Cell division of the so-called eubacteria and coryneform bacteria was studied by the time lapse microscopy and microcinematography. The rodshaped bacteria were divided into the three types of simple type, snapping type, and bending type on the basis of the mode of cell division. From the results obtained the mode of bacterial cell division is considered to indicate a taxonomic significance, and eubacteria capable of growing by simple type division are clearly distinguished from coryneform bacteria which multiply by snapping or bending type.
Two rare fungi isolated from the soils of Delhi have been described. Aspergillus penicilliformis KAMYSCHKO seems to be a link between the enera Aspergillus and Penicillium. Preussia aurantiaca RAI and TEWARI has been transferred to Pycnidiophora aurantiaca (RAI & TEWARI) MUKERJI and RAO comb. nov. A key to the genus Pycnidiophora Clum is included.
Some prototrophic revertants from a homoserine auxotroph of Brevibacteriumflavum No. 2247 (ATCC No. 14067), which grew as rapidly as No. 2247 in a minimal glucose-salts medium produced large amounts of lysine, whereas No. 2247, the original strain, produced little. The cell growth in a minimal medium of revertant strain, S-20, which produced 23g of L-lysine monohydrochloride from 100g of glucose, was completely inhibited by the addition of 10μg/ml of L-methionine (or L-threonine) and recovered by the further addition of L-threonine (or L-methionine). It was concluded that much lower homoserine dehydrogenase activity of S-20 than that of No. 2247 was the primary result of the mutation, which might cause apparent increase in the sensitivity of the cell growth to inhibition by L-methionine (or L-threonine) and further production of lysine through lowering of the threonine pool inside the cell. Some of the threonine auxotrophs derived from such revertant strains as S-20 produced much larger amounts of lysine than the parental strains or simple threonine auxotrophs directly derived from No. 2247. The amount of lysine produced was nearly equal to that of homoserine auxotroph, H-1013, derived from No. 2247. By-production of homoserine was small in contrast with the simple threonine auxotrophs as expected. These threonine auxotrophs were still sensitive to higher concentration of L-threonine.
1. Enzymatic studies were made on the oxidative decarboxylation of 6-phosphogluconate in typical heterolactic acid bacteria, and it was concluded that mechanism of the oxidative decarboxylation of 6-phosphogluconate in these bacteria can be classified into three types as follows: (1)6-phosphogluconate+NAD→ribulose 5-phosphate+CO2+NADH2 (2) 6-phosphogluconate+NAD→2-keto-6-phosphogluconate+NADH2 2-keto-6-phosphogluconate→ribulose 5-phosphate+CO2 (3) mixed reactions of (1) and (2). 2. It was found that 6-phosphogluconate dehydrogenase (decarboxylating) [EC 22.214.171.124] obtained from Lactobacillus brevis ATCC 8281 consists of 6-phosphogluconate dehydrogenase (not decarboxylating) [EC 126.96.36.199] and 2-keto-6-phosphogluconate decarboxylase.
Transformation of progesterone by various microorganisms such as actinomycetes, yeast and mould fungi of different 53 strains had been studied. 19 different strains was able to oxygenate progesterone at C11. The transformation products, other than 11α-hydroxyprogesterone, which were formed by these active strains had been identified. These studies proved that the active organisms were capable of introduction of oxygen function at different positions other than position 11 of progesterone e.g. positions 17 and 21. Side chain degradation reaction with and without lactone formation of ring D of progesterone had been also found to be performed by some of these organisms.
The resolution of 30 different C21, C19 and C18 steroids by various solvent systems on silica gel chromatoplates was reported. Effective resolution of Δ4-pregnene, 5α, axial-equatorial hydroxyl epimers and positional isomers was successfully achieved. The differentiation between these compounds by using four different colour reagents has been also reported.
A group of bacteria isolated from brewery sewage was studied taxonomically. They were gram-positive, facultatively anaerobic, pleomorphic, branching, non-motile, non-sporulating, non-acid-fast, and catalase-positive rods (0.6-1.0×0.8-10.0μ). They formed cystites and showed bending-type cell division. They produced a yellow pigment and reduced nitrate, hydrolyzed starch, and liquefied gelatin. They produced acids from various carbohydrates. These characteristics were compared with those of 18 strains of related microorganisms. The isolates seemed to belong to the genus Arthrobacter, but no corresponding species was found in the taxa appearing in Bergey's Manual (7th Ed.). The name Arthrobacter luteus was, therefore, newly proposed for these isolates. While the new species was in accord with those of the genus Arthrobacter in basic characteristics, it also had similarities to some species of the genera Nocardia, Cellulomonas, Microbacterium, and Corynebacterium. These observations suggested that the species occupied an intermediate position between the families Corynebacteriaceae and Actinomycetaceae.
