A carotenoid pigment-producing Brevibacterium strain No. 103 was isolated from a gas field. For the cell production of this bacterium, it was suitable to use a mixture of ammonium nitrate and urea as nitrogen source, and normal alkanes of C14, C16, C17 and C18 as a carbon source. The visible absorption maxima of three of the four fractionated pigments were identical with those of β-carotene, astacin, and astaxanthin. The remaining one pigment was not identified. The main components of these carotenoids were astacin and astaxanthin.
The loci of succinic dehydrogenase in Bacillus stearothermophilus were sought, using as a marker of activity tellurium deposits resulting from the reduction of tellurite. The tellurium was located in spindle-like structures found within the cytoplasmic membrane. There was evidence also of some kind of internal structure within the spindle. Upon disintegration of the latter, particles were obtained which still retained dehydrogenase activity.
The elution profiles of yeast (Saccharomyces cerevisiae) t-RNA from DEAE-cellulose 23 and 40 were compared. The shoulder present in the elution patterns from DEAE-cellulose 23 was not found in those from DEAE-cellulose 40. The elution profiles of L-histidine acceptor t-RNA by DEAE-cellulose 23 column from various microorganisms were compared. The patterns of L-histidine acceptor t-RNA from yeast and Neurospora crassa on DEAE-cellulose columns showed marked similarities, but those from bacterial sources, Escherichia coli and Microbacterium ammoniaphilum, were different from those of yeast and N. crassa. N. crassa histidine-t-RNA synthetase was strongly inhibited by NaCl and hence differed from histidine-t-RNA synthetase of Saccharomyces cerevisiae.
A comparative study was made on three salt-tolerant, dextro-rotatory lactic acid-forming pediococci, Pediococcus halophilus, P. soyae, and P. homari, and related species, P. urinae-equi and Aerococcus viridans, with reference to P. pentosaceus and P. acidilactici. The former three species were sufficiently similar in their morphological, physiological, and nutritional characteristics, and DNA Tm value to place them into a single species. P. urinaeequi is almost similar to them, especially nutritionally, but differed from them only on the point of salt sensitivity. It was proposed that their boundary be the growth on 12% salted medium. A. viridans has characters much similar to P. urinae-equi to be classified within the species, although its preference for aerobic conditions and other non-fermentative characters suggest its relation with Staphylococcus-Micrococcus group. The usefulness of nutritional requirement for the classification of this genus was discussed.
Leuconostoc mesenteroides B07, a typical heterolactic fermenting coccus, contains a new enzyme catalyzing the decarboxylation of 2-keto-6-phosphogluconate. Basic properties of 2-keto-6-phosphogluconate decarboxylase were studied and decarboxylation product was isolated and identified as ribulose 5-phosphate. It is postulated that, in this organism, 6-phosphogluconate may be oxidized to 2-keto-6-phosphogluconate by an NAD-linked dehydrogenase (not decarboxylating) (EC 184.108.40.206) and, thereafter, ribulose 5-phosphate and CO2 are formed by enzymatic decarboxylation.
From the intact cells of 66 strains of acetic acid bacteria, ubiquinones were extracted with ether-ethanol mixture (3:1) and purified by treatment with acetone, followed by thin-layer chromatography using silica gel plates and benzene. Mass spectrometric and paper chromatographic analyses of the ubiquinone system showed the characteristic existence of ubiquinone-10 in genus Gluconobacter and ubiquinone-10 and -9 in "peritrichously flagellated" intermediate strains, while that of ubiquinone-9 and -8 in genus Acetobacter as well as ubiquinone-8 and -7 in "polarly flagellated" intermediate strains. These results indicate that the kind of ubiquinone present may be used to distinguish the genera Gluconobacter and Acetobacter as one of simple and effective criteria. Some discussions are made on the taxonomical positions of the so-called intermediate strains.
