Bacillus coagulans
[CAS# 68038-65-3]

Identification

• Classification: Biochemical >> Inhibitor >> Microbiology
• Name: Bacillus coagulans
• CAS Registry Number: 68038-65-3
• EC Number: 924-436-4

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H303-H316-H320
• Precautionary Statements: P264+P265-P301+P317-P305+P351+P338-P332+P317-P337+P317

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2B	H320
Acute toxicity	Acute Tox.	5	H303
Skin mild irritation	Skin Mild Irrit. 99	3	H316

Discovory and Applicatios

Bacillus coagulans (recently reclassified as *Heyndrickxia coagulans*) is a spore-forming, Gram‑positive, facultatively anaerobic bacterium first isolated in 1915 by B. W. Hammer at the Iowa Agricultural Experiment Station following outbreaks of coagulation in evaporated milk. It was initially described as *Lactobacillus sporogenes* due to its combination of lactic acid production and spore formation but was later placed within *Bacillus*, with a taxonomic revision in 2023 to *Heyndrickxia*. The species naturally thrives at elevated temperatures (optimal around 50–55 °C), forming spores that enable survival in adverse environments such as canned foods.

Despite early identification in food spoilage, B. coagulans gained attention in the mid‑20th century for its high thermotolerance and lactic acid production. These features made it especially useful in industrial fermentation processes, including production of optically pure L‑lactic acid from biomass at temperatures above 50 °C, enabling non‑sterile fermentation. Genome sequencing of several strains (e.g., 2‑6, DSM114, XZL9) highlighted high carbon‑efficiency metabolic pathways, a unique xylose isomerase, and phage resistance systems. Such characteristics support its role in sustainable biotechnology and bio‑chemical synthesis.

Because it stabilizes gut flora and lacks toxin production or notable antibiotic resistance, B. coagulans has been recognized as generally regarded as safe (GRAS) and is widely used as a probiotic. Clinical trials with strains such as MTCC 5856, Unique IS2, and BC99 have demonstrated therapeutic benefits in conditions including irritable bowel syndrome (IBS), constipation, antibiotic-associated diarrhea, and functional gas symptoms. Randomized controlled studies showed that ingestion of B. coagulans at doses ranging from 1 to 2 billion CFU per day significantly improved stool consistency, reduced abdominal pain frequencies, and alleviated IBS severity compared to placebo groups.

One multicenter clinical trial involving strain IS2 (ATCC PTA‑11748) in adult IBS patients found nearly 85% of treated participants achieved ≥50% reduction in abdominal pain and increased complete spontaneous bowel movements (CSBMs) after eight weeks, versus only \~13% in the placebo arm. Adverse events were minimal and not significantly different between groups. Additionally, the strain BC99 demonstrated significant weight reduction in overweight adults during an eight‑week intervention, without adverse lipid profile changes, and stimulated beneficial shifts in gut microbial β‑diversity.

B. coagulans also shows promise in veterinary and animal‑feed applications. Certain strains have been used to promote growth, improve feed conversion, and reduce gastrointestinal disturbances in livestock, due to enzyme production, acid tolerance, and pathogen inhibition. Its spore‑forming property allows incorporation into heat‑treated feed formulations.

At the molecular and cellular levels, B. coagulans produces various functional substances such as bacteriocin‑like peptides (e.g., coagulin) with antimicrobial activity and thermostable enzymes including lipases and β‑glucosidases. These contribute to food safety, shelf‑stable product development, and novel biocatalytic applications.

B. coagulans is of growing interest in emerging probiotic and industrial biotech domains, owing to its resilience, metabolic versatility, and safety profile. Its stability at high temperatures enables open fermentation for lactic acid production, while its probiotic capabilities offer therapeutic options for gastrointestinal disorders. Genomic insights continue to support strain‑specific trait optimization and engineering for improved performance.

In summary, Bacillus coagulans is a historically significant, thermophilic lactic acid-producing spore bacterium first identified as a food spoilage agent. It evolved into an industrial workhorse for lactic acid fermentation and now is widely applied as a probiotic in human and animal health. Evidence from clinical trials confirms its safety and efficacy in relieving IBS symptoms and improving gut function. Its spore-forming resilience, lack of toxin production, and beneficial enzymatic capabilities make it a valuable organism in both industrial biotechnology and probiotic applications.

References

Su F et al. (2014) Genomic analysis of thermophilic Bacillus coagulans strains reveals mechanisms for high‑efficient lactic acid production and thermal tolerance. *Scientific Reports* 4:3926 DOI: 10.1038/srep03926