摘要:

AbstractThe effects of ambient pressure and ultrasonic power on the disintegration of yeast suspension have been investigated. The results obtained are, in the main, consistent with the theory that cell breakage is primarily a phenomenon dependent on producing gaseous cavitation in the medium. The importance of the experimental results and techniques applied to Commercial cell disintegrators is briefly discussed. A simple flow system is described which is easily attached to probe‐type disintegrators. The use of a crystal pickup for tuning and control purposes is describe

ISSN:0006-3592    

DOI:10.1002/bit.260060302

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

年代:1964

数据来源: WILEY

摘要:

AbstractAeration and agitation conditions in 250 l. baffled fermenters with different impeller diameters, speeds, and air flows were studied during fermentations for the production of rifamycin, a new antibiotic produced byStreptomyces mediterranei. Dissolved oxygen concentration was continuously measured and the courses of power input, oxygen diffusion rateQO2, dry weight, viscosity, pH, sugar utilization, and antibiotic titer determined. Higher antibiotic yields occurred when the oxygen demand of the culture was satisfied and an excess of dissolved oxygen was still present during a critical period of the fermentation between the 50th and the 80th hr. To meet this requirement a power input of about 3.0 w./l. and an air flow ranging from 0.8 to 1.5 l./l./min. were found to be necessary.

ISSN:0006-3592    

DOI:10.1002/bit.260060303

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

年代:1964

数据来源: WILEY

摘要:

AbstractSemicontinuous sulfide fermentation has been conducted with distillery spent liquor as the source of carbon employing a strain similar toDesulphovibrio rubentschikii. Mineral barites and gypsum have been used as the hydrogen acceptors during the studies. Results reveal that mineral barites can also react very favorably as hydrogen acceptors. Sulfates have been used both in powdered (200 mesh) and lumpy (1/4‐1/2 in. size) forms. When applied in lumpy form in a packed tower, both the mineral sulfates produced higher yields of sulfide compared to their corresponding finely pulverized states. Thus, under similar conditions, fermentation conducted with pulverized gypsum showed a yield of 450–550 p.p.m. hydrogen sulfide, whereas the yield was as high as 750–1025 p.p.m. when gypsum lumps were used as a packing. Corresponding figures with barites are 300 and 540 p.p.m., respectively. Continuous sulfide fermentation has also been conducted in a packed tower containing lumpy gypsum as the packing under total recirculation. Daily buildup of sulfide was observed to be as high as 180 mg./l. of fermenting medium. Appreciable reduction in COD of the effluent was observed during the above studies. Thus, with barites, per cent COD reduction values were 30–35, 45–50, 60–65, and 75–80 with retention periods of 10, 15, 25, and 35 days, respectively. With gypsum, per cent COD reduction was 50–70 with 10 days's residence time. The effects of the retention period on sulfide yield and volatile acid content were also studied. The longer the retention period, the higher is the sulfide yield and the lower the volatile acid content of the discharge becomes. Studies were also conducted to find the correct composition of volatile acids in the discharge, as well as the levels of their concentration during continuous feeding and discharge over a number of days. It has been observed that during 18 hr. of fermentation in a batch, volatile acid concentration increased from 6.76 m. to 15.01 mmoles per liter of medium of which 10 mmoles are acetic, 0.833 mmoles butyric, and 4.16 mmoles propionic acid. Studies on soluble and insoluble sulfate balance have also been made in a synthetic medium containing calcium acetate as the substrate. Unaccounted for sulfates were negligible and a deviation between the actual and calculated sulfide yield did not exceed 2%. It is also observed that, when fermentations are conducted in sulfate packed columns, the color of the effluent becomes paleyellow containing very little suspended and volatile matter compared to the deep‐black color of the emuent emerging from a ferrnenter fed with pulverized sulfates. This liquor contains 0.5271% soluble ash (computed as potash) and might be a good

ISSN:0006-3592    

DOI:10.1002/bit.260060304

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

年代:1964

数据来源: WILEY

摘要:

AbstractA soil isolate, HD‐5, identified as closely resemblingCandida intermedia, was grown on normal alkanes ranging from dodecane (C12) to octadecane (C18). The growth rate of the organism increased with increasing length of the alkane chain. The shortest generation time was 4.5 hr. with octadecane as the carbon source. Cell yields of 82% were common with even numbered alkanes from C14through C18. The cell yields appeared to decrease with shorter chain (C12or below) and odd‐numbered chain alkanes. The cellular nitrogen ranged from 6.9 to 7.5% and the highest lipid content found was 10.3% (with C