One hundred and fifty-three strains of Escherichia coli were isolated from sporadic cases of gastroenteritis from cows, calves, buffaloes, buffalocalves, goats, and kids. Thirty-six biochemical tests were conducted. On the basis of fermentation reaction of six selected sugars (rhamnose, sucrose, dulcitol, raffinose, salicin, and starch), 153 strains were classified into 28 biotypes. Biotypes I, V, VI, XI, XVIII, and XX appeared more common than the others. These six biotypes accounted for over 60% of the total (153) strains isolated from diarrhoea, dysentery, or white scours. Biotype XX predominated in buffaloes and buffalocalves, and Type VI in cows and calves, and in goats and kids. Again Type VI predominated in diarrhoea and dysentery and Type XI in white scour. Only 137 strains could be identified serologically. Sixty-five strains belonged to 7 human enteropathogenic ‘O’ groups (O26: B6, O55: B5, O86: B7, O112: B11, O119: B14, O125: B15, and O126: B16). Group O26 predominated in goats and kids, O125 in buffaloes and buffalocalves, and O119 in cows and calves. Another 72 strains belonged to 31 ‘O’ groups, which are not known to be associated with infantile diarrhoea and gastroenteritis of human. Serological heterogenicity was observed within a single biotype and, similarly, strains within a single serotype differed in their biochemical characters.
The conserved portion in bacterial ribosomal RNA was studied by the DNA-RNA hybridization method. The hybridization percentages were as follows: Bacillus subtilis DNA and B. subtilis 23S rRNA, 0.16; Escherichiacoli DNA and E. coli 23S rRNA, 0.15; B. subtilis DNA and E. coli 23S rRNA, 0.03; E. coli DNA and B. subtilis 23S rRNA, 0.04. The RNA's extracted from the heterologous hybrids could be rehybridized with DNA's of B. subtilis and E. coli. The average chain lengths of the RNA's were estimated by sucrose density gradient centrifugation and Sephadex gel filtration. The results suggested that the size might be larger than 30 nucleotides. Nucleotide compositions of the RNA's in the hybrids w ere also studied. Both RNA's contained higher molar percentages of guanylic acid and cytidylic acid than the whole rRNA's.
COLD SHOCK OF BACTERIA
II. MAGNESIUM-MEDIATED RECOVERY FROM COLD SHOCK AND EXISTENCE OF TWO CRITICAL TEMPERATURE ZONES IN VARIOUS BACTERIA
Escherichia coli, Pseudomonas fluorescens, and Bacillus subtilis cells, harvested at the logarithmic phase of growth, were susceptible to cold shock as judged by their loss in viabilities. Viabilities of cold shocked cells increased rapidly upon incubation at 30° with suitable additives. Among the effective agents, magnesium ion was the most important, because no appreciable recovery in viability was observed in the absence of magnesium. When the cold shocked E. coli cells were incubated at 30° with 5×10-3M of magnesium acetate for 10 to 20min, the viability of shocked cells became equal to that of unshocked cells. The addition of 2, 4-dinitrophenol to such systems inhibited the magnesium-mediated recovery almost completely. When NAD or ATP plus nicotinamide was further added to the reaction mixture, the inhibition by 2, 4-dinitrophenol was released. This result suggests that NAD, possibly as an energy source, is involved in the recovery process. An increase in permeability of cold shocked E. coli cells was demonstrated with the aid of 8-anilino-1-naphthalenesulfonate. The stimulatory effect of NAD or ATP added to the reaction mixture on the recovery from the cold shock could be explained by this permeability increase. The presence of two critical temperature zones in the cold shock was confirmed with both B. subtilis and Ps. Fluorescens. When the initial temperature of the cell suspension before the cold shock was lowered by 5°, both temperature zones moved to lower temperatures approximately by 3-5°.
A process of development of Coprinus kimurae HONGO et AOKI cultured in this laboratory was morphologically and histochemically observed. The process was tentatively divided into seven stages according to morphogenesis. Activities of cytochrome oxidase, succinic dehydrogenase, and acid and alkaline phosphatases were mainly found at active growth zones of this mushroom such as top part of stalk and margin of cap. Both kinds of phosphatases were not detected in gills at stages 3 and 4 but were detected in gills at stage 5 when cap grew remarkably and spores formed.
Edited and published by : Applied Microbiology, Molecular and Cellular Biosciences Research Foundation/Center for Academic Publications Japan Produced and listed by : TERRAPUB, Center for Academic Publications Japan/Shobi Printing Co., Ltd. (-Vol.60,No12), Center for Academic Publications Japan/InternationalAcademic Printing Co., Ltd.(-Vol.54,No1)