Penicillium sp. — PRODUCER OF EXTRACELLULAR α-L-RHAMNOSIDASE

The purpose of this work was to investigate α-L-rhamnosidase that hydrolytically cleaves the terminal unreduced α-1,2-, α-1,4- and α-1,6-linked rhamnose residues in both synthetic and natural glycosides, oligo-, and polysaccharides, various glycoconjugates: flavonoid derivatives such es rutin, neohesperidin, hesperidin, naringin, quercitrin, saponins, terpene glycosides. These properties of the enzyme could be used for the needs of food industry, pharmaceutical and chemical industry: to improve the quality of beverages (reduction of bitterness, flavor enhancing wines), for production of food additives, medicine preparations and rhamnose. As a result of screening conducted among 9 strains of micromycetes, ability to synthesize α–Lrhamnosidase was revealed only in Penicillium sp. 2918. Complex enzyme preparation was obtained from culture supernatant of this micromycete by fractionation with ammonium sulfate (90% saturation) and its physico-chemical properties such as pH- and thermooptimum, pH- and thermal stability and substrate specificity were studied as well. It is shown that enzyme has pH optimum is about 6.0 and thermooptimum is about 60 оC. Preparation of Penicillium sp. 2918 with α-L-rhamnosidase reveals α-D-glucosidase, α-D-galactosidase and α D-glucosaminidase activity.