Myxococcus xanthus induces actinorhodin overproduction and aerial mycelium formation by Streptomyces coelicolor.
Bottom Line: Interaction of the predatory myxobacterium Myxococcus xanthus with the non-motile, antibiotic producer Streptomyces coelicolor was examined using a variety of experimental approaches.The interaction increases actinorhodin production by S. coelicolor up to 20-fold and triggers aerial mycelium production.These studies offer new clues about the expression of genes that remain silent or are expressed at low level in axenic cultures and open the possibility of overproducing compounds of biotechnological interest by using potent inducers synthesized by other bacteria.
Affiliation: Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain Area de Microbiología, Departamento de Biología Funcional, Facultad de Medicina, IUBA, Universidad de Oviedo, 33006 Oviedo, Asturias, Spain.Show MeSH
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Mentions: As shown in the movie, M. xanthus DK1622 cells moved towards S. coelicolor spores lysing them even from some distance. However, Streptomyces recovers coincident with spore germination suggesting that growing Streptomyces cells are partially resistant (see below). As the M. xanthus cells enter the S. coelicolor colony intense lysis of Streptomyces hyphae occurs. The use of the LIVE/DEAD Baclight kit demonstrates that control cultures of S. coelicolor without Myxococcus contained mainly living cells (Fig. 2A). However, the co‐cultures were predominantly red indicating a high proportion of dead mycelia (Fig. 2A). Scanning electron microscopy showed that the cells at the distal edges of the Streptomyces and Myxococcus drops that did not have contact with each other looked healthy (Fig. 2B). Myxococcus cells in the interaction zone also appeared healthy having the normal bacillar shape whereas Streptomyces hyphae exhibited aberrant morphologies (Fig. 2B). The cell density for both bacterial species in this zone was lower than at the distal edges due to competition and predation.
Affiliation: Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, E-18071 Granada, Spain Area de Microbiología, Departamento de Biología Funcional, Facultad de Medicina, IUBA, Universidad de Oviedo, 33006 Oviedo, Asturias, Spain.