Formulation and optimization of alternative culture media for probiotic bacteria growth using tofu liquid waste

Abstract

Probiotics from lactic acid bacteria (LAB) are widely used in the livestock industry to replace the use of Antibiotics Growth Promoters (AGPs). LAB is a culture starter that is widely used in fermented foods. LAB has the ability to adapt to different substrates, resulting in its wide use in the fermentation of various food products. MRS (De Man Rogosa Sharpe) medium is a growth medium for LAB, but for the industrial-scale requires a high cost, therefore innovation is needed to find alternative culture media using local raw material. Tofu Liquid Waste (TLW) can be used as a growth medium for probiotic bacteria because it still contains enough nutrients source for growth. This study aims to determine the formulation and optimization of culture media for LAB isolates using tofu liquid waste. Six Lab isolates from chickens gastrointestinal tract were used in experiments to determine the ability to grow on TLW culture media. The growth assays are conducted by inoculating LAB isolates in the culture media formulation that divided into 4 groups, consisting of medium A (TLW+molasses 1,5%+skim milk 5%), B (TLW+molasses 1,5%+skim milk 2,5%), C (TLW+molasses 3%+skim milk 5%), and D (TLW+molasses 3%+skim milk 2,5%). The best LAB isolate to grow on TLW medium was Lactobacillus paracasei. The best TLW modification medium for Lactobacillus paracasei growth is D media. Modified media consisting of TLW, molasses and skim milk can be used as an alternative medium for LAB growth.