Affiliation:
1. Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
2. Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
3. National Center for Agricultural Utilization Research, USDA-ARS, Peoria, Illinois, USA
Abstract
ABSTRACT
Two related actinomycetes,
Glycomyces
sp. strain NRRL B-16210 and
Stackebrandtia nassauensis
NRRL B-16338, were identified as potential phosphonic acid producers by screening for the gene encoding phosphoenolpyruvate (PEP) mutase, which is required for the biosynthesis of most phosphonates. Using a variety of analytical techniques, both strains were subsequently shown to produce phosphonate-containing exopolysaccharides (EPS), also known as phosphonoglycans. The phosphonoglycans were purified by sequential organic solvent extractions, methanol precipitation, and ultrafiltration. The EPS from the
Glycomyces
strain has a mass of 40 to 50 kDa and is composed of galactose, xylose, and five distinct partially
O
-methylated galactose residues. Per-deutero-methylation analysis indicated that galactosyl residues in the polysaccharide backbone are 3,4-linked Gal, 2,4-linked 3-MeGal, 2,3-linked Gal, 3,6-linked 2-MeGal, and 4,6-linked 2,3-diMeGal. The EPS from the
Stackebrandtia
strain is comprised of glucose, galactose, xylose, and four partially
O
-methylated galactose residues. Isotopic labeling indicated that the
O
-methyl groups in the
Stackebrandtia
phosphonoglycan arise from
S
-adenosylmethionine. The phosphonate moiety in both phosphonoglycans was shown to be 2-hydroxyethylphosphonate (2-HEP) by
31
P nuclear magnetic resonance (NMR) and mass spectrometry following strong acid hydrolysis of the purified molecules. Partial acid hydrolysis of the purified EPS from
Glycomyces
yielded 2-HEP in ester linkage to the
O
-5 or
O
-6 position of a hexose and a 2-HEP mono(2,3-dihydroxypropyl)ester. Partial acid hydrolysis of
Stackebrandtia
EPS also revealed the presence of 2-HEP mono(2,3-dihydroxypropyl)ester. Examination of the genome sequences of the two strains revealed similar
pepM
-containing gene clusters that are likely to be required for phosphonoglycan synthesis.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Cited by
24 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献