Metabolomic Study of Heterotrophically Grown Chlorella sp. Isolated from Wastewater in Northern Sweden

Abstract

There are numerous strains of Chlorella with a corresponding variety of metabolic pathways. A strain we previously isolated from wastewater in northern Sweden can grow heterotrophically as well as autotrophically in light and has higher lipid contents under heterotrophic growth conditions. The aims of the present study were to characterize metabolic changes associated with the higher lipid contents in order to enhance our understanding of lipid production in microalgae and potentially identify new compounds with utility in sustainable development. Inter alia, the amino acids glutamine and lysine were 7-fold more abundant under heterotrophic conditions, the key metabolic intermediate alpha-ketoglutarate was more abundant under heterotrophic conditions with glucose, and maltose was more abundant under heterotrophic conditions with glycerol than under autotrophic conditions. The metabolite 3-hydroxy-butyric acid, the direct precursor of the biodegradable plastic PHB (poly-3-hydroxy-butyric acid), was also more abundant under heterotrophic conditions. Our metabolomic analysis has provided new insights into the alga’s lipid production pathways and identified metabolites with potential use in sustainable development, such as the production of renewable, biodegradable plastics, cosmetics, and nutraceuticals, with reduced pollution and improvements in both ecological and human health.

The potential of Nordic microalgae in nutrient removal from anaerobic digestion effluents

“…This is comparable to the biomass produced in CKM by the Nordic Chlorella vulgaris strain in this study (1.42 ± 0.17 g L −1 ) and significantly (p‐value ≤0.05) lower than its biomass produced in PPS (1.82 ± 0.12 g L −1 ). The amount of biomass produced in PPS by Chlorella vulgaris is also higher than in municipal wastewater after 13 days (1.15 ± 0.06 g L −1 ; Ferro et al (2018) or 8 days (1.25 ± 0.9 g L −1 ; Nzayisenga and Sellstedt (2021) of cultivation. In a study on microalgal cultivation in liquid digestates from anaerobic digestion of pulp and paper sludge, it was shown that biomass concentrations of Chlorella vulgaris can be achieved between 2.02 and 2.91 g L −1 within 15 days, depending on the growth medium.…”

Characterization of Planktochlorella nurekis Extracts and Virucidal Activity against a Coronavirus Model, the Murine Coronavirus 3

“…Alcohols have a highly negative effect on metabolism, especially glycerol in microalgae. It has been reported that this compound inhibits the production of three metabolites, such as glucose-6-phosphate, fructose-6-phosphate, and glyceric acid-3-phosphate, key intermediates in carbon metabolism [ 42 ]. In addition to alcohols, the hexane extract contained higher concentrations of dimethyl sulfone and creatinine than the other extracts.…”

Valorization of carbon dioxide (CO2) to enhance production of biomass, biofuels, and biorenewables (B3) in Chlorella saccharophilaUTEX247: a circular bioeconomy perspective

“…characterized the metabolic changes related to lipid biosynthesis to improve the understanding of lipid production in heterotrophically grown Chlorella sp. using metabolomics 87 . In the current study, GC‐MS based qualitative metabolomics was used to understand the metabolic imprints of C. saccharophila subjected to VLC and HC supplementation.…”

“…using metabolomics. 87 In the current study, GC-MS based qualitative metabolomics was used to understand the metabolic imprints of C. saccharophila subjected to VLC and HC supplementation. Due to alternative derivatization, repetition of identical metabolites was observed in the raw data files; the relative abundance of such metabolites was totaled and the peaks were manually curated to obtain 23 metabolites.…”