Bioprocess for the Sustainable Production of Prebiotic Mannooligosaccharides Using a Bacterial Mannanase

Mannooligosaccharides (MOS) are non-digestible oligosaccharides that have garnered significant attention due to their functional properties, including prebiotic, antioxidant, immunomodulatory and other bioactive attributes. Despite numerous reports on MOS, limited work has been done to optimize their production in an economical and sustainable manner, which is essential for large-scale applications. The present study aimed to standardize the conditions for the enhanced production of MOS from copra meal using β-mannanase (MAN-7) from Bacillus subtilis MAN7. A 4.6-fold increase in MOS production was achieved, with yield reaching as high as 560 mg per gram of copra meal. β-MOS with a degree of polymerization (DP) between 2-6 were purified using activated carbon and ethanol treatment. Spectroscopic, chromatographic and other characterization techniques confirmed their DP and properties typical of oligosaccharides. MOS demonstrated a prebiotic effect by promoting the growth of health-promoting bacteria (e.g., Lactobacillus spp.) while remaining non-utilizable by enteropathogens. Additionally, MOS were resistant to digestive juices and exhibited no cytotoxic effects. These prebiotic properties suggest that β-MOS are suitable as candidate prebiotic agents or functional food ingredients. The optimized enzymatic conditions established in this study provide a sustainable and cost-efficient bioprocess for the valorization of agro-wastes into functional β-MOS.