Tamio Mase

High-yield synthesis of monoglyceride by mono- and diacylglycerol lipase from Penicillium camembertii U-150

Glyceride synthetic action of mono- and diacylglycerol lipase (MDGL) from Penicillium camembertii U-150 was investigated. MDGL could synthesize monoglyceride as a main product and diglyceride, but not triglyceride, from oleic acid and glycerol with no positional specificity. Long-chain (C18) unsaturated and medium-chain (C10 and 12) saturated fatty acids were efficient acyl donors. The conversion (oleic acid consumption) and the composition of the formed glycerides were affected by the molar ratio of glycerol to oleic acid and the initial water content in medium. Under the optimal conditions, more than 90 wt% of monoglyceride in the formed glyceride was obtained with up to 76% of the conversion. The addition of molecular sieves increased the conversion of ca. 90% to 97.3% resulting in 74 wt% of monoglyceride, 23.3 wt% of diglyceride and 2.7 wt% of unesterified fatty acid. The conversion of diglyceride to monoglyceride was also observed by the addition of molecular sieves. Glycerolysis of fatty acid vinyl ester by MDGL yielded monoglyceride with a higher yield (90% of total peak area from TLC/FID analysis).

Purification and characterization of mono-and diacylglycerol lipase isolated from Penicillium camembertii U-150

SummaryA novel enzyme hydrolysing mono- and diacylglycerol was found in the culture filtrate of an isolated fungus, Penicillium camembertii. The enzyme was separated into two forms (A- and B-enzyme) with almost the same molecular weight (37,000–39,000), amino acid composition and identical N-terminal amino acid sequence. B-Enzyme, a major component, was purified approximately 210-fold with an activity yield of 2.6%. The B-enzyme was specific to mono- and diacylglycerols and hydrolysed long-chain monoacylglycerols most efficiently. Triacylglycerols were completely inert as substrates for the enzyme. The B-enzyme preferred to attack α-position to β-position of monoacylglycerol, but showed no stereospecificity on mono- and diacylglycerol. Both Fe3+ and Hg2+ inhibited B-enzyme activity significantly.

Purification and characterization of a novel glucoamylase from Acremonium sp. YT-78

Abstract A novel glucoamylase (EC 3.2.1.3, 1,4-α- d -glucan glucohydrolase) was purified to homogeneity from the culture filtrate of Acremonium sp. YT-78 isolated from soil. The enzyme had a molecular mass of 74 kDa by SDS-PAGE and 148±2 kDa by gel filtration, and its isoelectric point was 5.10. The optimum temperature and pH were around 50°C and 5.0, respectively. The enzyme was stable in a pH range from 5.0 to 9.0 and at below 40°C. The enzyme hydrolyzed α- d -glucans in an exo -manner and the glucose residue released by the action of the enzyme was β-configuration. The enzyme had stronger pullulan-hydrolyzing activity than any glucoamylase so far reported. Panose, a saccharide containing an α-1,6-glucosidic linkage, was hydrolyzed by the enzyme, but it showed no activity towards isomaltose or dextran.