%0 Journal Article
%T Spirulina (Arthrospira): An Important Source of Nutritional and Medicinal Compounds
%A Abdulmumin A. Nuhu
%J Journal of Marine Biology
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/325636
%X Cyanobacteria are aquatic and photosynthetic organisms known for their rich pigments. They are extensively employed as food supplements due to their rich contents of proteins. While many species, such as Anabaena sp., produce hepatotoxins (e.g., microcystins and nodularins) and neurotoxins (such as anatoxin a), Spirulina (Arthrospira) displays anticancer and antimicrobial (antibacterial, antifungal, and antiviral) activities via the production of phycocyanin, phycocyanobilin, allophycocyanin, and other valuable products. This paper is an effort to collect these nutritional and medicinal applications of Arthrospira in an easily accessible essay from the vast literature on cyanobacteria. 1. Introduction Cyanobacteria are ancient photosynthetic organisms that are found in various aquatic environments [1¨C3]. Their photosynthetic pigments confer different colors on them, but they are generally regarded as blue-green. Calling them algae is, however, a misnomer since they are truly prokaryotes that share most of the characteristics of eubacteria. Some of these organisms have nitrogen-fixing potential which makes them important in rice paddy waters [4]. Cyanobacteria form colonies [5] or live as individual cells [6]. They also form coccoid [7] or filamentous structures [8]. The filamentous colonies show the ability to differentiate into three different cell types [9]. Vegetative cells, the normal photosynthetic cells formed under favorable growth conditions; climate-resistant spores in harsh environmental conditions and a thick-walled heterocyst containing the enzyme nitrogenase for nitrogen fixation. In the last 3.5 billion years, cyanobacterial morphology has been largely maintained as they are very resistant to contamination. Sigler et al. [10] have shown that cyanobacteria form monophyletic taxon. Culture-based morphological characteristics of endolithic cyanobacteria have been extensively described by Al-Thukair and Golubic [11]. Since characterization of microorganisms based on morphology is highly subjective and sometimes very speculative, the shift by genome-based characterization is now gaining momentum. Koksharova and Wolk [12] have presented a good review on the available genetic tools for cyanobacteria studies. Cyanobacteria are very resistant as they produce protective compounds which shield them against harsh environmental conditions [13]. Some of these compounds also have strong insecticidal activities [14]. Toxic species, including Anabaena species, produce toxins such as microcystins and nodularins which are hepatotoxic, and neurotoxins such as
%U http://www.hindawi.com/journals/jmb/2013/325636/