Community structure and antibiotic production of Streptomyces nodosus bioreactors cultured in liquid environments.
Bottom Line: When cell proliferation was encouraged, substrate hyphae were found inside the alginate matrix and within multicellular projections on the surface of the capsule.These organisms sporulated with reduced antibiotic production compared with free-dwelling cultures.The commitment to sporulate was independent of a surface but dependent on community size and nutritional status.
Affiliation: University of Western Sydney, School of Natural Sciences, Parramatta Campus, Locked Bag 1797, Penrith South DC 1797 NSW, Australia.Show MeSH
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Mentions: Double‐cross‐over homologous recombination was used to inactivate amphA and make S. nodosus MAΩhyg1 (Fig. 5a). A disruption plasmid pMAΩhyg1 (Fig. 5a) was made with amphA providing homology sequences of 3.4 kb and 0.8 kb flanking a hygromycin resistance cassette and introduced into S. nodosus spores [1 × 107 colony‐forming units (cfu)] by conjugation with Escherichia coli. After 14 days of growth with hygromycin selection, colonies were tested for apramycin sensitivity as HygRAprR colonies originate from a single cross whereas HygRAprS colonies result from a double‐cross‐over recombination event.
Affiliation: University of Western Sydney, School of Natural Sciences, Parramatta Campus, Locked Bag 1797, Penrith South DC 1797 NSW, Australia.