摘要:

AbstractAcinetobacter calcoaceticusbildet beim Wachstum auf längerkettigenn‐Alkanen oder 1‐Alkanolen eine NADP+‐abhängige Aldehyddehydrogenase, wenig dagegen auf Fett‐ oder Aminosäuren. Das Enzym hat am Ende der logarithmischen Phase seine höchste spezifische Aktivität. Die Induktion des Enzyms kann durch Chloramphenicol oder Puromycin verhindert werden. Als Induktoren wirken auch mittelkettige 1‐Alkanole (Hexanol, Heptanol, Octanol) und Alkanale (Octanal), obwohl sie nicht als C‐Quelle dienen können. Die Aldehyddehydrogenase wird nach der Übertragung von einemn‐Alkan‐ auf ein Hefeextrakt‐Medium von den sich vermehrenden Zellen in 2 Std. um fast 60% abgebaut, in nicht‐wachsenden Zellen betr

ISSN:0044-2208    

DOI:10.1002/jobm.19770170402

出版商:Akademie‐Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractVon 6 methanutilisierenden und 11 methanolutilisierenden Bakterienspecies wurden spektralphotometrische Analysen durchgeführt. Damit liegen einschließlich der Befunde von DAVEY u. MITTON (1973), TONGEet al.(1974) sowie ANTHONY (1975) die Cytochromspektren von 9 methan‐ und 14 methanolutilisierenden Bakterien vor. Obwohl zwischen obligat und fakultativ methylotrophen Bakterien unterschieden werden kann, die Assimilation der C1‐Verbindungen über zwei prinzipiell verschiedene Sequenzen erfolgt und sich die einzelnen Species in morphologischen, ultrastrukturellen und physiologischen Merkmalen erheblich unterscheiden, besitzen alle methanutilisierenden Bakterien ein qualitativ nahezu identisches Cytochromkomplement, das sich von den Spektren der methylotrophen, aber Methan nicht utilisierenden Bakterien, die bis auf Ausnahmen fakultativ methylotroph sind, nicht signifikant unterscheidet. Charakteristisch ist der hohe Gehalt an Cytochromcundosowie die sehr geringe Konzentration anb. Alle methanutilisierenden Bakterienstämme sowie dieHyphomicrobium‐Species verfügen über den Cytochromaa3‐Komplex; in den methanolutilisierenden Bakterien konnte dieser nicht in allen Fällen sicher nachgewiesen werden.Das Cytochromspektrum ist weder zur Differenzierung methanoxydierender Bakterien mit verschiedenen internen Membransystemen geeignet noch kann es zur Unterscheidung von obligat und fakultativ methylotrophen Species dienen.Das prinzipiell identische Cytochromkomplement sowie die Tatsache, daß die Cytochrome der „methanotrophen”︁ Bakterien mit Methan wie mit Methanol reduzierbar sind, werden als Hinweis auf die generelle funktionelle Bedeutung für die Met

ISSN:0044-2208    

DOI:10.1002/jobm.19770170403

出版商:Akademie‐Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractThe iron oxidation byThiobacillusferrooxidans was studied in the presence of different concentrations of metals as sulphates, chlorides, nitrates, and in some other compounds. The bacteriological oxidation of ferro‐ions develops in all solutions in nearly the same way, with the only difference that, as the ion concentration increases, the beginning of measurable oxidation is postponed,i. e., with ion concentration increasing, the lag‐phase expands. When salts are mixed in different proportions, the toxic concentration of such a mixture corresponds, in a defined way, to the total of salts,i. e., of their i

ISSN:0044-2208    

DOI:10.1002/jobm.19770170404

出版商:Akademie‐Verlag    

年代:1977

数据来源: WILEY

摘要:

The inactivation of stationary phase cells by ultraviolet light (UV) and N‐methyl‐N′‐nitro‐N‐nitrosoguanidine (MNNG) was examined in eight wild strains ofRhodotorula, six of which are the sporidial yeast phase ofRhodosporidium, a basidiomycetous fungus. It thas been found that (1) the UV‐resistance ofRhodosporidiumandRhodotorulayeasts is higher and the MNNG‐resistance lower than the resistance ofCandidaandHansenulayeasts, (2) the shape of the survival curves is sigmoid in the case of UV and two‐phase exponential in the case of MNNG, (3) the mutagen sensitivities but not the inactivation kinetics of the strains are different, (4) the UV‐ and MNNG‐ sensitivities for each of the strains are correlated, (5) the relatively high resistance to UV cannot be due to the carotenoid pigments of the cells, (6) mutations to UV‐sensitivity can be induced with a high rate, (7) the sigmoidal character of the UV survival curves were reduced or transformed to an exponential sha

ISSN:0044-2208    

DOI:10.1002/jobm.19770170405

出版商:Akademie‐Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractVesicular bodies are observed during enzymatic degradation of the yeast cell wall and in the course of wall regeneration. In both cases various types of vesicles are formed and exocytated by different mechanisms. They are characterized cytochemically and their possible role in cell wall regeneration is discussed.

