Abstract
This data evaluated the capacity of Bacillus spp. isolated from Thai milk kefir to produce exopolysaccharide (EPS) on cassava pulp and tested its antioxidant and antibacterial properties. Thailand's starch industry generates million tons of cassava pulp, which is underutilized or bio-transformed into higher-value bioproducts. Antioxidant and antibacterial bacterial exopolysaccharides are beneficial in the food, feed, pharmaceutical, and cosmetic industries. Moisture, ash, fat, protein, fiber, starch, sugar, neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) were analyzed from cassava pulp as an EPS substrate. After 3 days of bacterial fermentation, EPS generation, culture pH, reducing sugar amount, and bacterial count were recorded. Antioxidant activities and bioactive content including hydroxyl radical scavenging activity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP), total phenolic and flavonoid content (TPC and TFC), and antimicrobial activity against two Nile tilapia pathogens (Streptococcus agalactiae and Staphylococcus aureus) from different Bacillus species were evaluated. Proximate analysis, dinitrosalicylic acid assay, pH value record, bacterial count using spread plate method, antioxidant activity and bioactive content assays via spectrophotometry, and agar disk diffusion were the main approaches. This study used microbial cell factories to convert agro-biowaste, such as cassava pulp, into EPS bioproducts which accords with a bio-circular green economy model.