ISSN:0006-3592    

DOI:10.1002/bit.260060305

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

年代:1964

数据来源: WILEY

摘要:

AbstractThe authors describe continuous cultivations ofEscherichia colipossessing high penicillin‐acylase activity in corn‐steep liquor, peptone, and ammonium phenylacetate containing nutrient medium. If the cultivation is performed in the absence of ammonium phenylacetate the enzymic activities of cells from the batch as well as the continuous cultures are very low. The enzymic activity of cells in the batch process was considerably increased by the addition of 0.015% ammonium phenylacetate to the nutrient medium. Further increase of ammonium phenylacetate concentration did not result in any further increase of acylase activity. Continuous cultivation of the bacteria at the above ammonium phenyl‐acetate concentration was unsuccessful, as the enzymic activity of the bacteria constantly decreased during the process. On increasing the concentration of ammonium phenylacetate in the medium to 0.15% the authors succeeded in maintaining the enzymic activity of the bacteria at the same level as in the batch process performed at 0.015% concentration, throughout the whole continuous cultivation. At the dilution rateD= 0.5 hr.−1the concentration of cells in the culture effluent from the fermentor at the steady state was equal to cell concentration at the end of batch cultivation. In relation to the cultivation time the output of cells in continuous cultivation is almost seven times higher as compared with the batch

ISSN:0006-3592    

DOI:10.1002/bit.260060306

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

年代:1964

数据来源: WILEY

摘要:

AbstractVarious methods for the removal of extraneous matter from vaccinia virus suspensions are described and compared. Of ten procedures tested, differential centrifugation and Freon extraction were the most successful. Both the partially purified suspensions and the dried products prepared from them had high virus titers in embryonated eggs and high infectivity for mice. Although both processes resulted in products with the same titers, the differentially centrifuged product was approximately tenfold more purified as shown by the percentage solids of the suspensions before freeze drying.

ISSN:0006-3592    

DOI:10.1002/bit.260060307

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

年代:1964

数据来源: WILEY

摘要:

AbstractDuring investigations of submerged fermentation of penicillin and chlortetracycline, we reached the conclusion that production in relation to oxygen transfer is relatively uninfluenced by the composition of the fermentation medium. The maximum penicillin production, using the strainPenicillium chrysogenumNG in flasks on a shaker was uniformly achieved in all investigated media with an oxygen transfer rate of 0.81; and in chlortetracycline, using strainStreptomyces aureofaciensBMK−11, with an oxygen transfer rate of 0.59 ml. O2/ml./hour. The primary factor which influences the antibiotics production is the transfer of oxygen into the liquid. The absolute volume of production is, however, partly influenced by mechanical conditions of fermentation and the composition of the mediu

ISSN:0006-3592    

DOI:10.1002/bit.260060308

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

年代:1964

数据来源: WILEY

摘要:

AbstractThe oxygen uptake rate to suspended cells ofPseudomonas ovaliswas measured in two ways using the same cell suspension. Initially the rate was found by measuring the rate of production of gluconic acid by cells suspended in a nitrogenfree, aerated medium. Then, an oxygen electrode was used to measure the rate of transfer of dissolved oxygen to cells suspended in a liquid that was being agitated but not sparged. These rates were markedly different. It was found that agitation affected the oxygen transfer rates in aerated solutions at dissolved oxygen concentrations well above the critical level, but had no affect on the oxygen uptake rates by cells suspended in an unsparged but agitated medium. The data suggested that an additional path existed for oxygen transfer. This alternate route, parallel to the conventional pathway of oxygen transfer, becomes operative when the liquid films surrounding the cells and bubbles merge. The resulting shorter path presents a mechanism for direct transfer of oxygen which increases in importance as the gas−liquid interfacial area increase

ISSN:0006-3592    

DOI:10.1002/bit.260060309

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

年代:1964

数据来源: WILEY

摘要:

AbstractThe ability ofBacillus subtilisto accumulate guanosine 5′‐monophosphate (5′‐GMP) extracellularly was demonstrated by isolation of 85% pure 5′‐GMP from the broth. In addition, a compound with the properties of guanosine 5′ diphosphate was obtained from t

ISSN:0006-3592    

DOI:10.1002/bit.260060310

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

年代:1964

数据来源: WILEY

ISSN:0006-3592    

DOI:10.1002/bit.260060301

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

年代:1964

数据来源: WILEY