本研究以1、2、4、7及28日齡雞隻的糞便進行乳酸菌株分離試驗，共分離631菌株，再分別進行凝乳反應( curdling reaction )、革蘭氏染色 ( Gram stain ) 及觸酶反應 ( catalast test ) 等試驗，共得到17 7株類乳酸菌株。然後再將此些菌株進行16S rDNA序列分析鑑定，其中1、2日齡樣品之類乳酸菌株比對出40株菌，分別屬於2個菌屬：Uncultured bacterium、Enterococcus faecalis；4、7及28日齡樣品之類乳酸菌株共比對分析出6株菌，分屬於3個乳酸菌屬：Lactobacillus johnsonii、Lactobacillus reuteri及Lactobacillus salivarius。
測試所分離之六株乳酸菌株 ( Lactobacillus ) 之產酸、生長速率及對酸及對0.3 % 膽鹽的耐受性。其中以所分離得到的Lactobacillus salivarius 28DM-68菌株之產酸能力最好。再模擬6株乳酸菌株於類胃液及消化道環境之耐受性，得出耐酸及耐膽鹽性較佳的乳酸菌株，為 Lactobacillus johnsonii 4DM-45。
挑選耐酸、耐膽鹽較佳的Lactobacillus reuteri 4DM-45菌株及產酸性較佳之Lactobacillus salivarius 28DM-68菌株，利用低溫冷凍乾燥方法，製作乾燥菌粉，將作為日後動物飼料添加劑之實驗材料。 A total number of 177 strains of lactic acid bacteria (LAB) were screened from the 631 colonies isolated from the feces of 1, 2, 4, 7 and 28 days old chickens by curdling reaction, Gram’s stain and catalyst test. Among them, 40 strains screened from the feces of the 1 and 2 days old chickens were identified as Enterococcus by 16S rDNA sequencing, while 6 strains screened from the feces of the 4, 7 and 28 days old chickens were Lactobacillus johnsonii, Lactobacillus reuteri and Lactobacillus salivarius.
The 6 Lactobacillus strains were then examined for their acid productivities, growth rates and resistant abilities to acid and bile salt. The Lactobacillus salivarius 28DM-68 had the best acid productivity, and Lactobacillus johnsonii 4DM-45 performed well in resistance to acid (pH 2.0) and bile salt (0.3%). These two stains were mass cultured and freeze-dried to make probiotic feed additive for broiler chickens.
