Bacillus safensis

Bacillus safensis is a Gram-positive, spore-forming, and rod bacterium, originally isolated from a spacecraft in Florida and California. B. safensis could have possibly been transported to the planet Mars on spacecraft Opportunity and Spirit in 2004. There are several known strains of this bacterium, all of which belong to the Firmicutes phylum of Bacteria. This bacterium also belongs to the large, pervasive genus Bacillus. B. safensis is an aerobic chemoheterotroph and is highly resistant to salt and UV radiation. B. safensis affects plant growth, since it is a powerful plant hormone producer, and it also acts as a plant growth-promoting rhizobacteria, enhancing plant growth after root colonization. Strain B. safensis JPL-MERTA-8-2 is (so far) the only bacterial strain shown to grow noticeably faster in micro-gravity environments than on the Earth surface. Thirteen strains of the novel bacterium Bacillus safensis were first isolated from spacecraft surfaces and assembly-facility surfaces at the Kennedy Space Center in Florida as well as the Jet Propulsion Laboratory in California. The bacterium gets its name from the JPL Spacecraft Assembly Facility (SAF). Researchers used customary swabbing techniques to detect and collect the bacteria from cleanrooms where the spacecraft were put together in the Jet Propulsion Laboratory. The bacterium was accidentally brought to Mars during space missions due to contamination of clean rooms. Contamination of clean rooms during space travel is an area of concern for planetary protection as it can threaten microbial experimentation and give false positives of other microbial life forms on other planets. V.V. Kothari and his colleagues from Saurashtra University in Gujarat, India, first isolated another strain, B. safensis VK. Strain VK was collected from Cuminum cyminum, a cumin plant in the desert area of Gujarat, India. Specifically, the bacteria were collected from the rhizosphere of the cumin plant. Ram S. Singh and colleagues discovered one of the strains, AS-08, in soil samples of root tubers of asparagus plants in a botanical garden at Punjabi University in India. B. safensis AS-08 was found to have inulase activity, which is used for the production of fructooligosaccharides and high-fructose corn syrup. Fructooligosaccharides are used as artificial sweeteners and can be found in many commercial food products. Corn syrup is also found in many processed foods. Davender Kumar and colleagues from Kurukshetra University in India isolated strain DVL-43 from soil samples. This strain was found to possess lipase, which is an important enzyme for fat digestion. Lipases are a class of chemicals that are abundant in nature amongst plants, animals and microorganisms that are widely used in industry for production of food, paper products, detergents and biodiesel fuel. P. Ravikumar of the Government Arts College at Bharathiar University in India isolated strain PR-2 from explosive-laden soil samples. This strain was identified by its 16S rDNA sequence by Sanger dideoxy sequencing method and deposited in the GenBank in Maryland, U.S. It carries the accession number KP261381 with 885 base pairs of linear DNA and the base count 175 a 295 c 199 g 216 t. Bacillus safensis is a Gram-positive, spore-forming rod bacterium. B. safensis is also an aerobic chemoheterotroph. Cell size ranges from 0.5 to 0.7 μm in diameter and 1.0–1.2 μm in length. This species is motile, and use polar flagella for locomotion. Cells are considered mesophilic, as they can grow in temperatures of 10–50 °C (50–122 °F). B. safensis FO-036b has an optimal temperature range of 30–37 °C (86–99 °F), and cannot grow at 4 or 55 °C (39 or 131 °F). B. safensis FO-036b prefers 0–10% salt, and a pH of 5.6. This strain was also found to produce spores that are resistant to hydrogen peroxide and UV radiation. Strain VK of B. safensis is a salt-tolerant microorganism, and can grow beyond the 0–10% salt range of the general microbial species. This strain can grow in 14% NaCl, with a pH ranging from 4 to 8. Strain VK also contains genes that encode for 1-aminocyclopropane-1-carboxylate deaminase enzyme. This enzyme is able to generate 2-oxobutanoate and ammonia (NH3) by cleaving the precursor of plant hormone, ethylene 1-aminocyclopropane-1-carboxylate. This enables the plant to tolerate salt, heavy metals, and polyaromatic hydrocarbons. Because of these features, B. safensis VK is a powerful plant hormone producer.