Increase in hyaluronic acid production by Streptococcus equi subsp. zooepidemicus strain deficient in β-glucuronidase in laboratory conditions

• Published in: Applied microbiology and biotechnology 2006-07, Vol.71 (4), p.415-422
• Main Authors: Krahulec, Ján, Krahulcová, Jana
• Format: Article
• Language: English
• Subjects: bacteria; beta-glucuronidase; Biological and medical sciences; Biotechnology; Chromatography, Gel; energy; Fundamental and applied biological sciences. Psychology; Glucuronidase - deficiency; Glucuronidase - metabolism; humans; hyaluronic acid; Hyaluronic Acid - biosynthesis; Hyaluronic Acid - metabolism; immune response; Molecular Weight; Mutation; operon; Streptococcus equi; Streptococcus equi - enzymology; Streptococcus equi - metabolism; Streptococcus equi subsp. zooepidemicus
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-005-0173-9

Streptococcus equi subsp. zooepidemicus is known to produce a hyaluronic acid capsule to resist the host immune defense. As the structure of the polysaccharide is identical to the one produced by humans, the bacteria S. equisubsp. zooepidemicusis used in biotechnological production of hyaluronic acid. In our laboratory we prepared mutated strains that are β-glucuronidase deficient. Comparing the wild-type strain, which is positive in β-glucuronidase activity, with the mutated strains named clone1 and clone2 in laboratory conditions, we observed that β-glucuronidase influences the production of hyaluronic acid considerably and the molecular weight of hyaluronan slightly. The production of hyaluronic acid by the mutated strains is higher by approximately 20% and the molecular weight is larger by about 2%. The significant increase in the production of hyaluronic acid and the slight increase in the molecular weight are probably caused by an absence of free β-glucuronic acid, due to its removal from the non-reducing termini of the polysaccharide by β-glucuronidase. The presence of free β-glucuronic acid would likely induce the expression of the β-glucuronic-acid-utilizing operon, which in turn would reflect into a misuse of energy in the glucose-rich media.