THE PROTEOLYTIC ENZYMES OF MICROORGANISMS: V. EXTRACELLULAR PEPTIDASES PRODUCED BY FUNGI GROWN IN SUBMERGED CULTURE

1953 ◽  
Vol 31 (8) ◽  
pp. 697-704 ◽  
Author(s):  
W. B. McConnell ◽  
E. Y. Spencer ◽  
J. A. Trew
Keyword(s):  
Activation Energy ◽  
Glutamic Acid ◽  
Submerged Culture ◽  
Culture Media ◽  
Proteolytic Enzymes ◽  
Gliocladium Roseum ◽  
Rapid Hydrolysis ◽  
Hydrolysis Of ◽  
Extracellular Peptidases ◽  
Dipeptidase Activity

The culture media from selected fungi grown in submerged culture have been shown to contain enzymes capable of hydrolyzing some synthetic dipeptides and their derivatives. Readily measurable amounts of aminopeptidase, carboxypeptidase, and dipeptidase activity were found, and differences between the systems elaborated by different organisms were observed. The most rapid hydrolysis of N-cbzo-α-L-glutamyl-L-glutamic acid (I) and of N-cbzo-α-L-glutamyl-DL-alanine (II) by Gliocladium roseum PRL 86 occurred at pH 4.8 to 4.9. I was hydrolyzed most rapidly by Alternariatenuis PRL 369 at pH 4.7. The activation energies for the hydrolysis of I by PRL 369 and of II by PRL 86 were found to be 11,000 and 15,000 calories per mole, respectively. The activation energy for the hydrolysis of I by PRL 86 was estimated as being between 10,000 and 13,000 calories per mole.

THE PROTEOLYTIC ENZYMES OF MICROORGANISMS: III. SOME CHARACTERISTICS OF EXTRACELLULAR PROTEASES PRODUCED IN SUBMERGED CULTURE

1950 ◽  
Vol 28c (6) ◽  
pp. 600-612 ◽  
Author(s):  
W. B. McConnell
Keyword(s):  
Low Temperatures ◽  
Free Amino ◽  
Submerged Culture ◽  
Culture Medium ◽  
Proteolytic Enzymes ◽  
Amino Groups ◽  
Extracellular Proteases ◽  
Egg Albumin ◽  
Rapid Hydrolysis ◽  
Hydrolysis Of

Some of the general characteristics of the proteases liberated into the culture medium by molds and actinomycetes grown in submerged culture have been studied. Species of Alternaria, Streptomyces, Mortierella, and Gliocladium were used. The enzymes resemble trypsin in that they are most active at a pH slightly above 7 and are inhibited by a preparation of egg albumin. They are stable at low temperatures but suffer marked losses in activity when stored for 16 hr. above 40 °C. The most rapid hydrolysis of gelatin occurs at temperatures between 40 °C. and 50 °C. The enzymes from different organisms show definite differences with respect to their ability to attack different proteins, gelatin and casein being in general the most readily digested. The protease systems from different organisms also vary with respect to the extent to which they can digest gelatin; some enzymes are able to release about three times as many amino groups from gelatin as others. The limit of the hydrolysis is not dependent upon substrate concentration but is slightly affected by the concentration of enzyme. The enzymes were effective in liberating free amino acids from gelatin.

THE PROTEOLYTIC ENZYMES OF MICROORGANISMS: I. SURVEY OF FUNGI AND ACTINOMYCETES FOR PROTEASE PRODUCTION IN SUBMERGED CULTURE

1950 ◽  
Vol 28c (6) ◽  
pp. 577-585 ◽  
Author(s):  
W. M. Dion
Keyword(s):  
Submerged Culture ◽  
Proteolytic Enzymes ◽  
Protease Production ◽  
Gliocladium Roseum ◽  
Alternaria Tenuis ◽  
High Yields

Of 289 fungi and actinomycetes tested, only 20 were found to produce high yields of proteolytic enzymes when grown in submerged culture. Strains of Gliocladium roseum and Alternaria tenuis were found to be consistently proteolytic, and other good strains were also found in the genera Chaetomium, Sordaria, Epicoccum, Rhizoctonia, and Streptomyces.