Glucoamylase produced by Aspergillus niger was observed to increase in culture media at two specific intervals, namely, after three days and after six days of incubation. The lowest levels of enzyme production occurred when the nitrogen source was asparagine, trypticase or urea. Intermediate quantities of enzyme were formed when the fungi were grown on a nitrogen source of yeast extract. Corn steeping liquor and nutrient broth (2.5%) gave highest enzyme activity. The inorganic nitrogen source providing the best glucoamylase yield was ammonium-N. Nitrate-N or a mixture of ammonium-N and nitrate-N was less effective. When inorganic nitrogen was employed, the two periods of glucoamylase production were not as readily demonstrated. With ammonium-N, all the glucoamylase is produced during the fourth or fifth day of incubation, thus showing only one period of enzyme synthesis. The quantity of glucoamylase produced depended upon the monosaccharide added to the growth medium. Glucose yielded the highest level of enzyme regardless of the nitrogen sources. Mannose, usually, was slightly more effective than sorbitol and produced about half the quantity of glucoamylase obtained from glucose. Lowest levels of enzyme occurred when fructose or xylose served as carbon sources. Growth on 1.0 or 2.0% carbohydrate, rather than 5.0%, was found to result in higher levels of glucoamylase. Although A. niger NRRL 330 was the principle organism tested, the characteristics of glucoamylase synthesis were not specific for this strain since similar results were obtained with A. niger NRRL 3122 and A. awamori NRRL 3112.
Citramalate condensing enzyme has been purified 95-fold by ammonium sulfate fractionation, and by Sepharose 4B and DEAE-cellulose column chromatography from RD petite mutant strain of Saccharomyces carlsbergensis. On the basis of the fact that (-)-citramalate fraction had all of the radioactivity while (+)-citramalate fraction contained no radioactivity when enzymically formed radioactive citramalic acid with authentic carrier DL-citramalic acid was subjected to optical resolution, it was made clear that this enzyme catalyzed the formation of (-)-citramalate from pyruvate and acetyl-CoA. The optimal pH of the enzyme was 7.4 and the Km value for pyruvate was 2.3×10-3M. The purified enzyme preparation still has an activity toward α-ketobutyrate and α-ketoisovalerate. The Km value for α-ketoisovalerate was 2.6×10-5M. L-Leucine inhibits to the same extent the respective condensation reactions between these three α-keto acids and acetyl-CoA. α-Ketoisovalerate is an effective inhibitor of citramalate condensing reaction. The enzyme was strongly inhibited by p-chloromercuribenzoate, Cu2+, Zn2+, Hg2+, Pb2+, and Cd2+. Citramalate condensing enzyme appears to be identical with α-isopropylmalate synthetase in the leucine biosynthetic pathway. The role of this enzyme in RD petite mutant strains of Saccharomyces carlsbergensis was discussed in relation to citramalate formation.
The passage of small molecular substances through the walls of Staphylococcusaureus is reduced in presence of 95% ethanol, as well as solutions of aniline, dimethyl aniline and nitrobenzene in 95% ethanol. But these three solvents, unlike 95% ethanol alone, can extract dye from Gram-stained Staphylococcus aureus almost completely, indicating the inadequacy of the permeability theory of Gram staining. It has been observed that, if iodine from Gram-stained Staphylococcusaureus is removed by thiosulphate, the retained dye can be extracted by 95% ethanol. However, if after thiosulphate treatment Staphylococcus aureus with the retained dye is treated with graded amounts of iodine, extractibility of the dye by 95% ethanol is progressively reduced. This supports the model proposed for the mechanism of Gram staining which involves retention of crystal violet by the cell component presumably by electrostatic bonds and formation of chargetransfer complex of crystal violet and iodine through π-electrons. Stability of this cell component-dye-iodine complex towards 95% ethanol determines the Gram character of the cell.
1. For the production of single-cell protein, isolation of yeast strains from oil-soaked soils and water was carried out. Out of several yeasts isolated, nine were identified and found to belong to the genus of Candida, Trichosporon, Pichia, and Saccharomyces. 2. Strains of Candida and Trichosporon grow well in gas oil with high specific growth rates. 3. Crude protein content of the dried cells vary between 48 and 62%.