摘要:

AbstractEleven alternative fermentation schemes for ethanol production are compared. Conventional batch, continuous, cell recycle, and immobilized cell processes, as well as membrane, extraction, and vacuum processes which remove ethanol from the broth selectively as it is produced, are considered. The processes are compared on identical bases using a consistent model for the yeast metabolism. Both molasses and cellulose hydrolyzate are considered as feeds. Optimized ethanol plants, including feed preparation, fermentation, and product recovery sections are designed and total costs are projected.

ISSN:0006-3592    

DOI:10.1002/bit.260260902

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

年代:1984

数据来源: WILEY

摘要:

AbstractAfter transforming host cells ofBacillus stearothermophilusCU21 with a recombinant plasmid pLP11 that harbored constitutive penicillinase genes ofB. licheniformisCO1, both the stability of the plasmid and specific rate of penicillinase production were studied. The temperature at which the plasmid could be kept in a stable fashion in the transformant ofB. stearothermophilusCU21 (pLP11) ranged nearly from 44 to 50°C, irrespective of batch and continuous cultures. Continuous and steady‐state cultures of the transformant could only be realized within this narrower temperature range. Indeed, the approximate temperature ranges of growth for the host and transformant were from 40 to 70°C and from 40 to 63°C, respectively. Clearly, the upper limit for the growth temperature of host cells decreased when they were transformed. Kinetic patterns of penicillinase production in continuous culture of the transformant (with plasmid) from 44 to 50°C differed remarkably from that ofB. licheniformisCO1 (without plasmid) at

ISSN:0006-3592    

DOI:10.1002/bit.260260903

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe process of enzyme immobilization under the diffusion‐controlled regime (i.e., fast attachment of enzyme compared to its diffusion) is modeled and theoretically solved in this article. Simple and compact solutions for the penetration depth of immobilized enzyme and the bulk enzyme concentration versus time are presented. Furthermore, the conditions for the validity of our solutions are also given in this article so that researchers can discover when the theoretical solutions can be applied to their system

ISSN:0006-3592    

DOI:10.1002/bit.260260904

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe conversion of ethanol to ethyl acetate has an advantage as a method of ethanol recovery since ethyl acetate is amenable to simple solvent extraction. The potential ofCandida utilisin this conversion was studied. The kinetics of accumulation of ethanol and ethyl acetate in glucose‐grownC. utilisshowed that ester formation resulted from ethanol utilization under appropriate aeration and was inhibited by Fe3+supplementation.Candida utilisconverted ethanol to ethyl acetate optimally at pH 5.0–7.0. The five‐hour rate of ester production increased as the ethanol concentration increased to 10 g/L, and rapidly declined to zero at concentrations exceeding 35 g/L. Thus,C. utilishas potential to recover dilute ethanol in the form of ethyl ac

ISSN:0006-3592    

DOI:10.1002/bit.260260905

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

年代:1984

数据来源: WILEY

摘要:

AbstractIn the wake of an earlier advanced multicomponent–multispecies biological treatment model, the authors suggest algorithms to substantially decrease the number of free coefficients. Operation of a number of experiments with the multicomponent‐multispecies model has helped to further our understanding of the mechanism of biological treatm

ISSN:0006-3592    

DOI:10.1002/bit.260260906

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

年代:1984

数据来源: WILEY

摘要:

AbstractFour fluidized bed reactors were used to evaluate single‐and separated‐phase anaerobic treatments of a high strength wastewater. Two reactors were fed with a synthetic wastewater, containing glucose as the primary carbon source, with a COD of 1.2 × 104mg/L while the remaining pair were fed with a wastewater with a COD of 6000 mg/L. AT each influent strength, one fluidized bed reactor was operated as a single‐phase system while the other was operated as a methanogenic reactor which was preceded by an acidification reactor in a separatedphase system. The reactors were operated under steady‐state and variable process conditions. The separated‐phase system consistently gave a better quality effluent with lower effluent suspended solids and total COD, and the methane yield was also improved. Under variable process conditions, the separated‐phase system was inherently more stable and recovered more rapidly following a shock loading. Propionate and acetate degradation studies indicated that the biomass in the methanogenic fluidized beds of the two‐phase systems was more adapted to volatile acid degradation than the biomass in the single‐phas

ISSN:0006-3592    

DOI:10.1002/bit.260260907

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe effectiveness of attaching flavin adenine dinucleotide (FAD) via a C bridge to Teflon‐bonded carbon black (CB), and the subsequent immobilization of glucose oxidase on the FAD‐modified electrodes has been studied by cyclic voltammetry. When FAD alone is bound to the electrode, it undergoes reduction and oxidation at −0.62 and −0.5 V, respectively—values similar to those obtained with free FAD. Compared to the free enzyme, the reduction of FAD as part of the immobilized enzyme is 200 mV more cathodic, while the oxidation potential remains the same in b

ISSN:0006-3592    

DOI:10.1002/bit.260260908

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

年代:1984

数据来源: WILEY

摘要:

AbstractIndividual monosaccharides present in bagasse hemicellulose were determined using HPLC and other chromatographic procedures. The presence of higher oligomers of the monosaccharides could also be determined. No single procedure can separate and identify all the naturally occurring monosaccharides. The pentosan fraction of bagasse wa successfully hydrolyzed and extracted with 5% (m/v)HCl, and the rate of release of individual monosaccharides was determined. Xylose was the main component in the hydrolyzates, while glucose, arabinose, and galactose present in the side chains of the pentosans were initially released at a fast rate. This treatment resulted in obtaining 229 mg/g xylose (85% of theoretical maximum) and 44 mg/g glucose from bagasse. Only arabinose (2.8 mg/g) and galactose (0.75 mg/g) was also present in detectable quantities. A total of 309 mg monosaccharides were obtained from 1 g of bagasse by this treatment. The results indicated that hydrolysis conditions for specific plant materials depend on the composition of the specific material being utilized. A part of the pentosan fraction (77.1%) was hydrolyzed at a high rate, while 22.9% was more stable and hydrolyzed more slowly. Although 39.8% dry bagasse could be obtained in solution by treatment with dilute alkali, only about 72% of the available hemicelluloses could be extracted in this way if the bagasse was not delignified beforehand. Amino acids and peptides or proteins were also extracted to very much the same with the alkali.

ISSN:0006-3592    

DOI:10.1002/bit.260260909

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

年代:1984

数据来源: WILEY

摘要:

AbstractIn search of hypercellulolytic microorganisms, ultraviolet irradiation carried out withPenicillium funiculosumhas yielded a superior mutant. The investigations reported in this article are shake flask studies on some important nutritional requirements of the mutant, namely, nitrogen source, carbon source, and inducers. The mutant shows an ability to metabolize inorganic nitrogen sources like urea and sodium nitrate both for growth and enzyme production. A comparison of the long‐term saccharification ability and the utilization efficiency of the mutant enzyme with those reported in the literature is also carried out, showing the superior performance of the mutant enzym

ISSN:0006-3592    

DOI:10.1002/bit.260260910

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe rationale behind KISR's involvement in SCP is explained and emphasis towards the use of aerobic thermophilic/thermotolerant methanol‐utilizing bacterial cultures is stressed. An attempt is made to correlate different pilot plant harvesting procedures for biomass recovery with product quality. The latter is expressed as crude and true protein content, moisture and ash content, mineral composition of the ash, and amino acids profiles. The most suitable harvesting procedures were found to be those using a mild heat–acid or acid–heat treatment. Both of these procedures gave high recovery efficiencies and suitable product nutr

ISSN:0006-3592    

DOI:10.1002/bit.260260911

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

年代:1984

数据来源: WILEY