摘要:

AbstractCharacterization of proteolytic activity in preparations or fermentation broth is accomplished by methods based on a combination of disc electrophoresis and visualization of the activity. The methods permit a direct, comparison with reference preparations. All alkaline proteases studied, including the three subtilisins, were found to consist of several proteolytic components. The zymograms of the subtilisin type preparations show an irregular pattern. At least 14 different components may be observed, belonging to 6 types of mobility pattern, 3 of which could be assigned to the subtilisins. None of the components belongs to the group of metalloproteases. A quite regular pattern is shown by the zymogram of protease preparations produced by the alkalophilicBacillusstrains.A few of the components of the subtilisin preparations Maxatase and protease A were isolated by preparative disc electrophoresis and by disc electrofococusing, allowing a further characterization. Special attention was directed to the determination of properties specific for the application of subtilisins as additives in household detergents. Thermostability in sodium tripolyhosphate solution was found to range from about 10% for one of the minor components to 80% for the main component of Maxatase. Three types of curves representing the effect of pH on the activity were observed. The curve of the main component of Maxatase shows a characteristic shape with a maximum at pH 10.3: with other components lower pH optima were observed. Isoelectric points of the component were found to range from pH 7 to 10.

ISSN:0006-3592    

DOI:10.1002/bit.260140502

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

年代:1972

数据来源: WILEY

摘要:

AbstractPullulanase (EC 3.2.1.9) prepared from a culture ofAcrobacter aerogeneshas been covalently bound to an inert crosslinked copolymer of aerylamide‐acrylic acid by using a water‐soluble carbodi‐imide. The binding yield based on the amount of added pullulanase was 34%. The residual enzymic activity was 43%, of that of free enzyme. Coupling in the presence of the substrate pullulan gave a 5‐fold increase in activity over that obtained when substrate was lacking. The effect of different carbodi‐imide concentrations on the coupling has been investigated. The isoelectric point of the pullulanase preparation (3.5–4.0) was determined using isoelectric, focusing, in order to find optimal pH conditions for the coupling procedure. The immobilized pullulanase in a packed bed column was used to debranch amylopeetin to low molecular wei

ISSN:0006-3592    

DOI:10.1002/bit.260140503

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

年代:1972

数据来源: WILEY

摘要:

AbstractRelease of protein from a suspension of bakers' yeast (Saccharomyces cerevisiae) by disruption in an industrial agitator mill has been studied. Protein release on disruption in the mill is a first‐order rate process. The rate constant is dependent on at least six parameters. Increased disruption efficiency was obtained at higher agitator speeds, greater loading of bead attritive elements and lower rates of upward recycle of yeast suspension through the mill. An increase in temperature from 5 to 42°C was accompanied by a reduction in disruption efficiency of approximately 20%. With optimal values of the parameters examined the throughput of the mill is 5.32 kg/hr of soluble protein for 90% disrupti

ISSN:0006-3592    

DOI:10.1002/bit.260140504

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

年代:1972

数据来源: WILEY

摘要:

AbstractThe effect of a nonionic surfactant, polyoxyethylenesorbitan monolaurate (Tween 20), on the hen egg‐white lysozyme catalyzed lysis of a dried cell suspension ofMicrococcus lysodeikticusis analysed. A rate enhancement of up to 70% is observed in the presence of surfactant at concentrations above the critical micelle concentration. This activity increase may be explained by postulating the existence of a micelle‐enzyme complex in which enzyme molecules are bound to micelles with preferential orientation of their active sites.The reaction is found to be second order with respect to substrate. A mechanism is postulated in which a substrate particle is assumed to be an energy‐furnishing collision partner to the enzyme‐substrate complex. This mechanism correlated data over a wide range of enzyme and substrate concentrations.Data from kinetic, ultrafiltration, ultraviolet, and fluorescence studies provide convincing evidence for the existence of a micelle‐lysozyme complex. The results suggest that it is possible that immobilized enzymes mat in general be more reactive than corresponding fre

