Reproduction of Cephalosporium eichhorniae as spheroplasts

About 0.7% of the conidia and 0.3% of the enzymatically produced spheroplasts of Cephalosporium eichhorniae 152 (ATCC 38255) grew as colonies of spheroplasts on agar medium containing 0.8 M glucose. Both primary (enzymatically produced) and cultured spheroplasts were osmotically sensitive. Cultured spheroplasts contained from 0 to 10 nuclei each. They were larger than primary spheroplasts with the most frequent size classes having volumes of 49.6 and 6.2 μm3, respectively. Cultured spheroplasts gave high yields of colonies (31%) in medium with 0.6 M KCl, while neither spores nor primary spheroplasts grew on this medium. Cultured spheroplasts grew slowly in gently shaken liquid media, containing various osmotic stabilizers, to produce dense growth (3.9 × 107 spheroplasts/mL) in 8 days.