L-(-)-malic acid production by Saccharomyces spp. during the alcoholic fermentation of wine (1)

In an attempt to increase the acidity of wine by biological means, malate-producing yeasts were selected from a collection of 282 strains isolated in different parts of Spain. Only 4% of these strains (all of which belonged to Saccharomyces cerevisiae) produced l-(-)-malic acid in the range of 0.5-1 g/L. This was formed between days 2 and 6 of alcoholic fermentation, reaching a maximum on days 3 and 4; the concentration remained stable from day 7. Malic acid production was favored by temperatures in the 18-25 degrees C range and by musts with a high pH and low concentrations of sugar, initial malic acid, and yeast-assimilable nitrogen. Oxaloacetic acid, a precursor of malic acid, had no influence on malate production. The precursors pyruvic and fumaric acid did, however, have a significant effect on the production of this acid in some strains. No direct relation between pyruvate and malate metabolism was observed.     

Morphological study of Socorro Island Merino sheep and its crosses with hair breeds

Tropical Animal Health and Production - A study was conducted with the objective to characterize the morphology of Socorro Island Merino sheep. A total of 67 sheep, 62 females, 26 purebred and 36...     

Reduction of apple tree height (Malus domestica Borkh) cv. Ultra Red Gala/MM111 does not decrease fruit yield and quality

In Chile, like in other countries, a high percentage of apple (Malus domestica Borkh) orchards are grafted on vigorous or semi-vigorous rootstocks. The need to decrease the amount of labor involved and increase efficiency has motivated this study on the effect of reducing the height of cv. Ultra Red Gala/MM111 trees in a commercial orchard in the Maule Region of Chile. Apple trees were planted in 2003, and their tree heights were adjusted to 2.5, 3.0 and 3.6 m prior to blooming in 2006. The reduction of plant height from 3.6 m to 2.5 m determined a significant reduction in canopy volume (26% and 29% in 2007/2008 and 2008/2009, respectively), but no differences were detected in leaf area index (LAI) and the photosynthetic active radiation (PAR) transmitted through the canopy. However, a higher proportion of the canopies of the shorter trees had over 30% of incident PAR, the threshold for the production of good fruit quality and flower-bud differentiation. There were no differences in fruit production among plant heights, accumulating 131 tonnes ha⁻¹ in the three growing seasons. Over the three seasons, the shortest plants (2.5 m) required 19, 57 and 42% less labor time at harvest, respectively, than the plants maintained at a height of 3.6 m. There were no evident differences in fruit quality among the treatments; flesh firmness varied between 73.0 and 74.0 N, soluble solids between 11.6 and 12.6°Brix, mean weight between 180 and 200 g, and the percentage of red coloring exceeded 59% of the Premium fruit in the three growing seasons. Our results suggest that it is possible to manage plants with reduced height on semi-vigorous rootstocks and thus reduce the time necessary for harvesting, without affecting fruit yield and quality.