scholarly journals Tagasaste, leucaena and paulownia: three industrial crops for energy and hemicelluloses production

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Alberto Palma ◽  
Javier Mauricio Loaiza ◽  
Manuel J. Díaz ◽  
Juan Carlos García ◽  
Inmaculada Giráldez ◽  
...  
Keyword(s):  
Activation Energy ◽  
Acid Hydrolysis ◽  
Energy Production ◽  
Combustion Process ◽  
Operating Conditions ◽  
Raw Material ◽  
Energy Of Combustion ◽  
Increasing Temperature ◽  
Hydrolysis Of ◽  
Chamaecytisus Proliferus

Abstract Background Burning fast-growing trees for energy production can be an effective alternative to coal combustion. Thus, lignocellulosic material, which can be used to obtain chemicals with a high added value, is highly abundant, easily renewed and usually inexpensive. In this work, hemicellulose extraction by acid hydrolysis of plant biomass from three different crops (Chamaecytisus proliferus, Leucaena diversifolia and Paulownia trihybrid) was modelled and the resulting solid residues were used for energy production. Results The influence of the nature of the lignocellulosic raw material and the operating conditions used to extract the hemicellulose fraction on the heat capacity and activation energy of the subsequent combustion process was examined. The heat power and the activation energy of the combustion process were found to depend markedly on the hemicellulose content of the raw material. Thus, a low content in hemicelluloses resulted in a lower increased energy yield after acid hydrolysis stage. The process was also influenced by the operating conditions of the acid hydrolysis treatment, which increased the gross calorific value (GCV) of the solid residue by 0.6–9.7% relative to the starting material. In addition, the activation energy of combustion of the acid hydrolysis residues from Chamaecytisus proliferus (Tagasaste) and Paulownia trihybrid (Paulownia) was considerably lower than that for the starting materials, the difference increasing with increasing degree of conversion as well as with increasing temperature and acid concentration in the acid hydrolysis. The activation energy of combustion of the solid residues from acid hydrolysis of tagasaste and paulownia decreased markedly with increasing degree of conversion, and also with increasing temperature and acid concentration in the acid hydrolysis treatment. No similar trend was observed in Leucaena diversifolia (Leucaena) owing to its low content in hemicelluloses. Conclusions Acid hydrolysis of tagasaste, leucaena and paulownia provided a valorizable liquor containing a large amount of hemicelluloses and a solid residue with an increased heat power amenable to efficient valorization by combustion. There are many potential applications of the hemicelluloses-rich and lignin-rich fraction, for example as multi-components of bio-based feedstocks for 3D printing, for energy and other value-added chemicals.

On the activation energy for the hydrolysis of bis-(2-chloroethylethyl) sulfide. II

1987 ◽  
Vol 114 (2) ◽  
pp. 313-317 ◽  
Author(s):  
Yu-Chu Yang ◽  
J.Richard Ward ◽  
Robert B. Wilson ◽  
Wes Burrows ◽  
John S. Winterle
Keyword(s):  
Activation Energy ◽  
Hydrolysis Of

scholarly journals Research on hydrogen generation from rapid hydrolysis of aluminum in sodium fluoride solution

2019 ◽  
Vol 118 ◽  
pp. 03048
Author(s):  
Changchun Li ◽  
Yuxin Wu
Keyword(s):  
Hydrogen Production ◽  
Kinetic Model ◽  
Sodium Fluoride ◽  
Hydrogen Generation ◽  
Hydrogen Yield ◽  
Shrinking Core Model ◽  
Fluoride Solution ◽  
Shrinking Core ◽  
Rapid Hydrolysis ◽  
Hydrolysis Of

