摘要:

AbstractRemoval of the Hepatitis B surface antigen (HBsAg) from whole blood and blood products, using human antibody (HBAb) immunosorbent, was studied and kinetics of complexing were monitored using radioimmunoassay (RIA). An intermittent complexing process was developed that minimizes damage to the cellular components of blood. HBsAg concentration in blood was reduced 1.5 to 2 logarithmic cycles in 3 hr with this system. Free HBsAg remaining in solution at equilibrium was further reduced by transferring the blood to a vessel containing unused immunosorbent. Through multiple stage treatment of a blood sample, it may be possible to reduce the probability of contamination with HBsAg to below the infectious level. This process may be applied to the selective removal of other proteins from blood and plasma.

ISSN:0006-3592    

DOI:10.1002/bit.260221102

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

年代:1980

数据来源: WILEY

摘要:

AbstractThe gas environment is solid‐substrate fermentations of rice significantly affected levels of biomass and enzyme formation by a fungal species screened for high amylase production. Constant oxygen and carbon dioxide partial pressures were maintained at various levels in fermentations byAspergillus oryzae. Control of the gas phase was maintained by a “static” aeration system admitting oxygen on demand and stripping excess carbon dioxide during fermentation. Constant water vapor pressures were also maintained by means of saturated salt solutions. High Oxygen pressures stimulated amylase productivity significantly. On the other hand, amylase production was severely inhibited at high carbon dioxide pressures. While relatively insensitive to oxygen pressure, maximum biomass productivities were obtained at an intermediate carbon dioxide pressure. High oxygen transfer rates were obtained at elevated oxygen pressures, suggesting, in view of the stimulatory effect of oxygen on amylase production, a stringent oxygen requirement for enzyme synthesis. Solid‐substrate fermentations were highly advantageous as compared with submerged cultures in similar gas environments. Not only were amylase productivities significantly higher, but the enzyme was highly concentration in the aqueous phase of the semisolid substrate particles and could be extracted in a small volume of liquid. Results of this work suggest that biomass and product formation in microbial processes may be amenable to control by the gas environment. This is believed to offer an interesting potential for optimizing selected industrial fermentation processes with respect to productivity and energy cons

ISSN:0006-3592    

DOI:10.1002/bit.260221103

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

年代:1980

数据来源: WILEY

摘要:

AbstractCultivation ofTrichoderma reeseiQM 9414 on 3% (w/v) cellulose medium (C/N ratio = 8.5) produced 4.5 IU/ml celulase 180 hr at a cell growth of 8.0 g/liter (0.266 g cell/g cellulose). It corresponded to an average cellulase productivity 25.0 IU/liter/hr (3.5 IU/g cell/hr). In the same medium 9.5 g/liter cell mass (0.316 g cell/g cellulose), 6.2 IU/ml cellulase, and 38.75 IU/liter/hr (4.0 IU/g cell/hr) cellulase productivity could be obtained using pH cycling condition during cultivation. Cell mass, cellulase yield, and productivity were further increased to 10.0 g/liter, 7.2 IU/ml, and 44.0 IU/liter/hr (4.5 IU/g cell/hr), respectively, by simultaneous pH cycling and temperature profiling strategy. Results are described.

ISSN:0006-3592    

DOI:10.1002/bit.260221104

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

年代:1980

数据来源: WILEY

摘要:

AbstractA method of enzyme immobilization by graft copolymerization on polysaccharides is reported. Glycidylmethacrylate was used as a vinylating reagent and the reaction product with enzymes (HRP, GOD, Am, ChT) was copolymerized with different matrices (cellulose, Sepharose, Sephadex, Starch). Various factors affect the final activity of copolymers; these include the redox system, the type of support, and the quantity and type of vinyl monomer added. Using a fixed quantity of enzyme and support (3 mg enzyme, 100 mg support), the coupling efficiency varied from 2 to 50%. The most important characteristics in these immobilized systems were tested (stability in continuous washing, kinetic characteristics, storage, thermal, and lyophilization stability). Immobilized‐enzyme graft copolymers have very similar kinetic behavior to that of the free enzyme. Diffusion is not seriously limited, as shown by kinetic parameters and energy activation values, and this indicates that the immobilization reaction does not alter the enzymatic activit

ISSN:0006-3592    

DOI:10.1002/bit.260221105

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

年代:1980

数据来源: WILEY

摘要:

AbstractA process has been developed that allows a direct conversion of lignocellulosic materials into fungal biomass. The thermotolerant white‐rot fungusSporotichum pulverulentiumhas been used in continuous laboratory fermentations as well as in a 25 m3batch fermentation. Fungal cell mass for feeding trials was produced and the economics of the process were estimated. The investigation shows that the process works satisfactorily on the small continuous scale as well as in the large batch culture. The process also seems easy to scale up. The economic evaluations show the conversion of solid lignocellulosic materials to protein feed is not feasible by our process unless the material to be fermented has a certain negative value. A mixed wastewater, such as the white water system in paper and fiber board mills, containing both water soluble mono‐ and oligosaccharides and solid lignocellulosic material, can, however, be fermented in an economically feasible way due to the combined effect of protein production and water purification. Data on the nutritional value of the product are presented in an accompanying pa

