摘要:

AbstractA new method of optimization of the medium composition by biostatistical methods is reported. The well‐known Box‐Wilson scheme combined with the method of optimum curves was applied for an exploration of the response surface. The primary goal has been to optimize the concentration of nutrients for the production of gibberellic acid by the fungusGibberella fujikuroiwith a minimum number of experiments. As the result, a nearly fivefold improvement yield of the was achieved performing only two experime

ISSN:0233-111X    

DOI:10.1002/jobm.3620310402

出版商:Wiley‐VCH    

年代:1991

数据来源: WILEY

摘要:

AbstractThe active form of isocitrate lyase (ICL) from the yeastYarrowia lipolyticawas eluted as single peak from ion exchange on DEAE‐cellulose. The enzyme had a specific activity of 7.4 U/mg. Its molecular mass was estimated to be approximately 200 to 210 kDa by gel filtration chomatography on Sephadex G 200. In SDS‐polyacrylamide gel electrophoresis the enzyme was characterized by an unique protein band of about 50 kDa, thus indicating that ICL is a tetramer of identical subunits. The optimum pH was 6.0 in 50 mm phosphate buffer at 30°C. TheKmvalue of the 35‐fold purified ICL for threo‐ds‐isocitrate in 50 mm phosphate buffer at pH 6.0 was 0.3 mm. In regulation studies ICL was found to be noncompetitive inhibited by succinate and oxaloacetate.Antibodies against ICL were raised in rabbits. The specificity of the anti‐ICL‐antibodies was estimated by Ouchterlony tests and by a competitive ELISA on mic

ISSN:0233-111X    

DOI:10.1002/jobm.3620310403

出版商:Wiley‐VCH    

年代:1991

数据来源: WILEY

摘要:

AbstractWith four individual germ tubes (GTs), the distinct time of birth of branches was correlated to the kinetics of GT‐elongation. During the first three hours, corresponding to five doubling times, branching was suppressed. The time of birth of the first branch (tb1) coincided with the 5thstep of the typical stepwise increase of the GT elongation rate (α). During this time, the quasi‐exponential kinetics of α changed to linear kinetics, which was attained either at the 5thof 6thα‐step. At the 5thstep, the quotient of successive α‐values had been reduced from 2 at the beginning of outgrowth to 1.2.Once the first branch had been formed, further branches appeared as clusters (additional 2, 4, and 8 branches) atD‐intervals representing the doubling time of the hyphal length.The first branch appeard always in the vicinity of the spore. The average distance to the spore of 6.6 μm corresponded to four unit cells. Attb1, the unbranched region located between the first branch and the tip of the GTs was 42 μm long. The data concernning timing and location of the first branching in GTs suggest that initiation of branching was dependent on the accumulation of enve

ISSN:0233-111X    

DOI:10.1002/jobm.3620310404

出版商:Wiley‐VCH    

年代:1991

数据来源: WILEY

摘要:

AbstractThe thermotolerant mycelial fungus,Aspergillus terreus17p, was shown to be capable of utilizing various carbon substrates, e.g., cellulose, glucose, hexadecane, methanol. In all cases the fungal hyphae cytoplasm contained microbodies differing in morphology with a carbon source. A cytochemical reaction with 3,3‐diaminobenzidine revealed catalase within microbodies. A comparative enzymatic analysis was carried out for cell‐free extract from fungi grown on various carbon substrates. The activities of the enzymes (alcohol oxidase, formaldehyde‐ and formate dehydrogenases, dihydroxyacetone synthase and dihydroxyacetone kinase) catalyzing methanol dissimilation and assimilation were estimated in the methanol‐grown mycelium. Maximum values of hexokinase and glucose‐6‐phosphate dehydrogenase activities were observed in hyphae cultivated with glucose and cellulose. Synthesis of cytochrome P‐450 and oxidase of higher fatty alcohols involved inn‐alkane dissimilation is induced by hexadecane. Activities of the citric acid cycle enzymes, fumarase and isocitrate dehydrogenase, were not essentially influenced by the nature of ca

ISSN:0233-111X    

DOI:10.1002/jobm.3620310405

出版商:Wiley‐VCH    

年代:1991

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620310407

出版商:Wiley‐VCH    

年代:1991

数据来源: WILEY

摘要:

AbstractInfluence of some sugars was studied on activity of purified cellulase enzymes produced by two white‐rot basidiomycetes cultures in submerged fermentation. Exo‐ and endo‐glucanases were found to be stimulated by glucose, sucrose and xylose, but β‐glucosidase was inhibited by all sugars tested except sucrose being neutral. Cellobiose severely inhibited all three cellulase activities at all three concentrations taken in reaction

ISSN:0233-111X    

DOI:10.1002/jobm.3620310408

出版商:Wiley‐VCH    

年代:1991

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620310410

出版商:Wiley‐VCH    

年代:1991

数据来源: WILEY

摘要:

AbstractIsolates of basidiomycetes have been studied for the production of extracellular cellulases in submerged shaken cultures using whole sugar cane bagasse (without delignification) as substrate. Cultures produced maximum exo‐β‐1,4,glucanase (FPD), endo‐β‐1,4,glucanase (E.C.3.2.1.4.) (CMCase) on the 4–5th day and β‐glucosidase (salicinase) (E.C.3.2.1.21.) on the 6th day of fermentation. Production of these enzymes could be manipulated for maximum yields by implication of selected cultural factors like growth medium, incubation condition, pH of fermentation, particle size of bagasse and var

ISSN:0233-111X    

DOI:10.1002/jobm.3620310411

出版商:Wiley‐VCH    

年代:1991

数据来源: WILEY

摘要:

AbstractTyrosinase ofStreptomyces michiganensisDSM 40015 was purified 61‐fold from the culture broth: After a fractionated ammonium sulfate precipitation the enzyme was separated by hydrophobic interaction chromatography with Phenyl‐Sepharose and ionic interaction chromatography with CM‐Cellulose; finally a gel filtration with Sephadex G‐75 yielded 1.7% of the originally existent enzyme. SDS gel‐electrophoresis of the purified enzyme showed two bands representing a size of 34500 and 32000 dalton, respectively. However, by isoelectric focussing only one band could be found exhibiting an isoelectric point of approximately 9.0. Temperature and pH‐optimum of the enzyme activity were 33°C and pH 7.0, respectively. Whereas the enzyme is specific in regard to the aromatic part of its substrate variations of the aliphatic rest a

ISSN:0233-111X    

DOI:10.1002/jobm.3620310412

出版商:Wiley‐VCH    

年代:1991

数据来源: WILEY

摘要:

AbstractA yeast strain isolated in the laboratory was studied and classified as aCandida molischiana.The β‐glucosidase of this yeast strain was then purified. Its molecular weight, estimated by gel filtration, was 100,000. The enzyme consisted of only one subunit, identified after treatment with sodium dodecyl sulfate. Maximum activity was obtained at 55°C and pH 4 but the enzyme still possessed activity at pH 2.5. Active against different glucosides with β(1–2), β(1–3), β(1–4), β(1–6), and α(1–4) configurations it presented an α(1–6)‐arabinofuranosidase activity. The enzyme was competitively inhibited by glucose (Ki9.5 mm). A glucosyltransferase activity appeared in the presence of ethanol. The enzyme was constitutive but its synthesis w

ISSN:0233-111X    

DOI:10.1002/jobm.3620310413

出版商:Wiley‐VCH    

年代:1991

数据来源: WILEY