Laminarinases reveal potential application in the field of food and biotechnology.In this research,a novel GH16 family laminarinase,designated as Lam16A_Wa,was cloned from the genome of marine bacterium Wenyingzhuangi...Laminarinases reveal potential application in the field of food and biotechnology.In this research,a novel GH16 family laminarinase,designated as Lam16A_Wa,was cloned from the genome of marine bacterium Wenyingzhuangia aestuarii OF219 and expressed in Escherichia coli.Lam16A_Wa demonstrates a relatively low optimal reaction temperature(35℃)and a cold-adapted feature.Its optimal pH value is 6.0 and is stable in a broad pH range from 3.0 to 11.0.A glycomics strategy was employed to investigate the hydrolytic pattern of Lam16A_Wa.The enzyme was confirmed as a random endo-acting glycoside hydrolase.Its minimum substrate was laminarin pentasaccharide,and the major final products are oligosaccharides,including disaccharide to pentasaccharide.The Lam16A_Wa provides a novel and well-defined tool for the molecular tailoring of laminarin.展开更多
We isolated a novel laminarinase ULam111 from Flavobacterium sp. strain UMI-01. Purified ULam111 showed degradation activity against laminarin with the specific activity of 224 ± 18 U/mg at 30°C and pH 6.0. ...We isolated a novel laminarinase ULam111 from Flavobacterium sp. strain UMI-01. Purified ULam111 showed degradation activity against laminarin with the specific activity of 224 ± 18 U/mg at 30°C and pH 6.0. Its optimum temperature was 50°C, and degradation activities against laminarin were observed at 4°C - 80°C. With a laminarin degradation system, we investigated the preparation and properties of immobilized ULam111 with the use of the 11 types of carriers. The high activity recoveries of immobilized ULam111 were as follows: 19.4% for IB-S60P carrier beads (the non-ionic type), 15.6% for IB-S60S carrier beads (the non-ionic type), 11.9% for IB-150P carrier beads (the covalent type), and 7.1% for IB-C435 carrier beads (the cationic type). With the repeated use of immobilized ULam111, the enzyme activities immobilized on IB-S60S and those on IB-S60P remained at 40% and 30% respectively after the sixth trial. We selected IB-S60S as suitable beads for enzyme immobilization, and we attempted to construct a reactor system with ULam111 immobilized on IB-S60S beads. In this system, 1.2 - 1.9 g/L glucose was repeatedly produced from 30 mg/mL laminarin solutions after 20 hr when the reactor operation was repeated 10 times. We examined ethanol fermentation from the saccharified solutions with a marine-derived yeast (Saccharomyces cerevisiae C-19), and 0.51 - 0.58 g/L bioethanol was produced from the saccharified solution that contained 1.71 - 1.86 g/L of glucose.展开更多
基金supported by the National Key R&D Program of China(No.2018YFC0311203)the Fundamental Research Funds for the Central Universities(No.201941005).
文摘Laminarinases reveal potential application in the field of food and biotechnology.In this research,a novel GH16 family laminarinase,designated as Lam16A_Wa,was cloned from the genome of marine bacterium Wenyingzhuangia aestuarii OF219 and expressed in Escherichia coli.Lam16A_Wa demonstrates a relatively low optimal reaction temperature(35℃)and a cold-adapted feature.Its optimal pH value is 6.0 and is stable in a broad pH range from 3.0 to 11.0.A glycomics strategy was employed to investigate the hydrolytic pattern of Lam16A_Wa.The enzyme was confirmed as a random endo-acting glycoside hydrolase.Its minimum substrate was laminarin pentasaccharide,and the major final products are oligosaccharides,including disaccharide to pentasaccharide.The Lam16A_Wa provides a novel and well-defined tool for the molecular tailoring of laminarin.
文摘We isolated a novel laminarinase ULam111 from Flavobacterium sp. strain UMI-01. Purified ULam111 showed degradation activity against laminarin with the specific activity of 224 ± 18 U/mg at 30°C and pH 6.0. Its optimum temperature was 50°C, and degradation activities against laminarin were observed at 4°C - 80°C. With a laminarin degradation system, we investigated the preparation and properties of immobilized ULam111 with the use of the 11 types of carriers. The high activity recoveries of immobilized ULam111 were as follows: 19.4% for IB-S60P carrier beads (the non-ionic type), 15.6% for IB-S60S carrier beads (the non-ionic type), 11.9% for IB-150P carrier beads (the covalent type), and 7.1% for IB-C435 carrier beads (the cationic type). With the repeated use of immobilized ULam111, the enzyme activities immobilized on IB-S60S and those on IB-S60P remained at 40% and 30% respectively after the sixth trial. We selected IB-S60S as suitable beads for enzyme immobilization, and we attempted to construct a reactor system with ULam111 immobilized on IB-S60S beads. In this system, 1.2 - 1.9 g/L glucose was repeatedly produced from 30 mg/mL laminarin solutions after 20 hr when the reactor operation was repeated 10 times. We examined ethanol fermentation from the saccharified solutions with a marine-derived yeast (Saccharomyces cerevisiae C-19), and 0.51 - 0.58 g/L bioethanol was produced from the saccharified solution that contained 1.71 - 1.86 g/L of glucose.