ISSN:0006-3592    

DOI:10.1002/bit.260140505

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

年代:1972

数据来源: WILEY

摘要:

AbstractA method and an apparatus that reduce the heavy expenses involved in traditional methods for the large‐scale monolayer production of primary and secondary, strain and line cells and of the biologicals derived therefrom are described. The method is based on the principle of gathering in a single unit a sheaf of columns by means of general manifolds fitted with cocks. The growth of cells on the glass walls is irrespective of the number, length, and diameter of the columns used. The apparatus, placed in a thermo‐adjustable room and connected to adequate devices which allow it to rotate on its longitudinal axis and to be set in a vertical position, need not be dismounted nor transported since it can be connected by a number of tubes to the necessary services. Sterilization is carried out by flowing steam and fluids are poured in or drained off by vacuum or pressure. A microscope fitted to the bearing structure allows the operator to observe the cell monolayers and the cytopathic effect of viruses on the whole length of the outer columns. During the various working stages pH is under continuous control and automatically adjusted. The whole working cycle is extensively described (cleaning, sterilization, seeding, incubation, trypsinization of the monolayer, culture and harvesting of the virus) and results compared with those obtained by traditional meth

ISSN:0006-3592    

DOI:10.1002/bit.260140506

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

年代:1972

数据来源: WILEY

摘要:

AbstractThe effects of carbon dioxide‐enriched air on the rate of zinc extraction during the microbiological leaching of a, high‐grade zinc sulfide concentrate byThiobacillns ferrooxidanshave been studied. Under normal air‐aeration conditions, the leach rate is limited initially by the availability of solid substrate surface area per unit volume of leach liquor, then by availability of carbon dioxide. If carbon dioxide‐enriched air is supplied, along with excess substrate, the zinc extraction rate increases as the carbon dioxide content increases until some other, as yet unknown, factor becomes l

ISSN:0006-3592    

DOI:10.1002/bit.260140507

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

年代:1972

数据来源: WILEY

摘要:

AbstractA simple dynamic model is proposed which will allow fermenters to be run at throughputs which fully utilize the mass transfer capabilities of the fermenters while not decreasing the yield from the substrate. The model is compared with one previously proposed, which was originally formulated for double substrate limitation when both substrates were supplied in the feed. Computer solutions of the model are given which show the effects of the parameters used. Experimental results from growingCandida utilison a high concentration of glucose were found to be similar to those predicted by the model.

ISSN:0006-3592    

DOI:10.1002/bit.260140508

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

年代:1972

数据来源: WILEY

摘要:

AbstractGrowing cultures, washed cells, and cell‐free preparations ofGluconobacter melanogecnusIFO 3293 convertedL‐sorbose to 2‐keto‐L‐gulonic acid, toD‐sorbitol (which was metabolized further) and to 5‐ke

ISSN:0006-3592    

DOI:10.1002/bit.260140509

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

年代:1972

数据来源: WILEY

摘要:

AbstractCell‐free extracts ofGluconobacter melanogenuscells grown inL‐sorbose‐containing media contained an enzyme system capable of convertingL‐sorbose to 2‐keto‐L‐gulonic acid while cells grown in glycerol media did not. This inducible enzyme was located in the participate fraction

ISSN:0006-3592    

DOI:10.1002/bit.260140510

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

年代:1972

数据来源: WILEY

摘要:

AbstractThe algaChlorella pyrenoidosahas been grown in mass quantities on 94 at. %13CO2. The algal cells have been labeled to the 90 at. %13C level. Neither inhibition nor a requirement for adaptation was encountered; changes in morphology were not evident. A statistically significant increase in mass of cells produced in the presence of13CO2was observed.

ISSN:0006-3592    

DOI:10.1002/bit.260140511

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

年代:1972

数据来源: WILEY