Development of arming yeast with amylase enzyme from Aspergillus niger as a model for delivery of enzyme

Alpha amylase enzyme from fungal origin is of great importance in food and feed industry. The enzyme is widely accepted in fermentation, brewing, pharmaceutical and textile industry. The aim of the study was to surface design yeast for anchoring of amylase enzyme on to the cell wall from Aspergillus niger using membrane protein and their characterization. The pYD1 vector was constructed enclosing amylase cDNA from A. niger and transformed into Saccharomyces cerevisiae EBY100 cells. The expression was induced by addition of galactose in the medium and assessed by immunofluorescence and plate assay methods. The amylase enzyme was successfully surface displayed using yeast as host, yielding an enzyme activity of 8.12 ± 0.8 μmol/min/mL. The yeast with surface-displayed amylase exhibited amylolytic activity and produced glucose and maltose as major hydrolysis products using starch as substrate. Further, the displayed enzyme was visualized by higher activity and immunofluorescence assay. Releasing glucose and maltose from starch, the surface display of amylase may help yeast with its survival and metabolic activity after ingestion by animals, enhancing its positive effects on animals. The surface-displayed amylase showed maximum activity at temperature of 50°C and optimal pH of 7.