Biodegradation of Cholesterol by Enterococcus faecium YY01

Area of Science:

• Microbiology
• Biochemistry
• Genomics

Background:

• Cholesterol (CHOL) is a significant risk factor for atherosclerosis and cardiovascular diseases.
• Biodegradation of cholesterol by microorganisms presents a potential therapeutic avenue.

Purpose of the Study:

• To isolate and identify a bacterial strain capable of degrading cholesterol.
• To elucidate the metabolic pathways involved in cholesterol biodegradation by the identified strain.

Main Methods:

• Isolation and identification of a bacterial strain from the gut microbiota using 16S rDNA sequencing.
• Optimization of growth conditions (carbon and nitrogen sources) for bacterial strain YY01.
• Whole-genome sequencing of strain YY01 using Illumina HiSeq.
• Bioinformatic analysis to identify genes involved in cholesterol metabolism.

Main Results:

• Enterococcus faecium YY01 was isolated and demonstrated significant cholesterol biodegradation, reducing 1.0 g/L to 0.5 g/L in 5 days.
• Optimal growth conditions for YY01 were determined using glucose and beef extract as carbon and nitrogen sources, respectively.
• Genome sequencing identified key genes (gene0586, gene1890, gene2442) encoding enzymes like choloylglycine hydrolase, crucial for converting cholesterol metabolites into bile acids.
• Choloylglycine hydrolase was found to be closely linked to primary and secondary bile acid biosynthesis.

Conclusions:

• Enterococcus faecium YY01 possesses a robust cholesterol biodegradation capability.
• The identified metabolic pathway provides insights into microbial cholesterol metabolism.
• This study highlights the potential of YY01 for developing novel bacterioactive drugs to combat hypercholesterolemia.