TITLE:
Preliminary Characterizations of a Carbohydrate from the Concentrated Culture Filtrate from Fusarium solani and Its Role in Benzo[a]Pyrene Solubilization
AUTHORS:
Etienne Veignie, Evgeny Vinogradov, Irina Sadovskaya, Charlène Coulon, Catherine Rafin
KEYWORDS:
Fusarium solani; Benzo[a]Pyrene; Polysaccharides; Glycoprotein; Nuclear Magnetic Resonance
JOURNAL NAME:
Advances in Microbiology,
Vol.2 No.3,
September
25,
2012
ABSTRACT: In order to investigate the mechanism of benzo[a]pyrene uptake by a filamentous fungus Fusarium solani, a biochemical characterization of its concentrated culture filtrate has been conducted. The preparation contained approximately (w/w): 50% of total carbohydrate, 6.5% of uronic acid and 6% protein, as determined by colorimetric tests. Gel filtration and anion-exchange chromatographic profiles indicated that the main product of the culture filtrate was a glycoprotein, which contained mannose, glucose and galactose in an approximate molar ratio of 1.5: 0.8: 1. The polysaccharide fraction of the culture filtrate was prepared by treatment with proteinase K, followed by gel-filtration chromatography. Its chemical structure was studied by methylation analysis, gas-liquid chromatography-mass spectrometry (GC-MS) and Nuclear Magnetic Resonance spectroscopy (NMR). The major carbohydrate was a polymer of β-(1 → 6)-linked galactofuranose units fully branched at positions O-2 by single residues of α-glucopyranose. The Fusarium concentrated culture filtrate increased 4-fold the BaP solubilization in comparison with its aqueous solubility and suggested that the carbohydrate present in this filtrate should probably be involved in this enhancement. Our findings point out the potential role of fungal glycoproteins in PAH microbial bioavaibility, an important step for PAH biodegradation.