Purification and characterization of a novel alkaline β-1,3-1,4-glucanase (lichenase) from thermophilic fungus Malbranchea cinnamomea

Abstract

A novel alkaline β-1,3-1,4-glucanase (McLic1) from a thermophilic fungus, Malbranchea cinnamomea, was purified and biochemically characterized. McLic1 was purified to homogeneity with a purification fold of 3.1 and a recovery yield of 3.7 %. The purified enzyme was most active at pH 10.0 and 55 °C, and exhibited a wide range of pH stability (pH 4.0-10.0). McLic1 displayed strict substrate specificity for barley β-glucan, oat β-glucan and lichenan, but did not show activity towards other tested polysaccharides and synthetic p-nitrophenyl derivates, suggesting that it is a specific β-1,3-1,4-glucanase. The K m values for barley β-glucan, oat β-glucan and lichenan were determined to be 0.69, 1.11 and 0.63 mg mL(-1), respectively. Moreover, the enzyme was stable in various non ionic surfactants, oxidizing agents and several commercial detergents. Thus, the alkaline β-1,3-1,4-glucanase may have potential in industrial applications, such as detergent, paper and pulp industries.

Loop 3 of Fungal Endoglucanases of Glycoside Hydrolase Family 12 Modulates Catalytic Efficiency

“…Besides, NfEG12A showed higher activity toward ␤-1,3-1,4-glucans than CMC-Na, which makes it different from GH16 and GH17 glucanases. For example, McLic1 from Malbranchea cinnamomea (20), RmLic16A from Rhizomucor miehei (21), and ␤-glucanase from A. niger US368 (22), belonging to GH16, exhibited strict substrate specificity for mixed ␤-1,3-1,4-glucans (barley ␤-glucan and lichenin), whereas they displayed no activity on CMC. In contrast, GH17 glucanases hydrolyze internal ␤-1,3 glycosidic linkages in ␤-glucan oligo-and polysaccharides (23).…”

Fungal β‐1,3‐1,4‐glucanases: production, proprieties and biotechnological applications

“…Furthermore, β ‐1,3‐1,4‐glucanase from M. cinnamomea exhibited an excellent stability in the presence of all of the ingredients widely used in detergents, including Triton X100, Tween 80, sodium dodecyl sulfate, sodium hypochlorite and H 2 O 2 , retaining more than 90% of its original activity. Moreover, the enzyme also showed remarkable stability in the presence of some commercial liquid and solid detergents such as Fresh'n Hygiene, OMO and Blue moon as washing liquids; OMO, Diao and Tide as washing powders; and Super as natural soap powder, with 101%, 97%, 103%, 106%, 100%, 90% and 93% of enzyme activities being retained, respectively …”

“…microspores, R. miehei CAU432 . Only β ‐1,3‐1,4‐glucanases from fungal M. cinnomomea , which was isolated from compost at a waste treatment plant in Vietnam, had a pH optimum at 10 . Moreover, β ‐1,3‐1,4‐glucanase from the mutant Pol6 of P. occitanis was active at pH 3.0 and kept more than 50% of its activity in the range pH 1.0–5.0 …”

“…The values of the K m constant on barley β‐glucan for P. thermophila and L. sulphureus var. miniatus, A. niger US368 and M. cinnamomea are 2.4, 0.67, 0.62 and 0.69 mg mL −1 , respectively . However, these were lower than the K m constants obtained for P. occitanis , T. emersonii and R. microsporus var.…”

“…Likewise, the enzyme from M. cinnamomea exhibited the highest specific activity toward barley β ‐glucan (52.7 U mg −1 ) followed by oat β ‐glucan (43.2 U mg −1 ) and lichenan (23.0 U mg −1 ). The purified enzyme EGL from P. occitanis Pol6 was also active on barley β ‐glucan (100%) and lichenan (93.51%) . Meanwhile, the β ‐1,3‐1,4‐glucanase from L. sulphureus var.…”