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Five commercially available Bacillus probiotic strains consisting of Bactisubtil, Enterogermina, Biosubtyl Nha Trang, Biosubtyl Da Lat and Subtyl, were characterized for determining their potential attributes that would account for their claimed probiotic properties and are available for human use. Evidence was provided for the colonization, immunostimulation and antimicrobial activity, which facilitate the hypothesis that the organisms have a potential probiotic effect.

The studies have shown that the inner-coat oxalate decarboxylate (OxdD) has exposed an endogenous phytase, a commonly used feed for monogastric animals, in an active form at the spore surface. The potential of OxdD as a carrier protein is documented through the spore display of a bioactive heterologous passenger, the tetrameric [beta]-glucuronidase enzyme from Escherichia coli.

A study is conducted where the isolation of 237 presumptive gut-associated Bacillus spp. isolates that were obtained by heat and ethanol treatment of fecal material from organically reared broilers followed by aerobic plating. The result suggests that some of the sporeformers isolated have the potential to persist in or transiently associate with the complex gut ecosystem.

The Bacillus cereus spore surface layers consist of a coat surrounded by an exosporium. We investigated the interplay between the sporulation temperature and the CotE morphogenetic protein in the assembly of the surface layers of B. cereus ATCC 14579 spores and on the resulting spore properties. The cotE deletion affects the coat and exosporium composition of the spores formed both at the suboptimal temperature of 20°C and at the optimal growth temperature of 37°C. Transmission electron microscopy revealed that ΔcotE spores had a fragmented and detached exosporium when formed at 37°C. However, when produced at 20°C, ΔcotE spores showed defects in both coat and exosporium attachment and were susceptible to lysozyme and mutanolysin. Thus, CotE has a role in the assembly of both the coat and exosporium, which is more important during sporulation at 20°C. CotE was more represented in extracts from spores formed at 20°C than at 37°C, suggesting that increased synthesis of the protein is required to maintain proper assembly of spore surface layers at the former temperature. ΔcotE spores formed at either sporulation temperature were impaired in inosine-triggered germination and resistance to UV-C and H2O2 and were less hydrophobic than wild-type (WT) spores but had a higher resistance to wet heat. While underscoring the role of CotE in the assembly of B. cereus spore surface layers, our study also suggests a contribution of the protein to functional properties of additional spore structures. Moreover, it also suggests a complex relationship between the function of a spore morphogenetic protein and environmental factors such as the temperature during spore formation., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)