Lactic acid bacteria (LAB) which produce reuterin, a low molecular weight antimicrobial substance, were screened by incubating LAB cells with glycerol in an anaerorobical system. Among the 148 strains of LAB tested, Lactobacillus coryniformis 394 displayed the highest ability to produce reuterin. This strain produced a mixture of reuterin and the corresponding hydrate form which were identified by H-NMR and C-NMR spectrum analyses. Highest amount of reuterin was produced in a glycerol solution containing 0.5% CaCO3 at 25•Ž under anaerobic conditions. Reuterin from L. coryniformis 394 strongly inhibited the growth of fungi, yeast and various strains of bacteria but showed no inhibitory effect on LAB.

No abstract

No abstract

As continuation of our study on the characterization of column packings in normal-phase HPLC analysis, the retention indices of ten fat-soluble vitamins on aminopropyl and cyanopropyl bonded silica columns were systematically estimated using binary solvents containing ethyl acetate (EtOAc), tetrahydrofuran (THF) or 2-propanol (PrOH) in n-hexane. A linear relationship between the logarithm of the capacity ratio and that of the solvent composition was confirmed.The retentivity and selectivity for these chemically bonded packing columns were determined as follows: the amino-type column has stronger and cyano-type column weaker retentivity than the bare silica column for n-hexane-EtOAc or THF binary systems. Specific adsorption of tocopherol derivatives containing phenolic hydroxyl groups on the amino column was observed.To obtain high efficiency in the separation of fat soluble vitamins, peak sharpness and asymmetry factors were measured using three columns and three binary solvents.The bare silica and PrOH binary solvent generally gave superior peak shape for all vitamin samples. 739Copymht 0 1989 by Marcel Uckkrr, Ino.

No abstract