Yeasts are the most used microorganisms for biotechnological purposes. Although they have been mainly recognized for their application in the beverage and bioethanol industries, these microorganisms can be efficiently employed in pharmaceutical and food production companies. In these industrial sectors, yeasts are highly desirable for their capacity to produce bioactive compounds from simple substrates, including wastes. In this review, we present the state of the art of bioactive compound production in microbial cell factories and analyze the avenues to increase the productivity of these molecules, which benefit human and environmental health. The article addresses their vast biological activities, from preventing to treating human diseases and from pre to postharvest control on agroindustrial streams. Furthermore, different yeast species, genetically engineered or not, are herein presented not only as biofactories of the referred to compounds but also as their targets. This comprehensive analysis of the literature points out the significant roles of biodiversity, bioprospection, and genome editing tools on the microbial production of bioactive compounds and reveals the value of these approaches from the one health perspective.

The literature is full of studies reporting environmental and health issues related to using traditional pesticides in food production and storage. Fortunately, alternatives have arisen in the last few decades, showing that organic agriculture is possible and economically feasible. And in this scenario, fungi may be helpful. In the natural environment, when associated with plants, these microorganisms offer plant-growth-promoting molecules, facilitate plant nutrient uptake, and antagonize phytopathogens. It is true that fungi can also be phytopathogenic, but even they can benefit agriculture in some way—since pathogenicity is species-specific, these fungi are shown to be useful against weeds (as bioherbicides). Finally, plant-associated yeasts and molds are natural biofactories, and the metabolites they produce while dwelling in leaves, flowers, roots, or the rhizosphere have the potential to be employed in different industrial activities. By addressing all these subjects, this manuscript comprehensively reviews the biotechnological uses of plant-associated fungi and, in addition, aims to sensitize academics, researchers, and investors to new alternatives for healthier and more environmentally friendly production processes.

Biorefineries require residual biomass as a raw material for their processes.Among all the possible products, 2G ethanol is undoubtedly the most studied and isprobably the most desired in environmental terms. Carbohydrate-rich feedstocks usedin biorefineries are mainly composed of polysaccharides, cellulose and hemicellulose(xylan), which initially require the action of hydrolytic enzymes to release theirconstituent monosaccharides, mostly glucose (from cellulose) and xylose (fromhemicellulose). The conversion of glucose into ethanol is carried out by the yeastSaccharomyces cerevisiae with an efficiency close to the theoretical maximum yield (>90%). Although it is the most widely used yeast in alcoholic fermentation processes, S.cerevisiae cannot metabolize xylose unless it undergoes genetic or evolutionaryengineering. However, in recent decades, wild yeasts with an innate capacity to fermentthis pentose and even hydrolyze the polysaccharides from lignocellulosic biomasseshave been isolated and characterized from natural environments. Facing this duality,we conducted a major literature review and presented the data both in favor ofengineering S. cerevisiae and the prospective use of wild yeasts in this chapter. Toanalyze the strengths of each strategy, this chapter also highlights the applications ofintegrated hydrolysis and fermentation processes and the possibility of simultaneouslygenerating xylitol as the second product in biorefineries.

Biofilm-associated infections on biomedical devices represent a major clinical challenge due to their high tolerance to antimicrobial treatments and their association with chronic and recurrent infections. Pseudomonas aeruginosa is a clinically relevant biofilm-forming pathogen, particularly on titanium-based implants used in medical and dental applications.In this study, we quantitatively evaluated the antibiofilm activity of bacteriophages (phages) against P. aeruginosa biofilms on titanium by assessing reductions in viable cell counts and biofilm biomass. The phages were tested both for their ability to eradicate mature biofilms and to prevent the formation of new ones. Phage treatment resulted in a marked reduction of biofilm biomass and viable cells(reductions exceeding 90%). . For the ATCC strain, reduction efficiencies ranged from 50.53% to 99.78%, while for the clinical isolate, reductions varied from 0.01% to 99.94%. Phages PA4 and PA5 showed the highest and most consistent activity, achieving reductions above 99%. Prophylactic application effectively inhibited biofilm formation. No clear dose–response relationship was observed, and efficacy varied depending on strain, phage, and infection conditions. Phages show strong potential as antibiofilm agents on titanium surfaces. The observed variability highlights the complexity of phage–biofilm interactions and supports further in vivo studies and the development of tailored phage-based strategies for device-associated infections.

As leveduras, fungos unicelulares amplamente empregados na indústria de alimentos e bebidas, estão desempenhando um papel cada vez mais relevante na síntese de metabólitos naturais para fins biotecnológicos. Esses metabólitos, de natureza diversificada, encontram aplicações em diversos setores, particularmente na área da saúde, e abrangem uma variedade de moléculas com atividades biológicas vantajosas, tais como antimicrobiana, antioxidante, anti-inflamatória e antineoplásica. Nesse contexto, este capítulo visa explorar as leveduras que ocorrem naturalmente como produtoras de metabólitos bioativos, explanando os tipos de compostos que elas produzem e destacando suas potenciais aplicações em benefício da saúde humana. Também são discutidas as abordagens biotecnológicas mais promissoras para a produção de metabólitos terapêuticos a partir de leveduras, que incluem (1) o isolamento de leveduras e a otimização de processos de fermentação e extração dos compostos, (2) a engenharia genética de leveduras para melhorar a produção desses compostos, e (3) testes de citotoxicidade e avaliação do potencial terapêutico dos metabólitos de leveduras. Em síntese, as leveduras desempenham um papel crucial na produção de metabólitos naturais com múltiplas propriedades benéficas para a saúde, e este capítulo investiga as estratégias e avanços biotecnológicos que estão impulsionando o potencial terapêutico desses compostos.

Biofilm-associated infections on biomedical devices are a major clinical challenge. These infections are resistant to antimicrobial treatments and often cause chronic and recurrent problems. Pseudomonas aeruginosa is a significant biofilm-forming pathogen, particularly on titanium-based implants used in medical and dental applications. Bacteriophages have emerged as a promising alternative for preventing and eradicating biofilms. This study evaluated the effectiveness of bacteriophages in controlling P. aeruginosa biofilms on titanium. It tested their ability to eradicate mature biofilms and prevent the formation of new ones. Microbiological assays, efficacy analyses, and scanning electron microscopy (SEM) were used. Bacteriophages significantly reduced biofilm biomass, with reductions over 90% in most cases. For the ATCC strain, efficiencies ranged from 50.53% to 99.78%. For the clinical strain, reductions varied between 0.01% and 99.94%. Among the tested phages, PA4 and PA5 were the most effective, consistently achieving reductions of over 99%. Prophylactic treatment completely inhibited biofilm formation, regardless of phage concentration or bacterial strain. Although variations in efficacy were observed depending on strain, phage type, and multiplicity of infection, complicating the establishment of a clear dose-response relationship, the results confirm the strong potential of bacteriophages as both therapeutic and preventive agents against biofilm-related infections on titanium biomedical devices. These findings provide a crucial foundation for future clinical and industrial applications, contributing to the development of safer and more reliable titanium-based implants.