Milk‐clotting enzymes produced by Aspergillus flavo furcatis strains on Amazonic fruit waste

Abstract

Summary Six strains of Aspergillus flavo furcatis were screened to investigate milk‐clotting enzyme production by fermentation in natural liquid medium. The growth media comprised extracts of cupuaçu exocarp+rice bran [10% or 20% (v/v) CE+RB] and açai waste+rice bran [10% or 20% (v/v) AW+RB] with or without supplementation of 0.1% (w/v) yeast extract and 0.5% (w/v) gelatin. Significant values of milk‐clotting activity were determined by A. flavo furcatis DPUA 1461 and DPUA 1608, in the standard and natural media, respectively. According to criteria of clot and whey formations, 8.3% of the samples tested were classified as strong coagulation, 41.70% showed weak coagulation and in 50% was not observed milk coagulation. The enzyme optimal action of DPUA 1608, the selected strain, was at 40 °C and pH 7.0. Milk‐clotting proteases were inhibited by pepstatin (94.72%) and moderately inhibited by the others metal ions tested.

Pleurotus albidus: A new source of milk-clotting proteases

“…Similar result of clot formation was reported in the study of Alecrim et al (2015) with enzymes from A. flavo furcatis, an anomorphic fungus.…”

“…Silva et al (2014) reported milk-clotting activity ( 60.5 U/ml) and coagulant ratio (510) in Thermomucor indicae-seudaticae N31. In the study of Alecrim et al (2015), Aspergillus flavo furcatis DPUA 1493 presented milk-clotting activity of 68.61 U/ml and coagulant ratio of 1.81. Milk-clotting enzymes from Termitomyces clypeatus presented values of 333.33 U/ml and 64.70 of milk-clotting activity and coagulant ratio, respectively, in the study of Majumder et …”

“…The relation of milk-clotting activity and proteolytic activity is associated with the enzymatic specific in the clot formation and influences in the selection of a new source of milk-clotting enzymes (Alecrim et al, 2015).…”

“…To select a strain and characterize its enzymes, the samples were grouped into three classes according to the formation of compact milk clot and milk whey separation in the test tube: strong milk coagulation (distinct clot and abundant whey); weak milk coagulation (clot formation without clear separation of the whey); and milk without coagulation (clot and whey absent) (Alecrim et al, 2015).…”

Production and characterization of proteases from edible mushrooms cultivated on amazonic tubers

“…Residual enzyme activities were determined and compared with the control which was incubated without the inhibitors (0% inhibition) and metal ions and corresponds to 100% of enzyme activity. All samples were prepared in triplicate (Alecrim et al, 2015). Table 2 shows the results of radial growth of L. citrinus and P. ostreatoroseus in solid medium, for six days.…”