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 catalase-positive, spore-forming, motile, facultative anaerobe rod shaped microbe. H. coagulans is usually seen as Gram positive when a Gram stain test is performed. However, if the Gram stain test is performed while H. coagulans is entering the stationary phase of growth the microbe may appear Gram negative. H. coagulans grows best at 50 °C (122 °F), but the microbe can sustain growth on a temperature range of 30–55 °C (86–131 °F).
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.
Microbiology The bacterium H. coagulans has been found in various environments including an array of different fruits and vegetables such as potatoes, pickles, corn, and potatoes. In addition, H. coagulans appears in fermented rice and soil. The environmental persistence of this bacteria suggests a significant influence on its properties. The spores are activated in acidic environments such as the stomach and allow the bacteria to survive in a wide range of ecological niches. This creates the tolerance of H. coagulans to persist in gastric juices, bile salts, and adhere to intestinal mucosa, all essential traits for probiotic efficacy. Genome analysis confirmed antibiotic resistance of H. coagulans meaning it can withstand the presence of antibiotics and continue to live in the gut microbiome. Key genes associated with fermentation, stress response, and adhesion were found from genome mining of B. coagulans VHBAX-04. This strain also lacks pathogenicity-related genes, confirming its safety for human use. In fact, some genes identified are responsible for the production of peptides aiding in the suppression of pathogenic bacteria, and maintaining balance of gut microbiota. In-vitro tests performed on B. coagulans JBI-YZ6.3 demonstrated tolerance to gastrointestinal environments as well as storage stability.
Genome analysis H. coagulans' genome consists of a circular chromosome containing over 3,000,000 base pairs, and over 3,400 genes. Of these genes over 97% accounted for coding sequencing genes while just over 100 code for RNA. The microbe has a genome completeness of over 90%. Genes associated with carbohydrate metabolism including xylA (xylose isomerase) and galT (UDP-glucose--hexose-1-phosphate uridylyl transferase) were identified through genome analysis of B. coagulans AO1167B, which equip this microbe to metabolize a diverse range of sugars allowing it to grow and produce energy in the gut microbiome. Other genes present which provides the bacteria with the ability to ferment lactose and other prebiotic sugars confirm a beneficial relationship with the hosts microbiome. Both ackA (acetate kinase) and pka (phosphotransacetylase) support H. coagulans' ability to produce acetate which support the integrity of the intestinal barrier and metabolic regulation. Other important genes such as bioB (biotin synthase) and thieE (thiamine phosphate synthase) allows the strain to synthesize essential vitamins including biotin, vitamin B12, and thiamine. This evaluation of the microbial genome of B. coagulans provides insightful information on the bacteria's ability to improve stress resistance, enhance immune response, and be used as an effective probiotic.
Motility The bacterium H. coagulans is a motile species. The rod-shaped microbe is equipped with flagella. This is due to the contribution of genes that directly regulate flagellar assembly and function. Additionally, genomic analysis has also led to the discovery of genes present that are responsible for quorum sensing in the bacteria. This allows for communication between microbes by the sending and receiving of chemical signals within the species. These genes have a regulatory relationship with one another in regards to their functions. While the genes encoding for flagellar assembly do not directly cause quorum sensing, and the genes encoding for quorum sensing do not cause motility by flagella, they can enhance and regulate one another. This is because the flagella causes motility which in turn can cause an increase or decrease in quorum sensing. Reciprocally, quorum sensing can regulate the microbes motility from flagella as well. This is notable because these genes' relationship could encourage and enhance microbe colonization capabilities, making it more effective as a probiotic.
… excerpt ends here. Continue reading the full article.
