> What's one of the largest, if not the largest, single-celled organisms in theworld?And the answer: bubble algae. Photo courtesy: WikipediaThe Valonia ventricosa, also known as bubble algae or sailor's eyeballs, is aspecies of algae found in warm ocean waters around the world. Recognizable bytheir brilliant green color, they're made of one single cell, but can grow up to5 cm in diameter.Bubble algae is unique in its size and unicellular composition. While mostvisible organisms are equipped with specialized cells to carry about thenecessary processes of life, unicellular organisms depend upon just one cell forall of its functions. Bubble algae is one of the largest unicellular organismson the planet.The term "algae" covers many different organisms capable of producing oxygenthrough photosynthesis. These organisms are not necessarily closely related, andnot all unicellular, but each is united in its ability to derive energy from thesun. Photosynthesis is essential to the precocity of life on this planet. Muchof the Earth's atmosphere is derived from oxygen-producing powerhouses such asalgae. Interestingly, algae could be a sustainable replacement for high energy fossilfuels. All algae have the ability to produce energy-rich oils, while severalspecies naturally accumulate high levels of oil in their dry mass. Algae canalso be found in diverse habitats and reproduce quickly, while efficiently usingcarbon dioxide.Join the conversation about algae sustainable fuel by checking out the videobelow.