In situ visualization of dynamic interactions of cellulase and cellulose molecules

Enzymatic hydrolysis of cellulose from biomass is potentially considered as a new approach for the next generation of biofuels for sustainable energy. However, because of the rigid and complex structure of cellulose, the low efficiency of the enzymatic hydrolysis has been deemed as the bottleneck in biorefining industry. The mechanism of enzymatic hydrolysis of cellulose is not well understood due to the absence of direct observation methods. In the present study, in order to study the mechanism of enzymatic hydrolysis of cellulose, we used an atomic force microscopy (AFM) to dynamically observe the changes happening during the cellulase and cellulose interaction. To improve the imaging rate of AFM (which was too slow to capture the interactions between these two nano structures), a scan strategy named compressive scan is used, associated with prior knowledge based image reconstruction methods. With the help of compressive scan, we are able to dynamically capture the action of the cellulase-CBH I (from family 7 cellobiohydrolase) on the cellulose crystal nanofibrils. The result is helpful for understanding the mechanism of enzymatic interaction and increasing the efficiency of hydrolysis process.