Prevalence of Intestinal Parasitic Infections among Patients Attended to Alribat University hospital, Khartoum State, Sudan, 2017 by Leonardo Brantes Bacellar Mendes in Cohesive Journal of Microbiology & Infectious Disease
https://crimsonpublishers.com/cjmi/fulltext/CJMI.000540.php
Interest in alternative fuel sources to oil has fluctuated throughout contemporary history according to the availability of this resource. The biggest impact of the reduction in the supply of oil is the increase in the price of the barrel practiced in the international market.
The first oil shock in 1973 showed that the price of the barrel rose rapidly, from US $ 2.90 /barrel to US $ 11.65/barrel in three months, causing enormous losses in the economy of countries that do not have strategic oil and gas reserves (e.g.: Germany, France and Italy).
In the late 1970s amid the second oil shock, when the price of a barrel of oil exceeded US$ 80.00, renowned German and Italian scientists began research to obtain microalgae fuels - notably from Tetraselmis sp - in southern Italy.
Throughout the 1980s, with the normalization of oil prices in the international market, the interest for fuels from microalgae was very low and the activities of microalgae cultivation were directed to aquaculture, nutraceutical production and fine chemical compounds, highlighting the genera Chlorella and Dunaliella, as well as the cyanobacterium of the genus Arthrospira.
It is important to note that even during this period with less demand for microalgae fuels the US government did not cease its investments and promoted research and development activities to obtain products such as ethanol and biodiesel over 15 years through the Aquatic Species Program. A new moment arose between 2008 and 2009 when the price of oil surpassed US $ 120/barrel, making the interest in research and development focused on microalgae fuels resurface once more on the international scene.
Since then, new governmental incentives have been allocated in several countries, A. Mainly in the USA through the National Renewable Energy Laboratory. It has given a considerable boost to many universities and small companies with expertise in micro-algal biotechnology.
Several projects aimed at obtaining microalgae biomass were developed using photobioreactors, open ponds or heterotrophic culture technologies in bioreactors in the absence of light. Among the main scientific problems presented during the upstream projects were the high cost of investment for photobioreactors and the difficulty in achieving stability and high productivity in open ponds.
As regards the processing of microalgae biomass, there were also several research and development projects aimed at improving the efficiency and cost-effectiveness of the steps of harvesting, cell disruption, extraction and conversion of the target compounds into biofuels (e.g.: ethanol, biodiesel and jet fuel).
