The electrophoretic behavior of 34 strains of Conidiobolus obscurus was examined in an attempt to study both the interspecific differences from other entomopathogenic Conidiobolus species and the intraspecific variability existing among C. obscurus strains. Initially, the non-significant variability occurring among strains was estimated by comparing isozymic patterns of mycelial samples of a particular strain grown under variable culture conditions or collected at different growth stages. The species C. coronatus, C. osmodes, C. thromboides, and C. apiculatus look electrophoretically homogeneous: comparisons of electrophoretic profiles between strains of the same species produced coefficients of similarity (CS) greater than 0.67, the baseline value established to measure non-significant differences. Strains of C. obscurus, unlike the other Conidiobolus species, appeared heterogeneous with certain pairs having a calculated CS value less than 0.1. The relationships among the C. obscurus strains appeared to be independent of the insect host from which they were isolated and from the locality of origin. An analysis of a dendrogram constructed for C. obscurus having known in vitro growth characteristics produced 3 major groups of strains. The clustering of these strains appeared to depend on their ability to produce resting spores in vitro. The first group were capable of producing azygospores in both liquid and solid media. Group II strains were able to sporulate on solid media but not in liquid culture, and group III strains were unable to produce resting spores in vitro.
The effects of illumination on nitrifying bacteria were investigated with and without substrate. NH4+-oxidizing bacteria (strain H-1, probably Nitrosospira sp.) and NO2--oxidizing bacteria (strain O-1, probably Nitrobacter sp.), isolated from Lake Kizaki, were inhibited by light (about 75μEinsteins/m2/sec, 12-hr light: 12-hr dark). Photoinhibited H-1 and O-1 cells recovered after several to tens of days under dark conditions. However, H-1 cells, illuminated for 7 to 10 days in the absence of NH4+, did not produce NO2- significantly for 120 to 350 days in a medium containing 50uM NH4+. The substrate (NH4+) was found to protect H-1 from photoinhibition, while such an effect of NO2- on O-1 was not so clear. O-1 was more sensitive to light than H-1 in the short illumination period. However, the inhibitory effect of prolonged illumination was greater on H-1 than on O-1. It was indicated from growth kinetic analysis that the photoinhibitory effects on both NH4+-oxidizing bacteria and NO2--oxidizing bacteria were not only lethal but also bacteriostatic.
Pectate lyase of Erwinia carotovora Er was separated into two active protein fractions, pectate lyases I (pI10.7) and II (pI10.1), by electro-focusing. These enzymes could be distinguished by SDS slab gel electrophoresis. Although they showed many similar properties, the optimal temperatures of pectate lyases I and II were 50° and 60°, respectively, and their Km values were 0.12mg/ml and 1.1mg/ml. The amino acid composition was very similar in the two enzymes, but pectate lyase I contained a few more residues of lysine, valine, glycine and proline than pectate lyase II and fewer residues of isoleucine. The neutral sugar content of the lyases was 2.500 and 4.8%, respectively. From these results, pectate lyases I and II seem to be different enzyme proteins despite the fact that they have quite similar properties.
B2-level host strains, HV514 (trpC2 metB5 leuA8 thr-5 sird spo0C9VuvrA114 dal-1 nonA nonB) and HV553 (trpC2 metB5 leuA8 thr-5 hisA1argC4 sird spo0C9V uvrA114 dal-1 nonA nonB recE4), of Bacillus subtilis were constructed from the B. subtilis Marburg strain PS9, which has no restriction-modification enzyme system and requires six amino acids and one base. Genetic markers dal-1, uvrA114, spo0C9V, strd and recE4 were introduced sequentially into strain PS9 by congression with purB+ and amino acid prototroph. Survival of HV514 and HV553 in nonpermissive conditions was 10-4 to 10-5 lower than that of the wild type strain 168Trp. The sporulation frequency of HV514 and HV553 was less than 10spores/ml, while that of 168Trp was more than 108spores/ml. The sensitivity of these strains to ultraviolet light was 105 to 106 higher than that of 168Trp. These strains have normal viability under permissive conditions and high protoplast transforming activity. These properties make the strains highly safe and useful hosts for recombinant DNA experiments.
A method for protoplast induction with penicillin G (PCG) in Bifidobacteriumbifidum Es5 was examined. Growing cells were converted into protoplasts in a nutrient broth containing PCG without addition of any osmotic stabilizers. The maximal rate of protoplast induction was approximately 50% after 6hr incubation with 1unit PCG per ml. Supplementing the PCG-treatment culture with 0.1 to 0.2M sucrose raised the induction rate to 80% or more. It is suggested that sucrose makes the bacteria more sensitive to PCG, and subsequently stabilizes the protoplasts. In addition, sucrose by itself caused a decrease in the number of viable cells but not in the turbidity of the culture without PCG. L-colonies of strain Es5 developed from bacterial suspensions and also from protoplast suspensions inoculated on nutrient agar plates containing PCG alone or PCG and sucrose.
