ICDSUPL1-P001

Volume: 1, 2022
1^st International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland: ENVIRONMENT  – PLANT  – ANIMAL  – PRODUCT

Abstract number: P001

DOI: https://doi.org/10.24326/ICDSUPL1.P001

Published online: 26 April 2022

ICDSUPL, 1, P001 (2022)

Effect of glucose supplementation on the biochemical composition of EPS

Wioleta Babiak¹*, Magdalena Czemierska², Marlena Szymańska¹, Anna Wilkołazka-Jarosz², Izabela Krzemińska¹

¹ Institute of Agrophysics, Polish Academy of Sciences, Doświadczalna 4, 20-290 Lublin, Poland

² Department of Biochemistry and Biotechnology, Maria Curie-Sklodowska University, Akademicka 19, 20-033 Lublin, Poland

^{* Corresponding author:  w.babiak@ipan.lublin.pl}

Abstract

Unicellular algae are photosynthetic microorganisms, some of which show the ability to growth in mixotrophic conditions. Unicellular algae may excrete extracellular polymeric substances (EPS). It has been reported that mixotrophic conditions (in the presence of glucose in the culture medium) enhance the productivity of extracellular polymeric substances. However, the effect of mixotrophic growth on the biochemical composition of EPS is poorly investigated. The aim of the study was to assess the effect of mixotrophic growth conditions on the synthesis and biochemical composition of exopolysaccharides synthesized by Parachlorella kessleri, Chlorella vulgaris, Eustigmatos magnus, and Graesiella vacuolata. Microalgae were cultivated on BG-11 medium with and without glucose (control). EPS were collected through centrifugation, precipitation, and dialysis. Freeze-dried samples of EPS were analyzed for the content of total sugars and protein. EPS was then hydrolyzed with 4 M trifluoroacetic acid. For the measurement, EPS was dissolved in demineralized water to a final concentration of 1 mg mL^-1. The following compounds were determined: reducing sugars, uronic acids, amino sugars, phenolic compounds, and amino acids. The monosaccharide composition was determined using thin layer chromatography (TLC). The results show that the supplementation of the culture medium with the organic carbon source increased the efficiency of EPS synthesis. In mixotrophic conditions, the content of total and reducing sugars, proteins, amino sugars, and phenolic compounds increased. The analysis of the TLC plates indicated that EPS obtained from biomass growing in the control conditions did not contain glucose. To sum up, glucose supplementation exerts an impact on microalgal metabolism and the EPS composition. 

How to cite

W. Babiak, M. Czemierska, M. Szymańska, A. Wilkołazka-Jarosz, I. Krzemińska, 2022. Effect of glucose supplementation on the biochemical composition of EPS. In: 1st International PhD Student’s Conference at the University of Life Sciences in Lublin, Poland: Environment – Plant – Animal – Product. https://doi.org/10.24326/ICDSUPL1/P001