摘要:

AbstractA potent inhibitory agent against human plasmin, fibrinolytic proteinase, has been found in the extracts of callus tissue ofScopolia japonica. Effects of cultural conditions on cell growth and production of the plasmin inhibitory substance by this cell line in suspension cultures were examined in MurashigeSkoog's medium. More than l.5 mg of the inhibitor, ast‐amino cyclohexane carboxylic acid, a synthetic plasmin inhibitor, were observed to accumulate per ml of medium containing 0.83 g of NH4NO3and 7.6 g of KNO3per liter as well as suitable levels of growth hormones.Addiction of antibiotics and deformers were examined in preliminary tests for large scale cultivation. Semicontinuous culture on a small scale in a glass cylinder, was also tested and growth rate of 1.29 g/liter/day (by dry wt) was obtained. Plasmin inhibitory activities in the extracts of the results intact plant and in cultured cells ofS. japonicawere compared and the results indicated that cell suspension culture was superior to extraction the natural plant for inhibitor productio

ISSN:0006-3592    

DOI:10.1002/bit.260170302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1975

数据来源: WILEY

摘要:

AbstractAcid tolerant lactase (I), α‐chymotrypsin (II), and acid phosphatase (III) were immobilized on chitin with glutaraldehyde. Pretreatments of the chit in with acid, alkali, ammonia, and pronase were compared with respect to release of titratable amino groups and ability to retain lactase activity. Shrimp chitin appeared to be more sensitive to pretreatment conditions and so effort was concentrated on crab. An acid‐alkali pretreatment was selected as most practical and economical, and the properties of enzymes fixed on crab chitin were studied intensively. The pH optima of the fixed enzymes were shifted about one pH unit; the shift for I was toward more acid pH, for II was toward alkaline pH, and for III was toward acid pH. The retained activity of immobilized I was approximately 60% that of the native enzyme. A column in continuous operation with I on chitin‐glutaraldehyde gave an apparent activity half‐life of

ISSN:0006-3592    

DOI:10.1002/bit.260170303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1975

数据来源: WILEY

摘要:

AbstractThe growth and protein production ofSporotrichum pulverulentum, formerly calledChrysosporium lignorum, have been studied in submerged cultures using lignin‐containing waste fibers from a newsprint mill as the only carbon source. The influence of different nitrogen sources on the growth parameters has been particularly investigated. The regulation of the production of extracellular enzymes and their interaction with the fibers is discussed. Experiments with cellulose of different degrees of polymerization and crystallinities showed that the protein content in the residual substance decreased, particularly when the crystallinity increased. When the highly crystalline powder cellulose was used as carbon source, the protein content in the residual substance was only 6% and with the mechanical waste fibers 14%. The results obtained demonstrate that the more complex the carbon source the more difficult it is to digest and the more enzyme has to be produced for its degradation. This puts a heavy burden on the protein synthesizing mechanism. Utilizing results from other work, where the endo‐ and exo‐l, 4‐β‐glucanases produced byS. pulverulentumfor the degradation of cellulose have been quantitatively purified, it has been calculated that the extracellular enzymes under these conditions can together account for approximately 30% of the protein in the mycelium. The endo‐ and exo‐1,4‐β‐glucanases account for up to 55% of the extracellular protein.Certain possibilities of producing a final product with a high protein content using complex carbon sources

ISSN:0006-3592    

DOI:10.1002/bit.260170304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1975

数据来源: WILEY

摘要:

AbstractGrowing cultures, washed cells, and cell‐free extracts ofGluconobacter melanogenusIFO 3293 were found to convertL‐sorbose toL‐sorbosone. The product was identified by thin layer chromatography of the 2, 4‐dinitrophenylhydrazone, and by paper partition chromatography using chemically prepared materials as standards. Factors influencing the conversion included incubation temperature and composition of the growth medium. Addition of betaine or choline to the growing cultures stimulated conversion ofL‐sorbose toL

ISSN:0006-3592    

DOI:10.1002/bit.260170305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1975

