Isolation and Characterization of the Pigment Esters of Xanthomonas juglandis (campestris)

Abstract

Separation of the pigment esters of Xanthomonas juglandis (campestris) on silica gel columns yielded four bands. Two of the bands, esters 1 and 2, made up over 95% of the mixture. Both esters were phospholipids, with ester 1 containing the alcohol moieties glycerol and sorbitol, and ester 2 only glycerol. Both appeared to be mixtures containing different xanthomonadin pigment molecules but the results suggested that ester 1 consisted of one pigment molecule esterified to glycerophosphoryl sorbitol, whereas ester 2 consisted of 2 pigment molecules esterified to glycerophosphate.

Biosynthesis of the yellow xanthomonadin pigments involves an ATP‐dependent 3‐hydroxybenzoic acid: acyl carrier protein ligase and an unusual type II polyketide synthase pathway

“…D). This is highly consistent with previous findings that although there is substantially more chlorine than bromine in the environments, no natural occurrence of chlorinated relatives of the xanthomonadin pigments have yet been observed (Starr et al, ; Aririatu and Kester, ). Xcc probably has the unusual ability to scavenge bromine from its environments (including plants, soil and culture media) for xanthomonadin biosynthesis.…”

“…This is further supported by the previous findings that that pigB ( xanB1 and xanB2 ) mutant supernatant extracts stimulated a 10‐fold greater extracellular enzyme production in rpfF mutants than the extracts from the parent strain (B‐24) (Poplawsky et al, ). In addition, Aririatu and Kester () proposed a sorbitol moiety‐containing structure for xanthomonadins. The present study suggests that the glycosyltransferase encoded by the gene xanK is responsible for transferring the sugar donor to xanthomonadin.…”

“…Separation of the pigment esters of Xcc on silica gel columns yielded two major bands, which were referred to as esters 1 and 2. Both esters were phospholipids, with ester 1 containing the alcohol moieties glycerol and sorbitol, and ester 2 containing only glycerol (Aririatu and Kester, ). This finding was further supported by the recent finding that xanthomonadins are always co‐extracted from Xcc together with phospholipids, such as phosphatidylcholine, phosphatidylethanolamine and cardiolipin (Moser et al, ).…”

Simple and complex lipids: their occurrence, chemistry, and biochemistry

“…jug1andis. 207 By enzymatic and chemical hydrolysis and n.m.r. spectrometric analysis of the fragments, a major phosphoglycolipid from the Grampositive bacterium Deinococcus radiodurans was identified as the 2'-0- ( I ,2-diacyl-sn-glycero-3-phospho)-3'-0-(a-~-galacto-sy1)-N-D-glyceroylalkenamine (3).234 When E. coli was cultured in the presence of 600 mM D-mannitol, it synthesized phospha-0 0…”

A functional 4-hydroxybenzoate degradation pathway in the phytopathogen Xanthomonas campestris is required for full pathogenicity

“…A characteristic feature of Xanthomonas is the production of yellow, membrane-bound pigments called xanthomonadins 4 . These pigments are mixtures of unusual brominated, aryl-polyene esters 5 6 . A previous study conducted by Poplawsky and Chun 7 has shown that xanthomonadin production in Xanthomonas is regulated by a diffusible factor (DF).…”