摘要:

AbstractThe immobilization process of some biologically active proteins on acrylic ion exchange supports was studied. The cross‐linking and swelling coefficient, as well as the molecular weight of the enzyme, were proved to influence the immobilization process. The kinetic data indicate mainly a binding process controlled by diffusion. The uptake coefficient values of different proteins ranged between 35.0 and 98.0%. The laboratory experiments per formed with some of the obtained enzymic preparation certify the preservation of the catalytic activity following the immobilization proces

ISSN:0006-3592    

DOI:10.1002/bit.260300502

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe competition between flocculating and nonflocculating microorganisms was investigated in a continuous reactor‐settler system (e.g. activated sludge). Co existence states were found to be possible, over a certain domain of operating conditions, even with simple monotonic kinetics and simple competition. Multiple solutions exist when coexistence states are unstable. Coexistence solutions are stable when the flocculating bacteria grow faster at feed conditions as in the activated sludge problem. The analysis applies to one or several mixed or plug flow reactors. Other effects, such as enrichment of the recycle stream by the flocculating microorganism or substrate adsorption and storage, may change the structure of solutio

ISSN:0006-3592    

DOI:10.1002/bit.260300503

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe conversion is described of phenolsulphonephtalein (phenol red) to 3,3′,5,5′‐tetrabromophenolsulphonephthalein (bromophenol blue) by bromoper‐oxidase from the brown algaAscophyllum nodosum.This reaction provides a convenient assay for the detection of bromoperoxidase activityin vitro.Bromoperoxidase was shown to be stable under turnover conditions for three weeks at room temperature, catalyzing the bromination of phenol red into bromophenol blue. When stored at room temperature in organic sol vents such as acetone, methanol, ethanol [present up to 60% (v/v)], and 1‐propanol [40% (v/v)], bromoperoxidase was stable for more than one month. As far as we know this is the first example of an oxidoreductase which displays such great stability. This enhances the applicability of the enzyme in organic

ISSN:0006-3592    

DOI:10.1002/bit.260300504

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

年代:1987

数据来源: WILEY

摘要:

AbstractThree anaerobic fluidized bed reactors at 37°C were utilized to observe the effects of startup and operational procedures on biomass attachment. Using a meat‐based synthetic waste and stepped‐loading regime, the influences of synthetic polymer addition and maintenance of anaerobiosis during startup were investigated. Subsequently, increasing bed expansions were applied to assess shear effects. Synthetic polymer addition enhanced biomass retention but did not improve process performance. Maintenance of a reduced environment ameliorated fluctuating process parameters during start up and aided biomass retention and substrate removal. A bed expansion of 5% was detrimental to biomass attachment and COD removal but system stability was maintained at expansions between 10% and 30%. Startup was achieved in 56 days. Anaerobiosis appeared to enhance the initial evolution of a stable, well‐adapted microbial population, whereas polymer addition interfered with this. Moderate bed expansions had negligible effects on attachment and perfo

ISSN:0006-3592    

DOI:10.1002/bit.260300505

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe effectiveness of a new immobilized cationic triazine dye was investigated alongside two new amphoteric triazine dyes and two well known anionic triazine dyes, Procion Red H‐3B and Procion Blue H‐B, as chromatographic media for binding four familiar proteases–trypsin, chymotrypsin, thrombin and carboxypeptidase‐B–as well as a typical oxidoreductase, lactate dehydrogenase, and human serum albumin. The new affinity adsorbent, CL‐Sepharose‐immobilized Cationic Dye, specifically binds trypsin‐like proteases such as trypsin, thrombin, and carboxypeptidase‐B, but none of the other proteins tested. In contrast, the amphoteric and anionic immobilized dyes bind all the other proteins tested in a similar fashion. The specificity of the cationic dye was exploited in the resolution of trypsin and chymotrypsin from a crude activated bovine pancreatic extract. The procedure described here affords trypsin with specific activity of 7400 units/mg with a 79% overall yield in a single step. The immobilized cationic dye, unlike previously reported adsorbents for trypsin, is inexpensive, readily synthesized, and displays a workable capacity of 4000 trypsin units or 0.55 mg protein/g moist weight gel (1.2 μmol dye/g moist weight gel) from a crude bovine pancreatic extract and, thus, is potentially amenable to proces

ISSN:0006-3592    

DOI:10.1002/bit.260300506

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

年代:1987

数据来源: WILEY

摘要:

AbstractThis article describes the synthesis and regulation of β(1‐3)glucanase and protease enzymes from the cell lytic system ofOerskovia xanthineolyticaLL‐G109 in continuous culture using different concentrations of carbon source (glucose) and inducer (glucan). These two enzyme activities are the main components of a lytic system capable of lysing and disrupting whole yeast cells; it is subject to catabolite repression by glucose and is induced by yeast glucan. Peaks of β(1‐3)glucanase and protease activity are obtained at dilution rates of between 0.05 and 0.15 h−1. The glucanase‐protease ratio is very high compared to other strains. At dilution rates above 0.15 h−1all activities are similar to those obtained in batch culture. The lytic enzyme system appears to contain several β(1‐3)glucanase enzymes. In continuous culture both productivity and enzyme concentrations are greatly in creased when compared to batch culture, 11‐ and 4.4

