Preparation of mycelial and yeast-like spheroplasts fromMucor rouxii by a lytic enzyme preparation fromPenicillium islandicum

1983 ◽  
Vol 9 (5) ◽  
pp. 301-304 ◽  
Author(s):  
Emma Reyes ◽  
Monique Novaes-Ledieu ◽  
Concepción Garcia Mendoza
Keyword(s):  
Enzyme Preparation ◽  
Lytic Enzyme

Protoplast release from fungi capable of steroid transformation

1984 ◽  
Vol 30 (1) ◽  
pp. 57-62 ◽  
Author(s):  
J. Długoński ◽  
L. Sedlaczek ◽  
A. Jaworski
Keyword(s):  
Cell Wall ◽  
Enzyme Preparation ◽  
Trichoderma Viride ◽  
Transformation Product ◽  
Lytic Enzyme ◽  
Cunninghamella Elegans ◽  
Steroid Hydroxylation ◽  
Steroid Transformation ◽  
No Inhibition ◽  
Protoplast Suspension

Protoplasts were obtained from Hyphoderma roseum (Fries) and Cunninghamella elegans (Lendner), fungi capable of steroid 11-hydroxylation. The lytic enzyme preparation was derived from Trichoderma viride CBS 354-33. Homogeneous protoplast suspension, free of mycelial debris and cell wall fragments, transformed cortexolone and 6α-fluorocortexolone-16,17-acetonide to the same products as the intact mycelium of the microorganisms. Liberation of protoplasts and their stabilizaiton during steroid transformation was the most effective in 0.8 M MgSO4; still, this compound impaired steroid hydroxylation. Consequently, the concentration of the transformation product formed was nearly the same as in sucrose, mannitol, and sorbitol, compounds which caused no inhibition but which were less effective stabilizers.

Formation and regeneration of protoplasts from the ectomycorrhizal basidiomycete Laccaria bicolor

1986 ◽  
Vol 64 (6) ◽  
pp. 1224-1226 ◽  
Author(s):  
Bradley R. Kropp ◽  
J. A. Fortin
Keyword(s):  
Pinus Banksiana ◽  
Enzyme Preparation ◽  
Lytic Enzyme ◽  
Laccaria Bicolor ◽  
Dikaryotic Mycelium ◽  
Osmotic Stabilizer

Protoplasts were released from dikaryotic mycelium of the ectomycorrhizal basidiomycete Laccaria bicolor using the lytic enzyme preparation NovoZyme 234. Protoplast release depended strongly on mycelium age, osmotic stabilizer, and temperature. The protoplasts could regenerate to form both monokaryotic and dikaryotic cultures capable of forming normal ectomycorrhizae with Pinus banksiana.

scholarly journals Studies on the cell-free biosynthesis of β-lactam antibiotics

1977 ◽  
Vol 162 (3) ◽  
pp. 681-687 ◽  
Author(s):  
P E Bost ◽  
A L Demain
Keyword(s):  
Cell Walls ◽  
Enzyme Preparation ◽  
Helix Pomatia ◽  
Lytic Enzyme ◽  
Cephalosporium Acremonium ◽  
Digestive Juice ◽  
Enzyme Preparations ◽  
A Cell ◽  
Protoplast Preparation ◽  
Osmotic Lysis

Cell walls of Cephalosporium acremonium mycelia were lysed by enzyme preparations from either Helix pomatia (snail) digestive juice or Cytophaga. The yield of protoplasts depended on the lytic-enzyme preparation and the age of the culture, and it increased after the mycelia were pretreated with dithiothreitol. A cell-free preparation, obtained by osmotic lysis of protoplasts, synthesized labelled penicillin N from L-[14C]valine. Approx. 0.03-0.06% of the amino acid was incorporated into penicillin N. Under conditions of penicillin N synthesis, the broken-protoplast preparation failed to produce significant amounts of cephalosporin C or its precursors, deacetylcephalosporin C and deacetoxycephalosporin C.

Impairment of Platelet Aggregation by Echis colorata Venom Mediated by L-Amino Acid Oxidase or H2O2

1982 ◽  
Vol 48 (03) ◽  
pp. 277-282 ◽  
Author(s):  
I Nathan ◽  
A Dvilansky ◽  
T Yirmiyahu ◽  
M Aharon ◽  
A Livne
Keyword(s):  
Hydrogen Peroxide ◽  
Amino Acid ◽  
Platelet Aggregation ◽  
Snake Venom ◽  
Oxidase Activity ◽  
Enzyme Preparation ◽  
Acid Oxidase ◽  
Crude Venom ◽  
Amino Acid Oxidase ◽  
Hemostatic Disorders

SummaryEchis colorata bites cause impairment of platelet aggregation and hemostatic disorders. The mechanism by which the snake venom inhibits platelet aggregation was studied. Upon fractionation, aggregation impairment activity and L-amino acid oxidase activity were similarly separated from the crude venom, unlike other venom enzymes. Preparations of L-amino acid oxidase from E.colorata and from Crotalus adamanteus replaced effectively the crude E.colorata venom in impairment of platelet aggregation. Furthermore, different treatments known to inhibit L-amino acid oxidase reduced in parallel the oxidase activity and the impairment potency of both the venom and the enzyme preparation. H2O2 mimicked characteristically the impairment effects of L-amino acid oxidase and the venom. Catalase completely abolished the impairment effects of the enzyme and the venom. It is concluded that hydrogen peroxide formed by the venom L-amino acid oxidase plays a role in affecting platelet aggregation and thus could contribute to the extended bleeding typical to persons bitten by E.colorata.

THE INFLUENCE OF ETHANOL ON THE CONVERSION OF PREGNENOLONE TO PROGESTERONE BY HUMAN PLACENTAL MICROSOMES

1974 ◽  
Vol 76 (1) ◽  
pp. 178-188 ◽  
Author(s):  
H. Lübbert ◽  
K. Pollow ◽  
R. Wagner ◽  
J. Hammerstein
Keyword(s):  
Kinetic Parameters ◽  
Enzyme Preparation ◽  
Ethanol Concentration ◽  
Hydroxysteroid Dehydrogenase ◽  
Product Formation ◽  
Linear Increase ◽  
Maximal Velocity ◽  
Microsomal Enzyme ◽  
Temperature Optima ◽  
Substrate Concentrations

ABSTRACT The effects of ethanol on kinetic parameters of placental Δ5-3β-hydroxysteroid dehydrogenase were studied. In the presence of high pregnenolone concentrations (50 μm, [S] > Km) the microsomal enzyme preparation exhibited an almost linear increase in activity as the ethanol concentration in the medium was raised from 2.5 to 15 % (v/v). At lower substrate concentrations ([S] << Km) ethanol caused inhibition. Other effects of ethanol were: linearity of product formation with time was prolonged; the maximal velocity was markedly increased; the Km for pregnenolone slightly decreased with increasing ethanol concentrations (2.5 to 10 %, v/v) whereas the Km for NAD remained the same. The pH and temperature optima of the reaction were unaffected by ethanol. Other organic solvents caused similar effects.

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