Heterotrophic cultivation of Euglena gracilis on chemically pretreated media

Abstract

In this research, the impact of chemical agents on the growth of Euglena gracilis and contaminants (S. cerevisiae and B. subtilis) in different cultivation media was studied. E. gracilis was cultivated on modified Hutner and complex medium in Erlenmeyer flasks and a stirred tank bioreactor. H 2 O 2 and antimycin were used as suppressors of contaminant growth activities during algae cultivation. The use of antimycin as a chemical suppressor of contaminants is not recommendable because of its significant impact on the E. gracilis growth. At a H 2 O 2 concentration of 5 mg L-1 contaminant growth activities were almost completely suppressed. In these conditions, E. gracilis is capable to grow, but a further increase of H 2 O 2 concentration is related to significant reduction of algae growth. H 2 O 2 as a suppressor of contaminants has great potential for industrial application, but its optimal concentration for a particular bioprocess has to be determined in order to obtain the maximal bioprocess efficiency.

Effects of destruction of Euglena gracilis by ultrasonic cavitation

“…46) E. gracilis has been studied for largescale cultivation because of its high paramylon content and ability to grow under various culture conditions, including autotrophic, heterotrophic, and mixotrophic. [47][48][49] Although researchers have explored different paramylon extraction methods such as sodium dodecyl sulfate extraction, highpressure French press treatment, and ultrasonication, these methods have yet to be thoroughly investigated. [50][51][52] Therefore we aimed to destruct E. gracilis by ultrasonic cavitation and to elucidate the mechanism.…”