The role of the particle size reduction and morphological changes of solid substrate in the ultrasound-aided enzymatic hydrolysis of cellulose

The contribution of ultrasound-aided particle size reduction to the efficiency of the subsequent enzymatic hydrolysis and the accompanying morphological changes of bleached cotton and linen powders were investigated. The aqueous suspensions of cellulosic powders were pretreated either with an ultrasonic bath (US-B) or with a horn-type reactor (US-H). Results revealed that the impact of US-H was more pronounced than that of the US-B. Clearly, the linen particles were more sensitive to ultrasonication than cotton. The US-H modified the particle size distribution differently for the cotton and linen powders and reduced the mean size of particles from 49 to 40 mu m and from 123 to 63 mu m, respectively. A significant increase in the water retention and water sorption capacity was also measured. The smaller particles with increased accessibility were preferably digested in the enzyme treatment, resulting in a considerably higher concentration of reducing sugars and an enrichment of the residual particles with a larger average size (cotton: 47 mu m; linen: 66 mu m).

Automated summary

The study investigated the contribution of ultrasound-aided particle size reduction to enzymatic hydrolysis efficiency and morphological changes of bleached cotton and linen powders. Results showed that linen particles were more sensitive to ultrasonication than cotton, with the horn-type reactor having a stronger impact. The smaller particles with increased accessibility led to higher concentration of reducing sugars and larger average size of residual particles after enzyme treatment.