Saccharomyces cerevisiae cells lacking the zinc vacuolar transporter Zrt3 display improved ethanol productivity in lignocellulosic hydrolysates

• Autor(a) principal: Terra-Matos, Joana
• Data de Publicação: 2022
• Outros Autores: Teixeira, Marta Oliveira, Pereira, Cátia Sofia Santos, Noronha, Henrique, Domingues, Lucília, Sieiro, Carmen, Gerós, H., Chaves, Susana Alexandra Rodrigues, Sousa, Maria João, Côrte-Real, Manuela
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: https://hdl.handle.net/1822/75597
• topic: Saccharomyces cerevisiae; Acetic acid; Lignocellulosic hydrolysates; Vacuolar zinc transporter; Lignocellulosic ethanol; Science & Technology

Yeast-based bioethanol production from lignocellulosic hydrolysates (LH) is an attractive and sustainable alternative for biofuel production. However, the presence of acetic acid (AA) in LH is still a major problem. Indeed, above certain concentrations, AA inhibits yeast fermentation and triggers a regulated cell death (RCD) process mediated by the mitochondria and vacuole. Understanding the mechanisms involved in AA-induced RCD (AA-RCD) may thus help select robust fermentative yeast strains, providing novel insights to improve lignocellulosic ethanol (LE) production. Herein, we hypothesized that zinc vacuolar transporters are involved in vacuole-mediated AA-RCD, since zinc enhances ethanol production and zinc-dependent catalase and superoxide dismutase protect from AA-RCD. In this work, zinc limitation sensitized wild-type cells to AA-RCD, while zinc supplementation resulted in a small protective effect. Cells lacking the vacuolar zinc transporter Zrt3 were highly resistant to AA-RCD, exhibiting reduced vacuolar dysfunction. Moreover, zrt3Δ cells displayed higher ethanol productivity than their wild-type counterparts, both when cultivated in rich medium with AA (0.29 g L−1 h−1 versus 0.11 g L−1 h−1) and in an LH (0.73 g L−1 h−1 versus 0.55 g L−1 h−1). Overall, the deletion of ZRT3 emerges as a promising strategy to increase strain robustness in LE industrial production.