ISSN:0006-3592    

DOI:10.1002/bit.260300507

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

年代:1987

数据来源: WILEY

摘要:

AbstractA mathematical model that describes the dynamic behavior of the elution stage of biospecific adsorption (affinity chromatography) in a fixed bed is developed and solved. Both non‐selective and selective elution methods are considered. The results show that the duration of the elution stage for a given bed length decreases as the value of the Porath parameter for elution increases. The concentrating effect of the elution stage on the adsorbate of interest increases as the bed length and the value of the Porath parameter for elution increase. It is shown that it is inappropriate to assume that the eluent is infinitely fast distributed within the pores of the particles, and an interesting result involving a local maximum in the effluent concentration of the selective eluent is obtained when the direction of flow in the elution stage is the same as in the adsorption and wash stages and the bed length is large. When the direction of flow during elution is opposite (as compared to being the same) to that employed in the adsorption and wash stages, a shorter total elution time is obtained. The advantage gained with a reversed flow increases as the bed length decrease

ISSN:0006-3592    

DOI:10.1002/bit.260300508

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

年代:1987

数据来源: WILEY

摘要:

AbstractA modified bench scale calorimeter has been employed to determine the heat generated by various microbial strains growing on a range of different substrates, covering degrees of reduction from 3 to 6.13. The results are analyzed, and interpreted in the light of coupled enthalpy and elemental balances. The heat released by the microbial cultures has been found to correlate linearly with other process variables, such as biomass generation and oxygen uptake. The ratio between the heat generated and the biomass formed, the so‐called “heat yield” (YQ/x), has been shown both on theoretical and experimental grounds to increase with increasing degree of reduction of the substrate and to decrease with increasing biomass yield. The two effects could be combined into a simple model which permits the amount of heat released per unit of biomass formed to be predicted from the degree of reduction of the substrate as the only independent variable. The ratio between the heat generated and the oxygen taken up was constant at 440 kJ (mol O2)−1throughout all experiments as expected from theoretical considerations for strongly aerobic pr

ISSN:0006-3592    

DOI:10.1002/bit.260300509

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

年代:1987

数据来源: WILEY

摘要:

AbstractKinetics of methanogenesis from acetate was studied using pure cultures ofMethanosarcina barkeriandMethanosarcina mazei.Methane formation was found to be associated with cell growth. Nearly equimolar methane was produced from acetate during the methanogenic growth, and about 1.94 g of cells were formed from each mole of acetate consumed. Cell growth can be estimated from methane production. Significant substrate inhibition was found when acetate concentration was higher than 0.12 M. Among the three methanogenic strains studied,M. mazeistrain S6 had the highest specific growth rate at all acetate concentrations studied and was least sensitive to environmental factors investigated (e.g., acetate concentration). The maximum specific growth rate found for strain S6 was 0.022 hr−1at acetic acid concentration around 7 g/L. The other two strains studied wereM. barkeristrain 227 and strain MS. Growth ofM. barkeriwas completely inhibited at sodium acetate concentrations higher than 0.24 M. The maximum specific growth rate found for strains 227 and MS was 0.019 and 0.021 h−1at acetic acid concentrations of 3.6 and 6.8 g/L, respectively. A kinetic model with substrate inhibition was developed and can be used to simulate the methane formation fromM. mazeistrain S6 grown on acetate at 35°C,

ISSN:0006-3592    

DOI:10.1002/bit.260300510

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe enzymatic saccharification of plant material has been shown to be of interest in various fields, such as the production of fruit juices1,2and the utilization of biomass.3A combination of cellulase, pectinase, and hemicellulases is usually used because of the chemical composition of the matrix of plant cell walls.For apples, beet pulp, and potato fiber, almost a complete hydrolysis of polysaccharides is obtained by combining cellulose and pectinase. For nonparenchymatic tissue, the situation is somewhat different: pectin is a minor component and the hemicellulose content is much higher. Enzyme action is restricted by the lignin barrier and by the high crystallianity of cellulose in this material. For such materials, mechanical, thermal, or chemical pretreatments are necessary to achieve hydrolysis.4,5This communication describes various enzymatic treatements and chemical and physical pretreatemtn, using brewers' spent grain as substrate. Spent grain is the residue of malt and grain which remains in the mash‐kettle after the liquefied and saccharified starch has been removed by filtratio

ISSN:0006-3592    

DOI:10.1002/bit.260300511

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

年代:1987

数据来源: WILEY