Enzymatic Saccharification and Ethanol Production of Xylem from Purwodadi Botanical Garden Trees

Abstract

Recent studies have revealed that sengon (Paraserianthes falcataria) xylem consists of soft walls which are easily hydrolysable with a commercial cellulase preparation. We felt it important to determine the saccharification levels for fast-growing tropical trees, of which sengon, one of the fastest growing tree species in Indonesia, was used as the control wood species. The aim of this study was to screen and evaluate the xylem of Purwodadi Botanical Garden trees for saccharification in order to assess their potential usefulness in bioethanol production. Saccharification and fermentation were first examined in the xylem derived from the branches of 32 trees. The xylem was then milled into powder using a ball mill, and the powdered xylem was digested with a commercial cellulase preparation (Accelerase, Palo Alto, USA) derived from Trichoderma viride. The levels of enzymatic hydrolysis of cellulose and ethanol production were higher for Firmiana malayana and Pterocarpus indicus than for sengon.

Analysis on Chemical Components of Woods to Predict Ethanol Production Values

“…Previous results showed the levels of enzymatic saccarification varied among xylems from the 32 trees. At 48 h, the highest level of saccharification was obtained from the xylem of F. malayana, which had released 36.9 mg of sugars/100 mg wood meal (Sakata et al 2012), while sengon only released 29 mg of sugars/100 mg wood meal (Kaida et al 2009a). The higher incidence of cellulose hydrolysis was also observed in P. indicus (34.0 mg/100mg wood meal) which was higher than in sengon (Sakata et al 2012).…”

“…A. catechu has the highest cellulose content while its sugars released was only 28.4 mg/100 mg wood meal (Sakata et al 2012). Therefore, the levels of enzymatic saccharification was regardless of the cellulose content (Dwianto et al 2011).…”

“…The amount of hemicellulose in xylems varied between 8.0 to 26.9%, in which xyloglucan content varied between 0 to 0.1425%. Alstonia scholaris has the lowest hemicellulose content while its sugar released was only 12.6 mg/100 mg wood meal (Sakata et al 2012). Therefore, the levels of enzymatic saccharification was regardless of the hemicellulose content (Dwianto et al 2011).…”