The effect of vinasse in various trophic conditions on the growth rate and metabolite contents of Euglena sp. with CO2 aeration

Euglena sp. is capable of accumulating valuable metabolites in its biomass, making it useful across various industries. Due to the high cost of production, this research explores the utilization of cost-effective and readily available carbon sources, such as vinasse. This research aimed to determine the effect of vinasse on Euglena sp. cultivation under various trophic conditions with CO2 aeration on the growth rate and metabolite contents. The study involved measuring cell density daily using spectrophotometry, while biomass and metabolite contents were measured every three days over an 18-day observation period using standard dry-weight and biochemical assay methods. Cell size and morphology were measured at the beginning and end of cultivation. Data were analyzed using one-way ANOVA followed by Duncan’s multiple-range test. The results indicated that the heterotrophic condition yielded the highest growth rate, biomass, carbohydrates, protein, and paramylon contents. Meanwhile, the positive control exhibited the highest lipid and pigment contents. Aspect ratio value showed that the control treatment produced spindle and elongated-shaped cells, while heterotrophic and mixo-heterotrophic conditions resulted in spherical and spindle-shaped cells. Mixotrophic conditions produced a mix of spherical, spindle, and elongated cells. Our findings suggest that vinasse has potential as an alternative medium for cultivating Euglena sp., offering a cost-effective approach for metabolite production.