Effective production of bioenergy from marine Chlorella sp by high-pressure homogenization

This study investigated the use of a high-pressure homogenization process for the production of high shear stress on Chlorella sp. cells in order to effectively degrade their cell walls. The high-pressure homogenization process was conducted by using various pressure conditions in the range of 68.94-275.78MPa with different numbers of repeated cycles. The optimal high-pressure homogenization pretreatment conditions were found to be two cycles at a pressure of 206.84MPa, which provided an extraction yield of 20.35% (w/w) total cellular lipids. In addition, based on the confocal microscopic images of Chlorella sp. cells stained by using nile red, the walls of Chlorella sp. cells were disrupted more effectively using this process when compared with the disruption achieved by conventional lipid-extraction processes. By using the by-product of Chlorella sp., 47.3% ethanol was obtained from Saccharomyces cerevisiae cultures. These results showed that the high-pressure homogenization process efficiently hydrolysed this marine resource for subsequent bioethanol production by using only water.