Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Sources of cyclopropanoid fatty acids in the mummichog Fundulus heteroclitus (1984)
    Springer
    Marine biology 78 (1984), S. 139-146 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The saturated fatty acids in lipids of the mummichog Fundulus heteroclitus (L.) contain the characteristic bacterial cis-9,10-methylenehexadecanoic and cis-9,10-methyleneoctadecanoic acids in addition to straight-chain, iso, anteiso and multi-branched fatty acids. To ascertain whether the cyclopropanoid fatty acids (CFA) might be used as a marker for bacterial components in the mummichog diet, the saturated fatty acids of detritus were compared with those of fish intestines and their contents, and with those of eviscerated fish. The relative amounts of individual fatty acids in each sample indicated that microorganisms or invertebrate animals that consume microorganisms constitute a part of the mummichog's diet. A similar analysis of anterior and posterior sections of the fish intestines showed a higher concentration of CFA in the posterior section, suggesting that at least some of the cyclic acids might originate from the resident bacterial gut population. When a group of mummichogs was maintained on a beef-liver diet devoid of cyclic acids, carcass lipids were not depleted of CFA. Instead, an increase in concentration was observed. It was concluded that the intestinal microflora have a role in supplying CFA to mummichog lipids. Since the overall results indicate that these acids are derived from commensal bacteria as well as from bacteria associated with the diet, it is not possible to use such compounds as food-chain markers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00394693
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Functions of Secondary Metabolites (1990)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Microbiology 44 (1990), S. 395-427 
    Details
    ISSN: 0066-4227
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1146/annurev.mi.44.100190.002143
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Secondary metabolism (1992)
    Springer
    World journal of microbiology and biotechnology 8 (1992), S. 90-91 
    Details
    ISSN: 1573-0972
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02421504
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Cephamycin production and isopenicillin N synthetase activity in cultures of Streptomyces clavuligerus (1987)
    Springer
    Applied microbiology and biotechnology 27 (1987), S. 240-246 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The relationships between growth, cephamycin production and isopenicillin N synthetase (IPNS) activity in cultures of Streptomyces clavuligerus were examined to establish conditions that optimize the yield and specific activity of the enzyme. Unexpectedly for a secondary metabolic pathway component, IPNS was synthesized preferentially during rapid growth and reached its maximum specific activity in cultures supplied with readily assimilated sources of nitrogen. The activity decreased sharply as cultures entered stationary phase. On the other hand, comparisons of growth and antibiotic production on a range of carbon and nitrogen sources as well as measurements of IPNS activity in chemostat cultures implicated “catabolite repression”, a mechanism usually associated with separation of trophophase and idiophase activities, as an important factor in controlling expression of the secondary metabolic pathway. An explanation for the timing of IPNS biosynthesis is suggested.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00252925
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Lysine cataboism and α-aminoadipate synthesis in Streptomyces clavuligerus (1991)
    Springer
    Applied microbiology and biotechnology 35 (1991), S. 358-363 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The intracellular α-aminoadipic acid pool in Streptomyces glavuligerus mycelium growing in a starch-peptone medium decreased during the late exponential and stationary phases when cephamycin was being produced; however, the amino acid accumulated extracellularly. Although the specific activity of lysine ɛ-aminotransferase (LAT) decreased during this period, there was no indication that the extracellular α-aminoadipic acid functioned as a precursor reserve for synthesis of the β-lactam antibiotic. Measurement of LAT activity in cultures grown in defined media with starch and various nitrogen sources indicated that the enzyme was synthesized preferentially only during early growth. In its insensitivity to induction by a precursor, and in its susceptibility to carbon catabolite repression, LAT behaved as a secondary metabolic pathway enzyme. Unexpectedly, however, the enzyme increased in specific activity when cultures were supplemented with excess phosphate. Unlike LAT, cadeverine aminotransferase was inducible by lysine or cadaverine and insensitive to phosphate; its features were consistent with a role in the catabolism of lysine by S. clavuligerus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00172726
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Biosynthesis of chloramphenicol (1969)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 11 (1969), S. 1125-1134 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The current knowledge concerning the biosynthesis of chloramphenicol is discussed. Cultures of Streptomyces sp. 3022a fed 14C-shikimie acid incorporated the label to the same extent into phenylalanine, tyrosine, and chloramphenicol. Of possible precursors of the phenylpropanoid nucleus of this antibiotic only p-aminophenylalanine and DL-threo-p-amino phenylserine specifically labeled chloramphenicol. On the basis of these results a pathway for the biosynthesis of chloramphenicol is presented. The lack of specific incorporation of 15N-nitrogen from a competitive feeding experiment in which both l5N-nitrate and 14N-DL-serine were fed to growing cultures suggests that both the amido- and the nitro-nitrogen atom present in this antibiotic are derived from a common pool. Studies on the enzyme, DAHP synthetase, show that in streptomyces sp. 3022a it is not subject to feed back inhibition by either phenylalanine, tyrosine, or chloramphenicol.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260110609
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...