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

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

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。

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.