Dairy Fermentation: Lactic Acid Bacteria (LAB). This sector utilizes specific bacterial consortia to transform milk. 4.1. Biochemical Principle: Lactic Acid Fermentation is the conversion of lactose (milk sugar) into lactic acid. Result: The accumulation of lactic acid induces a pH drop from 6.7 to 4.6 (isoelectric point of casein). Physicochemical Consequence: This causes the destabilization of casein micelles, leading to their aggregation and the formation of a semi-solid coagulum (gel/curd). Lesson duration: 50 minutes. Theme: classicChalk. Subject: Biology. Grade: university-en