Matches in SemOpenAlex for { <https://semopenalex.org/work/W2123703958> ?p ?o ?g. }
- W2123703958 endingPage "195" @default.
- W2123703958 startingPage "195" @default.
- W2123703958 abstract "Many different Rhizobium strains produce melanin (Mel+) when grown on solid media supplemented with L-tyrosine. The composition of the media and the culture conditions are of great importance for pigment production. Previous reports showed that some Rhizobium leguminosarum biovar phaseoli strains that produce the pigment in complete solid media (TY) failed to produce the pigment in minimal media (SY) supplemented with L-tyrosine or in TY liquid media. In this paper we have investigated different R. fredii, R. meliloti, R. etli and R. leguminosarum bv. trifolii and phaseoli strains (all of them Mel+ in solid media) for their ability to produce the pigment in liquid media. All Rhizobium species tested, except Rhizobium etli, were Mel+ in liquid media and in all cases the pigment yielded maximum absorption peaks at 280 and 315 nm. Melanin production by other bacteria (such as Vibrio, Streptomyces or Azospirillum) is enhanced by the presence of amino acids other that tyrosine. In this paper we show that the addition of L-methionine, which is not a precursor of rhizobial melanins, stimulated pigment production by Rhizobium cultures supplemented with L-tyrosine. The role of melanin production by Rhizobium strains is unclear. One hypothesis is that the Rhizobium tyrosinase, a bifunctional copper-containing enzyme that is essential for melanin biosynthesis, could detoxify polyphenolic compounds which might accumulate in senescing nodules. We show here that R. etli and R. fredii bacteroids produced melanin, which supports the idea that bacteroids contain the enzyme tyrosinase. Previous reports showed that, in R. leguminosarum bv. phaseoli strain 8002, the expression of the tyrosinase gene (melA) is dependent on the presence of nifA, a regulatory gene that is located in the symbiotic plasmid. However, transfer of R. leguminosarum bv. phaseoli melA gene to pSym-cured derivatives of R. leguminosarum bv. trifolii and viciae, R. fredii and Rhizobium sp. (Hedysarum) produced Mel+ transconjugants. DNA-hybridisation experiments showed that the pSym-cured strains did not contain any copy of nifA. Therefore, in contrast to the results reported on R. leguminosarum bv. phaseoli strain 8002, the expression of the melA gene in other rhizobia is not nifA-dependent. Key words: Rhizobium, melanin." @default.
- W2123703958 created "2016-06-24" @default.
- W2123703958 creator A5017624219 @default.
- W2123703958 creator A5035750942 @default.
- W2123703958 creator A5049514242 @default.
- W2123703958 creator A5073325237 @default.
- W2123703958 date "1997-01-01" @default.
- W2123703958 modified "2023-10-18" @default.
- W2123703958 title "Expression of the Rhizobium leguminosarum biovar phaseoli melA Gene in Other Rhizobia Does Not Require the Presence of the nifA Gene" @default.
- W2123703958 cites W1536736614 @default.
- W2123703958 cites W1543101582 @default.
- W2123703958 cites W1565243917 @default.
- W2123703958 cites W1576648541 @default.
- W2123703958 cites W1921813415 @default.
- W2123703958 cites W1934646542 @default.
- W2123703958 cites W1965415366 @default.
- W2123703958 cites W1967242895 @default.
- W2123703958 cites W1975501554 @default.
- W2123703958 cites W1989606355 @default.
- W2123703958 cites W1993234114 @default.
- W2123703958 cites W1995518280 @default.
- W2123703958 cites W2000219385 @default.
- W2123703958 cites W2027229485 @default.
- W2123703958 cites W2047615672 @default.
- W2123703958 cites W2072382362 @default.
- W2123703958 cites W2081205493 @default.
- W2123703958 cites W2084568631 @default.
- W2123703958 cites W2104214209 @default.
- W2123703958 cites W2106939093 @default.
- W2123703958 cites W2112890976 @default.
- W2123703958 cites W2129224556 @default.
- W2123703958 cites W2132785421 @default.
