Industrial yeast strains competence in mixed culture with wild flocculent yeast

Unveiling the fitness of Saccharomyces cerevisiae strains for lignocellulosic bioethanol: a genomic exploration through fermentation stress tests

Lignocellulosic biomass holds significant promise as a substrate for bioethanol production, yet the financial viability of lignocellulosic fermentation poses challenges. The pre-treatment step needed for lignocellulosic substrates generates inhibitors that impede Saccharomyces cerevisiae growth, affecting the fermentation process and overall yield. In modern sugarcane-to-ethanol plants, a rapid succession of yeast strains occurs, with dominant strains prevailing. Therefore, yeast strains with both dominance potential and inhibitor tolerance are crucial towards the development of superior strains with industrial fitness. This study adopted a hybrid approach combining biotechnology and bioinformatics to explore a cluster of 20 S. cerevisiae strains, including industrial and oenological strains exhibiting diverse phenotypic features. In-depth genomic analyses focusing on gene copy number variations (CNVs) and single nucleotide polymorphisms (SNPs) were conducted and compared with results from fermentation tests once inoculated in multiple strains kinetics under stressing conditions such as low nitrogen availability and high formic or acetic acid levels. Some strains showed high resistance to biotic stress and acetic acid. Moreover, four out of 20 strains - namely S. cerevisiae YI30, Fp89, Fp90 and CESPLG05 - displayed promising resistance also to formic acid, the most impactful weak acids in pre-treated lignocellulosic biomass. These strains have the potential to be used for the development of superior S. cerevisiae strains tailored for lignocellulosic bioethanol production.

Compositional analysis of baru (Dipteryx alata Vogel) pulp highlighting its industrial potential

Baru (Dipteryx alata Vogel), a fruit native to the Brazilian Cerrado, has gained scientific interest due to its nutritional potential and commercial value. Its edible seed, of high commercial value, represents around 5 % of the fruit. On the other hand, its pulp, a byproduct of the baru processing industry, is normally discarded, generating a huge volume of waste with reported antioxidant properties. This study investigates the composition and bioactive properties of baru pulp, aiming to identify the antioxidant components in this byproduct. Our analysis revealed that baru pulp is rich in sugars (41.86 %), fiber (29.12 %), and essential minerals, along with commercially valuable bioactive compounds such as trigonelline (139.10 mg 100 g-1), tannins (429.16 mg tannin equivalent 100 g-1), vitamin C (109.57 mg 100 g-1), and phenolic compounds such as trans-cinnamic acid (5.91 mg 100 g-1), chlorogenic acid, and gallic acid (1.07 mg 100 g-1). Industrially relevant sesquiterpenes, such as α-copaene and bicyclogermacrene, account for 42.75 % of the volatile profile, alongside germacrene D (11.69 %), aromadendrene (9.05 %), α-cubebene (6.84 %), β-elemene (5.90 %), and ledene (5.82 %), which are commonly used in essential oil production from other food matrices. While further studies are required to optimize extraction methods, these findings highlight baru pulp as a promising and low-cost alternative to traditional sources of bioactive compounds, with potential applications in functional food formulations and sustainable industrial processes. Specifically, the use of in natura pulp or its flour for food enrichment is recommended, supporting sustainability through the valorization of agro-industrial waste.