Electric fields to support microalgae growth with a differentiated biochemical composition

Abstract

Microalgae are a group of microorganisms well-known for their high metabolic plasticity and biomass with commercial interest for several industries. In the present work, the influence of in-situ electric field application (INEF) on the growth and biochemical composition of Pavlova gyrans was, for the first time, assessed. Electrical protocols were tested, namely by applying INEF in different growth stages, in varying treatment times and even by combining it with dark phase of cells' photoperiod. INEF did not promote a stimulatory effect on growth but influenced the biochemical composition of P. gyrans – maximum increases of 74.9 and 66.2 % in the chlorophyll a and carotenoid content and of 4.72, 18.7 and 5.41 % in the lipid, carbohydrate and protein content were observed in independent experiments. Hence, with this study, the potential of INEF application as a strategy to modulate growth and to promote biochemical composition alterations was proven.

Industrial relevance

Microalgae, with their unique ability to efficiently convert sunlight and carbon dioxide into biomass, offer a sustainable platform for the synthesis of diverse bioactive compounds. By subjecting microalgae to controlled electric stress conditions, their metabolic pathways can be redirected towards the production of specific target compounds. This strategy has the potential to enhance the yield of high-value molecules, including biofuels, pharmaceuticals, nutraceuticals, and pigments, whilst minimizing resource inputs. Additionally, metabolic stress responses in microalgae often trigger the accumulation of secondary metabolites with bioactive properties. Harnessing the metabolic plasticity of microalgae through controlled stress manipulation represents a cutting-edge strategy for sustainable and economically viable bioproduction systems that align with the goals of green chemistry and circular economy principles.