Chlorella
<p ><i><b>Chlorella</b></i> is a <a href="http://en.wikipedia.org/wiki/Genus" title="Genus" >genus</a> of single-<a href="http://en.wikipedia.org/wiki/Cell_(biology)" title="Cell (biology)" >cell</a> green <a href="http://en.wikipedia.org/wiki/Algae" title="Algae" >algae</a>, belonging to the phylum <a href="http://en.wikipedia.org/wiki/Chlorophyta" title="Chlorophyta" >Chlorophyta</a>. It is spherical in shape, about 2 to 10 <a href="http://en.wikipedia.org/wiki/Micrometre" title="Micrometre" >μm</a> in diameter, and is without <a href="http://en.wikipedia.org/wiki/Flagella" title="Flagella" class="mw-redirect" >flagella</a>. <i>Chlorella</i> contains the green photosynthetic pigments <a href="http://en.wikipedia.org/wiki/Chlorophyll" title="Chlorophyll" >chlorophyll</a>-a and -b in its <a href="http://en.wikipedia.org/wiki/Chloroplast" title="Chloroplast" >chloroplast</a>. Through <a href="http://en.wikipedia.org/wiki/Photosynthesis" title="Photosynthesis" >photosynthesis</a>, it multiplies rapidly, requiring only<a href="http://en.wikipedia.org/wiki/Carbon_dioxide" title="Carbon dioxide" >carbon dioxide</a>, <a href="http://en.wikipedia.org/wiki/Water" title="Water" >water</a>, <a href="http://en.wikipedia.org/wiki/Sunlight" title="Sunlight" >sunlight</a>, and a small amount of <a href="http://en.wikipedia.org/wiki/Mineral" title="Mineral" >minerals</a> to reproduce.<sup id="cite_ref-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Chlorella#cite_note-0" >[1]</a></sup></p>
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The name <i>Chlorella</i> is taken from the <a href="http://en.wikipedia.org/wiki/Greek_language" title="Greek language" >Greek</a> <b>chloros</b>, meaning <i>green</i>, and the <a href="http://en.wikipedia.org/wiki/Latin" title="Latin" >Latin</a> diminutive suffix <b>ella</b>, meaning <i>small</i>. <a href="http://en.wikipedia.org/wiki/Germany" title="Germany" >German</a> <a href="http://en.wikipedia.org/wiki/Biochemist" title="Biochemist" >biochemist</a> and cell physiologist <a href="http://en.wikipedia.org/wiki/Otto_Heinrich_Warburg" title="Otto Heinrich Warburg" >Otto Heinrich Warburg</a>, awarded with the <a href="http://en.wikipedia.org/wiki/Nobel_Prize_in_Physiology_or_Medicine" title="Nobel Prize in Physiology or Medicine" >Nobel Prize in Physiology or Medicine</a> for his research on cell respiration in 1931, also studied photosynthesis in<i>Chlorella</i>. In 1961, <a href="http://en.wikipedia.org/wiki/Melvin_Calvin" title="Melvin Calvin" >Melvin Calvin</a> of the <a href="http://en.wikipedia.org/wiki/University_of_California" title="University of California" >University of California</a> received the <a href="http://en.wikipedia.org/wiki/Nobel_Prize_in_Chemistry" title="Nobel Prize in Chemistry" >Nobel Prize in Chemistry</a> for his research on the pathways of carbon dioxide assimilation in <a href="http://en.wikipedia.org/wiki/Plant" title="Plant" >plants</a> using <i>Chlorella</i>. </p>
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In recent years, researchers have made less use of <i>Chlorella</i> as an <a href="http://en.wikipedia.org/wiki/Model_organism" title="Model organism" >experimental organism</a> because it lacks a <a href="http://en.wikipedia.org/wiki/Biological_life_cycle" title="Biological life cycle" >sexual cycle</a> and, therefore, the research advantages of <a href="http://en.wikipedia.org/wiki/Genetics" title="Genetics" >genetics</a> are unavailable<sup class="Template-Fact" >[<i><a href="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed" >citation needed</a></i>]</sup>.
Many people believed <i>Chlorella</i> could serve as a potential source of food and energy because its <a href="http://en.wikipedia.org/wiki/Photosynthetic_efficiency" title="Photosynthetic efficiency" >photosynthetic efficiency</a> can, in theory, reach 8%,<sup id="cite_ref-1" class="reference" ><a href="http://en.wikipedia.org/wiki/Chlorella#cite_note-1" >[2]</a></sup> comparable with other highly efficient crops such as sugar cane.
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<h2 >Aquarium</h2>
<p ><i>Chlorella</i> can create green and opaque water problems in <a href="http://en.wikipedia.org/wiki/Aquarium" title="Aquarium" >aquaria</a>. <i>Chlorella</i> can grow due to high <a href="http://en.wikipedia.org/wiki/Nitrate" title="Nitrate" >nitrate</a> and <a href="http://en.wikipedia.org/wiki/Phosphate" title="Phosphate" >phosphate</a> levels or direct sunlight. Decreasing phosphate and nitrate by partial water change and moving the aquarium to shade can help alleviate the problem.</p>