Hebbale Deepthi, Bhargavi R, Ramachandra T V
Energy & Wetlands Research Group, Centre for Ecological Sciences, Indian Institute of Science, Bangalore, 560012, India.
Centre for Sustainable Technologies, Indian Institute of Science, Bangalore, 560012, India.
Heliyon. 2019 Mar 20;5(3):e01372. doi: 10.1016/j.heliyon.2019.e01372. eCollection 2019 Mar.
Marine macroalgal cell wall is predominantly comprised of cellulose (polysaccharide) with the complex chain of glycosidic linkages. Bioethanol production from macroalgae entails breaking this complex chain into simple glucose molecule, which has been the major challenge faced by the industries. Cellulases have been preferred for hydrolysis of cellulose due to the absence of inhibitors affecting the subsequent fermentation process. Cellulose degrading bacteria were isolated from wide-ranging sources from marine habitats to herbivore residues and gastrointestinal region. The investigation reveals that bacteria has higher hydrolytic capacity with salt tolerance up to 14% and 3.5% salinity is optimum for growth. Higher hydrolytic activity of 2.45 was recorded on carboxymethyl cellulose medium at 48 h and hydrolytic activity of 2.46 on hydrolysate, 3.06 on hydrolysate at 72 h of incubation. Total activity of enzyme of 2.11 U/ml and specific activity of 6.05 U/mg were recorded at 24 h. Enzyme hydrolysis of macroalgal biomass; and produced 135.9 mg/g and 107.6 mg/g of reducing sugar respectively. The study reveals that the enzyme extracted from salt tolerant bacteria is suitable for optimal saccharification of seaweed polysaccharides towards biofuel production.
海洋大型藻类的细胞壁主要由具有复杂糖苷键链的纤维素(多糖)组成。从大型藻类生产生物乙醇需要将这种复杂的链分解成简单的葡萄糖分子,这一直是该行业面临的主要挑战。由于不存在影响后续发酵过程的抑制剂,纤维素酶已成为纤维素水解的首选。从海洋栖息地到食草动物残留物和胃肠道区域等广泛来源中分离出纤维素降解细菌。调查显示,该细菌具有较高的水解能力,耐盐性高达14%,3.5%的盐度最适合其生长。在羧甲基纤维素培养基上,48小时时记录到较高的水解活性为2.45,水解产物在72小时培养时的水解活性为2.46,水解产物在72小时培养时的水解活性为3.06。在24小时时记录到酶的总活性为2.11 U/ml,比活性为6.05 U/mg。大型藻类生物质的酶水解; 和 分别产生了135.9 mg/g和107.6 mg/g的还原糖。该研究表明,从耐盐 细菌中提取的酶适用于海藻多糖的最佳糖化以用于生物燃料生产。