Sunday, July 24, 2011
Grand Ballroom, 5th fl (Sheraton New Orleans)
The demand for novel enzymes of industrial use is continuing to stimulate the screening and isolation of new microorganisms. Macrophomina phaseolina is a non specific phytopathogenic filamentous fungus that attacks a wide variety of economically important crops like beans, corn, sunflower, and the cucurbit family, among others. Literature about extracellular enzymes produced by this fungus is sparse, the majority being on cellulases and endoglucanases. The radial growth rate of thirteen M. phaseolina isolates collected from several hosts at different geographical regions of Brazil was determined on semi-solid media containing different substrates, including biodiesel (100). Also, the production of extracellular pectinases, amylases, proteases, and lipases in these media was tested. The radial growth rates of the isolates were quite variable, depending on the type of substrate. The thirteen isolates also showed variability in the production of the enzymes. However, seven of them showed activity on all substrates tested. Isolate AJAM displayed a quite different profile, producing only pectinase. Proteases, pectinases and lipases were the most commonly produced enzymes. Isolate CMM 2105 distinguished itself for showing fast growth and the production of the corresponding hydrolase in all the media tested. In conclusion, some isolates of M. phaseolina show potential industrial use due to the production of extracellular hydrolases and high growth rates.