We also constructed a cmcax complement strain, F2-2(pSA-CMCase/
k), in which the complementation plasmid pSA-CMCase/k (an
approximately 1.9-kb fragment of G. xylinusDNAwith cmcax and
aKmr gene included in the shuttle vector pSA19) was inserted into
F2-2. A 5-mm-thick pellicle (Fig. 1B, arrow) was formed after 1