Optimization of enzymatic ramie degumming using thermoalkaliphilic xylanase from Bacillus halodurans CM1 and a commercial pectinase

Ramie (Boehmeria nivea L. Gaud) is a versatile plant with potential as a cotton alternative in textiles. Its cellulose content, second only to cotton, requires degumming to remove fiber gum before industrial use. This study scaled up enzymatic degumming to 1 kg of ramie fiber, employing a dual enzyme approach: local Bacillus halodurans CM1 xylanase and commercial pectinase. This was optimized under varying conditions, including temperatures (30, 50, and 70 °C), durations (1, 2, and 3 h), and solid-liquid ratios (SLRs; 1:15, 1:22.5, 1:30), utilizing response surface methodology. Optimal outcomes were achieved at 50 °C and a 1:15 ratio, with a 3-h treatment duration, resulting in the highest reducing sugar yield (5.25 mg/mL) and a 102.03% enhancement in ramie fiber brightness compared to the enzyme-free control. This enzymatic process effectively separated gum from fibers while improving the quality, fineness, and tensile strength of cellulose fibers.