The Four Main Types of Fermentation and Their Relevance to Organic Fertilizer Production

Fermentation, a vital biochemical process driven by microorganisms, is widely applied in food production, energy generation, and agriculture. In 2026, fermentation is typically classified by its primary end products or industrial technical methods. Based on biochemical pathways, there are four main types of fermentation: lactic acid fermentation, alcoholic (ethanol) fermentation, acetic acid fermentation, and butyric acid/alkali fermentation. Beyond these well-known categories, fermentation also plays a foundational role in organic fertilizer production, converting organic wastes into nutrient-rich, plant-friendly fertilizers through microbial decomposition. Understanding these fermentation types and their agricultural applications is key to leveraging microbial activity for sustainable production.

Lactic acid fermentation is dominated by lactic acid bacteria, such as Lactobacillus, which convert sugars like glucose or lactose into lactic acid. This process is anaerobic, meaning it occurs without oxygen, and the resulting lactic acid lowers the environment’s pH, inhibiting harmful microbes—making it ideal for food preservation. Its most common applications include the production of dairy products like yogurt and cheese, as well as fermented vegetables such as sauerkraut, kimchi, and pickles. In the human body, lactic acid fermentation also takes place in muscle cells during intense exercise when oxygen supply is insufficient, producing lactate that causes muscle fatigue. While less directly used in organic fertilizer production, lactic acid bacteria are occasionally added as probiotics to improve soil microbial balance, indirectly enhancing fertilizer efficiency.