Production and partial characterization of polygalacturonases produced by thermophilic Monascus sp N8 and by thermotolerant Aspergillus sp N12 on solid-state fermentation

Paula Mendes de Freitas, Natalia Martin, Dênis Silva, Roberto da Silva, Eleni Gomes
2006 Brazilian Journal of Microbiology  
Polygalacturonases production by newly isolated Monascus sp N8 and Aspergillus sp N12 strains was carried out in solid-state fermentation using mixtures of wheat bran, sugar cane bagasse and orange bagasse as carbon sources. The maximal activity values of exo-polygalacturonases (exo-Pg) from Monascus sp and Aspergillus sp were obtained using wheat bran/sugar cane bagasse/orange bagasse mixture (6.6 U/mL) and wheat bran/orange bagasse mixture (10 U/mL), respectively. Enzyme production by both
more » ... ains was higher at 45ºC after 72 h and 1.6 U/mL at 50ºC after 120 h. Endo-polygalacturonase (endo-Pg) production was higher in wheat bran/orange bagasse mixture and was not affected by temperature of incubation for both fungi. Endo-Pg production by Monascus was 1.8 U/mL at 45ºC and 50ºC, after 72. Similar values were obtained in Aspergillus sp culture, 1.9 U/mL at 45ºC and 1.8 U/mL at 50ºC.Exo-Pg from both strains showed optimum activity at pH 5.5. Maximal activity was determined at 60ºC for enzyme from Monascus sp and 50ºC for that produced by Aspergillus sp. Exo-Pg from Monascus sp was stable at pH range 4.5-6.0 whereas that from Aspergillus sp enzyme was stable at pH 4.0. Both enzymes showed stability when incubated at 50ºC for 1 h, in absence of substrate. Figure 7. Stability of the exo-polygalacturonases produced by Monascus sp N8 and Aspergillus sp N12 against temperature. = exo-Pg from Monascus sp N8, = exo-Pg from Aspergillus sp N12.
doi:10.1590/s1517-83822006000300019 fatcat:ys522amolfbolfbhcjiwnpmrzi