The production of biofuels is currently presented as a possible answer in the search for sustainable alternatives for the total or partial substitution of fossil fuels. One of the most successful biofuels that have be...The production of biofuels is currently presented as a possible answer in the search for sustainable alternatives for the total or partial substitution of fossil fuels. One of the most successful biofuels that have been developed is bioethanol. However, bioethanol production has been limited since it relies on the use of sugar cane or cereals. These materials are important sources of food and their demand as both a biofuel and a foodstuff has led to the price increase and may lead to possible shortages. Our group has focused on searching for native microalgae as sources of carbohydrates and bioethanol, with the goal of finding a sustainable source of bioethanol. Currently, twelve different strains which reach growth rates between 0.7 - 1.8 g/L and present carbohydrate production under osmotic shock conditions have been isolated. In this work, we demonstrate the results obtained with the Chlorella sp. [1] strain and the results obtained with the Scenedesmus sp. strain. The Scenedesmus sp. strain showed an increase in the production from 22 to 650 mg/sugar/g of biomass (dry weight), after 24 hours of osmotic shock with 0.1 M NaCl. The osmolytes which were produced after osmotic shock were identified as sucrose and trehalose, both of which are fermentable. These results demonstrate that this strain, through the photosynthetic pathway and osmotic shock, is a potential source of fermentable sugars.展开更多
The production of microalgae in laboratory systems is restricted almost exclusively since 500 mL to 20 liters tanks of transparent materials such as glass and plastic, under fluorescent lamps on shelves. In this work ...The production of microalgae in laboratory systems is restricted almost exclusively since 500 mL to 20 liters tanks of transparent materials such as glass and plastic, under fluorescent lamps on shelves. In this work we developed a laboratory system which produced up to 50 liters of micro- algae cultivation with comparable productivity to the traditional system in the laboratory, with the potential to increase productivity scale and lower energy consumption per produced volume. The system is built with opaque plastic tank, and illuminated by Plastic Optics Fiber (POF) and LED. The quality of the biomass grown in the culture system on LED is comparable to the tradi- tional cultivation, with scale-up without increasing the occupied area, only with increased height of the tank. The productivity of the tank on LED to the strain Scenedesmus sp. with a phototrophic cultivation reached productivity of around 20 mg•L<sup>–</sup>1•d<sup>–</sup>1 and continuing studies may increase further.展开更多
基金Funding by Instituto Politecnico Nacional PIFI-20100242.
文摘The production of biofuels is currently presented as a possible answer in the search for sustainable alternatives for the total or partial substitution of fossil fuels. One of the most successful biofuels that have been developed is bioethanol. However, bioethanol production has been limited since it relies on the use of sugar cane or cereals. These materials are important sources of food and their demand as both a biofuel and a foodstuff has led to the price increase and may lead to possible shortages. Our group has focused on searching for native microalgae as sources of carbohydrates and bioethanol, with the goal of finding a sustainable source of bioethanol. Currently, twelve different strains which reach growth rates between 0.7 - 1.8 g/L and present carbohydrate production under osmotic shock conditions have been isolated. In this work, we demonstrate the results obtained with the Chlorella sp. [1] strain and the results obtained with the Scenedesmus sp. strain. The Scenedesmus sp. strain showed an increase in the production from 22 to 650 mg/sugar/g of biomass (dry weight), after 24 hours of osmotic shock with 0.1 M NaCl. The osmolytes which were produced after osmotic shock were identified as sucrose and trehalose, both of which are fermentable. These results demonstrate that this strain, through the photosynthetic pathway and osmotic shock, is a potential source of fermentable sugars.
文摘The production of microalgae in laboratory systems is restricted almost exclusively since 500 mL to 20 liters tanks of transparent materials such as glass and plastic, under fluorescent lamps on shelves. In this work we developed a laboratory system which produced up to 50 liters of micro- algae cultivation with comparable productivity to the traditional system in the laboratory, with the potential to increase productivity scale and lower energy consumption per produced volume. The system is built with opaque plastic tank, and illuminated by Plastic Optics Fiber (POF) and LED. The quality of the biomass grown in the culture system on LED is comparable to the tradi- tional cultivation, with scale-up without increasing the occupied area, only with increased height of the tank. The productivity of the tank on LED to the strain Scenedesmus sp. with a phototrophic cultivation reached productivity of around 20 mg•L<sup>–</sup>1•d<sup>–</sup>1 and continuing studies may increase further.
