ISSN:0098-6445    

DOI:10.1080/00986448608911367

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0098-6445    

DOI:10.1080/00986448608911368

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Hydrocarhon uptake was studied in three microbial systems with different flocculation characteristics. An integrated mechanistic model, based on different substrate sources, has been developed for both flocculating and nonflocculating hydrocarbon fermentation systems. Simulated growth kinetics were compared with experimental results. The model illustrates the role of microbial characteristics in uptake kinetics and identifies the controlling parameters to better understand microbial uptake of hydrocarbons.

ISSN:0098-6445    

DOI:10.1080/00986448608911369

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Clostridium thermohydrosulfuricum has a number of characteristics which make it an attractive organism to use in a process to convert pretreated, lignocellulosic materials into alcohol. One such characteristic is its ability to convert the major products of cellulose hydrolysis, glucose, cellobiose, xylose and xylobiose into ethanol at relatively high yields. Experiments were carried out to investigate the kinetics of multiple sugar utilization. Results showed that glucose repressed the utilization of cellobiose, xylose and xylobiose all of which could otherwise be catabolized simultaneously in the absence of glucose. Further experiments with the glucose/cellobiose system showed that both transient and permanent repression occurred. A mathematical model was developed which successfully described the growth of Cl. thermohydrosulfuricum on mixtures of glucose and cellobiose in both batch and continuous culture.

ISSN:0098-6445    

DOI:10.1080/00986448608911370

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The Clostridium thermocellum-Clostridium thermosaccharolyticum mixed culture system has been scaled down into flasks in defined medium MJ with Solka Floe as carbon source. The best saccharolytic culture for use with the cellulolytic, anaerobic thermophile C. thermocellum ATCC 27405 was found to be C. thermosaccharolyticum HG-8 when compared to Clostridium thermo-hydrosulfuricum strain 39E or Thermoanaerobacter ethanolicus ATCC 31937. The defined medium was optimized for a high cellulose concentration by increasing the level of FeSO4and by replacing 3-[N-morpholino] propane sulfonic acid (MOPS) buffer by sodium bicarbonate.

ISSN:0098-6445    

DOI:10.1080/00986448608911371

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Clostridium sp. ATCC 29797 converts H2and CO2to acetic acid in stationary phase in almost 100% yield. The resting cells are stable for up to 300 h and produce acetate to a final product concentration of 221 mM. The specific productivity of acetate during the stationary phase appears limited by the specific activity of hydrogenase. A high pressure fermentor was constructed to investigate the use of pressure, as a general strategy, for increasing the rates of microbial syngas conversions. Fermentations were conducted at pressures up to 1000 psig using various mixtures of H2and CO2. The use of high pressure proved to be an effective method for eliminating gas transfer resistances and increasing the volumetric productivity. Hydrostatic pressure had little effect on the specific productivity of acetate, however, high partial pressures of hydrogen caused the specific productivity and total acetate accumulated to decrease. High pressures of hydrogen also caused a decrease in the specific activity of hydrogenase. These results suggest that Clostridium sp. ATCC 29797 attempts to control the input of reducing power by regulating the activity of hydrogenase.

ISSN:0098-6445    

DOI:10.1080/00986448608911372

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The solvents acetone and butanol are produced by Clostridium acetobutylicum during batch culture only after a considerable lag. The influence of limiting nutrients on the onset of solvent production has been investigated by studying the continuous fermentation under conditions of carbon, nitrogen and phosphate excess over a wide range of dilution rates. A maximum solvent concentration of 12 gl−1was obtained at the lowest dilution rate investigated, namely 0.05 hr−1, and the average yield of solvents over the range of dilution rates approximated 0.3. These data confirm that a limitation of either of these nutrients is not essential for solvent production.

ISSN:0098-6445    

DOI:10.1080/00986448608911373

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Biogas recovery from the anaerobic digestion of sewage sludge which is discharged from municipal wastewater treatments generally requires a large scale digester owing to the slow biodegradability of the sludge compounds. To achieve an effective methanogenesis from the sludge as the raw materials, thermal pretreatmenls of the sludge were conducted to improve the sedimentation efficiency of the treated sludge and the filtrate obtained was anaerobically digested in fixed-bed bioreactors with baked clay, melted slug and rhyolitic lava.

ISSN:0098-6445    

DOI:10.1080/00986448608911374

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0098-6445    

DOI:10.1080/00986448608911375

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The sugar concentrations in the bulk of the solution, in the pressed juice and in the residual solid and the ethanol concentration in the bulk of the solution and the pressed juice were obtained for two S. cerevisiae strains and three fresh sugarcane particle size in a static EX-FERM process at 35°C. The data show that cane particle size affects the sugar concentration in the bulk of the solution decreasing the extraction rates as the size increased. As a direct consequence the maximum amount of sugar in the bulk of the solution was higher for the smaller particle size. Yeast presumably physically interacted with the cane particles penetrating and adsorbing on the solid, so that there was also an in situ sucrose conversion within the solid matrix. Ethanol concentration within the solids was higher than in the bulk of the solution specially in the first hours of the fermentation due to this effect. Chip size had a strong effect on batch time required to reduce sugar concentration within the cane solid matrix. The time for the smaller chip size was about 60% of the one for the larger particles.

ISSN:0098-6445    

DOI:10.1080/00986448608911376

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor