Heyndrickxia Coagulans

''Heyndrickxia coagulans'' (formerly ''Bacillus coagulans'') is a lactic acid–forming bacterial species. This species was transferred to '' Weizmannia'' in 2020, then to ''Heyndrickxia'' in 2023.

Description

''H. coagulans'' is a Gram-positive, catalase-positive, spore-forming, motile, facultative anaerobe rod that measures approximately 0.9 μm by 3.0 μm to 5.0 μm. It may appear Gram negative when entering the stationary phase of growth. The optimum temperature for growth is ; the range of temperatures tolerated is . IMViC tests VP and MR (methyl red) are positive.

Taxonomic history

The species was first isolated and described in 1915 by B.W. Hammer at the Iowa Agricultural Experiment Station as a cause of an outbreak of coagulation in evaporated milk packed by an Iowa condensary. Separately isolated in 1935 and described as ''Lactobacillus sporogenes'' in the fifth edition of ''Bergey's Manual of Systematic Bacteriology'', it exhibits characteristics typical of both genera ''Lactobacillus'' and ''Bacillus''; its taxonomic position between the families Lactobacillaceae and Bacillaceae was often debated. However, in the seventh edition of ''Bergey's'', it was finally transferred to the genus ''Bacillus''. DNA-based technology was used in distinguishing between the two genera of bacteria, which are morphologically similar and possess similar physiological and biochemical characteristics.

In 2020, further genetic evidence shows that it is sufficiently different from other members of ''Bacillus'' to be transferred into its own genus. As a result, it became the type species of ''Weizmannia''. In 2023, even further genetic evidence shows that ''Weizmannia'' was not sufficiently distinct from ''Heyndrickxia'' to be an independent genus; as a result, all members of ''Weizmannia'' were moved to ''Heyndrickxia''.

Uses

''H. coagulans'' has been added by the EFSA to their Qualified Presumption of Safety list and has been approved for veterinary purposes as GRAS by the U.S. Food and Drug Administration's Center for Veterinary Medicine, as well as by the European Union, and is listed by AAFCO for use as a direct-fed microbial in livestock production. It is often used in veterinary applications, especially as a probiotic in pigs, cattle, poultry, and shrimp. Many references to use of this bacterium in humans exist, especially in improving the vaginal flora, improving abdominal pain and bloating in irritable bowel syndrome patients, and increasing immune response to viral challenges. There is evidence from animal research that suggests that ''H. coagulans'' is effective in both treating as well as preventing recurrence of ''Clostridioides difficile'' associated diarrhea. Further, one animal research study showed that it can alter inflammatory processes in the context of multiple sclerosis. One strain of this bacterium has also been assessed for safety as a food ingredient. Spores are activated in the acidic environment of the stomach and begin germinating and proliferating in the intestine. Sporeforming ''H. coagulans'' strains are used in some countries as probiotics for patients on antibiotics.

Marketing

''H. coagulans'' is often marketed as ''Lactobacillus sporogenes'' or a 'sporeforming lactic acid bacterium' probiotic, but this is an outdated name due to taxonomic changes in 1939. Although ''H. coagulans'' does produce L+lactic acid, the bacterium used in these products is not a lactic-acid bacterium, as Bacillaceae species do not belong to the lactic acid bacteria (Lactobacillales). By definition, lactic acid bacteria (''Lactobacillus'', ''Bifidobacterium'') do not form spores. Therefore, using the name ''Lactobacillus sporogenes'' is scientifically incorrect.

The 2023 name ''H. coagulans'' is nowhere as common as the former name ''Bacillus coagulans''. The former name remains valid under the Prokaryotic Code.

References

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Notes

External links

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{{Taxonbar, from1=Q2603895

coagulans
Digestive system
Probiotics
Bacteria described in 1915