Cristian Millán

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Ethanol tolerance, ATPase activity and the lipid composition of the plasma membrane to study potential relationship among them were examined in five different wine yeast strains. Yeast cells were subjected to ethanol stress (4% v/v). Principal component analysis of the results revealed that the wine yeasts studied can be distinguished in terms of ATPase(More)
In this paper we propose a Multi-Objective Ant Colony Optimization (MOACO) algorithm called CHAC, which has been designed to solve the problem of finding the path on a map (corresponding to a simulated battlefield) that minimizes resources while maximizing safety. CHAC has been tested with two different state transition rules: an aggregative function that(More)
Urea, ammonium, and free amino acid contents were quantified in a must from Vitis vinifera cv. Pedro Ximenez grapes and in fermented wine and after a short aging of this wine by Saccharomyces cerevisiae race capensis yeast under variable oxygen availability conditions. The previous compounds were also determined in a wine in which the nitrogen source was(More)
The fatty acid, phospholipid and sterol composition of one strain of Saccharomyces cerevisiae under different oxygen levels during grape must fermentation was studied. Anaerobiosis partially inhibited yeast growth and resulted in a drop in the unsaturation index of the fatty acids throughout the fermentation, as well as an abnormally low(More)
The changes in the specific activity of alcohol dehydrogenase (ADH-I and ADH-II) and aldehyde dehydrogenases [AIDH-NADP+ and AIDH-NAD(P)+] from Saccharomyces cerevisiae during the first 48 h of fermentation of grape must were investigated. The biosynthesis of ADH-I and AIDH-NADP+ took place basically during the adaptation of the yeasts to the must (first 4(More)
CHAC, a Multi-Objective Ant Colony Optimization (MOACO), has been designed to solve the problem of finding the path that minimizes resources while maximizing safety for a military unit. The new version presented in this paper takes into acount new, more realistic, conditions and constraints. CHAC’s previously proposed transition rules have been tested in(More)
hCHAC, a MOACO implemented to solve the problem of finding the path that minimizes resources, while maximizing safety for a military unit in realistic battlefields, is compared with some other approaches: two extreme methods, which only considers one objective in the search, and a mono-objective algorithm, which combines the two objectives terms of the(More)
The effect of skin maceration and must filtration on the growth and fermentative capacity of one strain of Saccharomyces cerevisiae was studied. Skin maceration increased the fatty acid concentration of the must, thus affecting the lipid composition of the yeast cell membranes. Sterile filtration resulted in a reduction of the fatty acid content of the must(More)
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