Lipase Production in Solid-State FermentationMonitoring Biomass Growth of Aspergillus nigerUsing Digital Image Processing

摘要

The aim of this study was to monitor the biomass growth of Aspergillus niger insolid-state fermentation (SSF) for lipase production using digital image processingtechnique. The strain A. niger 11T53A14 was cultivated in SSF using wheat bran assupport, which was enriched with 0.91% (m/v) of ammonium sulfate. The addition ofseveral vegetable oils (castor, soybean, olive, corn, and palm oils) was investigated toenhance lipase production. The maximum lipase activity was obtained using 2% (m/m)castor oil. In these conditions, the growth was evaluated each 24 h for 5 days by theglycosamine content analysis and digital image processing. Lipase activity was alsodetermined. The results indicated that the digital image process technique can be used tomonitor biomass growth in a SSF process and to correlate biomass growth and enzymeactivity. In addition, the immobilized esterification lipase activity was determined for thebutyl oleate synthesis, with and without 50% v/v hexane, resulting in 650 and 120 U/g,respectively. The enzyme was also used for transesterification of soybean oil and ethanolwith maximum yield of 2.4%, after 30 min of reaction.