摘要:

AbstractSaccharomyces cerevisiaeandSaccharomyces carlsbergensiswere grown in batch culture with and without oxygen control.The concentrations of A‐, B‐ and C‐type cytochromes of both yeasts were dependent on the oxygen concentration during growth as well as on the initial glucose concentration of the growth medium.S. cerevisiaecytochromes were maximal after growth in low glucose and low oxygen;S. carlsbergensiscytochromes were maximal after growth in low glucose and high oxygen. Except when glucose was in very low concentration, its catabolism byS. carlsbergensiswas directed predominantly towards ethanolic fermentation regardless of the oxygen concentration. Growth rate, total cell mass and yield were maximal, and anabolism was closely balanced with catabolism, when glucose and oxygen ofS. carlsbergensiscultures were both high. Under these conditions neither catabolism, respiratory or ethanolic, nor glucose uptake were ma

ISSN:0006-3592    

DOI:10.1002/bit.260130102

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

年代:1971

数据来源: WILEY

摘要:

AbstractMicroscope electrophoresis was used to measure the electrophoretic mobility of polystyrene latex particles and bacterial, and mammalian tissue cells. The submicroscopic hydrophilic colloids (gelatin, serum albumin, and staphylococcal enterotoxin B) were adsorbed on latex carrier particles to determine their electrophoretic mobility and the effect of concentration, pH, electrolyte addition, and buffer ionic strength. Mobility curves as a function of pH were established for latex particles at 1 ppm concentration indicating an isoelectric point (IEP) at pH 3.6. The IEP forEscherichia coliB cells was measured at pH 2.8,Serratia marcescensat pH 2.6,Bacillus subtilisvar.nigerat pH 2.9, and L strain mouse fibroblast cells at pH 4.4. Using an adsorption technique, isoelectric points were measured for proteins: gelatin (acid form) at pH 9.4, serum albumin at pH 4.9, and staphylococcal enterotoxin B at pH 6.3.Procefures for examining electrophoretic characteristics of microscopic and submicroscopic biological particles are described in order to standardize procedures and to generate results applicable to an understanding of parameters influencing concentration and purification of colloidal biological particles.

ISSN:0006-3592    

DOI:10.1002/bit.260130103

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

年代:1971

数据来源: WILEY

摘要:

AbstractSingle cell protein production was studied in a mixed bacterial culture grown in methane using batch and continuous culture techniques. Overall productivity was found to be higher in the continuous culture which gave a maximum productivity value p = 0.15 g/l/h. Methane and oxygen were consumed in the relation 1 : 1.7. Yield coefficients for methane, oxygen, and ammonium chloride were Y CH 4= 0.90, Y O 2= 0.26, and Y NH 4Cl= 0.14. The crude protein content of the biom

ISSN:0006-3592    

DOI:10.1002/bit.260130104

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

年代:1971

数据来源: WILEY

摘要:

AbstractThe growth ofSaccharomyces carlsbergensisin continuous culture has been studied when dissolved oxygen and glucose concentrations were held constant at a series of steady‐state levels. Both oxygen and glucose controlled the degree of aerobic metabolism and of ethanolic fermentation. When the glucose uptake rate was low (between 1.2 and 2.8 mmoles per hour per gram of yeast) the relative distribution of glucose between ethanolic and aerobic fermentation was sensitive to oxygen: when dissolved oxygen was near to saturation, glucose metabolism was 0.98 aerobic; when dissolved oxygen was 0.01 saturated, 0.8 of intake glucose metabolism was by ethanolic fermentation. On the other hand when glucose intake was high (between 7.6 and 18.2 mmoles) metabolism was predominately by ethanolic fermentation even when dissolved oxygen concentration was at saturation. The extent, to which catabolism proceeded by an anaerobic or aerobic pathway, as judged by ethanol production, was controlled more by the uptake of glucose than of oxyge

ISSN:0006-3592    

DOI:10.1002/bit.260130105

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

年代:1971

数据来源: WILEY

摘要:

AbstractExtensive screening studies on cellulolytic bacteria and fungi led to the selection ofMyrothecium verrucariaas the organism producing the maximum rate of protein biosynthesis from ball‐milled newspaper. Studies in aerated stirred‐jar fermentors were carried out to determine the conditions for maximum protein synthesis rate and maximum final protein concentration. The optimum aeration rate was 250 to 374 mM of oxygen at 300 to 400 rpm stirring rate. The pH optimum was broad, from 3.9 to 6.5. Urea at 0.03% and yeast autolysate at 0.1% stimulated growth rate and protein production. The maximum rate of protein biosynthesis and the maximum protein yield were 0.3 g/liter/day and 1.42 g/liter, respectively, from medium G3 with 4% ball‐milled newspaper. The final product, obtained by evaporation of the total culture, was 33.7 g from one liter of medium which originally contained 40 g of ball‐milled newspaper and 11.3 g of other dissolved materials. The protein content of this final product was 3.3 g, calculated from total organicN× 6.25 or 1.42 g calculated from the biuret method. Both the synthesis rate and the final cell yield are below those obtainable by growingFungi Imperfecti, yeasts or bacteria on soluble materials such as

ISSN:0006-3592    

DOI:10.1002/bit.260130106

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

年代:1971

数据来源: WILEY

摘要:

AbstractA combination of Fickian diffusion and Michaelis–Menten kinetics is proposed to describe the rate of diffusion‐coupled biochemical reactions. This postulate leads to a nonlinear mathematical model which is solved by a perturbation technique. The result is a relation which permits identification of zones of relative diffusion or reaction influence. The conversion of cellulose to protein byMyrothecium verrucariais a heterogeneous process that is well‐suited to this type of analysis, although the data requirements are s

ISSN:0006-3592    

DOI:10.1002/bit.260130107

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

年代:1971

数据来源: WILEY

摘要:

AbstractValues of cell yield collected over a period of eight years for heterogeneous populations of sewage origin acclimated to glucose in both batch and continuous culture were subjected to statistical analysis. The cell yield for this sole source of carbon (glucose) ranged from 36 to 88 per cent in batch culture, and 32 to 69 per cent in continuous culture. Because experimental conditions were known and well defined, the variability in cell yield is attributable to the ecological variation inherent in a heterogeneous population. The data presented demonstrate the futility of attempts to defineYfor such populations as a precise theoretical constant dependent upon thermodynamic properties of the substrate.

ISSN:0006-3592    

DOI:10.1002/bit.260130108

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

年代:1971

数据来源: WILEY

摘要:

AbstractIn a previous report it was concluded that steady‐state operation of completely mixed reactors for growth of heterogeneous microbial populations, i.e., activated sludge processes, was extremely difficult to attain if maintenance of a constant sludge recycle ratio,c, was required, and equations were devised in which the concentration of cells in the recycle,xR, rather than the recycle ratio, was constant. In this report the equations are developed and computational analysis shows the effect on substrate and cell concentrations in the reactor of operational variables such as inflowing feed concentration, hydraulic recycle ratio, recycle sludge concentration, dilution rate, and the biological “constants” μm,ks, andY. The stabilizing effect of operating with constantxRon the dilute‐out pattern

ISSN:0006-3592    

DOI:10.1002/bit.260130109

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

年代:1971

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260130110

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

年代:1971

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260130111

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

年代:1971

数据来源: WILEY