การคัดแยก และศึกษาคุณสมบัติของบาซิลลัสเพื่อใช้เป็นสารเสริมโพรไบโอติกในไก่ไข่

Abstract

This study aimed to isolate Bacillus sp. spore forming bacteria from environments. Environment samples were crustacean intestine, shrimp pond sludge, hot spring soil and chicken feces. These samples were examined, according to the morphological and biochemical tests. The result showed that thirteen isolates had biochemical traits corresponded to Bacillus sp. The efficient spores with probiotic properties were extracting with over 70% of the spore efficiency OYNH31, CPPESO1T2, CKNJh11, SHPS1, HHPS5 and THPS1. Antibiotic susceptibility test showed that the isolates CPPESO1T2, CKNJh11 and HHPS5 were susceptible to antibiotics. Antibacterial activity of OYNH31, CPPES01T2 and THPS1 were also revealed against tested pathogenic bacteria and was showed tolerances to heat at 95°C for 30 minutes and 70% alcohol. All isolates CPPES01T2, CKNJh11 and THPS1 showed non-hemolysis and tolerance to bile salt and lower pH after 3 hours of incubation. When isolated bacteria were mixed into the feed for egg-laying hen, the survival rate of isolated bacteria was increased more than 80%. By using gyrA gene isolate CKNJh11 was identified as Bacillus sp., whereas 165 DNA gene sequence analysis indicated 100% identity with Bacillus aryabhattai B8W22. Supplementation of encapsulated spores in laying hen diet at 10% spores tended to increase egg production, egg mass and eggshell weight. In the feces content, numbers of Salmonella sp. and Escherichia coli were decreased, while the numbers of lactic acid bacteria in the feces was increased. Therefore, this study clearly suggested the efficacy of Bacillus sp. as promising spore forming probiotic bacteria for further development in poultry production.