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The Small World Initiative (SWI) and Tiny Earth are a consolidated and successful education programs rooted in the USA that tackle the antibiotic crisis by a crowdsourcing strategy. Based on active learning, it challenges young students to discover novel bioactive-producing microorganisms from environmental soil samples. Besides its pedagogical efficiency to impart microbiology content in academic curricula, SWI promotes vocations in research and development in Experimental Sciences and, at the same time, disseminates the antibiotic awareness guidelines of the World Health Organization. We have adapted the SWI program to the Spanish academic environment by a pioneering hierarchic strategy based on service-learning that involves two education levels (higher education and high school) with different degrees of responsibility. Throughout the academic year, 23 SWI teams, each consisting of 3-7 undergraduate students led by one faculty member, coordinated off-campus programs in 22 local high schools, involving 597 high school students as researchers. Post-survey-based evaluation of the program reveals a satisfactory achievement of goals: acquiring scientific abilities and general or personal competences by university students, as well as promoting academic decisions to inspire vocations for science- and technology-oriented degrees in younger students, and successfully communicating scientific culture in antimicrobial resistance to a young stratum of society.

Seven yeasts strains have been isolated from sewage sludge. Also six samples of compost with different sieving, composting times and origins, have been analysed. Apparently, composting processes negatively affect the viability of yeasts, as none could be isolated from the compost samples. The margins of tolerance of the yeasts to Cd, Cu and Zn have been determined. The physiological response to metals was similar in all the species studied, and in general, kinetic parameters (mu and lag) were affected. Metal uptake ability was also studied and inter- and intra-specific heterogeneity was detected, thus indicating that both the tolerance to metals and the capacity of the uptake were dependent on ionic metal and yeast species. The effect of the presence of multi-metal ions on the uptake capacity of each individual metal was assayed for two selected yeasts, Pichia guilliermondii and Torulaspora delbrueckii. The uptake of each individual metal varied with the combination assayed, and when both strains were compared different results were also found.

The amplification by PCR of the intergenic spacer region (IGS) of rDNA followed by restriction fragment length polymorphism (RFLP) analysis was evaluated as a potential method for discriminating the 16 species belonging to the genus Debaryomyces. The digestion of this region with some or all the enzymes used in this study (HapII, HhaI and MboI) produced species-specific patterns that permitted differentiation of the species in the genus. With the exception of Debaryomyces vanrijiae, the technique was also efficient for distinguishing the varieties in the species Debaryomyces hansenii (var. hansenii, var. fabryi), Debaryomyces occidentalis (var. occidentalis, var. persoonii) and Debaryomyces polymorphus (var. africanus, var. polymorphus), respectively. PCR-RFLP analysis of the IGS region of rDNA is proposed as a clear and reproducible technique for the practical discrimination of species of the yeast genus Debaryomyces.