Proteomic analysis, production and manipulation of biomolecules in Chlorophyta e Cyanobacteria: a cell stimulus approach

Abstract

Microalgae are a natural source of valuable products, such as carbohydrates, proteins, and lipids, in addition to carotenoids and other antioxidant compounds that are related to human well-being and health. The interest in products from microalgae rests on the characteristics of being vegan, organic and the possibility of production in areas that do not compete with food production. Furthermore, as photosynthetic organisms, microalgae are efficient in incorporating CO2, an attraction to the carbon market. However, the cost-effectiveness of microalgal production still faces challenges, one of which is the increase in biomolecules yield. Given the physiological plasticity of microalgae, techniques for manipulating their biochemical composition have been proposed as via of increasing biomolecules per cell unit and, consequently, increasing the global yield. A recently proposed strategy considers the stimulation of cells, not their stress, so that the increase in production occurs during exponentially growing cells and, therefore, with biomass gain (IC FAPESP 2019/14152-3; INPI Patent BR 1020210197781). The addition of micronutrients in environmental concentrations that induce a possible hormesis effect, which in combination with other factors, such as exposure to blue and/or red light, is capable of such achievement. It is also known that through the characterization of gene expression induced by changes in environmental factors, the understanding of the mechanisms that lead to the probable increase in biomolecules can be accessed. The main objective of this project is to understand the physiological responses of microalgae Chlorophyta and Cyanobacteria under different concentrations of a trace metal micronutrient and in different colors of light (white, blue, green, red), applying the concept of microalgae stimulation. As physiological responses we consider photosynthetic process (PhytoPAM), population growth rates, production of biomolecules such as lipids, proteins and carbohydrates, phytosterols, fatty acids and amino acids profile, in addition to cell viability and pigments involved in photosynthesis. In this research we will carry out a study at the genetic level (gene expression) to understand the mechanism that will result in increased biomolecules. We emphasize that all experiments will be carried out under highly controlled conditions. For this, experimental cultures will be performed in high-performance photobioreactors (INPI Patent BR 1020200239945), where the pH is maintained within a narrow range defined by the operator through automatic CO2 input and constant internal light intensity regardless of cell density. Furthermore, rapid light curves will provide the specific light intensity for each strain to be investigated and, therefore, each one will be kept in optimal conditions. This proposal, which carries the attribute of innovation, will contribute to the understanding of the physiology of microalgae and cyanobacteria, and its results have potential to be used in microalgae biotechnology industry. (AU)