摘要:

AbstractUp to 70% of the theoretical protein content of shrimp waste was recovered by a boiling water extraction method. Digestion time, volume and concentration of calcium hydroxide were varied to optimise the yield of dry matter recovered on processing the shrimp waste. Amino acid analysis was carried out to characterise the protein content of the dry matter.

ISSN:0264-3421    

DOI:10.1002/jctb.280330402

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractThe kinetics of methanogenesis from a stirred batch‐fed calcium acetate enrichment culture have been studied. A detailed kinetic analysis of the culture allowed four distinct phases to be distinguished. Phase 1 was a period of very rapid increase (from low initial values) in the rate of methanogenesis upon addition of acetate, and was not thought to be associated with cell growth. In Phase 2 the rate of methanogenesis increased exponentially with time reflecting exponential growth. Phase 3 was characterised by an approximately constant rate of methane production, and is discussed in relation to the uncoupling of growth and methanogenesis. Phase 4 is a period of rapid decline associated with depletion of acetate. The apparent size of the population of the acetate‐utilising methanogenic bacteria subsequently declined, with a specific decay constant of 0.4 ± 0.1 d−1. The significance of these phases, in particular 2 and 3, for industrial anaerobic digestion is dis

ISSN:0264-3421    

DOI:10.1002/jctb.280330403

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractThin layer chromatography was demonstrated as an effective technique for observing the time course of hydrolysis of a substituted xylan (arabinoxylan) by crude preparations ofCellulomonas.The chromatograms revealed a sequential pattern of appearance of xylooligomers and arabinoxylooligomers, with early appearance of relatively large oligomers and subsequent accumulation of xylobiose and (to a lesser extent) xylose and arabinose. The pattern indicated that the dominant enzymic activity towards arabinoxylan is that of an endoxylanase.

ISSN:0264-3421    

DOI:10.1002/jctb.280330404

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractAn anaerobic fluidised bed reactor, operating at room temperature, was used to treat a synthetic meat extract wastewater with an influent COD of 1250 mg 1–1. It was subjected to large increases in influent COD and flow rate for 4‐and 8‐h periods. The reactor tolerated these transient changes satisfactorily and with no long term detrimental effects. Normal operation was regained within 9h. Variations in operating temperature and influent pH were also examined. Four hour duration, 10°C temperature increases and decreases had little effect on effluent quality, but long term operation at a low influent pH was considered inadvisable. A simulated working week experiment was carried out with a 48‐h 90% influent flowrate reduction, followed by a return to normal operation. The reactor tolerated these conditions well, with full recovery made within a few hours. The resistance of the reactor to unfavourable process conditions is discussed. The extrapolation of laboratory data to practical operating conditions is also co

ISSN:0264-3421    

DOI:10.1002/jctb.280330405

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractChaetomium cellulolyticumwas cultivated on Avicel and/or stream‐and NH3‐pre‐treated straw in a 20 litre stirred tank reactor with batch and/or fed‐batch operation. The influence of the substrate concentration, the impeller speed and the fed‐batch operation on cell productivity was investigated. Steam‐pretreated straw can be better utilised by the fungus than NH3‐pretreated straw. The optimal conditions at which maximum cell productivity and/or maximum cell mass concentration can be attained were evaluated for stream‐pretreated straw. At the beginning of the growth phase the oxygen consumption rate reaches a significant maximum. At this point the enzyme activity begins to increase. The investigations with Avicel indicate that the cell productivity could be significantly increased by fed‐batch operation. A microprocessor‐controlled fed batch process controlled by alkaline consump

ISSN:0264-3421    

DOI:10.1002/jctb.280330406

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

摘要:

AbstractThiobacillus ferrooxidanswas grown at pH 1.6 in continuous flow chemostat culture on ferrous sulphate as growth limiting substrate at dilution rates between 0.02–1.33 h−1. Iron oxidation and growth were subject to product inhibition by ferric iron and under some conditions substrate inhibition by ferrous iron. Product inhibition could be predominantly competitive or non‐competitive, and the mode observed depended partly on previous steady state conditions. The inhibition phenomena resulted in unique anomalous washout curves and complex relationships between steady‐state substrate, product and biomass concentrations, for which mathematical models are developed. For the growth states subject to non‐competitive inhibition by Fe3+atD0.073–0.99 h−1, the growth yield coefficient corrected for maintenance (YG) was 1.33 g dry wt (g atom Fe2+oxidized)−1and the maintenance coefficient (m) was 0.43 g atom Fe2+oxidized (g dry wt)−1h−1). For predominantly competitive states (D, 0.05–0.268 h−1) with 2–70 mM Fe3+in steady states,YGwas 0.36–0.38 andmwas 0–0.04. A consequence of product inhibition and substrate inhibition was the possibility of more than one steady state product value and yield for a single steady state substate concentration. This was demonstrated experimentally. Substrate saturation coefficient,Ks(giving half maximum specific growth rate) for Fe2+, was 0.7–2.4 mM and maximum specific growth rate (μm) 1.25–1.78 h−1. The results presented reveal unusual and novel properties ofT. ferrooxidansrelevant to describing its activities in natural environ

ISSN:0264-3421    

DOI:10.1002/jctb.280330407

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY

ISSN:0264-3421    

DOI:10.1002/jctb.280330401

出版商:John Wiley&Sons, Ltd.    

年代:1983

数据来源: WILEY