Abstract: In processes for recovery of biologically active polypeptides from fermentation cultures of recombinant host organisms, cell death is frequently a prerequisite for isolation processing of the recombinant product outside the fermentation vessel. Disclosed are improved methods for effecting efficient host cell death inside the fermentation vessel through uniformly contacting host cells in culture with microbicidal concentrations of benzyl alcohol. Illustratively, E. coli, B. subtilis, and P. aeruginosa cultures are advantageously treated with from 0.5 to 10.0% (v/v) of benzyl alcohol in the absence of pH or temperature changes within the fermentor.

Abstract: A process for the release of lactase from yeast cells comprising contacting the cells with an alkyl alcohol or a dialkyl ketone, followed by extraction of the lactase in an aqueous solution at a pH in the range 5.5 to 8.0 is disclosed. Also disclosed is a process for the selective reduction of protease activity in lactase preparations comprising heating an aqueous solution of lactase containing protease impurities in the presence of glycerol. Lactase stability during the heating process can optionally be enhanced by addition of manganous ion.

Abstract: A process for the preparation of 2,5-diketogluconic acid by the aerobic propagation of Acetobacter cerinus in a fermentation medium containing above about 20 and up to about 30% (wt/vol) glucose and at least about 0.04 wt. % choline based on the amount of glucose in the medium.

Abstract: 2-Ketogluconate present in a mixture with 2-ketogulonate is destroyed by fermentation with a strain of a Pseudomonas species leaving desired 2-ketogulonate intact. Subsequent hydrolysis of the 2-ketogulonate yields ascorbic acid.