Juan José Santana Rodríguez

The effect of environmental and meteorological variables on atmospheric corrosion of carbon steel, copper, zinc and aluminium in a limited geographic zone with different types of environment

Abstract Carbon steel, copper, zinc and aluminium test pieces were exposed to a large variety of environmental conditions in a reduced geographic area close to the coastline in order to ascertain the degree of deterioration of the same due to environmental corrosion. Calculations of corrosion rates were made via loss of weight (in the case of carbon steel, zinc and copper) and analysis of surface deterioration (in the case of aluminium) together with X-ray diffraction analyses. The levels of chlorides, SO 2 and time of wetness were also registered in order to be able to correlate the data with respect to corrosion rate with the environmental and meteorological parameters, using the potential law and a modified version of the same.

Structural characterization and metabolite profiling of the facultative marine fungus Paecilomyces variotii

A new Paecilomyces variotii strain was isolated from the marine habitat. The fungal biomass necessary for the chemical study was produced with success, at a laboratory scale. A total of 28 structural groups were identified from volatile compounds that, in the main, are normal lipid compounds involved in the fatty acid pathway, fragments from their catabolism, terpenoids, and a metabolite from the shikimic acid route. In addition, two non-volatile compounds, triolein and ergosterol peroxide, were isolated and identified by spectroscopy. This is the first report to describe these compounds for the species P. variotii, suggesting its potential use as a natural source to produce nutraceuticals and functional foods.

Biomolecules produced in liquid-state fermentation by a marine-derived fungus, Penicillium roqueforti

Screening of biomass of a new marine-derived strain of Penicillium roqueforti, as produced by liquid-state fermentation, led to the identification of several volatile organic compounds active in the fatty acid pathway as well as fragments produced by their catabolism, terpenoids, and metabolites from the shikimic acid pathway. In addition, five non-volatile organic compounds, triolein, ergosterol peroxide, 9(11)-dehydroergosterol peroxide, 4-hydroxybenzaldehyde, and d-mannitol, were isolated and identified by spectroscopy. The results showed that this fungal strain did not produce any mycotoxin in the culture conditions applied, and thus is useful for industrial applications, where high value-added biomolecules are generated.

Metabolite profiling of Schizochytrium sp. by GC-MS, an oleaginous microbial source of biodiesel

The chemical screening carried out on Schizochytrium sp. biomass led the identification of 24 types of organic compounds belonging to n-alkanes, 1-alkenes, 1-alkanols, free fatty acids, methyl and ethyl esters of saturated and unsaturated fatty acids, saturated tri- and diglycerides, unsaturated monoglycerides, wax esters, sterols, triterpenes, and mono- and sesquiterpenes. Moreover, a sample containing fully saturated ethyl biodiesel was obtained experimentally with a yield of 28.72% w/w of the crude extract, and an average chain length of 15.52 carbons. This strain produced no toxins, but showed important nutrients, making it potentially applicable to the field of functional food, and biodiesel production.