Bioassay evaluation of the antagonistic activities of five mycorrhiza associated Streptomyces isolates against bacteria. (a) Examples of co-culture phenotypes between the mycorrhiza associated Streptomyces isolates. AcM11 was confronted with other streptomycetes. (b) Degrees of inhibition between five mycorrhiza associated Streptomyces isolates. The bacteria were challenged with each other in a Petri dish co-culture bioassay (n = 9). The left hand column equals the singular line while the top row equals the three lines in the Petri dish. Box colours represent the degree of inhibition. No inhibition, white; inhibition of sporulation, yellow; inhibition of growth, red. (c) Antibiotic activity of five mycorrhiza associated Streptomyces isolates against non-Streptomyces bacteria. Gram-positive Mycobacterium phlei, Bacillus subtilis and Staphylococcus aureus, and Gram-negative Escherichia coli and Pseudomonas fluorescence were cultivated on agar medium and challenged by either the supernatant or the organic extract of a Streptomyces isolate, applied on a filter paper. Boxes represent average zones of inhibition (ZOI) by a given treatment and different colours indicate the degree of inhibition. ZOI = 0-2.5 mm, white; ZOI = 2.6-7.5 mm, light yellow; ZOI = 7.6-12.5 mm, orange; ZOI = 12.6-24 mm, red. Results are based on two separate repetitions with 3 Petri dishes each containing seven filter papers.