Growth and Metabolite Enhancement of Acidophile Euglena sp. Isolated from Indonesia under Different Photoperiod Cycles

Euglena sp. is a unicellular, flagellated microalga considered one of the most
promising microalgal feedstock species for biofuels. Reducing the level of liquid
waste pollutants can be done biologically by using microalgal organisms.
Its metabolites, including lipids, proteins, carbohydrates, and pigments, are
appropriate for producing biorefinery products such as biodiesel and jet fuels.
They can be isolated from extreme environments, such as highly acidic and
ammonia-rich environments, that are not conducive to their proliferation. This
study sought to determine the effect of the photoperiod or (light: dark) cycle (24
L:0 D, 12 L:12 D, 14 L:10 D, and 16 L:8 D) on the growth, biomass, metabolite
content consisting of lipids, carbohydrates, and proteins, and the rate of CO2
uptake by Euglena sp. As stated previously, the study was conducted by cultivating
Euglena sp. on a laboratory scale with four photoperiod regimens. The results
indicated that optimal growth, biomass content, and metabolite content were
obtained with a 24 D:0 L lighting cycle. The control treatment (24 L: 0 D) had
the highest biomass productivity (0.032 g.L-1.day-1 ± 0.004), lipid content (0.387
g.L-1 ± 0.031), protein content (0.542 mg.Ml-1 ± 0.007), carbohydrate content
(0.409 x104
g.L-1), chlorophyll a (6.237 g.L-1 ± 0.184), chlorophyll b (2.838 g.L-1
± 0.253), and total carotenoid (1.566 g.L-1 ± 0.105). Full light illumination (24
L:0 D) was significantly producing carotenoid content, including phaeophytin a,
phaeophytin b, violaxanthin, 9’-cis-neoxanthin, dino xanthin, and fucoxanthin.