摘要:

AbstractThis investigation used the glucose oxidase system to simulate oxygen transfer rate in fermentation broths. It was demonstrated that the fungal preparation contained sufficient lactonase activity so thatD‐glucono‐δ‐lactone did not accumulate and that the rate of production of gluconic acid was proportional to the oxygen uptake rate. Enzyme concentrations of 1.5–2 g/1 were found adequate to determine oxygen absorption rates in shake flasks while maintaining the dissolved oxygen concentration of low levels. The apparent Michaelis constant for oxygen,Km(O2), was found to be 27% saturation with air; this value along with experimentally determined uptake rates could be used to calculate dissolved oxygen concentration in lieu of using a dissolved oxygen probe. Enzyme concentrations of 5 g/l were sufficient to give linear acid production and low dissolved oxygen concentrations in a bench‐scale fermenter with no foaming or enzyme deactivation. The method is considered more valid and easier to employ than previously utilized techniques such as sulfite oxidation. Extension of the system to evaluating aeration effectiveness and scaleup of fermentation equipment is

ISSN:0006-3592    

DOI:10.1002/bit.260110102

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

年代:1969

数据来源: WILEY

摘要:

AbstractKinetic, studies were made on continuous cultivation applying the theory of microbial cell growth that was derived previously by the authors introducing the concepts of critical concentration and coefficient of consumption activity. General equations for microbial cell concentration for continuous cultivation in continuous‐stirred tank and tubular type reactors were derived theoretically. Productivity of cell mass in continuous cultivation was analyzed kinetically and the behavior of mutant populations in continuous cultivation is briefly discusse

ISSN:0006-3592    

DOI:10.1002/bit.260110103

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

年代:1969

数据来源: WILEY

摘要:

AbstractIn order to increase the availability of the cell bound protein inScenedesmusalgae, mechanical, enzymatic, and chemical methods of degrading the cell wall structure were investigated.Mechanical treatment involved the use of a ball‐mill. The algae suspension together with glass beads was milled in a water‐cooled chamber equipped with rotating disks. The enzyme tested was a cellulolytic enzyme (Meicelase) and the chemical employed was hydrogen peroxide.In the ball‐mill experiments a complete disintegration was achieved ina disintegrator, working with batches. Trails wwere also performed with a continuous disintegrator and the depedence of disintegration on bead size and flow rate was studied. The disintegration determined by microscropic cell count was compared to the increase of the pepsin digestibility.The meicelase treatment caused a slight increase of the pepsin digestibility, as measured after 3 hr pepsin incubation. No increase of the pepsin disgestibility could be detected with hydrogen peroxide treatment.After the ball‐mill disintegration 95% of contaminating bacteria were killed and yields of extractable proteins were higher. The capacity of availble continuous ball‐mills is such that they could be used on a pilot‐plant scale and the energy cost of disintegration would be of the same magnitude as that of

ISSN:0006-3592    

DOI:10.1002/bit.260110104

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

年代:1969

数据来源: WILEY

摘要:

AbstractA synthetic waste (with glucose as carbon source) devoid of a source of nitrogen was purified in a laboratory scale pilot plant by a new modification of the activated sludge process. The process makes use of a separate carbon assimilation (oxidative assimilation) phase and an endogenous phase in which ammonia is added to a portion of the settled sludge and non‐nitrogenous products stored in the cells in the assimilation phase are converted to protein. It was found that sludge so treated, when recycled to the assimilation tank, could carry out continuous oxidative assimilation of the waste. Various COD:N ratios were studied. At the highest, 70:1, 90% purificaton efficiency was achieve

ISSN:0006-3592    

DOI:10.1002/bit.260110105

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

年代:1969

数据来源: WILEY

摘要:

AbstractBatch experiments were run using heterogeneous populations to determine whether a hyperbolic equation of the type suggested by Monod could be used to depict the relation between specific growth rate, μ, and NH3‐N concentration when ammonia N was the growth‐limiting nutrient. The heterogeneous populations employed were developed from sewage seed grown on glucose at various levels of nitrogen and various dilution rates in completely mixed continuous flow reactors. It was found that the hyperbolic function could be used. Values of μmin the range of 0.4–0.7 hr−1were observed, and values ofKs, in general, ranged from 1.5 to 4.0 mg/l. Variation in the values of these growth “constants” did not follow any discernible pattern related to past growth history (i.e., COD:N ratio or dilution rate at which the cells were prev

ISSN:0006-3592    

DOI:10.1002/bit.260110106

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

年代:1969

数据来源: WILEY

摘要:

AbstractHeterogeneous populations of sewage origin were grown continuously at, dilution rates from 1/12 hr−1to dilute‐out (1/1 hr−1) using glucose (1000 mg/l) as carbon source and three concentrations of NH3‐N as the nitrogen source (COD:N = 70:1, 40:1, and 25:1). The effects of nitrogen level and growth rate (dilution rate) on substrate removal, biological solids production, cellular carbohydrate and protein, and NH 4+‐N in the effluent were examined. It was found that the optimum level of nitrogen supplementation for the synthetic nitrogen‐deficient waste employed should not be based solely on the desired effluent quality with respect to COD removal but should include due consideration of reactor detention time (or dilution rate) and the allowable (or desirable) level of nitrogen leakage in

ISSN:0006-3592    

DOI:10.1002/bit.260110107

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

年代:1969

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260110108

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

年代:1969

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260110109

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

年代:1969

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260110101

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

年代:1969

数据来源: WILEY