The Application Cases of Enterococcus faecalis (continued)
Introduction
Enterococcus faecalis is the type species of the genus Enterococcus, a Gram-positive facultative anaerobic bacterium that appears as spherical or ovoid cocci arranged in pairs or short chains. Its optimal growth temperature is 37°C, with a wide pH adaptation range (4.5-9.6), and it can still grow at 10°C or 45°C. This bacterium ferments various carbohydrates to produce acid, is catalase-negative, and shows a positive bile esculin test, which helps differentiate it from similar species such as Streptococcus agalactiae. Enterococcus faecalis is widely distributed in natural environments and colonizes the digestive tract of humans and other mammals as an intestinal commensal, being the most abundant enterococcus in feces (approximately 90%). This article explores the various applications of this probiotic.
Agriculture
1. Organic waste composting
Enterococcus faecalis is utilized in agricultural waste composting to expedite the decomposition of organic matter. This bacterium produces short-chain fatty acids via glycolysis, thereby promoting compost maturity. Additionally, its antimicrobial peptides inhibit pathogenic bacteria, reducing odor production. In vegetable cultivation, compost products are employed as organic fertilizers, enhancing soil fertility, decreasing reliance on chemical fertilizers, and fostering sustainable agricultural practices.
2. Plant growth promotion
Indole-3-acetic acid (IAA) secreted by Enterococcus faecalis has the effect of promoting plant growth. In greenhouse vegetable cultivation, this bacterium enhances plant absorption of nutrients and increases crop yields through root colonization. Its metabolites can also improve soil microbial community structure, enhance plant stress resistance, and reduce disease occurrence.
Industrial Sector
1. Biofuel production
Enterococcus faecalis is utilized in biofuel production, converting organic waste into energy substances such as ethanol through metabolic pathways. This bacterium efficiently decomposes cellulose and starch under anaerobic conditions, enhancing the utilization rate of raw materials. Its environmental adaptability enables it to play a role in the treatment of various industrial wastes, reducing production costs and promoting the development of green energy.
2. Food fermentation assistance
In the food industry, Enterococcus faecalis serves as a fermentation auxiliary strain for the production of organic acids such as lactic acid and acetic acid. This bacterium enhances food quality and safety by regulating the pH value during the fermentation process and suppressing harmful microorganisms. For instance, in kimchi fermentation, the application of this bacterium shortens the fermentation period while enhancing product flavor and shelf life.
