Abstract: 【Objective】 The aim of this study was to isolate Bacillus and Lactobacillus from goose feces,so as to provide references for the study of goose-derived functional bacteria and rational drug use.【Method】 The rectal feces of 30 50-week-old healthy Northern White geese were collected,and the strains were isolated and screened by specific culture medium and biochemical reaction test.The selected strains were identified by DNA extraction and PCR amplification 16S rDNA sequencing.The phylogenetic tree was established by comparing with the reference strains in GenBank and the strains were identified by homology comparison.After 48 h of culture,the growth characteristics,optimum pH and temperature of bacteria were detected.The growth status of bacteria under pH 7.0 and no bile salt environment was used as control.The ability of acid and bile salt tolerance was detected,and the tolerance of antibiotics was detected by drug sensitivity test.【Result】 After isolation and screening,9 strains of bacteria were obtained,and 2 strains were finally selected by biochemical test.According to the evolutionary distance and homology comparison of the phylogenetic tree,they were Bacillus tequilensis CC2FG2 and Weissella paramesenteroides JY0R2.The results of growth characteristics showed that Bacillus tequilensis CC2FG2 had the best proliferation effect under the condition of medium pH 6.5 and temperature 30 ℃ for 16 h,which could tolerate 1.2% bile salt,the number of viable bacteria was 69.2% of that without bile salt,and the acid resistance was strong.The number of viable bacteria under the strong acid environment of medium pH 3.5 was 81.5% of that of pH 7.0.The results of antibiotic tolerance showed that it was sensitive to ofloxacin,norfloxacin,kanamycin,streptomycin,clarithromycin,erythromycin,compound sulfamethoxazole and vancomycin,but not sensitive to cefuroxime,cefazolin,cefotaxime,ampicillin,nitrofurantoin,ciprofloxacin,gentamicin and tetracycline.In the medium with pH of 6.0 and temperature of 36.5 ℃,Weissella paramesenteroides JY0R2 had the best prolifervation effect when cultured for 18 h.Under 1.2% bile salt,the number of viable bacteria was 50.6% of that without bile salt.Under strong acid environment with pH 3.5,the number of viable bacteria was 87.6% of that with pH 7.0.It was sensitive to ciprofloxacin,ofloxacin,norfloxacin,clarithromycin and erythromycin,moderately sensitive to kanamycin,nitrofurantoin and tetracycline,and insensitive to cefuroxime,cefazolin,cefotaxime,ampicillin,compound sulfamethoxazole,vancomycin,gentamicin and streptomycin.【Conclusion】 The results of the above studies showed that Bacillus tequilensis CC2FG2 and Weissella paramesenteroides JY0R2 isolated from geese had good acid resistance and bile salt resistance,and Bacillus tequilensis could be used in combination with some β-lactams,quinolones,aminoglycosides,nitrofurans and tetracyclines,and Weisseria paramesenteroides could be used in combination with some β-lactams and aminoglycosides,providing a reference for the development of goose-derived functional bacteria.

Key words: Bacillus tequilensis; Weissella paramesenteroides; growth characteristics; acid-alkali tolerance