Transcriptomic analysis of liquid non-sporulating Streptomyces coelicolor cultures demonstrates the existence of a complex differentiation comparable to that occurring in solid sporulating cultures.
Streptomyces species produce many clinically relevant secondary metabolites and exhibit a complex development that includes hyphal differentiation and sporulation in solid cultures. Industrial fermentations are usually performed in liquid cultures, conditions in which Streptomyces strains generally do not sporulate, and it was traditionally assumed that no differentiation took place. The aim of this work was to compare the transcriptomes of S. coelicolor growing in liquid and solid cultures, deepening the knowledge of Streptomyces differentiation. Microarrays demonstrated that gene expression in liquid and solid cultures were comparable and data indicated that physiological differentiation was similar for both conditions. Eighty-six percent of all transcripts showed similar abundances in liquid and solid cultures, such as those involved in the biosynthesis of actinorhodin (actVA, actII-4) and undecylprodigiosin (redF); activation of secondary metabolism (absR1, ndsA); genes regulating hydrophobic cover formation (aerial mycelium) (bldB, bldC, bldM, bldN, sapA, chpC, chpD, chpE, chpH, ramA, ramC, ramS); and even some genes regulating early stages of sporulation (wblA, whiG, whiH, whiJ). The two most important differences between transcriptomes from liquid and solid cultures were: first, genes related to secondary metabolite biosynthesis (CDA, CPK, coelichelin, desferrioxamine clusters) were highly up-regulated in liquid but not in solid cultures; and second, genes involved in the final stages of hydrophobic cover/spore maturation (chpF, rdlA, whiE, sfr) were up-regulated in solid but not in liquid cultures. New information was also provided for several non-characterized genes differentially expressed in liquid and solid cultures which might be regulating, at least in part, the metabolic and developmental differences observed between liquid and solid cultures.
Área de Microbiología, Departamento de Biología Funcional and IUOPA, Facultad de Medicina, Universidad de Oviedo, Oviedo, Spain.
Paula
P
Yagüe
Instituto de Biotecnología de León, INBIOTEC, Parque Científico de León, León, Spain.
Antonio
A
Rodríguez-García
Área de Microbiología, Departamento de Biología Funcional and IUOPA, Facultad de Medicina, Universidad de Oviedo, Oviedo, Spain.
María Teresa
MT
López-García
Área de Microbiología, Departamento de Biología Funcional and IUOPA, Facultad de Medicina, Universidad de Oviedo, Oviedo, Spain.
Beatriz
B
Rioseras
Instituto de Biotecnología de León, INBIOTEC, Parque Científico de León, León, Spain.
Juan Francisco
JF
Martín
Área de Microbiología, Departamento de Biología Funcional and IUOPA, Facultad de Medicina, Universidad de Oviedo, Oviedo, Spain.
Jesús
J
Sánchez
Área de Microbiología, Departamento de Biología Funcional and IUOPA, Facultad de Medicina, Universidad de Oviedo, Oviedo, Spain.
Angel
A
Manteca
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D003470:Culture Media / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics; D013171:Spores, Bacterial / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D048372:Streptomyces coelicolor / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D059467:Transcriptome / Q000235:genetics*; D015854:Up-Regulation / Q000235:genetics
D001426:Bacterial Proteins; D003470:Culture Media