The Purification and Biochemical Characterization of a Weissella cibaria F1 Derived β-Mannanase for Its Use in the Preparation of Konjac Oligo-Glucomannan with Immunomodulatory Properties

Abstract

Mannanase with a molecular weight of 33.1 kDa was purified from Weissella cibaria F1. The F1 mannanase contained 289 amino acid residues and shared 70.0% similarity with mannanase from Bacillus subtilis (P55278 (MANB_BACIU)). The optimum reaction conditions of F1 mannanase were 50 °C and pH 6.5. After incubation at pH 4.5–8.0 and 30–60 °C for 2 h, the enzyme activity remained above 60%. The effects of metal ions on mannanase enzyme activity were measured, and Mn2+, Mg2+, and Cu2+ increased enzyme activity. The Km (16.96 ± 0.01 μmol·mL−1) and Vmax (1119.05 ± 0.14 μmol·min−1) values showed that the enzyme exhibited high affinity for locust bean gum. Mannanase was used to hydrolyze konjac glucomannan to produce konjac oligo-glucomannan (KOGM). KOGM increased the proliferation and phagocytosis of RAW264.7 macrophages and enhanced nitric oxide, and cytokine production in macrophages, which showed potent immunostimulatory activity. In this study, the advantages of mannanase derived from lactic acid bacteria were utilized to expand the application of KOGM in the medical field, which is helpful to explore the broad prospects of KOGM in functional food or medicine.

High NaCl concentrations induce the resistance to thermal denaturation of an extremely halotolerant (salt-activated) β-mannanase from Bacillus velezensis H1

“…In the present work, the ManH1 from B. velezensis H1 showed activity based on temperature range from 30 to 90 °C and the maximum activity was found at 50 °C. Optimal activity at 50 °C was previously reported for several Bacterial β-mannanases as Mannanase from Weissella cibaria F1 (Wang et al 2022) and Man37 from B. velezensis BS-37 (Lv et al 2021). The ManH1 appeared to be very stable and robust with almost no activity loss after 48 h incubation at 50 °C.…”

Structure and Properties of Exopolysaccharide Produced by Gluconobacter frateurii and Its Potential Applications

“…Metal-resistant bacteria and their EPSs are powerful in removing metals from wastewater and the environment [50]. The HDC-08 EPS had a comparatively high affinity towards Cu 2+ and Zn 2+ , with q values of 728.99 ± 0.75 mg/g and 689.15 ± 0.78 mg/g, respectively (Figure 8A).…”