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The growth rate and desulfurization capacity accumulated by the cells during the growth of Pseudomonas putida KTH2 under different oxygen transfer conditions in a stirred and sparged tank bioreactor have been studied. Hydrodynamic conditions were changed using different agitation conditions. During the culture, several magnitudes associated to growth, such as the specific growth rate, the dissolved oxygen concentration and the carbon source consumption have been measured. Experimental results indicate that cultures are influenced by the fluid dynamic conditions into the bioreactor. An increase in the stirrer speed from 400 to 700 rpm has a positive influence on the cell growth rate. Nevertheless, the increase of agitation from 700 to 2000 rpm hardly has any influence on the growth rate. The effect of fluid dynamics on the cells development of the biodesulfurization (BDS) capacity of the cells during growth is different. The activities of the intracellular enzymes involved in the 4S pathway change with dissolved oxygen concentration. The enzyme activities have been evaluated in cells at several growth time and different hydrodynamic conditions. An increase of the agitation from 100 to 300 rpm has a positive influence on the development of the overall BDS capacity of the cells during growth. This capacity shows a decrease for higher stirrer speeds and the activity of the enzymes monooxygenases DszC and DszA decreases dramatically. The highest value of the activity of DszB enzyme was obtained with cells cultured at 100 rpm, while this activity decreases when the stirrer speed was increased higher than this value.

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Although Colombia has the potential to be a cocoa producer for fine flavor and high value markets, it is not greatly recognized as such. In spite of the government’s interest to position the country as a major specialty cocoa producer, no strategic actions have been taken to develop and strengthen this aspect of the value chain. This study structured a technology roadmap for the sector that identifies major research and development investment opportunities by examining the current challenges and weaknesses in key dimensions of the sector (e.g., postharvest technology, quality, capacity, and markets) that impinge on quality and add value to the product. These challenges are identified through a multidimensional and region-specific gap analysis that integrates the advances and technological trends developed worldwide as ideal practice scenarios. The findings of this study should help in prioritizing the investment of public and private resources in the sector in order to better position Colombia in the global specialty cocoa market.

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