Development of a methodology for yeast's RNA and protein extraction

• Grant number: 22/08078-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2022
• End date: July 31, 2023
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Pedro de Oliva Neto
• Grantee: Mell Kimberly Damini
• Host Institution: Faculdade de Ciências e Letras (FCL-ASSIS). Universidade Estadual Paulista (UNESP). Campus de Assis. Assis , SP, Brazil

Abstract

Yeast biomass (Saccharomyces sp.) is produced in Brazil in three major industrial sectors: breweries, sugar and alcohol industries, and the bakery sector. Currently, the country is the world's largest producer of sugarcane, ranking second in the world's ethanol production. With regard to breweries in the last twenty years, the number of establishments is increasing. Thus, there is a high availability of yeast, residue from the fermentation, and high-quality raw material considering its composition. Yeast RNA, a by-product of high added value, stands out due to its bioactive properties, being of paramount importance for the food and pharmaceutical industry. Some techniques were found to obtain 5'-ribonucleotides, however, still without great extraction yields. The first step is autolysis, that is, the process of chemical elimination according to physical, chemical, and biological factors. Some processes are related to contamination by microorganisms like proteolytic and pathogenic bacteria, low extraction yield, difficulties in separating liquid and solid, addition, targeting autolysis into big interest products (RNA or protein, for example), the longer the autolysis time, more expensive and risky will be the process, in view of energy, labor costs, and contamination risk. In addition, studies on the Sporidiobolus paradoxes are promising. The species, in addition to being a biocontrol agent, also produces carotenoids, namely: ²-carotene, ³-carotene, toluene, and torularhodine; related to anti-tumor activities and produces fibrinolytic and amylolytic enzymes, something unusual for the Saccharomyces genre. Therefore, the interest and growing research around this yeast are undoubted, in order to be able to use it not only on "single cell protein", but as a possible probiotic lineage for animals in addition to other purposes yet to be explored such as biocontrole in agriculture. Moreover, the improvement of fractionation and purification of yeast is strategic to the country due to the growing application market for the product and the possibility of reusing the residue in agroindustries. In this sense, ethanol distilleries harvest the yeast biomass simply by discarding it or exporting it as a stoppage for a reduced price. However, the present project aims to optimize the autolysis of Saccharomyces cerevisiae yeast, aiming at the maximum extraction of ribonucleic acid and protein from the biomass. The variables studied will be pH, temperature, the concentration of sodium chloride and ammonia, process time, and methods of RNA recovery from the autolysate. (AU)