title: Taxonomy and chemically semi-defined media for the analysis of the tacrolimus producer 'Streptomyces tsukubaensis'.
abstract: 'Streptomyces tsukubaensis' was the first tacrolimus producer strain identified. Although it has been included in the Streptomyces genus, its taxonomic position has not been rigorously determined. By using a polyphasic approach, we have established that the tacrolimus producer strain 'S. tsukubaensis' NRRL 18488 represents a unique species in the Streptomyces genus, which is phylogenetically distant from other subsequently described producers. This fact means a horizontal transference of the tacrolimus-producing gene cluster. Physiology, nutrient requirement, and molecular genetics analyses of tacrolimus biosynthesis in 'S. tsukubaensis' necessitate chemically defined or semi-defined media, which work as a jigsaw puzzle and allow for pieces (nutrients) exchange. To date, studies related to 'S. tsukubaensis' have been mainly focused in the improvement of tacrolimus production using complex industrial fermentation media, which difficulty allows testing of tacrolimus overproduction enhancers or inhibitors because of the presence of non-defined substances. In the present work, two semi-defined media were developed in order to study the main factors involved in tacrolimus production in 'S. tsukubaensis'.
authors.affiliation: Instituto de Biotecnología de León, Parque Científico de León, Avda. Real, no. 1, 24006 León, Spain.
authors.forename: Miriam
authors.initials: M
authors.lastname: Martínez-Castro
authors.forename: Zahra
authors.initials: Z
authors.lastname: Salehi-Najafabadi
authors.forename: Francisco
authors.initials: F
authors.lastname: Romero
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Pérez-Sanchiz
authors.forename: Rosa Isabel
authors.initials: RI
authors.lastname: Fernández-Chimeno
authors.forename: Juan Francisco
authors.initials: JF
authors.lastname: Martín
authors.forename: Carlos
authors.initials: C
authors.lastname: Barreiro
mesh_terms: D015373:Bacterial Typing Techniques; D001482:Base Composition; D016000:Cluster Analysis; D003470:Culture Media / Q000737:chemistry*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013302:Streptomyces / Q000145:classification* / Q000254:growth & development / Q000378:metabolism*; D016559:Tacrolimus / Q000378:metabolism*
chemical_list: D003470:Culture Media; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S; D016559:Tacrolimus