Journal of Chemical Technology & Biotechnology

doi: 10.1002/jctb.280490301pmid: N/A

Moresi, Mauro; Trunfio, Antonio; Parente, Eugenio

doi: 10.1002/jctb.280490302pmid: N/A

Continuous whey fermentation by Kluyveromyces fragilis was studied in a 30‐dm3 stirred fermenter as a function of the dilution rate (D) and feed concentration of lactose (So). By using the concept of material and energy balances, it was possible not only to check the consistency of the experimental steady‐state responses, but also to develop an unstructured model based on a Monod‐type kinetic equation for cell growth and two independent linear equations for the consumption rates of lactose and oxygen. Moreover, a typical Lineweaver—Burk plot enabled the yeast specific growth rate to be described as that of an enzyme‐catalysed reaction in the presence of an unknown noncompetitive inhibitor (that was identified with a reference intermediate compound produced by the microorganism itself under partially anaerobic conditions and expressed in terms of ethanol equivalent). In this way, the experimental cell concentrations were reconstructed with a mean standard error of about 10%, thus confirming the capability of this model to provide a reliable basis for further scale‐up of this fermentation process.

Videla, Sebastian; Chamy, Rolando; Navarrete, Eduardo; Lema, Juan M.

doi: 10.1002/jctb.280490303pmid: N/A

A methane fermentation system can be considered as a multi‐objective optimization problem characterized by conflicting objectives such as investment cost, net biogas production and chemical oxygen demand (COD) removal. To this end, a k‐objective ‐constraint method was used to determine the optimal design and operation parameters of a continuously stirred anaerobic digester. This equipment treats leachates from the controlled solid urban wastes landfill at Garraf (Barcelona, Spain), which receives 5–6 × 105 tonnes of wastes per year. The optimal solutions were generated for two design criteria: (a) reduction of cost to a minimum and (b) maximization of net energy production with at least 75% removal of COD. The preferred solution was obtained by using the non‐inferior solution set.

Johansson, Hans J.; Pettersson, Torbjörn N.; Berglöf, Jan H.

doi: 10.1002/jctb.280490304pmid: 1366799

A process for large‐scale purification of staphylococcal enterotoxin B (SEB) is presented. The process consists of three chromatographic steps. The first two steps are based on ion‐exchange chromatography and the final one on gel filtration.

Yanni, A. S.; Mohharam, A. M.

doi: 10.1002/jctb.280490305pmid: 1367477

5‐Aryl (or alkyl)‐8‐hydroxyquinoline‐7‐sulphonic acids have been prepared by the Mannich reaction of 8‐hydroxyquinoline‐7‐sulphonic acid with primary and secondary amines. Their bactericidal activities have been determined.

Lee, J. B.; Boardman, W.; Edwards, G. S.

doi: 10.1002/jctb.280490306pmid: N/A

The copper amalgam electrode can be used for clean oxidative coupling of but‐1‐yn‐3‐ol in good yield. An electrochemically generated intermediate can be further coupled in a solution process by aeration of the electrolyte giving increased yields. Addition of pyridine depresses coulombic yields in the electrochemical system, although it increases the rate of the purely chemical process.

Pfeiffer, Dorothea; Ralis, Edmundas V.; Makower, Alexander; Scheller, Frieder W.

doi: 10.1002/jctb.280490307pmid: 1367478

Based on the glucose oxidase‐β‐galactosidase sequence an enzyme probe for the specific determination of lactose has been developed. β‐Galactosidases from different sources have been compared, the sensor containing β‐galactosidase from Curvularia inaequalis has been characterized in respect of optimal pH, enzyme loading, apparent activity and functional stability. The response of the bi‐enzyme probe depends linearly on lactose concentration between 0.02 and 3.00 mmol dm−3. The application to different milk and foodstuff samples resulted in good correlations toward enzymatic photometric (y = (0.956x‐1.67) mmol dm−3) and infrared detection (y = (1.0772x‐0.3909)%). Using a measuring frequency of 100 h−1 the serial imprecision is about 2% for diluted milk, urine, or foodstuff samples.

Gomez, S. Jimenez; Valdivia, L. M. Lopez; Iglesias, C. Gonzalez; Selas, M. I. Rico

doi: 10.1002/jctb.280490308pmid: N/A

The extraction and stripping of Co(II), Ni(II), Cr(III) and Fe(III) from aqueous solutions by rosin dissolved in toluene has been investigated. Results obtained show that rosin is better extractant than abietic or n‐lauric acids under comparable conditions.

Rangnekar, Dinesh W.; Puro, Sanjay S.

doi: 10.1002/jctb.280490309pmid: N/A

4‐Phenyl‐5‐aminopyrazole 2 obtained from phenylcyanoacetaldehyde 1 and hydrazine hydrate reacted with diethyl malonate to give 3‐phenyl‐5,7‐dioxopyrazolo[1,5‐a]pyrimidine 3, used as the key compound in the synthesis of arylazo dyes. The key compound 3 was coupled with various aryldiazonium salts 4 to yield 3‐phenyl‐7‐hydroxy‐6‐arylazopyrazolo[1,5‐a]pyrimid‐5‐ones 5. The resulting arylazo dyes (5) were refluxed in phosphorus oxychloride to give 3‐phenyl‐5,7‐dichloro‐6‐arylazo‐pyrazolo[1,5‐a]pyrimidines 6, which subsequently reacted with refluxing morpholine and piperidine to yield 3‐phenyl‐5,7‐bis(morpholino and piperidino)‐6‐aryiazopyrazolo[1,5‐a]pyrimidines 7. The arylazo dyes 5 and 7 were applied to polyester fibres as disperse dyes and the arylazo dyes 6 were applied to polyamide fibres as disperse reactive dyes. The spectral and dyeing properties of the dyes were studied.

Heinritz, Brigitte; Gehrhardt, Matthias; Baumann, Frank; Rogge, Gerlind; Hedlich, Rolf

doi: 10.1002/jctb.280490310pmid: N/A

An energy‐economic use of reaction heat is possible only if thermophilic microorganisms convert carbon substrates into biomass at temperatures above 65°C.