Growth curves and nucleic acids content of mycelial and yeast-like forms of Paracoccidioides brasiliensis

The growth curves of mycelial (M) and yeast-like (Y) forms ofParacoccidioides brasiliensis may be accounted for by short cubic root and exponential phases, respectively, followed in both forms by a linear growth phase. Most of the M form mass increase occurred in the linear growth phase, whereas the largest amount of Y form growth took place during the exponential phase. The Y form often grew in an atypical manner. Nucleic acids content per unit weight generally reached maximum values at the end of the initial growth phase. It is concluded that the initial growth phase of both M and Y forms is the most appropriate one for comparative studies of their metabolic activities.