ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Searching for microalgal species producing extracellular biopolymers

Michal Halaj, Beata Chválová, Vladislav Cepák, Jaromír Lukavský, and Peter Capek

Slovak Academy of Sciences, Bratislava, Slovakia

E-mail: chemcape@savba.sk

Abstract: Microalgae have been used in human applications for centuries, but in the mid-twentieth century, an industrial cultivation of some species began. In this study, 17 different microalgal species were screened for the production of extracellular polymeric substances (EPSs). EPS yields (16–1064 mg/L), carbohydrate (1–88%) and protein (0–16%) contents were found to vary greatly. Uronic acids have been identified in most EPSs, indicating their ionic nature. Monosaccharide compositions revealed the heteropolysaccharide type of all EPSs. Monosaccharide compositions revealed a high number of sugar units (6–8) in all EPSs. Besides, hexoses were found as the dominant sugar components in most species. Some EPSs were rich in deoxy-hexoses, i.e. rhamnose or fucose, and some had high pentose content, i.e. xylose or arabinose. In many EPSs partially methylated sugars have been determined. Of the 17 species of microalgae studied, six strains differed significantly in the production of EPSs from others and had a relatively high content of carbohydrates. Screening revealed the following major EPS producers: Chlorosarcinopsis sp. (Lukešová 1996/401), Klebsormidium flaccidum (Lukešová 1997/320), K. flaccidum (Kaštovská 1995/02), Dictyosphaerium chlorelloides (Kováčik 1978/11), Dictyosphaerium cf. tetrachotomum Printz (Fott 1959/1), and Dictyosphaerium cf. tetrachotomum Printz Růžička 1962/50). Dominant producers are selected for cultivation on a larger scale to obtain EPSs for detailed chemical studies and potential biological activities.

Keywords: Microalgae ; Screening ; Cultivation ; Biopolymers ; Carbohydrates ; Sugar analysis 

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-018-0517-4

Chemical Papers 72 (10) 2673–2678 (2018)