饲料中添加芽孢杆菌和中草药制剂对凡纳滨对虾生长及肠道菌群的影响

Effects of dietary Bacillus spp. and traditional Chinese medicines on growth and intestinal bacterial flora of shrimp Litopenaeus vannamei

研究了饲料中添加中草药和芽孢杆菌对凡纳滨对虾Litopenaeus vannamei生长和肠道细菌的影响。以基础饲料为对照(C),通过添加中草药和芽孢杆菌Bacillus spp.配制成4种实验饲料:0.2%中草药(M),0.20%中草药制剂+0.30%芽孢杆菌(BM1),0.10%中草药制剂+0.15%芽孢杆菌(BM2),0.30%芽孢杆菌(B)。实验分成5组,分别投喂上述饲料,共进行了56d。结果表明,各组对虾的成活率95.83%—98.33%,各处理间无显著差异(P>0.05);投喂实验饲料的各组对虾终末体重均高于对照组(C),其中BM2与C差异性显著(P<0.05);M、BM1和BM2的增重率和特定增长率显著高于C和B;M组的对虾肠道异养菌总数和弧菌数均高于其他各组,而共同添加组BM1和BM2的异养菌和弧菌数则最少。从各组选取菌落数在50—100,分布均匀的平板,随机挑取30株细菌进行分类鉴定,结果C、M、BM1、BM2和B组细菌属数分别为11、8、6、5和7个。饲料中添加中草药和芽孢杆菌促进了对虾的生长,且共同添加的效果好于单独添加,它们的使用改变了肠道细菌的数量和组成。

A feeding experiment was conducted to investigate the effects of Bacillus and traditional Chinese medicines（TCM） on growth and intestinal bacterial flora of shrimp L.vannamei.Four experimental diets were formulated by adding the Bacillus and TCM to basil diet（C）： 0.2% TCM（M）,0.20% TCM＋0.30% Bacillus（BM1）,0.10% TCM＋0.15% Bacillus（BM2）,0.30% Bacillus（B）.The concentration of Bacillus was 109 CFU·g-1.The TCM consisted of a mixture of herbs and plant materials Isatis tinctoria L.,Isatis indigodica Fort,Forsythia suspersa Vahl,Corydalis bungeana Turez,Pogostemon cablin（blanco） Benth and Astragalus menbranaceus（Fisch.） Bge.Acclimatized shrimp with an average initial weight of 1.91±0.03 g were selected and stocked into 15 cement tanks at a stocking density of 80 shrimp.Each aquarium contained 1500L of sand filtered seawater with a flow rate of 0.9L·min-1.The water was continuously aerated with two air stones.Each diet was given to shrimp four times（07：00,12：00,17：00,23：00） a day to saturation for a period of 56 days.During the experiment period,the water temperature fluctuated between 19.6 and 25.2oC,salinity between 30 and 31 psu.At the end of feeding trial,survival ranged from 95.83% to 98.33% with no significant difference（P〉0.05） among all groups.Growth measured as final weight was slightly higher（P〉0.05） in shrimp fed with BM1,M and B than that with C,and there was a significant difference（P〈0.05） between BM2 and C.In case of weight gain（WG） and specific growth rate（SGR）,the shrimp fed with M,BM1 and BM2 exhibited significantly（P〈0.05） higher values than that with C and B.Of the five diets,BM2 exhibited the best performance,followed by BM1.The combination of Bacillus spp.and TCM,therefore,proved to be more effective and economically viable.The total bacteria counts and Vibrio counts in shrimp fed with M were the most;the counts with shrimp fed with BM1 and BM2 were the least.In each group 30 bacterial strains were purified and identified.These bacterial strains belonged to 12,8,6,5,7 genera in C,M,BM1,BM2 and B,respectively.Most of the bacteria were gram negative bacteria;they counted a per-centage of 86% to 93% in each group.Vibrio spp.,Photobacterium spp.and Pseudomonas spp.were the predominant bacterial flora;however,their values varied in different groups.The results showed that the diets supplemented with TCM and Bacillus also changed the number and composition of intestinal bacterial flora.