Optimization of an effective growth medium for biomass production of Bacillus cereus

Abstract

Protein is the main source of nutrition in fish feed. It is necessary to use bacterial single-cell protein (SCPs) as a substitute for conventional protein. This study aims to determine the effectiveness of tofu liquid waste as a growth medium for biomass production of Bacillus cereus as an SCPs. The isolates used were B. cereus SN7 and B. cereus consortium (combination of 5 isolates of B. cereus with different strains). The method used was experimental where isolates were cultured in a medium containing tofu liquid waste with different concentrations (8%, 10%, and 12%) enriched with 10% skim milk. Furthermore, the analysis of an effective growth medium was carried out by three methods, namely total plate count, optical density, and cell-dry weight. Cell biomass measurements were carried out for 24 hours with an observation time of every 6 hours. The results showed the best growth medium used in the culture of B. cereus SN7 and B. cereus consortium was tofu liquid waste at a concentration of 12% enriched with 10% skim milk. In conclusion, the cell mass of B. cereus SN7 and B. cereus consortium significantly increased at 6 to 12 hours.

Utilization of molasses wastewater for medium production of Bacillus cereus

“…The technique used in the TPC is the spread plate method using plate count Agar (PCA) medium. Bacterial growth measurements were carried out for 24 hours with different observations sequentially 0, 6, 12, 18, and 24-hour incubation [1]. Bacterial growth was measured by taking 0.1 ml of bacterial suspension which was spread on the surface of PCA medium with three repeats test.…”

“…Medium is a compound nutrient used by microorganisms to grow, replicate, and produce metabolites. The complexity of the nutrients contained in the bacterial growth medium is a significant factor when cultivating and producing bacterial biomass [1]. However, the relatively affluent price of medium is often a problem in the laboratory, specifically when produced of bacterial biomass.…”