ISSN:0006-3592    

DOI:10.1002/bit.260190602

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

年代:1977

数据来源: WILEY

摘要:

AbstractRates of CO2desorption from fermentation broths under actual operating conditions were determined by measuring the CO2partial pressure in the exit gas. The concentrations of CO2physically dissolved in the broths were measured by the so‐called tubing method. Values ofkLafor CO2desorption calculated from these values agreed well with thekLavalues for oxygen absorption corrected for the difference in gas diffusivities. The dissolved CO2concentration in the broth, which seems to bean important operating parameter, can easily be estimated from the CO2partial pressure in the exit gas, a more easily measurable quantity, if thekLavalue is known. For a given value ofkLa, assumption of perfect mixing or plug flow in the gas phase made little difference in the calculated values of the dissolved CO2concentration, indicating that the gas phase was probably in between perfect mixing and plug flow.In industrial fermentors, the CO2partial pressure in the exit gas can practically be assumed to be in equilibrium with the dissolved CO2concentratio

ISSN:0006-3592    

DOI:10.1002/bit.260190603

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe principles of a method for the continuous manufacture of yogurt, based upon a two stage system, are given. The first stage, the prefermentation of milk at 45°C to a pH of 5.7, is described.The limitations of this continuous prefermentation are experimentally determined. No change in the balance of the yogurt bacteria,Lactobacillus bulgaricusandStreptococcus thermophilus,was observed. A mathematical approach is given for starting and stopping the process

ISSN:0006-3592    

DOI:10.1002/bit.260190604

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

年代:1977

数据来源: WILEY

摘要:

AbstractThe procedure and apparatus for the continuous coagulation of yogurt are described. The continuous coagulation takes place in a plug‐flow fermentor. Prefermented milk is brought into this fermentor with the help of a centrifugal distributor, which avoids any undesirable mixing of the prefermented milk with the acidifying milk. A special stirring plate allows a stirring treatment in the coagulation tank. By this procedure the acidity and the viscosity of the final yogurt can be controlled between certain limits. The organoleptic characteristics of the continuous manufactured yogurt are goo

ISSN:0006-3592    

DOI:10.1002/bit.260190605

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

年代:1977

数据来源: WILEY

摘要:

AbstractA new method to estimate the oxygen transfer coefficient (KLa) from the experimental dynamic response data is presented. Employing a linear model which allows for gas phase, diffusion film, and oxygen electrode dynamics, the first moment of the response curve is simply related to the sum of the model parameters. Two separate experiments are used to characterize the measurement dynamics and to measure the unknownKLaparameter. The simple calculation procedure involves only measuring the area above the response curves.

ISSN:0006-3592    

DOI:10.1002/bit.260190606

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

年代:1977

数据来源: WILEY

摘要:

AbstractA laboratory‐scale research program was undertaken to investigate the kinetics of the mesophilic (37°C) anaerobic digestion of brewery industry by‐product. The purpose was to develop data for the design and operation of full‐scale units which could be used to generate methane fuel gas from these materials. This is important because the brewery industry has been susceptible to shortages of natural gas in recent years. The minimum SRT is 2.3 days, although for design purposes as much as ten days is recommended. The biomass yield is 0.512 g volatile suspended solids (VSS)/g volatile solids (VS) or 0.421 g VSS/g chemical oxygen demand (COD). The maintenance requirement is 0.052 g VS/g VSS per day or 0.061 g COD/g VSS per day. The specific methane yield is 2.51 liter/g VSS, and the methane productivity is 0.32–0.41 liter/g dry substrate added or 0.69–0.91 liter/g destroyed. The maximum loading rate for which substrate inhibition is not observed is 6 g dry substrate added per liter per day. The results of the entire program indicate that processing brewery by‐product in this manner is both technically feasible and economicall

ISSN:0006-3592    

DOI:10.1002/bit.260190607

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

年代:1977

数据来源: WILEY

摘要:

AbstractA gram‐negative bacterium strongly lytic toward living cells of the food yeastSaccharomyces fragiliswas isolated by continuous‐flow enrichment from compost. The organism was identified as a species ofArthrobacter. The extracellular lytic enzyme complex produced by this bacterium contained β‐1,3‐glucanase, mannan mannohydrolase, and proteolytic activities. The polysaccharases were inducible by whole yeast cells. In chemostat cultures on chemically defined media, synthesis of the polysaccharases was very slight and only detectable at dilution rates below 0.02 hr−1. Enzyme production in defined media was not solely dependent on growth rate but also was influenced by the growth limiting substrate and the culture history. The production of individual depolymerases and of the lytic activity was studied in batch and chemostat cultures containing yeast as the limiting substrate. The maximum specific growth rate of theArthrobacterunder these conditions was 0.22 hr−1. β‐1,3‐Glucanase and proteolytic activities were synthesized by exponentially growing bacteria but maximum lytic titers did not develop until the specific growth rate was declining, at which time mannan mannohydrolase syntheses was induced. In yeast limited chemostats polysaccharase syntheses were greatest at the lowest dilution rates examined, namely 0.02 hr−1. Further optimization of enzyme production was achieved by feeding theArthrobacterculture to a second‐stage chemostat. A comparison of lytic enzyme productivities in batch and chemostat c

ISSN:0006-3592    

DOI:10.1002/bit.260190608

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

年代:1977

数据来源: WILEY

摘要:

AbstractWe have demonstrated that a simple electrochemical cell can serve as a detector of NADH concentration in a flow system thereby providing an assay technique for NADH dependent enzymes. When this is applied to NADH produced by enzymatic reaction, then a reproducible measure of enzyme activity is obtained. This method of enzyme activity assay is applicable to a number of oxidoreductase enzymes which employ NAD+or NADP+as coenzymes to achieve substrate modification. The presence of electroactive species in samples of human serum has proved a serious problem in the electrochemical analysis of serum activity. These species produce a large background anode current at the anode voltage appropriate for NADH oxidation. The presence of this high current limits the usefulness of amplification of the current output to detect small changes in NADH concentration.

ISSN:0006-3592    

DOI:10.1002/bit.260190609

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

年代:1977

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260190610

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

年代:1977

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260190611

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

年代:1977

数据来源: WILEY