23Na NMR spectroscopy was used to determine free Na+ concentrations in a halotolerant bacterium, Brewibacterium sp., and Escherichia coli. The internal Na+ concentration of both strains depended little on the growth phases and was unchanged after 5 d storage at 2 O C . In Brewibacterium sp. the level of intracellular sodium increased gradually at higher extracellular NaC! concentrations in both the presence and absence of yeast extract in the growth medium. E. coli cells accumulated a higher concentration of free Na+ than those of Brewibacterium sp. The change of Na+ concentration in both strains was inverse to that of growth rate. When appropriate amounts of osmoprotectants (proline, glycine betaine, or y-aminobutyrate) were added with the NaCI, internal free Na+ levels in Brewibacterium sp. were lowered, but those of E. coli were unchanged. While addition of KCI to medium containing NaCl increased the intracellular level of free Na+, the total sodium concentration in the cells remained unchanged, indicating that sodium that had been bound or attached was made free in the cytosol. In Brewibacterium sp. grown in the presence of 0.5 M NaCI, free and bound sodium concentrations in the cytosol were estimated to be 014 and 0-23 pmol (mg protein)-', respectively. As a result, visibility by 23Na NMR was 38%.
The productivity of ƒÀ-phenethyl alcohol (a-PA) from styrene by Pseudomonas 305-STR-1-4 was examined under various conditions. Under the optimum condition, 3.27mg/ml of fl-PA was produced from 20mg/ml of styrene. The metabolic inhibitor, pyrazole, aided ineffectively producing a-PA more reliably and promptly.ƒÀ-PA was extracted from the culture broth and purified to a semi-viscous, light-yellow liquid with a rose-like fragrance. Recovery was 90% and purity was 99.4%. IR spectrum of this liquid was identical with that of authentic sample. The mechanism of ƒÀ-PA production by strain 305-STR-1-4 was proposed based on the results of this experiment.
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