Determination of radial growth rate of colonies of Sclerotium rolfsii F-6656 for the evaluation of culture medium, optimum incubation temperature, osmo- and halotolerance

J.I. FARIÑA; F. SIÑERIZ; O.E. MOLINA; N.I. PEROTTI

REVISTA ARGENTINA DE MICROBIOLOGíA

Asociación Argentina de Microbiología

Lugar: Buenos Aires; Año: 1996 vol. 28 p. 190 - 196

0325-7541

The measurement of the colony radial growth rate (Kr) on solid medium of colonies of Sclerotium rolfsii Proimi F-6656 for the evaluation of scleroglucan production medium and other different media, incubation temperature and tolerance to diverse concentrations of sucrose and NaCl were studied. The optimum growth temperature observed was 30 degrees C. The Kr value reached on the Production Medium used (0.66 mm.h-1) showed no differences compared with those of the other media tested, indicating that all the requirements for growth were provided. Poor growth was only observed on Soil Extract Agar. The fungus tolerated concentrations of sucrose from 0.15 to 1.17 M, on both Czapek and production medium. Growth was limited by the highest concentrations of sucrose tested (0.88 and 1.17 M), as indicated by a slower increase in colony size. Addition of 0.86 M NaCl to the production medium and YM agar did not inhibit growth completely, but decreased the radial growth rate considerably (80 and 70% respectively).