Determination of enzymatic activities using a miniaturized system as a rapid method to assess soil quality

Soil 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 with other parameters, such as total carbon, nitrogenous content or microbial biomass carbon. The aim of this work was to investigate the possible use of the API ZYM strip, a semi-quantitative miniaturised system that determines 19 enzymatic activities, to study soil quality. To this end, we tested the system in different soil types, including albicArenosols, mollicLeptosols, rendzicLeptosols, haplicLeptosols, and calcaricRegosols. Fresh samples were sifted in 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 37ºC for 16 h. Our results show significant qualitative and quantitative differences among the different soil types studied, with soil characteristics and biological properties correlating with biochemical parameters. The results provide useful information to not only assess soil quality, but also to determine soil degradation. As a whole, our results suggest that the use of the API ZYM system could prove most useful in different soil environmental studies. Finally, some suggestions are presented such as modifications to the system which could improve its application in this field

The Cell Wall of Candida albicans: A Proteomics View

Candida species are a natural commensal of humans and when the immune system is compromised it can cause candidiasis. C. albicans is the main etiological agent of candidiasis, representing nearly 60% of the total cases worldwide. The cell wall provides protection against several physical and chemical aggressions and is responsible for the different shapes displayed by C. albicans. The cell wall is not a static structure, but a dynamic one, having great plasticity to allow different cell morphologies, molecular remodeling and changes in the cell wall composition as a result from adaptation to the surrounding environment. It is mainly composed of chitin, β-glucan and mannoproteins. Therefore, the cell wall components are putative targets for the discovery and development of new drugs. The cell wall reprograming in response to several conditions, including a host carbon source, blood, serum, high temperature, acidic environment, and morphogenesis, have a direct impact on the mannoprotein content and might be involved in adherence, drug resistance and virulence of C. albicans. In this chapter, we performed an analysis of the proteins that have been identified in the C. albicans cell wall by our group and others, which allowed the identification of proteins from different intracellular compartments

Els Casots (Subirats, Catalonia), a key site for the Miocene vertebrate record of Southwestern Europe

Altres ajuts: CERCA Programme/Generalitat de CatalunyaEls Casots is one of the richest fossil vertebrate sites of the Vallès-Penedès Basin (Catalonia, Spain). It was discovered in 1989 and excavated briefly during the 1990s, resulting in the recovery of thousands of remains and the erection of several new mammal species. Excavations were resumed in 2018 and continue to date. Here we provide updated results regarding the age, stratigraphy, biota and palaeoenvironment of the site. The age of the site is well constrained to ~15.9 Ma thanks to recent bio- and magnetostratigraphic data, thus coinciding with the Miocene Climatic Optimum (MCO). The stratigraphic succession at the site area indicates lacustrine to palustrine environments with cyclically oscillating water level. There are several fossiliferous layers that have yielded a vertebrate fauna comprising up to 75 different vertebrate species including amphibians, reptiles, birds and mostly mammals. The finding of several articulated partial skeletons indicate that the site records an autochthonous to parautochthonous assemblage. The abundance and completeness of the vertebrate remains together with a well-constrained age and detailed stratigraphic and palaeoenvironmental data, make els Casots a key site for understanding wetland ecosystems in southern Europe during the MCO