Figure 2.

Mapping the distribution of C. lytica and P. pseudonitzschiae SW within mixed colonies by sampling and selective viable counts. (a) Expanding colony of C. lytica PlyA3 and P. pseudonitzschiae SW on RMAR (0.8% w/v) agar, after 3 days incubation at 28°C. Sampling points are marked from 1 (centre) to 5 (edge) of the colony. Scale bar (upper right) indicates 1 cm. (b) Selective viable counts from a sampled RMAR plate as panel a, showing average cfu (calculated as cfu/mm²), with error bars indicating the upper limit of S.D. above the mean. Black bars: P. pseudonitzschiae SW viable counts as sampled from the plate shown in panel a. + indicates no cfu were detected for these samples, indicating a viable count of <100 cfu/mm². Light grey bars: cfu of C. lytica PlyA3. White bars: P. pseudonitzschiae SW sampled an RMAR plate similar to that shown in panel a but after 10 days. Dark grey bars: cfu of C. lytica PlyA3. * no cfu were detected for these samples, indicating a viable count of <100 cfu/mm². (c) Colony after coculture of C. lytica PlyA4 (nongliding) and P. pseudonitzschiae SW for 3 days on RMAR. Scale bar indicates 0.8 mm. Three sampling points are indicated. (d) Selective viable counts from the colony shown in panel c. Black bars: P. pseudonitzschiae SW. + indicates no P. pseudonitzschiae cfu were detected, indicating a viable count of <100 cfu/mm². Light grey bars: C. lytica PlyA4.