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Study of photorespiration in marine microalgae through the determination of glycolic acid using hydrophilic interaction liquid chromatography
Author(s) -
RigobelloMasini Marilda,
Penteado José C. P.,
Tiba Maurício,
Masini Jorge C.
Publication year - 2012
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201100488
Subject(s) - glycolic acid , chromatography , phaeodactylum tricornutum , chemistry , aeration , ammonium , ammonium bicarbonate , hydrophilic interaction chromatography , high performance liquid chromatography , algae , organic chemistry , botany , lactic acid , raw material , genetics , bacteria , biology
Determination of organic acids in intracellular extracts and in the cultivation media of marine microalgae aid investigations about metabolic routes related to assimilation of atmospheric carbon by these organisms, which are known by their role in the carbon dioxide sink. The separation of these acids was investigated by hydrophilic interaction liquid chromatography (HILIC) using isocratic elution with a mobile phase composed of 70:30 v/v acetonitrile/20 mmol/L ammonium acetate buffer (pH 6.8) and detection at 220 nm. HILIC allowed the determinations of glycolic acid, the most important metabolite for the evaluation of the photorespiration process in algae, to be made with better selectivity than that achieved by reversed phase liquid chromatography, but with less detectability. The concentration of glycolic acid was determined in the cultivation media and in intracellular extracts of the algae Tetraselmis gracilis and Phaeodactylum tricornutum submitted to different conditions of aeration: (i) without forced aeration, (ii) aeration with atmospheric air, and (iii) bubbling with N 2 . The concentration of glycolic acid had a higher increase as the cultures were aerated with nitrogen, showing higher photorespiratory flux than that occurring in the cultures aerated with atmospheric air.