数据来源: WILEY

摘要:

AbstractThe cellulase production by two strains of the cellulolytic fungusTrichoderma viridewas examined. The fungi were grown on different preparations of barley straw pretreated with NaOH under high pressure. The production of cellulases and microbial protein by the better strain (QM 9123) was investigated in an aerated 5‐liter fermenter under varying stirring rates (200‐350 rpm) and straw concentrations (1–2%). The pH was kept between 3.5 and 4.5. The growth of the fungus was followed by measuring the quantity of CO2produced and the cell protein. After 2–6 days growth ceased, the lag phases lasting 0–2 days, increasing with increasing straw concentrations. The maximum enzyme yields were reached after 4–10 days. The protein content of the product was 21–26% and up to 70% of the straw was utilized. The yield constants were calculated to be 0.40–0.56; of the same order as those which can be obtained by growing the fu

ISSN:0006-3592    

DOI:10.1002/bit.260170306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1975

数据来源: WILEY

摘要:

AbstractTwo models for predicting the behavior of cultures of microorganisms under both oxygen and carbon limiting conditions have been evlauated on a chemostat growingCandida utilison a glycolysis suppressing glycerol medium. The work indicated that parameter values obtained under wholly oxygen limiting or wholly carbon limiting conditions successfully predict the behavior of the chemostat under the wide range of flow and substrate concentration conditions tested. Both models are satisfactory and hence it is deduced that the simpler one may be used with confidence. It was found that Monod kinetics were applicable to the growth rate dependence on oxygen concentration but that Contois kinetics were superior for the corresponding dependence on carbon substrate concentration.

ISSN:0006-3592    

DOI:10.1002/bit.260170307

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1975

数据来源: WILEY

摘要:

AbstractA kinetic model is presented to explain microbial growth using liquid n‐alkanes as substrate. The model is based on the assumption that growth occurs on the soluble alkane and that the metabolite produced by the growing cells helps the dissolution of liquid alkanes in the aqueous medium. Growth curves based on that model fit well with growth data for batch and continuous culture reported by various authors. The model also explains the differences between the relative length of exponential and linear phases of growth reported earlie

ISSN:0006-3592    

DOI:10.1002/bit.260170308

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1975

数据来源: WILEY

摘要:

AbstractGlucose oxidase electrodes were constructed on a platinum screen using polyacrylamide gel, glutaraldehyde crosslinking, and glutaraldehyde crosslinking with +0.04 volts dc on the platinum screen as the methods of enzyme immobilization. The electrodes were evaluated in an electrochemical cell for the oxidation of glucose at the enzyme electrode and the reduction of oxygen at a platinum auxiliary electrode, using constant current voltametry or under external load operation. The method of immobilization affected the extrapolated opencircuit potential as well as the half‐cell potential and the steady current under external load operation. The charged glutaraldehyde electrode gave the best current performance; however, the small output (microamps) indicated that major problems in electron transfer from an enzyme catalyst to an external circuit must be resolved before such electrodes can be used in practical applicatio

ISSN:0006-3592    

DOI:10.1002/bit.260170309

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1975

数据来源: WILEY

摘要:

AbstractThe effect of internal diffusion on the slope and the intercept of the LineweaverBurk plots for the immobilized enzyme was considered theoretically and it was found that the slope and the intercept are influenced not only by the dimensionless termMbut also by the range of the dimensionless bulk substrate concentration ζb. The dependencies of the slope and the intercept onMand on the rate of ζbare shown graphically. Accurate estimations ofMand the maximum velocity of the immobilized enzyme give the true, not apparent, Michaelis constant. It is shown that the linear correlations in the Lineweaver‐Burk plots do not always coincide with the correlations for the estimation ofMand the maximum velocity. It also is shown that large values ofMmay induce a serious error in the estimation ofMwith large values of ζband in an estimation of the maximum velocity with small values o

ISSN:0006-3592    

DOI:10.1002/bit.260170310

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1975

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260170311

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1975

数据来源: WILEY