Potential probiotic thermophiles isolated from mice after compost ingestion

Abstract

Aims: The oral administration of a compost produced by the fermentation of marine animals with thermophiles confers health benefits for fish and pigs. This study aimed to isolate the beneficial bacteria from this compost that would modulate the physiological conditions of host animals. Methods and Results: The compost extract was orally administrated to germfree mice for 21 days, and thereafter, the culturable bacterial population within the caeca was surveyed. Sequence analyses of the 16S rRNA gene from the two predominant thermophilic isolates revealed organisms that were closely related to Bacillus thermoamylovorans and Bacillus coagulans. These bacteria could grow at 37°C, but more abundantly at 50-55°C, and they were minor components of the original compost extract. When an individual bacterial strain or a mixture of strains was administered to the conventionally maintained mice, their levels of faecal immunoglobulin A, an indicator of the gut immune response, were markedly raised. In addition, their feeding efficiency also changed among the tested mouse groups. Conclusions: These two kinds of thermophilic bacterial species, isolated from the caeca after compost ingestion to the germ-free mice, are candidate probiotics that could function in the mammalian gut. Significance and Impact of the Study: This study revealed that the compost used in agriculture can contain potential probiotic thermophiles.

Meta‐fermentation system with a mixed culture for the production of optically pure l‐lactic acid can be reconstructed using the minimum isolates with a simplified pH control strategy

“…In particular, C. hisashii exhibits probiotic properties in domestic animals. [ 28 ] However, C. hisashii and C. thermoamylovorans cannot be distinguished using general 16S amplicon analysis. The studies on developing a strategy to distinguish C. hisashii from C. thermoamylovorans are ongoing, which can aid further studies on the functions of each strain.…”

Bacillus hisashii sp. nov., isolated from the caeca of gnotobiotic mice fed with thermophile-fermented compost

“…To delineate the probiotic function of thermophile-fermented compost, potentially probiotic thermophilic bacteria were isolated from the caeca of gnotobiotic mice that had ingested this compost. The predominant isolates were closely related to Bacillus thermoamylovorans (Miyamoto et al , 2013). B .…”

“…The suspension containing this compost at a final concentration of 1 % (v/v) was incubated under aerobic conditions at 60 °C for at least 10 h. The compost extract was prepared by filtering this suspension through a nylon mesh (100 μm pore size). BALB/c germ-free male mice were fed with water containing 0.5 % (v/v) compost extract for 21 days (Miyamoto et al , 2013). The predominant isolates from the caeca of these mice were closely related to B. thermoamylovorans (Miyamoto et al , 2013).…”

“…BALB/c germ-free male mice were fed with water containing 0.5 % (v/v) compost extract for 21 days (Miyamoto et al , 2013). The predominant isolates from the caeca of these mice were closely related to B. thermoamylovorans (Miyamoto et al , 2013). After subculture on heart infusion agar (Nissui Pharmaceutical) at 37 °C, 15 well-grown isolates were further characterized.…”

“…Generally, these endospores can tolerate low pH gastric conditions, and the endospores of several species of the genus Bacillus have been used as probiotics (Colenutt & Cutting, 2014; Jeong & Kim, 2014). When endospores of strain N-11 T were orally administered to conventionally maintained mice, a slight increase in body weight, an increased tendency towards feeding efficiency and faecal IgA production were observed (Miyamoto et al , 2013). These results suggested that the administration of strain N-11 T improved the health of its host animals.…”