Hydrogen generation from rapid hydrolysis of aluminum in sodium fluoride solution was investigated through a hydrolysis experiment. Rapid and instant hydrogen yield were observed using sodium fluoride as additive. The experimental results demonstrate that the increase of temperature and the amount of additives in a certain range will boost the hydrogen production. The amount of additives outside the range only has an effect on the rapid hydrolysis of the aluminum during the initial stage, but the total amount of hydrogen produced doesn’t increased significantly. Theoretical analysis of the effects of the mixing ratio and the temperature on the hydrogen production rates were performed using the shrinking core model and the kinetic model. The shrinking core model parameter a and k indicate the film change degree of porosity and thickness and the effect of time on the diffusion coefficient. the kinetic model is verified and the activation energy confirming hydrogen yield control by a molecular diffusion process. Correspondingly, mechanisms of Al corrosion in NaF solutions under low and high alkalinity were proposed, respectively.

scholarly journals Isolation and characterization of fungal and bacterial proteolytic strains from chrome shavings

2020 ◽  
Author(s):  
Mariana Ferdes ◽  
Rodica Roxana Constantinescu
Keyword(s):  
Culture Media ◽  
Proteolytic Enzymes ◽  
Bacterial Strains ◽  
Fungal Strains ◽  
Isolation And Characterization ◽  
Finishing Process ◽  
The Media ◽  
Specific Culture ◽  
Yeasts And Molds ◽  
Leather Finishing

The chrome shavings waste obtained as a result of the leather finishing process accumulates in a large volume in tanneries and represent a major problem for the environment. This waste are particularly resistant to attack of microorganisms, due to the significant concentration of chromium and are thus difficult to degrade. In this study, chrome shavings were analyzed microbiologically by determining the total number of germs and the number of yeasts and molds on specific culture media. Several bacterial and fungal strains were isolated from the cultures in Petri dishes, after the growth of the colonies. These strains were characterized in terms of the production of proteolytic enzymes, by a method of screening on the media with casein, which allows the determination of proteolytic indices of microorganisms. As a result of the tests performed, five bacterial strains probably belonging to the genus Bacillus and two fungal strains from the genera Penicillium and Cladosporium were selected.

scholarly journals Hydrolysis of14C-labelled proteins by rumen micro-organisms and by proteolytic enzymes prepared from rumen bacteria

1983 ◽  
Vol 50 (2) ◽  
pp. 345-355 ◽  
Author(s):  
R. J. Wallace
Keyword(s):  
Proteolytic Enzymes ◽  
Rumen Fluid ◽  
Performic Acid ◽  
Cross Linking ◽  
Acid Oxidation ◽  
Rumen Bacteria ◽  
Rate Of Hydrolysis ◽  
Micro Organisms ◽  
Hydrolysis Of

1. Proteins were labelled with14C in a limited reductive methylation using [14C]formaldehyde and sodium borohydride.2. The rate of hydrolysis of purified proteins was little (< 10%) affected by methylation and the14C-labelled digestion products were not incorporated into microbial protein during a 5 h incubation with rumen fluid in vitro. It was therefore concluded that proteins labelled with14C in this way are valid substrates for study with rumen micro-organisms.3. The patterns of digestion of14C-labelled fish meal, linseed meal and groundnut-protein meal by rumen micro-organisms in vitro were similar to those found in vivo.4. The rates of hydrolysis of a number of14C-labelled proteins, including glycoprotein II and lectin from kidney beans (Phaseolus vulgaris), were determined with mixed rumen micro-organisms and with proteases extracted from rumen bacteria. Different soluble proteins were digested at quite different rates, with casein being most readily hydrolysed.5. Proteins modified by performic acid oxidation, by cross-linking using 1,6-di-iso-cyanatohexane or by diazotization were labelled with14C. Performic acid treatment generally increased the susceptibility of proteins to digestion, so that the rates of hydrolysis of performic acid-treated proteins were more comparable than those of the unmodified proteins. Cross-linking resulted in a decreased rate of hydrolysis except with the insoluble proteins, hide powder azure and elastin congo red. Diazotization had little effect on the rate of hydrolysis of lactoglobulin and albumin, but inhibited casein hydrolysis and stimulated the breakdown of γ-globulin.

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