Production of Lactic Acid by Simultaneous Saccharification and Fermentation Using Steam Pretreated Lespedeza Stalks as Inexpensive Raw Materials

Abstract:

Article Preview

The lespedeza stalks with steam pretreatment were fermented to lactic acid by simultaneous saccharification and fermentation (SSF) in this study. Orthogonal design methodology was used to evaluate the optimum SSF conditions that give maximum lactic acid yield. We have investigated the following relative factors, such as temperature, loading of cellulase, calcium carbonate and concentration of substrate. The optimum operating conditions were found to be temperature of 43 °C, cellulase loading of 30 FPU/g substrate, calcium carbonate of 3 % and substrate of 6 %. Comparisons of different steam pretreated conditions on lactic acid yield from lespedeza stalks were also made. The results showed that lactic acid yields from lespedeza stalks with 4 min pretreatment at pressure of 1.0, 1.25, 1.5 and 2.0 Mpa were 41.8 %, 42.5 %, 50.6 % and 64.0 % of the theoretical, respectively. The lactic acid yield from steam pretreated lespedeza stalks was much higher than that of lespedeza stalks without pretreatment (23.9 %). It can be concluded that the lactic acid yield was remarkably improved by steam pretreatment. The yield of lactic acid from steam pretreated lespedeza stalks was 1.68 times higher than that of untreated ones. Additionally, the lactic acid yield could be further promoted from 64.0 % to 89.4 % by washing pretreated stalks with water, which suggested that water processing is a promising method to remove inhibitors in broth to improve lactic acid yield.

Info:

Periodical:

Advanced Materials Research (Volumes 152-153)

Edited by:

Zhengyi Jiang, Jingtao Han and Xianghua Liu

Pages:

1404-1411

DOI:

10.4028/www.scientific.net/AMR.152-153.1404

Citation:

X. Qi et al., "Production of Lactic Acid by Simultaneous Saccharification and Fermentation Using Steam Pretreated Lespedeza Stalks as Inexpensive Raw Materials", Advanced Materials Research, Vols. 152-153, pp. 1404-1411, 2011

Online since:

October 2010

Export:

Price:

$35.00

In order to see related information, you need to Login.

In order to see related information, you need to Login.