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A Tallentire 《The Journal of applied bacteriology》1970,33(1):141-146
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T Cross 《The Journal of applied bacteriology》1970,33(1):95-102
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Analysis of the respiratory chain of spores of Dictyostelium discoideum, which lack a cyanide-sensitive respiration, indicated that cytochromes a-a3, b, and c-c1 are present at levels identical to those found in the vegetative amoebae. The specific activities of enzymes of both the respiratory chain and the citric acid cycle in the 600 x g supernatant fraction of sonically treated spores were at least as high as in similar preparations of amoebae. The activities of glutamic dehydrogenase and oligomycin-sensitive adenosine triphosphatase were reduced in the spores 30 and 56%, respectively. Intact spores appeared to lack a cyanide-sensitive respiration as a result of inadequate quantities of respiratory substrate and, more importantly, as a result of a lack of the cofactor nicotinamide adenine dinucleotide. The emergence phase of spore germination was sensitive to the antibiotic chloramphenicol, which is a specific inhibitor of mitochondrial protein synthesis. It is concluded that germination requires the early synthesis of oxidized nicotinamide adenine dinucleotide and generation of respiratory substrates and one or more mitochondrially synthesized proteins. 相似文献
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As previously found for spores of Bacillus species, dormant spores of Clostridium bifermentans contained essentially no adenosine triphosphate, a high level of adenosine monophosphate, a high level of 3-phosphoglyceric acid, and much transfer ribonucleic acid lacking a 3'-terminal adenosine monophosphate residue. As in spores of Bacillus species, germination of C. bifermentans spores was accompanied by utilization of the 3-phosphoglyceric acid, a large increase in the adenosine triphosphate level, and the disappearance of defective transfer ribonucleic acid. In contrast to spores of Bacillus species, dormant spores of C. bifermentans contained little free amino acid. 相似文献
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Triggering of germination in Bacillus megaterium QM B1551 spores with D-glucose was studied. First, the interaction of glucose with spores for less than 1 min resulted in triggering almost 90% of the spores after the glucose was removed by dilution. Therefore only a brief time is needed for glucose to trigger germination, and then the continuous presence of glucose is not necessary. Detectable uptake of glucose began 2 to 3 min after absorbance loss started, and a non-metabolizable glucose analog, methyl-alpha-D-glucopyranoside, triggered germination in the absence of detectable uptake. Several inhibitors that reduced or eliminated glucose uptake did not block triggering of germination. Therefore, glucose uptake may be a relatively late event and not a prerequisite for triggering of germination. 相似文献
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Germinated spores of Bacillus subtilis were incubated in outgrowth medium and tested periodically for capacity to sporulate when suspended in sporulation medium. Concurrent measurements were made of deoxyribonucleic acid (DNA) content and numbers of cell division septa and nucleoids. Sporulation potential is shown to reach a peak at about 110 min at which time the chromosomes are probably well into the second round of replication. Experiments with nalidixic acid show that sporulation potential can be generated in the outgrowth medium even when DNA synthesis is largely prevented. Further experiments show that nalidixic acid apparently does not prevent the formation of DNA initiation complexes, which can subsequently function after resuspension in the sporulation medium. The results support those previously obtained with a temperature-sensitive DNA mutant which indicated that sporulation could only be induced at a specific stage of chromosome replication, and then only if the cells are in a state of nutritional "step-down". 相似文献
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The hydrophobicities of spores and vegetative cells of several species of the genera Bacillus and Clostridium were measured by using the bacterial adherence to hexadecane assay and hydrophobic interaction chromatography. Although spore hydrophobicity varied among species and strains, the spores of each organism were more hydrophobic than the vegetative cells. The relative hydrophobicities determined by the two methods generally agreed. Sporulation media and conditions appeared to have little effect on spore hydrophobicity. However, exposure of spore suspensions to heat treatment caused a considerable increase in spore hydrophobicity. The hydrophobic nature of Bacillus and Clostridium spores suggests that hydrophobic interactions may play a role in the adhesion of these spores to surfaces. 相似文献
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Heat activation of Streptomyces viridochromogenes spores. 总被引:2,自引:2,他引:0
The lag period preceding germination of Streptomyces viridochromogenes spores during incubation in a defined germination medium was completely eliminated by a gentle heat shock. The rate of germination was not affected. The optimum pH for activation extended from 6.0 to 9.6. The time of heating required for maximum activation was 1 min at 60 C, 2 to 5 min at 55 C, 20 min at 50 C, and 40 to 50 min at 45 C. Activated spores had the same temperature and pH optima and nutritional requirements for germination as unactivated spores. Activated spores deactivated during incubation for 8 h at 25 C and were activated again by a second heat shock. Spores that had been aged for 4 weeks or longer did not germinate in the defined germination medium unless they were first heat activated. 相似文献
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Recent bioterrorism concerns have prompted renewed efforts towards understanding the biology of bacterial spore resistance to radiation with a special emphasis on the spores of Bacillus anthracis. A review of the literature revealed that B. anthracis Sterne spores may be three to four times more resistant to 254-nm-wavelength UV than are spores of commonly used indicator strains of Bacillus subtilis. To test this notion, B. anthracis Sterne spores were purified and their UV inactivation kinetics were determined in parallel with those of the spores of two indicator strains of B. subtilis, strains WN624 and ATCC 6633. When prepared and assayed under identical conditions, the spores of all three strains exhibited essentially identical UV inactivation kinetics. The data indicate that standard UV treatments that are effective against B. subtilis spores are likely also sufficient to inactivate B. anthracis spores and that the spores of standard B. subtilis strains could reliably be used as a biodosimetry model for the UV inactivation of B. anthracis spores. 相似文献
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M. Tyurin L. Starodubtseva H. Kudryavtseva T. Voeykova V. Livshits 《Biotechnology Techniques》1995,9(10):737-740
Summary Germinating spores of Streptomyces lividans, S. aureofaciens, S. rimosus and S. virginiae were electrotransformed with pIJ699, pIJ702, pWOR109 and pZAT22 plasmid DNAs. In all cases, thiostrepton resistant transformants were obtained with an efficiency of 1 × 102 to 5 × 103 per g of plasmid DNA. 相似文献
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A proteolytic activity is associated with the dormant spores of Bacillus cereus T and can be solubilized by washing the spores with 1 M KCl. This proteolytic activity is responsible for the attack of beta chains of ribonucleic acid-polymerase in extracts of dormant spores of this organism. 相似文献
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Spores injected intravenously into mice in numbers in excess of 10(2)/g of body weight were initially dispersed to most organs, but after a few days the remaining spores were concentrated in the liver, from which they were eliminated with a half-life of about 6 days. Intraperitoneal injection did not result in contamination of organs unless initial spore numbers exceeded 10(5)/g of body weight, in which case the spores behaved in the same manner as those injected intravenously. Oral administration of spores did not result in any contamination of tissues. 相似文献