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Gellan gum biosynthetic enzymes in producing and nonproducing variants of Pseudomonas elodea
Author(s) -
Martins LO,
SaCorreia I.
Publication year - 1991
Publication title -
biotechnology and applied biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.468
H-Index - 70
eISSN - 1470-8744
pISSN - 0885-4513
DOI - 10.1111/j.1470-8744.1991.tb00188.x
Subject(s) - enzyme , biochemistry , gellan gum , glucuronic acid , chemistry , biology , strain (injury) , pseudomonas , biosynthesis , bacteria , polysaccharide , microbiology and biotechnology , genetics , anatomy
A pathway for the synthesis of the repeating tetrasaccharide units in gellan gum from Pseudomonas elodea is proposed. The enzymes presumed to be involved in the synthesis of the activated precursors UDP‐glucose, TDP‐rhamnose, and UDP‐glucuronic acid were detected and assayed in crude cell extracts of the gellan‐producing (Gel+) P. elodea ATCC 31461. The levels of UDP‐glucose pyrophosphorylase and TDP‐glucose pyrophosphorylase were higher in cells grown in media leading to higher gellan yields. Moreover, these enzymes exhibited lower values in cells of a Gel‐ variant, spontaneously obtained from the Gel+ wild type. The activation or repression of their synthesis is thought to be involved in the expression of the mucoid phenotype. Nevertheless, based on results here reported, the involvement of other enzymes, that catalyze steps downstream from the formation of the precursors cannot be excluded.