摘要:

AbstractThe growth ofThermoactinomyces vulgarison solid media was studied by microculture technique. Starting from a germinating spore the further development was followed by phase contrast microscopy. From serially taken photographs the kinetics of growth and branching of the mycelium was calculated. Also some observations on morphological behaviour were made.Regarding the total mycelium developing from one spore the growth occurred with a constant exponential growth rate, at least for the time tested (about ten doublings). This constancy of the mycelial growth rate was not attributed to constant rates of hyphal growth or branching. The hyphal growth rate increased during the development of the mycelium, so that the length produced by a hypha within a given time was smallest after germination and largest at the end of the experiment. Between the first and the 10th doubling of the mycelium the mean hyphal growth rate increased by the factor 27, in some cultures even by the factor 40. While hyphal growth changed from exponential to linear, branching was first linear and then approached exponential kinetics.Under different conditions of cultivation mycelia could have identical doubling times, but different hyphal growth rates and vice versa. Yeast extract caused a reduction of the hyphal growth rate and an enhancement of branching. Likewise the diminution of the supply of oxygen did not reduce the mycelial growth rate, but markedly decreased the hyphal growth rate, especially of the germ tube.The data obtained concerning the kinetics of growth and branching can be explained by a special form of cooperation of cytoplasmic and cell wall synthesis. With respect to the synthesis of cytoplasm aT. vulgarismycelium behaves as one individual, which is not differentiated into replicating and non replicating areas (as recently was shown to be likely forStreptomyces hygroscopicusbySCHUHMANNandBERGTER1976). The mycelial growth rate thus reflects the rate of the synthesis of cytoplasm. The hyphal growth rate is moreover determined by the rate of cell wall synthesis at the tip of each hypha. The observed increase of the hyphal growth rate is explainable by an acceleration of the cell wall synthesis during the development of the mycelium. Probably the branching is regulated indirectly. According to the different manner of cytoplasmic and cell wall synthesis, within a hypha a balance between both processes is maintainable only for a limited time. As soon as the momentary apical capacity for cell wall synthesis is exhausted, the balance is attained anew by originating a new site for wall synthesis,i.e.by branching.Branching was often defective. Especially in the absence of yeast extract a lot of lateral branches arose, which ceased further growth at an average length of 2.5 μm. It is suggested that yeast extract supports the transport of the nucleoids into the lateral branches, which otherwise is often infeasible. Reduction of the supply of oxygen favoured apical branching, so that dichotomous forms resulted

ISSN:0044-2208    

DOI:10.1002/jobm.19780181002

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractIm Verlauf der Entwicklung eines Verfahrens zur Gewinnung einer neutralen Protease wurde ein Komplexmedium gefunden, in dem der verwendete StammBacillus megateriumeine hohe Enzymaktivität ausschüttet. Untersuchungen über den Umsatz der eingesetzten Kohlenhydrate während der Fermentation zeigten, daß die als C‐Quelle verwendete Lactose bei der Sterilisation des Nährmediums partiell in Lactulose überführt wird. Dieses fructosehaltige Disaccharid wird vom Produktionsstamm rasch umgesetzt. Es wird der Nachweis erbracht, daß die im Zellinneren lokalisierte β‐Galaktosidase die glykosidische Bindung der Lactulose angreift. Die Spaltungsrate ist etwa gleich hoch wie diejenige bei Einsat

ISSN:0044-2208    

DOI:10.1002/jobm.19780181003

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractComparative investigations on the inhibition of chitin synthetase ofMucor rouxiirevealed that in contrast to results obtainedin vivo, only few fungicides and other compounds inhibit the enzymein vitro. Besides the well‐known effect of polyoxin D, an inhibition was demonstrated for terrazol, tridemorph, hinosan, and formulated preparations of dimilin (PH 60‐40, 60‐38). The latter preparations, however, showed growth inhibition also with fungal species which do not synthesize chitin and the pure compounds are ineffective.Inhibition by phospholipase C, unsaturated fatty acids, and the reversibility of the inhibition caused by terrazol after addition of procain‐hydrochloride demonstrates that phospholipids are essential for the activity of the enzyme, whereas sterols seem to be ineffective. Action of trypsin, PCNB, pentachlorophenol, and some similar compounds results in significantly increased activity, which in the case of trypsin could be due to the hydrolysis of a protein inhibitor. Hinosan inhibits the enzyme indirectly in a still unexplored

ISSN:0044-2208    

DOI:10.1002/jobm.19780181004

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

摘要:

AbstractHydrostatic pressures greater thanca. 400 atm cause release of cellular components ofVibrio marinusMP‐1 in the order protein>RNA>malate dehydrogenase>DNA>amino acids. Increased pressures also slow the rate of cycloleucine (non‐metabolizable analogue of l‐leucine and l‐valine) uptake but increase its efflux rate.LINEWEAVER‐BURKplots (1/Vversus 1/[S]) of cycloleucine uptake indicate that theKmincreases with compression which suggests a decrease in affinity of the transport system for substrate at increased

ISSN:0044-2208    

DOI:10.1002/jobm.19780181005

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19780181006

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19780181007

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19780181009

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19780181011

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19780181014

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY

ISSN:0044-2208    

DOI:10.1002/jobm.19780181015

出版商:Akademie‐Verlag    

年代:1978

数据来源: WILEY