Growth characteristics of three Mallomonas species (silica-scaled chrysophytes) at different temperatures and pH

Three species of Mallomonas (M. crassisquama, M. elongata and M. tonsurata) were isolated from Kachang dam in Daegu, Korea and the individual species were grown as batch cultures in the laboratory. The growth characteristics of these species were investigated at different temperatures and pH. Mallomonas crassisquama exhibited the highest growth rates (mu(max)) at 18 degrees C, whereas the maximum growth rates of M. elongata and M. tonsurata were observed at 21 degrees C. The maximum growth rates of M. crassisquama and M. elongata were observed at pH 6, and M. tonsurata exhibited maximum growth rate at pH 5. Mallomonas crassisquama and M. tonsurata showed high growth rate between pH 4 and 6, and M. elongata showed high growth rate below pH 7. The three species showed similar growth characteristics except that M elongata proliferated at a narrower temperature range and at a wider pH range than other two species.