Intrasporangium

Intrasporangium is a genus of Gram positive, nonmotile, endosporeforming bacteria. The genus name refers to the ability to form sporangia intercalary in the mycelial hyphae.[1] The family Intrasporangiaceae is named after the genus, and Intrasporangium is the type genus for the family.[2]

The genus was first proposed in 1967. The type species I. calvum was first isolated from air in a school dining room in the Soviet Union.[1] The genus was monospecific until 2012, when three species were added to the genus. I. chromatireducens and I. mesophilum were proposed as new species, and the monospecific Humihabitans oryzae was reclassified as I. oryzae.[3][4] The novel genus and species Monashia flava was proposed in 2016, but was later found to be a member of Intrasporagium, most likely a strain of I. oryzae. The genus is currently defunct.[5][6]

Although the first isolation of Intrasporangium was from an air sample, subsequent isolations have mainly been from various types of soil. The soil sources include a manganese mine,[3] a former coal gasification site,[7] a uranium-contanimated site,[8] and the rhizospheres of a rice paddy and of Jatropha curcas.[4]