Fifty five strains of 13 species of Rhodospirillaceae and one strain of Chromatium vinosum were examined for isoprenoid quinone composition. These bacteria were divided into the following five categories on the basis of their predominant quinone patterns: Q-10-Rhodospirillum rubrum, Rhodopseudomonas palustris, Rhodopseudomonas capsulata, Rhodopseudomonassphaeroides, and Rhodopseudomonas sulfidophila; Q-10+MK-10-Rhodopseudomonas acidophila; Q-9+MK-9-Rhodospirillum fulvum, Rhodospirillum molischianum, Rhodopseudomonas viridis, and Rhodopseudomonas globiformis; Q-8-Rhodospirillum photometricum and atypical strains of Rhodopseudomonas gelatinosa; Q-8+MK-8-Rhodospirillumtenue, R. gelatinosa, and C. vinosum. The significance of the quinone system in Rhodospinillaceae taxonomy is discussed in comparison with available information on other taxonomic properties such as morphology and photosynthetic membrane systems and on some phylogenetic characteristics.
The occurrence of polyhedral inclusion bodies (PBs) (carboxysomes) was examined from the taxonomic point of view in the facultatively and obligately chemolithotrophic species of Thiobacillus. PBs were not found in any of the Group I-1 forms. These included the facultative chemolithotrophs with ubiquinone with 10 isoprene units (Q-10), T. versutus THI 041 and THI 024, T. novellus THI 031, and the thiocyanate assimilating Thiobacillus spp. THI 011 and THI 051. PBs occurred in the Group I-2 species of acidophilic organisms with Q-10, T. acidophilus THI 061 and THI 071. PBs were also found in all species of Group II, which included the facultative chemolithotrophs containing ubiquinone with 8 isoprene units (Q-8), T. delicatus THI 091, T. perometabolis THI 023, and T. intermedius THI 101, and all of Group III, which included the obligate chemolithotrophs with Q-8, T. thioparus THI 111, T. neapolitanus THI 122, and T. ferrooxidans THI 132 except "T. denitrificans" THI 151.
Kitasatosporia setalba KM-6054 forms two kinds of spores: aerial spores on an agar medium and submerged spores in a liquid medium. In this study, both kinds of spores were resistant to sonication, but sensitive to lysozyme digestion and moist heat. LL-2, 6-Diaminopimelic acid (A2pm), alanine, glutamic acid and glycine were detected as the main constituents in the cell walls of the aerial and submerged spores. The respective molar ratios were similar; 1.0:1.6:0.5:1.0 and 1.0:1.5:0.7:0.8. On the other hand, the vegetative mycelium on agar media and the filamentous mycelium in submerged cultures were sensitive to sonication and differed from the two kinds of spores in both amino acid composition and A2pm type.
The respiratory activities of Candida rugosa JF-101 and C. lipolytica No. 6-20 grown on glucose were studied in relation to the n-alkanes (n-C9H20-n-C18H38). Both yeasts readily oxidized n-decane, n-undecane and n-dodecane. Cells of both yeasts grown on glucose showed a lag in n-alkane oxidation, whereas the cells grown on n-alkane did not. n-Hexadecane was oxidized by cells grown on the same n-alkane better than by cells grown on n-decane and glucose. The respiratory action of each yeast on n-hexadecane tended to be induced and the activity on n-decane was constitutive. The glucose oxidation rates of the spheroplasts from C. rugosa and C. lipolytica were, respectively, 70-80% and 32-34% as high as those of the intact cells and the n-decane oxidation rates of the spheroplasts were 4-8% and 0% as high as the respective intact cells. Addition of the non-ionic surfactant Tween 80 restored the action of spheroplasts on n-decane to 10-19% as high as the intact cells, except for the spheroplasts from the glucose grown cells of C. lipolytica.
The ability of Erythrobacter to utilize light energy in the aerobic environment is reported. The cellular ATP level increased in light. Incorporation of 14CO2 was clearly enhanced by light. In contrast to other known photosynthetic bacteria, the CO2-incorporation activity in Erythrobacter was stimulated by oxygen. The favorable effect of light on the survival of Erythrobacter was observed in the absence of an organic energy source.
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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)