. 2000. A solvent extraction method was developed to concentrate lacidin from the culture of Lactobacillus acidophilus OSU133. The new method concentrates the bacteriocin at the interface between chloroform and the aqueous culture of the producing bacterium. Compared with other extraction procedures, the new method effectively recovers higher bacteriocin yield and results in relatively clean preparations. Recovery of lacidin by the chloroform extraction procedure, compared with ammonium sulphate precipitation and cell acidi®cation methods, was >10-fold and about 100-fold greater, respectively. The new extraction procedure saves time and is easy to perform. This method is also effective in recovering subtilin, bacillicin, pediocin and nisin from cultures of Bacillus subtilis ATCC 6633, B. subtilis OSY1115/C, Pediococcus acidilactici PO2 and Lactococcus lactis ATCC 11454, respectively.

Ascorbic acid (vitamin C) degradation during electrical and conventional heating was studied to determine if the presence of an electric field altered the rate of degradation. Experiments were peiformed using a static ohmic heating apparatus, and heating histories were matched using applied voltage in the electrical case and hot oil in the conventional case. A statistical analysis showed that electric field has no significant effect on ascorbic acid degradation. Pseudo first order degradation kinetics were observed for both conventional and ohmic cases. the activation energy and frequency factor for the conventional case was 12.6 kcal/mol and 19.95 × 105 min‐1, respectively; for the ohmic case, values were 12.5 kcal/mol and 19.59 × 1O5 min‐1. the effect of electrolysis on ascorbic acid degradation was also examined. Gas production and dissolution appeared

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Classification at the species level has been difficult in the genus Acanthamoeba. The taxonomic designations of a number of strains are in doubt and new approaches to classification are needed. We describe the use of electrophoretic patterns obtained with restriction enzyme digests of mitochondrial DNA as a basis for one new approach. Results from analysis of ten strains of A. castellanii, two of A. polyphaga and one of A. astronyxis are discussed. Examples both of nucleotide sequence diversity and of sequence conservation have been found among strains with the same species designation. Five strains from Europe, North America and New Zealand had identical digestion phenotypes with five enzymes; consequently, very similar nucleotide sequences are predicted. All are pathogenic to humans or mice. The mtDNA sequences of eight remaining strains are predicted to differ from this cluster and, in most cases, from each other at least as much as in sibling species of Paramecium aurelia.