We have established the chemical structure of (+)-bassianolone (3), the antimicrobial compound precursor of cephalosporolides E and F, and that of the furan metabolite 4 from the entomopathogenic fungus Beauveria bassiana.

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Candida albicans is an opportunistic fungus that is part of the normal microflora commonly found in the human digestive tract and the normal mucosa or skin of healthy individuals. However, in immunocompromised individuals, it becomes a serious health concern and a threat to their lives and is ranked as the leading fungal infection in humans worldwide. As existing treatments for this infection are non-specific or under threat of developing resistance, there is a dire necessity to find new targets for designing specific drugs to defeat this fungus. Some authors reported the presence of the transglutaminase activity in Candida and Saccharomyces, but its identity remains unknown. We report here the phenotypic effects produced by the inhibition of transglutaminase enzymatic activity with cystamine, including growth inhibition of yeast cells, induction of autophagy in response to damage caused by cystamine, alteration of the normal yeast division pattern, changes in cell wall, and inhibition of the yeast-to-mycelium transition. The latter phenomenon was also observed in the C. albicans ATCC 26555 strain. Growth inhibition by cystamine was also determined in other Candida strains, demonstrating the importance of transglutaminase in these species. Finally, we identified enolase 1 as the cell wall protein responsible for TGase activity. After studying the inhibition of enzymatic activities with anti-CaEno1 antibodies and through bioinformatics studies, we suggest that the enolase and transglutaminase catalytic sites are localized in different domains of the protein. The aforementioned data indicate that TGase/Eno1 is a putative target for designing new drugs to control C. albicans infection.

SummarySoil quality determination requires the analysis of a number of soil attributes using different approaches. In recent years, one of the most promising approaches has been the determination of enzymatic activities. Generally, only a few enzymes have been analysed and related to other soil properties such as total carbon, nitrogen content or microbial biomass carbon. The aim of this work was to investigate the possible use of the API ZYM strip, a semi-quantitative miniaturized system that determines 19 enzymatic activities, to study soil quality. To this end, we tested the system in different soil types, including albic Arenosols, mollic Leptosols, rendzic Leptosols, haplic Leptosols and calcaric Regosols. Fresh samples were sieved through a 2-mm sieve in the field and soil extracts were prepared by mixing 2-20 g (depending on the soil horizon characteristics) from each sample with 2-20 ml of sterile water. Next, 65-μl aliquots of the supernatant extract were placed into each API ZYM microtube and were incubated at 37• C for 16 hours. Our results show important qualitative and quantitative differences among the different soil types studied, with soil characteristics and biological properties correlating with biochemical information. The results provide useful information not only to determine soil quality, but also to assess changes in the soil environment. As a whole, our results suggest that the use of the API ZYM system could prove most useful in soil environmental studies. Finally, some suggestions are presented, including modifications to the system that could improve its application in this field.

The effect of three different periods of storage life (0, 15 and 30 days) on the microbiological quality of several foods elaborated with the sous vide cook–chill procedure in a restaurant was studied. These foods are grouped in three categories: meat (breast chicken, foie gras, pork loin and entrecote of veal), fish (codfish, gilt head sea bream, hake and salmon) and vegetable (broccoli, courgette, potato and carrot). Total plate counts in the products studied were in the range of <1.00–3.74 log10 cfu/g. Coagulase negative staphylococci were isolated in the three categories, Enterococcus spp. were isolated from foie gras and Pantoea agglomerans from salmon and carrot. Staphylococcus aureus, Escherichia coli, Salmonella spp., Listeria monocytogenes and Clostridium perfringens were not detected in any of the samples studied. As a consequence of our study, the restaurant has developed and implemented a traceability system to achieve food safety. PRACTICAL APPLICATIONS Nowadays, sous vide cook‐chill is an important type of food preparation. This study evaluates the microbiological quality of several products elaborated by this process and shows that the survival of microorganisms during processing is dependent on the initial load. The producer must carry out the implementation of the traceability system to guarantee the food safety in these products.