Escherichia coli of intestinal origin was grown in the presence of different fractions of turmeric (Curcuma longa L.). Curcumin (the pigment of turmeric) and the alcoholic extract of turmeric inhibited gas formation without inhibiting the growth of the bacteria. Curcumin, which is also a constituent of the alcoholic extract, bound iron in the medium. This inhibited the formation of the enzyme formic hydrogenlyase which in turn inhibited gas formation, with acid accumulation and reduced glucose utilization.
Sixty one strains of ascoideaceous yeasts belonging to twenty species of nine genera were examined from a taxonomical viewpoint based on a study of the electrophoretic comparison of the enzymes and the coenzymes Q (Co-Q) systems. The fifty strains, excluding those yeasts in which the detected number of enzymes was 3 or less, were divided into 4 clusters and 2 subclusters by numerical analysis of the relative electrophoretic mobilities (Rm) of 8 enzymes. On the other hand, the Co-Q systems of the ascoideaceous yeasts were Q-7, Q-8, or Q-9. These Co-Q systems and the septal ultrastructures coincided with each other. It is possible to divide these yeasts into four groups on the basis of similarity value according to the Rm of 8 enzymes: Saccharomycopsis lipolytica, other Saccharomycopsis spp. and related genera, Hyphopichia burtonii and/or Stephanoascusciferrii, and Ambrosiozyma and Hormoascus. Saccharomycopsislipolytica should be excluded from the genus Saccharomycopsis and is assigned to the genus Yarrowia. Ambrosiozyma and Hormoascus are considered to be cogeneric. Our data revealed close taxonomic relationship in the numerical classification based on the Rm of enzymes, Co-Q systems, and the septal ultrastructure.
Four proteins with molecular weights of 74, 000, 72, 000, 70, 000, and 68, 000 were readily detected by gel electrophoresis in the cap cells of the mature fruit bodies of Coprinus cinereus. But they were barely detectable in the stipe cells. The cap proteins were purified together and had a similar isoelectric point at around 8.0. They were all glycoproteins, and peptide mapping indicated that they shared common polypeptides. As measured by the immunoblotting method using antisera against them, these proteins were abundant in cap cells but extremely rare in stipe cells, in the primordia of fruit bodies, and in the mycelia of monokaryotic Fiscl and dikaryotic strains.
A polyphenol oxidase [EC class 1.10.3] was purified from culture filtrates of Chaetomium thermophile Isolate o-453 by procedures including salting- out by ammonium sulfate and combined column chromatography on DEAE-Toyopearl 650S, Con A-Sepharose, hydroxylapatite, and Sephadex G-200. The final enzyme preparation was homogeneous on polyacrylamide gel disc electrophoresis. Its estimated molecular weight was approximately 98, 000 by gel filtration. It showed maximum activity at pH 5.0 and at 55°C. The purified enzyme was very stable between pH 4.0 and 11.0 and up to 55°C. It was highly active toward d-catechin (100%), p- hydroquinone (45.7%), and N, N-dimethyl-p-phenylenediamine (63.0%). Though pyrocatechol (22.6%) was oxidized to some extent, DL-DOPA (0.33%) and o-phenylenediamine (3.1%) were hardly oxidized by the enzyme.
A mutant of Bacillus subtilis 168 unable to germinate in DL-alanine+fructose+glucose was isolated and proved to be deficient in response to fructose. Spores of this mutant responded to L-alanine fairly well although the germination rate was slower than the wild type. Analysis of the effect of fructose on the D-alanine inhibition of L-alanine-triggered germination showed that in wild type spores, fructose reversed the inhibition by lowering the spore's affinity with D-alanine whereas the mutant spores lacked this response. Since the mutation was mapped in the gerD locus, a standard gerD strain, 4738 (gerD48), was studied for comparison. Strain 4738 showed similar germination properties except that germination of this strain in L-alanine was much slower. These findings revealed a germinant-specific character of gerD mutants whose defect had been regarded as non-specific with respect to germinants. PBS1 transduction crosses suggested the gene order cysA-attSPO2-gerD-ada.
The isoprenoid compounds in gram-negative methanol-, methane-, and methylamine-utilizing bacteria were investigated. All strains tested contained ubiquinone, but none contained menaquinone. The ubiquinone types were Q-8, Q-9, or Q-10. The so-called obligate methylotrophs and methanotrophs (genus Methylobacillus, Methylophaga, Methylomonas, Methylococcus, and Methylovibrio) contained ubiquinone Q-8. The Hyphomicrobium strains contained Q-9. The other facultative methylotrophs and methylamine-utilizing bacteria contained Q-10. A large amount of squalene occurred in the Methylobacillus, Methylophaga, Methylomonas, and Methylococcus strains which utilize one-carbon compounds via the ribulose monophosphate pathway. The Protomonas extorquens and Methylobacterium organophilum strains contained a large amount of sterols (Hop-22(29)-ene and Hopan-22-ol), carotenoid pigments, and a small amount of squalene. The Hyphomicrobium strains contained a small amount of squalene and Hop-22(29)-ene. The Xanthobacter strains contained a large amount of carotenoid pigments (zeaxanthin, zeaxanthin monorhamnoside, and zeaxanthin dirhamnoside). The Protomonas and Methylobacterium strains were unique in the existence of sterols and large amounts of total isoprenoid compounds, 4.68 to 7.97mg/g of dry cell. The distribution of squalene, sterols, quinones, and carotenoid pigments conforms with the morphological, physiological, and other chemo- taxonomic characteristics in gram-negative methanol-, methane-, and methylamine-utilizing bacteria.
Replicative intermediates of M2 DNA, pulse-labeled with [3H]-thymidine, were isolated and the mode of its replication was examined. Compared with mature M2 DNA the replicative intermediates had the following properties: i) higher sedimentation coefficient in sucrose gradient, ii) higher buoyant density in CsCl equilibrium density gradient, and iii) sensitivity to nuclease Sl. Two types of intermediates were found by electron microscopic observation. One is unit-length duplex molecules with a single-stranded branch of various lengths. The other is unit-length linear molecules consisting of one single-stranded and one double- stranded region of variable proportions. Distribution of the radioactivity in pulse-labeled completed molecules was analyzed with restriction endonucleases. Both ends of the genome had higher radioactivity, showing that the ends are termini of replication. These results indicate that the replication of M2 DNA proceeds from each end by displacing parental single-stranded DNA.
Rhodobacter sphaeroides P47 was selected as a potent microorganism for SCP production. The selection criteria were: high growth rate, high growth yield from consumed sugar, ability to consume various sugars, high protein content with a balanced amino acid composition, and acceptable contents of vitamin B12 and carotenoids. When the cells grew aerobically on minimal medium containing glucose, fructose and xylose as sole carbon sources, they grew at the relatively high specific growth rate of 0.12-0.161/hr. Also, the growth yield from sugar, 0.52-0.55g of cells/g of sugar, was high compared with Rb. sphaeroides S as a standard. In the sugar uptake test, strain P47 not only preferably consumed glucose, fructose, xylose and mannose, but also consumed maltose, sucrose, cellobiose and treharose. Strain S consumed only glucose, fructose, xylose and mannose. Strain P47 cells cultured on pineapple waste medium had a relatively high protein content (66.6%) with balanced amino acid composition. The intracellular contents of vitamins B12 and E and carotenoids were 7.9, 21, and 80mg/100g of dry cells, respectively. These values were considerably higher than those of other photosynthetic bacteria.