Biotech Updates

Lime Pretreatments for Efficient Enzymatic Hydrolysis of Raw Sugarcane Bagasse

December 9, 2015
http://biotechnologyforbiofuels.biomedcentral.com/articles/10.1186/s13068-015-0384-y

Lime pretreatments have emerged as effective methods in preparing the lignocellulosic biomass for bioconversion. These pretreatments can be performed under mild temperature and pressure conditions, resulting in less sugar degradation. The team of Maira Prearo Grimaldi of Sao Paolo State University in Brazil evaluated the effect of these pretreatments on the efficiency of enzymatic hydrolysis of raw sugarcane bagasse.

The highest cellulose hydrolysis rate was obtained for raw sugarcane bagasse pretreated with lime for 60 min at 120°C compared with hydrothermally pretreated bagasse under the same conditions. Analysis of pretreated bagasse structure revealed that lime pretreatment damaged the bagasse fibers, including cell walls, exposing the cellulose-rich areas to enzymatic action.

Results showed that lime pretreatment is effective in improving enzymatic digestibility of raw sugarcane bagasse. It was also demonstrated that this pretreatment caused alterations in the structure and composition of raw bagasse resulting in an increase of cellulose hydrolysis rate. The use of raw sugarcane bagasse pretreated with lime may represent a cost reduction in ethanol production.