2株动物微生态制剂菌的分离鉴定及其生物学特性初步研究

目的从饲料中进行微生物的分离与培养,筛选动物微生态制剂候选菌株。方法利用变性梯度凝胶电泳(DGGE)筛选得到的7株微生物区分为2种菌,经测序确定其为热带假丝酵母和植物乳杆菌;检测了不同pH、温度、胆盐、金属铜和需/厌氧对其生长的影响。结果当pH小于2.5或铜离子高于150 ppm时,植物乳杆菌无法生长,而热带假丝酵母数量略有下降;胆盐和金属离子对2种菌影响较小,42℃培养条件下相对于30℃培养时热带假丝酵母数量下降了6个数量级。结论筛选得到的2株菌具有应用于动物微生态制剂的潜力,为动物微生态制剂候选菌筛选和评价提供了基础数据。

Identification of two animal feed probiotics and preliminary study on their biological functions

Objective To screen and identify the candidate strains from feedstuff,which may be used as the potential probiotics for Animal Micro-ecological Agent（AMEA）.Method The DGGE method as well as sequencing were applied to distinguish the 7 different isolates and 2 strains were determined as Candida tropicalis and Lactobacillus plantarum,respectively.Then,their tolerances to pH,temperature,bile salt,Cu2＋,aerobic/anaeobic atmosphere were evaluated.Result Lactobacillus plantarum were totally inhibited when pH was below 2.5 or the concentration of Cu2＋ exceeded 150 ppm,while the amount of Candida tropicalis just reduced a little in the same conditions.Bile salt and Cu2＋ showed minor impact on the the two bacteria,with the biomass of Candida tropicalis being reduced significantly at 42 ℃ than at 30 ℃.Conclusion Two strains which can be used as potential probiotics were obtained.The data provide a foundation for a further study on probiotics screening and AMEA evaluation.