What is a microalgae?

Biology

The term microalgae refers to the microscopic algae sensu stricto, and the oxygenic photosynthetic bacteria, i.e. the cyanobacteria, formerly known as Cyanophyceae (Richmond 2004). Microalgae is a photosynthetic microorganisms (including microalgae and cyanobacteria) convert sunlight energy into chemical energy using the following reaction:

6CO2 +  6H2O + sunlight = C6H12O6

Photosynthesis produces oxygen and carbohydrates mainly in two separate reactions that are called light and dark reactions: light reactions that only occur when the cells are illuminated, and carbon-fixation reactions, also known as dark reactions, that occur both in the presence and absence of light. The light reactions include light absorption, transfer of excitons and electron and proton translocation resulting in the production of NADPH2, ATP and O2. The phase dark reactions, which occur in the stroma, represent the reduction of carbon dioxide and the synthesis of carbohydrates using the NADPH2 and ATP produced in the light reactions.

A journey into the microalgae on Prezi

I invite you to see "A journey inside the microalgae" is actually a trip to my University and Laboratory of Bioprocess, a vision that will help create the mental map of the photosynthesis process in microalgae.

Distribution

Microscopic organisms are found in both marine and fresh water environments (Richmond 2004; Gouveia 2011). Microalgae are found all over the world. They are mainly distributed in the waters, but are also found on the surface of all type of soils. Although they are generally free-living, a certain number of microalgae live in symbiotic association with a variety of other organisms (Richmond 2004).

Importance

Can be classified into two groups: the importance at the ecosystem level and industry-wide importance. Ecological level marine microalgae are the dominant primary producers in aquatic systems. Although they comprise approximately only 1% of planetary photosynthetic biomass, they are responsible for similar amounts of annual global carbon fixation as terrestrial photosynthetic organisms. This is achieved by higher metabolic activity and higher turnover rates of marine microalgae compared with terrestrial plants (Stephenson, Moore, Terry, Zubkov, & Bibby, 2011). 

At the industry level and algae play an important role in the production of pharmaceutical products and there are a wide variety of bioproducts that can be obtained from them, ranging from the production of recombinant proteins (Specht, Miyake-Stoner, & Mayfield, 2010) to the production of gold nanoparticles (Dahoumane et al., 2012). Because the main purpose of this blog are microalgae biofuels, left for those interested in other bioproducts from microalgae reference the work of Dr. Danquah of the Laboratory of Bioengineering, University of Monash (Harun, Singh, Forde, & Danquah, 2010).

The interest on an industrial scale more important today (and for over 30 years) is given by the potential use of microalgal biomass for the production of a wide variety of third-generation biofuels. Oleaginous microalgae produce substantial amounts of neutral lipids, primarily comprised of triacylglycerides (TAGs) of favorable fatty acid chain length, making them an ideal feedstock for conversion to biodiesel or renewable diesel (Mutanda et al., 2011) and jet fuel (Guarnieri et al., 2011). And in practice all its products can be converted into biofuel sugars and proteins can be converted to ethanol (Huo et al., 2011; John, Anisha, Nampoothiri, & Pandey, 2011) and biomass generally methane (Parmar, Singh, Pandey, Gnansounou, & Madamwar, 2011). Some even raise the production of biohydrogen.

Well, this is small (very small) introduction to the subject of microalgae. For more information please ask, I'll help you gladly. My twitter is @fuelsmicroalgae Chao!

References

Dahoumane, S. A., Djediat, C., Yéprémian, C., Couté, A., Fiévet, F., Coradin, T., & Brayner, R. (2012). Recycling and adaptation of Klebsormidium flaccidum microalgae for the sustained production of gold nanoparticles. Biotechnology and bioengineering, 109(1), 284-8. doi:10.1002/bit.23276

Gouveia, L. 2011. Microalgae as a Feedstock for Biofuels. Springer Heidelberg Dordrecht London New York. Pag 75.

Guarnieri, M. T., Nag, A., Smolinski, S. L., Darzins, A., Seibert, M., & Pienkos, P. T. (2011). Examination of triacylglycerol biosynthetic pathways via de novo transcriptomic and proteomic analyses in an unsequenced microalga. PloS one, 6(10), e25851. doi:10.1371/journal.pone.0025851

 Harun, R., Singh, M., Forde, G. M., & Danquah, M. K. (2010). Bioprocess engineering of microalgae to produce a variety of consumer products. Renewable and Sustainable Energy Reviews, 14(3), 1037-1047. doi:10.1016/j.rser.2009.11.004

Huo, Y.-X., Cho, K. M., Rivera, J. G. L., Monte, E., Shen, C. R., Yan, Y., & Liao, J. C. (2011). Conversion of proteins into biofuels by engineering nitrogen flux. Nature biotechnology, 29(4), 346-51. doi:10.1038/nbt.1789

John, R. P., Anisha, G. S., Nampoothiri, K. M., & Pandey, A. (2011). Micro and macroalgal biomass: a renewable source for bioethanol. Bioresource technology, 102(1), 186-93. Elsevier Ltd. doi:10.1016/j.biortech.2010.06.139

Mutanda, T., Ramesh, D., Karthikeyan, S., Kumari, S., Anandraj, a, & Bux, F. (2011). Bioprospecting for hyper-lipid producing microalgal strains for sustainable biofuel production. Bioresource technology, 102(1), 57-70. Elsevier Ltd. doi:10.1016/j.biortech.2010.06.077

Parmar, A., Singh, N. K., Pandey, A., Gnansounou, E., & Madamwar, D. (2011). Cyanobacteria and microalgae: a positive prospect for biofuels. Bioresource technology, 102(22), 10163-72. Elsevier Ltd. doi:10.1016/j.biortech.2011.08.030

Richmond, A. 2004. Handbook of Microalgal Culture: Biotechnology and Applied Phycology. Blackwell Publishing Ltd. Pag 556

Specht, E., Miyake-Stoner, S., & Mayfield, S. (2010). Micro-algae come of age as a platform for recombinant protein production. Biotechnology letters, 32(10), 1373-83. doi:10.1007/s10529-010-0326-5

Stephenson, P. G., Moore, C. M., Terry, M. J., Zubkov, M. V., & Bibby, T. S. (2011). Improving photosynthesis for algal biofuels: toward a green revolution. Trends in biotechnology, 29(12), 615-23. Elsevier Ltd. doi:10.1016/j.tibtech.2011.06.005

The reason of "Biofuels from Microalgae"

"Biofuels from Microalgae" is the space for the generation of knowledge on the subject of microalgae

It has been widely reported that microalgae could theoretically generate a variety of fuels from its biomass (biological fuel source = biofuels). In this space, these issues will be discussed in detail, however there will be special emphasis on important topics that represent bottlenecks for the development thereof