FIGURE 3.

Bacterial isolates effect on axenic Ectocarpus sp. upright filaments development. (A) Portion of a representative Ectocarpus sp. individual showing filaments developed in a unialgal culture. (B) Axenic Ectocarpus sp. representative individual showing prostrate body development without any upright filaments. (C) Ectocarpus sp. representative individual grown in the presence of bacterial isolate 869_1 (Kocuria rosea) showing same morphology of axenic culture. (D,E) Ectocarpus sp. representative individuals grown in the presence of bacterial isolates Z3 (Halomonas sp.) and Z8a_1 (Marinobacter sp.), showing same phenotype of individuals in unialgal cultures with upright filaments developed. Images were taken 21 days post germination. All bars, 250 μm. (C–E) Accompanied by an epifluorescence microscopy image showing bacterial presence for each treatment. Bars, 50 μm. (F–H) Representative images of unialgal (F), axenic (G) and bacterial inoculated (H, e.g., Z3) individuals after 6-week cultivation. While bacterial inoculated Ectocarpus recovered most of the typical branched morphology, axenic individuals grew as “small balls” showing no filaments.