Maximizing production of Penicillium cyclopium partial acylglycerol lipase.

Penicillium cyclopium partial acylglycerol lipase production was maximized in shaken batch culture. The effect of inoculum size and substrate concentration on the lipase activity released in the culture medium was visualized using a surface response methodology based on a Doehlert experimental design. The main advantage of this approach is the low number of experiments required to construct a predictive model of the experimental domain.

Distinction between esterases and lipases: a kinetic study with vinyl esters and TAG.

The better to characterize enzymes hydrolyzing carboxyl ester bonds (carboxyl ester hydrolases), we have compared the kinetic behavior of various lipases and esterases against solutions and emulsions of vinyl esters and TAG. Short-chain vinyl esters are hydrolyzed at comparable rates by esterases and lipases and have higher limits of solubility in water than corresponding TAG. Therefore, they are suited to study the influence of the physical state of the substrate on carboxyl ester hydrolase activity within a large concentration range.

Optimal design for the maximization of Penicillium cyclopium lipase production.

Penicillium cyclopium triacylglycerol lipase production was maximized in stationary batch culture. We used a surface response methodology based on a Doehlert experimental design to study the effect on the lipase activity released in the culture medium of the three most important factors: substrate concentration, pH and inoculum. Besides reducing the number of experiments required for optimization, this technique allowed us to quantify the lipase activity in any part of the experimental domain.

Lipase-catalysed hydrolysis of short-chain substrates in solution and in emulsion: a kinetic study.

We have studied the enzymatic hydrolysis of solutions and emulsions of vinyl propionate, vinyl butyrate and tripropionin by lipases of various origin and specificity. Kinetic studies of the hydrolysis of short-chain substrates by microbial triacylglycerol lipases from Rhizopus oryzae, Mucor miehei, Candida rugosa, Candida antarctica A and by (phospho)lipase from guinea-pig pancreas show that these lipolytic enzymes follow the Michaelis-Menten model. Surprisingly, the activity against solutions of tripropionin and vinyl esters ranges from 70% to 90% of that determined against emulsions.

Kinetic properties of Penicillium cyclopium lipases studied with vinyl esters.

Penicillium cyclopium produces two lipases with different substrate specificities. Lipase I is predominantly active on triacylglycerols whereas lipase II hydrolyzes mono- and diacylglycerols but not triacylglycerols. In this study, we compared the kinetic properties of P.

Production of extracellular lipases by Penicillium cyclopium purification and characterization of a partial acylglycerol lipase.

Penicillium cyclopium, grown in stationary culture, produces a type I lipase specific for triacylglycerols while, in shaken culture, it produces a type II lipase only active on partial acylglycerols. Lipase II has been purified by ammonium sulfate precipitation and chromatographies on Sephadex G-75 and DEAE-Sephadex. The enzyme exists in several glycosylated forms of 40-43 kDa, which can be converted to a single protein of 37 kDa by enzymatic deglycosylation.

Biochemical and structural characterization of triacylglycerol lipase from Penicillium cyclopium.

An extracellular lipase, active on water-insoluble triacylglycerols, has been isolated from Penicillium cyclopium. The purified enzyme has a molecular mass of 29 kDa by gel filtration and SDS-polyacrylamide gel electrophoresis. It hydrolyzes emulsions of tributyrin, trioctanoin, and olive oil at the same rate as pancreatic lipase and shows very low activity against partial acylglycerols (monooctanoin and dioctanoin) and methyl esters.