APPLICATION OF LACTIC BACTERIA IN EXPERIMENTAL PRODUCTION OF BIO-DETERGENT FROM TOFU SOUR LIQUID
Abstract
This study attempted to produce a bio-detergent from lactic acid fermentation using tofu sour liquid. Ten strains of lactic acid bacteria were tested for lactic acid fermentation at 37°C and were analyzed for antibacterial activity against Bacillus subtilis as the indicator strain. The optimal conditions for the fermentation were investigated and the fermentation products were tested for the ability to clean carbohydrate, protein and lipid. As a result, 6 strains (L. casei L9, L. acidophilus L11, and L. plantarum (L26, L30, L37 and L52)) were selected due to their highest fermentation ability with the highest lactic acid content at 2.78-3.08 g/L. These 6 strains all had antibacterial properties with indicating B. subtilis and created an antibacterial range of 16.33 mm with L. plantarum L30. The suitable conditions for lactic acid production from tofu sour liquid of L. plantarum L30 are determined at a sugar content of 7.73% (w/v), pH 5.54 and lactic bacteria inoculum 107 cells/mL with a content of lactic acid reached 10.03 g/L and 10.39 g/L at 100 mL and 1 L scales, respectively. Fermented liquid at 1.0% (w/v) lactic acid has the ability to clean carbohydrates, proteins and lipids with the efficiency of 96.49%, 93.31% and 90.91%, respectively. The suitable surfactant content was determined at 10% CAPB, with the carbohydrate, protein and lipid cleaning efficiency at 97.91%, 98.08% and 93.00%.