ISSN:0044-2208    

DOI:10.1002/jobm.19770170406

出版商:Akademie‐Verlag    

年代:1977

数据来源: WILEY

摘要:

The toxicity for and the uptake bySaccharomyces cerevisiaeof the essential trace element Co2+and the non essential elements Cd2+and Pb2+were compared.Inhibition of yeast growth is observed 4 hrs after addition of Co at concentrations higher than 10−4M. Cd is about 100 times more toxic than Co and inhibits growth immediately after addition. No toxicity of Pb is observed with concentrations up to 5 · 10−4M.For uptake experiments the radioactive isotopes60Co,115mCd and210Pb were used. The yeast samples were washed with carrier solution in order to remove the isotopes adsorbed only by the cell wall and measured by γ‐scintillation counting.Co uptake by yeast is strongly dependent on glucose both under aerobic and anaerobic conditions. There is no efflux of Co once taken up. Dead yeast does not accumulate Co at all. Co already taken up is released from cells when killed, indicating that no irreversible binding in the cell interior takes place. Co transport follows biphasic saturation kinetics with the MICHAELIS constants K1= 10−4and K2= 8 · 10−4M and the maximal velocities ν1= 9.5 and ν2= 63 μ moles/g dry weight · hr. The Q10for Co uptake from 10−4M solution is 2.3.Uptake of Cd resembles that of Co. The absorption of Cd is also glucose‐dependent, but independent of the presence of air, no Cd is taken up by dead cells, and Cd previously taken up is released during killing the cells.There is a considerable Pb uptake irrespective of the presence of glucose, and even by dead yeast. Killing of the yeast during uptake does not lead to loss of Pb.It is concluded that the essential trace element Co is accumulated by an energy‐dependent, probably active, transport system in the membrane. Cd is similarly transported, probably because of its chemical similarity to Zn. In contrast, Pb appears to be taken up only by diffusion, but subsequently to be trapped by binding in the cell interior. In this way, the accumulation of Pb is similar in amount to those of Co or Cd although the me

ISSN:0044-2208    

DOI:10.1002/jobm.19770170407

出版商:Akademie‐Verlag    

年代:1977

数据来源: WILEY

摘要:

AbstractWhen a culture ofE. colistrain K‐10, grown in a complex medium was transferred to a defined medium containing glucose and ammonia, two‐phasic growth was observed under aerobic conditions; complex nutrients from the preculture were consumed for growth in the first phase and growth in the second phase depended on the defined nutrients. The cells in the second phase grew immediately in a defined medium when transferred after washing, but the cells from the preculture did not. Under anaerobic conditions, nitrate stimulated growth, but growth stopped at low levels depending on the amounts of complex nutrients, even though glucose remained. In nitrate respiration, cells could not adapt to growth on defined nutrients after the exhaustion of the complex nutrients, while cells obtained from an aerobic culture in defined medium could anaerobically grow in defined medium with nitrate.Metabolic products of glucose as well as cell growth were investigated under the conditions of nitrate respiration, fermentation, and respiration in defined and in complex media. When the pH was maintained at 7.4, ethanol, acetate, and formate were formed as main products in a ratio of 1:1:2 under anaerobic conditions in both media. Small amounts of succinate, lactate, and pyruvate were also formed, especially in the complex medium. In the presence of nitrate, ethanol disappeared and acetate increased with the formation of nitrite, while formate decreased a little at the end of the growth period. In the aerobic culture, transient formation of acetate was observed, especially in the complex medium; little ethanol, succinate, and lactate was formed in this case. The molar growth yields on glucose in the anaerobic cultures were twice as high in the presence of nitrate than in its absence in both media and 1.5 times higher in the complex than in the defined medium in the absence and presence of nitrate, but the yields under aerobic conditions were higher in the defined than in the complex med

ISSN:0044-2208    

DOI:10.1002/jobm.19770170408

出版商:Akademie‐Verlag    

年代:1977

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19770170409

出版商:Akademie‐Verlag    

年代:1977

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19770170411

出版商:Akademie‐Verlag    

年代:1977

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19770170414

出版商:Akademie‐Verlag    

年代:1977

数据来源: WILEY