L-arabinose induces synthesis of a secreted #beta#-galactosidase in the filamentous fungus Penicillium canescens

摘要

Some peculiarities of #beta#-galactosidase induction upon cultivation of the filamentous fungus Penicillium canescens on plant polysaccharide containing media have been studied. L-arabinose present in sugar beet pulp arabinan has been established to be a factor inducing the enzyme synthesis L-arabinose as well as its metabolite L-arabitol act as inducers at micromol concentrations. Apart from #beta#-galactosidase, L-arabinose initiated synthesis of other secreted carbohydrolases, including #alpha#-L-arabinofuranosidase. Either the increase of arabinose concentration or the addition of other carbon sources resulted in the repression of extracellular proteins. The putative role of #alpha#-L-arabinofuranosidase in the coordinate regulation of the P. canescens secreted enzymes is being discussed.