Lactid Acid Bacteria (LAB) Selection for Vitamin B12 (Cobalamin) Synthesizer

Abstract

Vitamin B12 is an essential nutrient for humans and animals. The vitamin B12 content is high in animal meat, so vegetarians and vegans need to look for suitable sources of vitamin B12. Tempeh is one of the most common vitamin B12 sources in Indonesia. Tempeh is made from soybeans with Rhizopus oligosporus, but in the process, it was contaminated with a lot of bacteria (Radita et al. 2021). Bacteria such as lactic acid bacteria, Klebsiella pneumoniae and Citrobacter freundii, are organisms that can synthesize vitamin B12 (Keuth dan Bisping, 1994). In this study, we isolated bacteria from tempeh and tested their ability to synthesize vitamin B12 with several existing bacterial collections. The research aim to obtain bacteria capable of synthesizing vitamin B12. This research includes isolation and characterization of LAB, screening of vitamin B12-synthesizing LAB, molecular analysis using 16S rRNA gene, and production of vitamin B12 using HPLC analysis. Ten isolates were analyzed for the ability to synthesize vitamin B12. Through its ability to grow on vitamin B12 assay media, eight isolates were obtained. Analysis of the 16S rRNA gene showed that the isolate from tempeh was closely related to Lactiplantibacillus fermentum. The results of HPLC analysis that five isolates can produce vit B12 but with a low concentration.