Many species of Bacillus are used as probiotics in animal feed not only due their proven effect on health and performance of animals, but also the resistance of the spores to the high temperature of the feed manufacturing process. After the spore is ingested by the host it needs to germinate to be metabolically active and provide a benefit to the animal. The germination time of a spore varies significantly depending on the environmental conditions that the spore is subjected to. Germination of Bacillus spores can be inhibited by low pH, amino acid analogues, fatty acids, alcohols, phenols, enzyme inhibitors, and sub-optimal germinants. The priming of Bacillus spores by coupling individual spores with optimized germinants enables.
In this study, a blend of 3 bacterial spores, hereafter Probiotic 1, containing Bacillus pumilus (BP), Bacillus licheniformis (BL), and Bacillus amyloliquefaciens (BA) was compared to 4 commercially available probiotics, hereafter Probiotic 2, containing B. subtilis (BS), and B. amyloliquefaciens, Probiotic 3 (B. licheniformis), Probiotic 4 (B. subtilis) and Probiotic 5 (B. licheniformis).
The germination rate of Probiotics 1 after 105 minutes incubation at pH 7 was 79.7% for BP, 71.9% for BA and 47.5% for BL. In contrast the germination rate for all the other probiotics was 0.0% except for probiotics 4 (BS) which germinated at 3.5% at pH 7. Similarly, the germination rate after 105 minutes at pH 3 for, Probiotic 1 was 29.1%, 6.9%, 61.0% for BP, BA and BL, respectively; while none of the other probiotics germinated at pH 3. The ability of Bacillus spores to germinate rapidly is important for animals like poultry that have very fast gastro-intestinal transit times. This novel probiotic blend could lead to improved consistency in field applications by increasing the consistency and speed of spore germination, leading to faster bacterial growth and metabolism.
Key Words: Bacillus, Germination, Probiotics, Spores