摘要:

AbstractStreptomyces viridosporusdegraded lignin and lignocellulose, producing low molecular weight phenolic compounds for potential industrial use.The main portion of lignin in the residues was released into the growth medium as a water soluble modified polymer. The polymer, an acid precipitable polyphenolic lignin (APPL), was recovered from spent culture media by an acid precipitation, and was shown to be mostly free of non‐lignin components, as compared to native lignin. Elemental and functional group analysis showed that APPL contained a higher hydrogen and oxygen content, lower carbon and also lower methoxyl group and higher phenolic content, than native lignin. From IR spectra, an absorption peak at 1,720 cm−1appeared in the infrared spectra of APPL. The ratio of the absorbance at 1,720 cm−1to the absorbance at 1.630 cm−1increased, due to higher levels of carbonyl and carboxyl

ISSN:0233-111X    

DOI:10.1002/jobm.3620280802

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280804

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractThe biosynthesis of avermectins was significantly affected by the nitrogen source used. The maximum yield of AVMs1) was achieved in a chemically defined medium with ammonium sulfate as the sole nitrogen source. Higher concentrations of ammonia inhibited the production of AVMs without the inhibition of the growth. AVMs of the group B were prevailing in the complex until 15 mM ammonium sulfate. At higher concentrations, AVMs of the group A predominated. Of various amino acids tested, lysine and asparagine were found to be the best for the biosynthesis of AVMs. The concentration of most amino acids higher than 0.2% inhibited the production, while the mycelium was still growing. The biosynthesis of AVMs was completely suppressed by 15.2 mM isoleucine, however, this inhibition was reversed by adding alanine at the beginning of cultivation.

ISSN:0233-111X    

DOI:10.1002/jobm.3620280805

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280807

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractSeveral polynucleotides were tested for interferon induction in comparison with the standard Poly (IC) in human diploid fibroblasts and in human leukocyte suspensions.We received high IFN‐titre following superinduction of the polynucleotides in human fibroblasts.These results show that under superinduction conditions partly 3 times more interferon is induced in comparison with the standard inductor Poly (IC).The tested concentration of 10 μg/ml polynucleotides did not result in any IFN yields or only in very low ones in human leukocytes, which were only within the range of detectabili

ISSN:0233-111X    

DOI:10.1002/jobm.3620280808

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280810

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractTwo bacterial isolates (i.e. strains An 117 and An 213) capable of growing with aniline, phenol as well as benzoate as the sole carbon and energy source were studied with respect to (i) their taxonomic position, (ii) the enzyme reactions which initiate catabolism of the respective aromatic compounds, and (iii) the general type of regulation of the respective enzymes.Both isolates were established to be representatives of the actinomycete‐genusRhodococcus. Experiments with resting cells and cell‐free extracts, respectively, revealed that in the two strains under study catabolism of each of the unsubstituted aromatic compounds occurs via the β‐ketoadipate pathway (with catechol as the central metabolite) due to the action of inducible enzymes. Although being potent inducers of the ring‐cleaving catechol 1,2‐dioxygenase in strains An 117 and An 213, all of the monochlorinated derivatives of aniline, phenol and benzoate, respectively, failed to support cell growth of the organisms.Cis, cis‐muconic acid proved to be non‐metabolizable by resting An 117 and An 213 cells, although substantial (inducible) muconate cycloisomerase activity was detectable in crude extracts prepared from the respective cell preparations. NADPH‐depending phenol hydroxylase activity could be demonstrated in crude extracts from phenol‐grown An 117 and An 213 cells. Evidence is presented that in bothRhodococcusstrains under study substantialde novosynthesis of at least the initial aromatics‐oxygenating enzymes can be induced by phenol and aniline, respectively, even in the presence of either succinate (An 117) or acetate (An 213) which are known to beortho

ISSN:0233-111X    

DOI:10.1002/jobm.3620280811

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractKinetic experiments were performed to examine the effect of glucose and some related compounds on the removal of different monochloroaromatic non‐growth substrates (i.e. monochloroisomers of aniline, phenol and benzoate, respectively) by resting pre‐adapted cells of eitherRhodococcussp. An 117 orRhodococcussp. An 213. With both strains, the use of glucose as the additional carbon substrate allowed to differentiate between “cometabolizable” monochloroaromatics (i.e. 2‐chloroaniline, 3‐chloroaniline, 3‐chlorophenol, 4‐chlorophenol whose turnover appeared to be primarily limited by the availability of reducing power and/or energy to the cells) and those which were weakly removed “under any condition” due to narrow substrate specificity of the enzymes initiating the transformation process.In a second line of investigation, the reduction of ferricyanide by resting An 117 or An 213 cells was shown to exhibit a pattern of cosubstrate‐dependence analogous to that found for turnover of the “cometabolizable” monochloroaromatics. As demonstrated with different cell preparations of strain An 117, whole‐cell ferricyanide reduction strongly interferred with the cometabolic turnover of various monochloroaromatic non‐growth substrates. The results obtained are those to be expected if the former (NAD(P)H‐dependent) type of process, in preference to the second one, would consume the reducing equivalents which become available from the metabolism of glucose. They point out the opportunity to make use of the carbon substrate‐dependent whole‐cell reduction of ferricyanide (or of other external electron acceptors) as a rapid and inexpensive assay of pre‐screening for carbon compounds which would function as energy‐replenishing cosubstrates in the (cometabolic) turnover of xenobio

ISSN:0233-111X    

DOI:10.1002/jobm.3620280812

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractNitrate and nitrite reductases in the crude extract of aerobically grownRhizobium melilotiwere determined with methylviologen as electron donor at pH 7. Nitrate reductase was detected in the cells grown in the medium that did not contain nitrate, and in the presence of nitrate the specific activity increased about 2‐fold.Nitrite reductase was induced by nitrate and produced ammonia from nitrite.In nitrate reducing cells, two kinds of O2labile nitrate reductase were found. One enzyme had optimal pH at 7 and was stabilized to O2by treating with DEAE‐Toyopearl 650M. The other had optimal pH at 9 and was stabilized by the addition of dithiothreitol and EDTA.Nitrate reductase stabilized by DEAE‐Toyopearl 650M treatment was purified 3,360‐fold from crude extract. The purified enzyme showed a single protein band in polyacrylamide gel electrophoresis, and there was no absorption peak in the visible region. It had a molecular weight of 64,000 in SDS PAGE and 58,000 on Sephadex G‐100 gel filtration.Kmfor nitrate was 0.9 mM. It was inhibited byp‐chloromercuribenzoate, cyanide, and α,

ISSN:0233-111X    

DOI:10.1002/jobm.3620280813

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280814

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY