摘要
旨在寻找具有益生菌特性的泥鳅(Misgurnus anguillicaudatus)养殖池塘土著芽孢杆菌(Bacillus),提供可靠和针对性强的制备微生态制剂的菌种,有效改善泥鳅养殖池塘水质。从泥鳅养殖池塘水体中分离到4株芽孢杆菌,通过降解培养液中亚硝酸盐筛选出1株优势目的菌株NQ1。根据形态学特征和生理生化特性结果,鉴定NQ1为枯草芽孢杆菌(Bacillus subtilis)。设置NQ1浓度105、106、107cfu/m L组、对照组(加入灭菌生理盐水)、NQ1+嗜水气单胞菌组(2种细菌的终浓度均为107cfu/m L)和嗜水气单胞菌组(107cfu/m L)进行安全性试验。3个NQ1组和对照组的泥鳅均能正常摄食和活动,成活率均为100%;嗜水气单胞菌组泥鳅的成活率仅为40%;加入1×107cfu/m L浓度NQ1组泥鳅成活率(65%)比单独加入1×107cfu/m L浓度嗜水气单胞菌攻毒组(40%)高。水质净化试验结果显示,在泥鳅养殖水体中加入1×107cfu/m L浓度的NQ1,14 d后氨氮和亚硝酸盐含量较对照组分别降低34.97%和89.46%。
The bacteria in probiotic preparations decompose organic matter to obtain energy for growth and reproduction,thereby improving water quality at low cost and without producing harmful residuals. Thus,probiotics have been widely used in aquacultural waters to improve water quality. However,there are few reports on the screening,growth characterization and application of probiotics for culturing loach. To provide reliable probiotic strains for water quality improvement in loach（ Misgurnus anguillicaudatus） culture ponds,we isolated and purified probiotic strains of native Bacillus from loach culture ponds. Four strains of Bacillus were obtained and a dominant strain,referred to as Bacillus NQ1,was screened for removal of ammonia and nitrite nitrogen. Based on morphological features and physiological-biochemical characteristics,NQ1 was identified as Bacillus subtilis. Research on growth characteristics of Bacillus NQ1 indicates that the strain entered the logarithmic growth phase after 4 h and reached the stable growth stage after 16 h. A safety test of B. subtilis NQ1 was conducted in a loach pond with six groups designated： three NQ1 test groups with final pond concentrations of 105,106 and 10^7cfu / mL; an Aeromonas hydrophilia group with a final concentration of 10^7 cfu / mL; an NQ1 plus A. hydrophilia group,both with final concentrations of 10^7 cfu / mL; the control group that received sterile normal saline. Suspensions of the designated solutions were added to a loach culture pond and an equal volume of sterile normal saline solution was added to a pond as the control. Each group contained 20 loaches and tests were run in triplicate. During the test,aeration was continuous and fish were fed once daily. After 14 days,the survival rates for each group were calculated. Results show that loach feeding and activity in the three NQ1 test groups and the control group were normal and the loach survival rate in all four groups was 100%. The loach survival rate in the NQ1 plus A. hydrophilia group was only 65%,but still higher than the survival rate（ 40%） in the A. hydrophilia group. In the water purification test,ammonia and nitrite nitrogen in the 1 × 10^7 cfu / mL NQ1 group decreased by 34. 97% and 89. 46% compared to the control group after 14 days. Therefore,B. subtilis NQ1 can improve water quality in aquaculture ponds and shows good potential as a probiotic for managing the microecology of loach culture ponds.
出处
《水生态学杂志》
CSCD
北大核心
2015年第4期86-91,共6页
Journal of Hydroecology
基金
江苏省水产三新工程重大项目(DY2012-3-8)
江苏省水产三项工程项目(PJ2011-62)
江苏省科技厅项目(BE2012354)
关键词
芽孢杆菌
菌株筛选
水质净化
泥鳅养殖
Bacillus
strain screening
water purification
loach（Misgurnus anguillicaudatus） breeding
