Panose production by a mutant of Streptomyces hygroscopicus subsp. limoneus

One of the mutant non-producers of validamycin from Streptomyces hygroscopicus subsp. limoneus JCM 4911, designated as strain GT 32, showed the accumulation of panose in the culture broth under the conditions for validamycin production by the original strain. Panose production was not detected in the culture broth of the original strain which was known to produce the antibiotic, validamycin, or in that of the other mutant strains studied. The structure of panose, O- α -D-glucopyranosyl-(1 → 6)-O- α -D-glucopyranosyl-(1 → 4)-O- α -D-glucopyranose, for the oligosaccharide specifically produced by the strain GT-32, was identified by sugar composition analysis, ion-spray mass spectrometry, methylation analysis, and 500 MHz ¹H-NMR. The maximum production (1.59 mg/ml) of panose by the strain GT32 was found in 5 d cultured broth at 37°C on a rotary shaker at 180 rpm.