Biodegradation of Cholesterol by Cellulosimicrobium cellulans YS01 Isolated from the Gut of Healthy Individuals

Area of Science:

• Microbiology
• Biochemistry
• Genomics

Background:

• Elevated serum cholesterol (CHOL) is a significant risk factor for cardiovascular diseases (CVDs).
• Developing effective CHOL-lowering strategies is crucial for public health.
• Microbial-based therapies offer a promising avenue for managing CHOL levels.

Purpose of the Study:

• To isolate and identify a CHOL-degrading bacterium from human intestinal microbiota.
• To investigate the CHOL biodegradation efficiency of the isolated bacterium and its enzymes.
• To elucidate the key genes and enzymes involved in the CHOL degradation pathway.

Main Methods:

• Isolation and identification of a CHOL-lowering bacterium (YS01) using average nucleotide identity (ANI) analysis.
• Quantification of CHOL degradation by bacterial cells and extracellular crude enzymes.
• Whole genome sequencing and analysis to identify genes encoding potential CHOL-metabolizing enzymes.

Main Results:

• Cellulosimicrobium cellulans YS01 demonstrated significant CHOL degradation, reducing 1.00 g/L to 0.26 g/L in 5 days.
• Extracellular crude enzymes from YS01 achieved a similar reduction (0.50 g/L to 0.13 g/L) within 24 hours.
• Genome analysis identified cholesterol oxidase (choD) and choloylglycine hydrolase (cbh) as key enzymes in CHOL biodegradation.

Conclusions:

• Cellulosimicrobium cellulans YS01 possesses a potent CHOL biodegradation capability.
• The identified genes choD and cbh play critical roles in the conversion of CHOL.
• This study provides a foundation for developing microbial therapies for CHOL management.