ISSN:0006-3592    

DOI:10.1002/bit.260221106

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

年代:1980

数据来源: WILEY

摘要:

AbstractThe production of single‐cell protein (SCP) based on cheap carbon sources such as spent liquor from paper mills is of interest for different reasons. The White‐rot fungus (Sporotrichum pulverulentum) has earlier been shown to degrade cellulose and lignin. The nutritive value of this fungus was investigated with rats, pigs, and sheep. The effect of different drying process was evaluated on rats. Experiments with piglets, growing pigs, and sheep were aimed at getting primary information on nutritive parameters with domestic animal species, Chemical analysis ofS. pulverulentumshowed that the sum of the amino acids corresponded to 70% and ammonia, GABA, and glucosamine to 20% of its crude protein content. Differences between drying treatments in their effect on protein digestibility were not noted. From a protein quality viewpoint, a tendency toward superiority was noted for two of the drying processes. The amino acid digestibility ofS. pulverulentumwas inferior to values for soybean oil meal given in textbooks. The piglet experiment confirmed the lower nutritive value ofS. pulverulentumcompared with soybean oil meal. in the piglet stage a content of metabolizable energy ofS. pulverulentumwas found which corresponded to 60% of that for soybean oil meal. With increasing age the ability of pigs to utilize the fungus increased. The limited nutritive value for monogastric animals is most certainly caused by the cell‐wall structure ofS. pulverulentumwith poor digestibility of the carbohydrates. The experiment with sheep showed more satisfactory results than with monogastric species, with digestibility of crude protein of 82% and a content of metabolizable energy of 70% of soybean oil

ISSN:0006-3592    

DOI:10.1002/bit.260221107

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

年代:1980

数据来源: WILEY

摘要:

AbstractThe kinetics of the hydrolyses of cellotriose and of cellotetraose by cellobiohydrolase were studied using a convenient integral technique. Reaction mechanisms and mathematical models were postulated to describe the reactions. The end‐products of the reaction were found to be inhibitory toward hydrolysis in a competitive mode. Hydrolysis of cellotetraose produces cellobiose and hydrolysis of cellotriose produces cellobiose and glucose. Both sugars inhibit the enzyme with cellobiose being a stronger inhibito

ISSN:0006-3592    

DOI:10.1002/bit.260221108

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

年代:1980

数据来源: WILEY

摘要:

AbstractThe generality of a fermentation kinetic model (developed earlier for xanthan gum production byXanthamonas campestris) is tested by application to several other polysaccharide‐producing fermentations. With literature batch data for exopolysac‐charides fromAzotobacter vinelandii, Pseudomonassp., andAureobasidium pullulans, the model is shown to provide a reasonable description for biomass (X), product (polysaccharide,P), and substrate (S) evolution in time. Thus a general kinetic model for microbial fermentations that produce exopolysaccharides is establis

ISSN:0006-3592    

DOI:10.1002/bit.260221109

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

年代:1980

数据来源: WILEY

摘要:

AbstractA steady‐state biofilm is defined as one that has neither net growth nor decay over time. The model, developed for steady‐state‐biofilm kinetics with a single substrate, couples the flux of substrate into a biofilm to the mass (or thickness) of biofilm that would exist at steady‐state for a given bulk substrate concentration. Based on kinetic and energetic constraints, this model predicts for a single substrate that a steady‐state bulk concentration,Smin, exists below which a steady‐state biofilm cannot exist. Thus, in the absence of adsorption of bacteria from the bulk water and for substrate concentration belowSmin, substrate flux and biofilm thickness are zero. Equations are provided for calculating the steady‐state substrate flux and biofilm thickness forSgreater thanSmin. An example is provided to demonstrate the use of the stea

ISSN:0006-3592    

DOI:10.1002/bit.260221110

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

年代:1980

数据来源: WILEY

摘要:

AbstractLaboratory‐scale biofilm reactors were used to evaluate a model of the kinetics of steady‐state biofilm and the concept that there is a minimum concentration,Smin, below which no steady‐state activity can occur. With acetate as the ratelimiting substrate, the steady‐state concept ofSminwas verified for naturally grown biofilms. Substrate removal and biofilm thickness declined rapidly as the substrate concentration approachedSmin, which was 0.66 mg/liter for acetate. Using independently derived kinetic parameters, the model of steady‐state‐biofilm kinetics successfully predicted substrate utilization and biofilm thickness without the need for fitting factors. The results imply that organic materials may persist in water and wastewater, in part, because they are too low in concentration to supply sufficient energy to sustain the mic

ISSN:0006-3592    

DOI:10.1002/bit.260221111

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

年代:1980

数据来源: WILEY