- W2123703958 cites W2133588978 @default.
- W2123703958 cites W2144456434 @default.
- W2123703958 cites W2156360392 @default.
- W2123703958 cites W2158937196 @default.
- W2123703958 doi "https://doi.org/10.1071/pp96076" @default.
- W2123703958 hasPublicationYear "1997" @default.
- W2123703958 type Work @default.
- W2123703958 sameAs 2123703958 @default.
- W2123703958 citedByCount "6" @default.
- W2123703958 countsByYear W21237039582014 @default.
- W2123703958 crossrefType "journal-article" @default.
- W2123703958 hasAuthorship W2123703958A5017624219 @default.
- W2123703958 hasAuthorship W2123703958A5035750942 @default.
- W2123703958 hasAuthorship W2123703958A5049514242 @default.
- W2123703958 hasAuthorship W2123703958A5073325237 @default.
- W2123703958 hasConcept C104317684 @default.
- W2123703958 hasConcept C107538193 @default.
- W2123703958 hasConcept C178790620 @default.
- W2123703958 hasConcept C181199279 @default.
- W2123703958 hasConcept C181440489 @default.
- W2123703958 hasConcept C185592680 @default.
- W2123703958 hasConcept C2776165026 @default.
- W2123703958 hasConcept C2776336279 @default.
- W2123703958 hasConcept C2777465193 @default.
- W2123703958 hasConcept C2779856404 @default.
- W2123703958 hasConcept C2780434414 @default.
- W2123703958 hasConcept C43144210 @default.
- W2123703958 hasConcept C523546767 @default.
- W2123703958 hasConcept C54355233 @default.
- W2123703958 hasConcept C55493867 @default.
- W2123703958 hasConcept C64584667 @default.
- W2123703958 hasConcept C86803240 @default.
- W2123703958 hasConcept C87554066 @default.
- W2123703958 hasConcept C89423630 @default.
- W2123703958 hasConceptScore W2123703958C104317684 @default.
- W2123703958 hasConceptScore W2123703958C107538193 @default.
- W2123703958 hasConceptScore W2123703958C178790620 @default.
- W2123703958 hasConceptScore W2123703958C181199279 @default.
- W2123703958 hasConceptScore W2123703958C181440489 @default.
- W2123703958 hasConceptScore W2123703958C185592680 @default.
- W2123703958 hasConceptScore W2123703958C2776165026 @default.
- W2123703958 hasConceptScore W2123703958C2776336279 @default.
- W2123703958 hasConceptScore W2123703958C2777465193 @default.
- W2123703958 hasConceptScore W2123703958C2779856404 @default.
- W2123703958 hasConceptScore W2123703958C2780434414 @default.
- W2123703958 hasConceptScore W2123703958C43144210 @default.
- W2123703958 hasConceptScore W2123703958C523546767 @default.
- W2123703958 hasConceptScore W2123703958C54355233 @default.
- W2123703958 hasConceptScore W2123703958C55493867 @default.
- W2123703958 hasConceptScore W2123703958C64584667 @default.
- W2123703958 hasConceptScore W2123703958C86803240 @default.
- W2123703958 hasConceptScore W2123703958C87554066 @default.
- W2123703958 hasConceptScore W2123703958C89423630 @default.
- W2123703958 hasIssue "2" @default.
- W2123703958 hasLocation W21237039581 @default.
- W2123703958 hasOpenAccess W2123703958 @default.
- W2123703958 hasPrimaryLocation W21237039581 @default.
- W2123703958 hasRelatedWork W1525367283 @default.
- W2123703958 hasRelatedWork W1542711284 @default.
- W2123703958 hasRelatedWork W1623168658 @default.
- W2123703958 hasRelatedWork W1970576895 @default.
- W2123703958 hasRelatedWork W1993717659 @default.
- W2123703958 hasRelatedWork W2123703958 @default.
- W2123703958 hasRelatedWork W2175510305 @default.
- W2123703958 hasRelatedWork W2182123714 @default.
- W2123703958 hasRelatedWork W2473975729 @default.