Algae represent a large, photosynthetic plant-like group which vary from being unicellular to multicellular. Algae exist in a variety of environments from snow, soil and water. The term “algae” is used as the plural form for representing these organisms, whereas “alga” is the term used when referring to algae singularly. Algae are found in a variety of different shapes and sizes. In the microscopic form, algae are referred to as microalgae and some examples are diatoms and cyanobacteria. Larger and more complex algae, called macroalgae are multicellular and some examples include seaweed and kelp.
Algae are considered to be photoautotrophs because they convert photons emitted by the sun to simple sugars and starches. Modern biotechnology in biofuel industries has modified algae to produce energy in dark conditions through heterotrophic fermentation, whereby algae are fed large amounts of sugars to produce biomass and oil.
Furthermore, researchers in 2001 introduced a human glucose-transporter gene into algae, representing another method which allows algae to produce energy while in darkness by feeding off of sugar1. This light-free technique is also beneficial in that it allows algae to avoid being grown in contaminated waters. Aside from biofuel, algae have many applications such as being key ingredients of cosmetics, food products and dietary supplements. Additionally, algae represent the base of many aquatic food webs and are thus, an important food source in many ecosystems.
A growing problem in water is the occurence of algal blooms, these are rapid increases in algal populations due to a combination of fertilizer-caused eutrophication, rising temperatures and seasonality. Consequences of algal blooms vary but most species cause discoloration of water, pollution of drinking sources, lower dissolved oxygen (DO) levels, and discomfort of aquatic organisms. However, Harmful Algal Blooms (HAB) produce high concentrations of cyanotoxins that are detrimental to all organisms including humans. Thus monitoring of polluted water and research on algal species has become increasingly important.
1.Whitfield, J. Grow in the dark algae. Retrieved from http://www.nature.com/news/2001/010615/full/news010614-13.html