Chemical and microbial changes during the natural fermentation of strawberry tree (Arbutus unedo L.) fruits

Aguardente de medronho is the name given in Portugal to a spirit made from the fermented fruit of Arbutus unedo (strawberry tree), a plant grown in the Mediterranean region. In order to gain a better understanding of the fermentation process, as it is performed in the farms, a natural fermentation with wild microbiota was carried out during 36 days, and some physicochemical and microbiological parameters were studied. The microbial parameters analyzed were total viable, lactic and acetic acids bacteria, and yeast counts. The physicochemical parameters monitored were sugars, minerals, ethanol, organic acids and pH. Yeasts were the main responsible for the fermentation of the fruits, as the lactic and acetic acids bacteria are absent. As the fermentation progressed, the sugars increased during the first 2 days and gradually decreased along the fermentation period. Maintaining the good quality of the product could contribute to the preservation and valorization of traditional resources that are of great importance to prevent their disappearance.

Phytoplankton and microbial plankton of the Bay of Biscay and Western Iberian Shelf

The region of the Northeast Atlantic represents a gradient between two oceanographic regimes: (i) the subtropical waters of southern Portugal and southwestern Spain, and (ii) the temperate waters characterizing the northwestern and northern Iberian coasts (Cantabrian Sea) and the rest of the Bay of Biscay along the French coast.

Effect of oxygen carriers in microbial and plant cell cultures.

Dissolved oxygen concentration is one of the most limiting factors in aerobic cultures, due to the poor solubility of oxygen in aqueous media. In many processes, the microorganisms growth and production can be affected as a result of insufficient oxygen supply to the broths [1, 2]. To increase oxygen solubility, some methods can be used, such as the increment of aeration or agitation rates or decrease of the solution temperature.