Prototheca blaschkeae subsp. brasiliensis subsp. nov., isolated from cow milk.

A strain of an achlorophyllic alga, named PR24 ^T , was isolated from cow milk samples from the state of Minas Gerais, Brazil. Based on 18S rDNA, 28S rRNA, D1/D2 region of the LSU rDNA and SSU rRNA gene sequence similarities, this strain was found to be a member of the genus Prototheca and closely related to Protothecablaschkeae SAG2064 ^T . However, the novel strain could easily be distinguished from recognized Prototheca species by internal transcribed spacer, species-specific PCR, single-strand conformation polymorphism-PCR analysis and phenotypic characteristics. The inability to grow in Sabouraud broth at pH 4.0 and the different cellular fatty acid composition clearly distinguished PR24 ^T from the reference strain of P. blaschkeae. The combination of genotypic and phenotypic data indicates that strain PR24 ^T represents a subspecies of P. blaschkeae, for which the name Prototheca blaschkeae subsp. brasiliensis subsp. nov. is proposed. The respective type strain is PR24 ^T (=DSM 103592 ^T =IHEM 26958 ^T ).