Production Of Extracellular Hydrolytic Enzymes Research Articles

Orange and potato peel extracts: Analysis and use as Bacillus substrates for the production of extracellular enzymes in continuous culture

Orange and potato peels were studied in terms of their chemical compositions and their ability to support the growth and extracellular hydrolytic enzyme production of Bacillus subtilis strain 11089. The orange and potato peel substrates were prepared by blending and removal of large particles by filtration. The chemical composition of the filtrates were similar to the crude peel ‘starting’ material and were shown to contain predominantly alcohol-insoluble solids (pectin, cellulose, starch), soluble sugars and minerals (mainly Ca, K, P, and Si). The composition of the orange peel (substrate) was different to that of the potato peel (substrate) mainly in terms of low levels of starch and protein, and higher levels of sugars, pectin, and cellulose. Bacillus species 11089 was capable of growth in continuous culture on both orange and potato substrates when these were used as the carbon-energy source in a mineral salts basal medium. Potato filtrate supported the highest growth ( μ max and biomass yield) but lowest specific activities of α-amylase, neutral and alkaline proteases, and polygalacturonate-lyase compared to orange filtrate as substrate; however, when enzyme activity was expressed as units per volume of culture, potato filtrate supported the highest levels. In all cases, enzyme production using the various filtrates alone or mixed (1:1) was similar to or better than that produced by glucose used at the equivalent weight-volume concentrations.

Productivity of hydrolytic enzymes by mycorrhizal mushrooms

To survey the potential for production of extracellular hydrolytic enzymes by mycorrhizal mushrooms, productivities of these exo-enzymes from mycelia on potato-dextrose liquid medium were determined.Tricholoma matsutake produced relatively high levels of CM-cellulase and avicelase activities in all test strains. It also produced higher activity of acid proteinase than neutral proteinase. Its xylanase activities seemed to be higher than those of the other carbohydrases. The productivities ofLyophyllum shimeji strains were at similar levels to those ofT. matsutake strains. CM-cellulase and avicelase activities ofL. shimeji were higher than those ofT. matsutake. Neutral proteinase inL. shimeji strains showed higher activity levels than acid proteinase. The relative productivities of hydrolytic enzymes between the groups of mycorrhizal mushrooms and wood-rotting mushrooms were also examined.T. matsutake andL. shimeji both produce many kinds of hydrolytic enzymes in their culture broth, and the potential for production of hydrolytic enzymes by mycorrhizal mushrooms was judged to be relatively high.

Biomass and extracellular hydrolytic enzyme production by six mushroom species grown on soybean waste

Soybean waste is a good substrate for biomass production, and the expression of amylolytic, xylanolytic and proteolytic enzymes, by selected mushroom fungi. Considerable potential exists for converting soybean wastes into added-value products using systems based on these fungi.

Extracellular hydrolytic enzyme production by pathogenic strains of Fusarium oxysporum f.sp. elaeidis

Extracellular pectin esterase, polygalacturonase, C x cellulase and C 1 cellulase enzyme activities were detected in culture filtrates of F. oxysporum f.sp. elaeidis strains pathogenic to oil palm. The ten strains examined secreted varying amounts of these enzymes. Generally, enzyme production and pH of the culture medium increased with incubation period and attained maximum values between the 5th and 7th day. Optimum production of pectin methylesterase and polygalacturonase occurred under alkaline conditions (pH 7·1–8·4), whereas a slightly acidic condition (pH 5·7–6·0) favoured C x cellulase and C 1 cellulase production. Polygalacturonase and C x cellulase were constitutively secreted although there was increased synthesis in presence of their specific substrates.

Characterization of proteinases excreted by Bacillus subtilis Marburg strain during sporulation.

Summary. This study has characterized 3 proteolytic enzymes during sporulation by Bacillus subtilis Marburg strain when grown in nutrient broth. A method of purification is described which permits the separation of 2 different proteinases: one belonging to the metal enzyme group and the other to the serine enzyme group. The third enzyme, probably an esterase, showed a high esterolytic activity, but only low proteolytic activity. Determination of the 3 enzymes in a mixture was accomplished by using specific substrates and inhibitors. They were excreted simultaneously between the end of the growth phase until the appearance of the prespores. During this entire period, 20% of the total proteolytic activity was due to the metal proteinase; 80% of the proteolytic activity and 15% of the esterolytic activity was due to the serine proteinase; 85% of the esterolytic activity was the result of the esterase. These findings will contribute to a more complete phenotypic characterization of those mutants of sporulation that appear to be involved in the production of extracellular hydrolytic enzymes.