Evaluating Burkholderia sacchari growth and bioproducts generation from glycerol

• Grant number: 24/07659-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2024
• End date: July 31, 2025
• Field of knowledge: Interdisciplinary Subjects
• Principal Investigator: Luiziana Ferreira da Silva
• Grantee: Rodrigo Santos Martines
• Host Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 24/20666-8 - Adaptive Laboratory Evolution (ALE) of Burkholderia sacchari for optimized growth rate on glycerol, BE.EP.IC

Abstract

More than 550,000 m3 of glycerol were generated in Brazil in 2022, as a by-product of the biodiesel industry, due to the growing legal demand for its addition to diesel. A very useful application for glycerol in the bioeconomy and circular economy scenario would be the production of bioplastics, such as polyhydroxyalkanoates (PHA) - biodegradable and biocompatible bacterial polyesters, which are an alternative to those of petrochemical origin. Considering that the substrate is the factor that affects the most the overall cost of the PHA production process, the use of glycerol provides an excellent opportunity to eliminate this barrier, as well as adding value to a by-product by using it as a raw material. To do so, it is essential to have microorganisms that are knownly good PHA producers and use glycerol. The PHA+ bacterium Burkholderia sacchari has been studied as a potential chassis for various synthetic biology models, being able to consume a range of carbon sources. For glycerol, however, consumption efficiency is low: OD600 does not reach even 0.5 in 48h of cultivation (preliminary studies). Something similar was observed for Cupriavidus necator, for which an evolutionary engineering approach generated clones that were capable of reaching OD600=1 in 17h, comparing to 110h for the wild strain. In addition, the data in the literature on glycerol consumption by B. sacchari is imprecise, as it measures the efficiency of glycerol use by providing it combined with other carbon sources, so more studies need to be carried out. The aim of this project is to characterize and increase the glycerol consumption rate and PHA production by B. sacchari using adaptive evolution.