Isolation and identification of amylase-producing, endospore-forming bacteria from the alimentary tract of commercially processed broilers

Authors: Hinton Jr, Arthur; Ingram, Kimberly

Submitted to: International Poultry Scientific Forum
Publication Type: Abstract Only
Publication Acceptance Date: 12/2/2016
Publication Date: 1/30/2017
Citation: Hinton Jr, A., Ingram, K.D. 3017. Isolation and identification of amylase-producing, endospore-forming bacteria from the alimentary tract of commercially processed broilers [abstract]. International Poultry Scientific Forum.

Interpretive Summary: none

Technical Abstract: Bacterial cultures of crop and cecal contents of adult poultry contain beneficial bacteria that reduce colonization of young poultry by Salmonella. Since endospore-forming bacteria may play a role in competitive exclusion of Salmonella in poultry, 3 trials were conducted to isolate these bacteria from the crop and cecal contents of commercially processed broilers. Pre-eviscerated, broiler carcasses were taken from a commercial poultry processing facility, placed on ice, and immediately transported to the laboratory for removal of crops and ceca. Crop and cecal contents were used to inoculate separate, 100 ml aliquots of media composed of (g/l) tryptose, 10; yeast extract, 5; sodium chloride, 5; glucose, 5; and beef extract, 2. Inoculated media was incubated aerobically or anaerobically at 35oC for 48 h. After incubation, 10 ml of each culture was transferred to test tubes and heated at 80oC for 10 min. Serial dilutions of the cultures were plated on Bacillus Agar, and plates were incubated at 30oC under the appropriate atmospheres for 24 h. Plates with isolated colonies were selected, and a replica plating tool was used to transfer colonies from the original plates to fresh Bacillus Agar plates. The original plates were flooded with Gram’s iodine, and colonies with clear zones were identified as presumptive amylase producers. Isolates were screened for amylase production because starch is a major component of broiler diets. Replica plates were incubated for 24-48 h at 30oC, and replicas of colonies that exhibited amylase production on the original plates were selected for identification with the Biolog Bacterial Identification System. Endospore production was confirmed by phase microscopy. Amylase production by pure colonies was confirmed by streaking cultures on Starch Agar, incubating for 48 h, and observing for zones of clearing around colonies on plates flooded with Grams’ iodine. Results indicated that there was no significant (p < 0.05) difference in the number of endospore-formers recovered from crop or cecal cultures and no difference in the number of these bacteria recovered from aerobic or anaerobic cultures. Isolates were identified as Bacillus pumilus, Bacillus niabensis, Paenibacillus provencensis, Paenibacillus borealis, and Paenibacillus tarimensis. Findings indicate that endospore-forming, amylase-producing bacteria are part of the normal flora of commercially processed broilers. The ability of these bacteria to digest starch can increase the concentration of simple carbohydrates available for metabolism by other beneficial bacteria. Therefore, these bacteria may be important components of effective, defined probiotic cultures.