when the cells lost viability at the stationary phase of cultural growth under the optimal conditions of illumination ( 1500 -- 2000 lx ) , in the dark or when nitrogen was deficient , the filaments became shorter ( 4 to 2.2 cells per filament on the average ) , the cells larger , 4.5x6 microns ) .
C0010851
filament
C0007634
cells