（WTB）.In addition,the main physical-chemical factors including temperature（T）,salinity（S）,pH,dissolved oxygen（DO）and major nutritive salt of water and sediment,were investigated. The results show that the quantity of WTB,water Vibrio（WV） and sediment Vibrio（SV） wave form 4. 8 × 10 4- 3. 8 × 10 5 cells/m L,2. 1 × 10 2- 1. 2 × 104 CFU/m L and 6. 0 × 10 4- 1. 9 × 10 6 CFU/g separately. Heterotrophic bacteria and Vibrio of Alimentary tract（AV） wave from4. 3 × 104- 5. 9 × 10 6 CFU/g and 2. 0 × 10 2- 7. 5 × 105 CFU/g separately. Correlation analysis results show that the quantity of heterotrophic bacteria in Alimentary tract（AHB） and AV both are very significant positive correlation with nitrite（P 〈 0. 01）,negative correlation with pH（P 〈 0. 05） and salinity（P 〈 0. 05）. WTB is negative correlation with dissolved oxygen（P 〈 0. 05）,WV is negative correlation with total phosphorus（P 〈 0. 05） and others are not obvious. Principal component analysis（PCA） show that WTB,WV,SV,as well as AHB and AV mainly affected by temperature,ammonia nitrogen and nitrite from September to the middle of November（autumn） while by water dissolved oxygen more in winter. In particularly,salinity and pH should be monitoring during the whole cultivation period.