Effects of intermittent addition of cellulase for production of L‐lactic acid from wastewater sludge by simultaneous saccharification and fermentation
- 21 February 2003
- journal article
- research article
- Published by Wiley in Biotechnology & Bioengineering
- Vol. 82 (3), 263-270
- https://doi.org/10.1002/bit.10573
Abstract
An attempt was made to create L‐lactic acid, a precursor of poly‐lactic acid, which is a biodegradable plastic, from wastewater sludge from the paper‐manufacturing industry. The sludge contained a high percentage of cellulose and needed to be hydrolyzed to glucose by the action of the cellulase before being treating with lactic acid bacteria. Therefore, a method involving simultaneous saccharification and fermentation (SSF) was carried out. The optimum pH of the SSF for production of the lactic acid by the newly isolated lactic acid bacterium with a high selectively of L‐lactic acid was found out to be around pH = 5.0, and the optimum temperature to be approximately 40°C. On the basis of the measurement of the cell density changes in the lactic acid bacteria, it was ascertained that the bacterial activity could continue at a high level for a relatively long period of time, and that the L‐lactic acid productivity was diminished by the rapid deactivation of the cellulase. With the intermittent addition of cellulase once daily for the sake of compensating for the cellulase deactivation, the L‐lactic acid attained a maximum concentration of 16.9 g/L, i.e., a 72.2% yield based on the potential glucose contained in the sludge under optimum pH and temperature conditions.© 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 82: 263–270, 2003.Keywords
This publication has 21 references indexed in Scilit:
- Simultaneous Saccharification and Extractive Fermentation of Lignocellulosic Materials into Lactic Acid in a Two-Zone Fermentor-Extractor SystemApplied Biochemistry and Biotechnology, 1999
- Product inhibition in simultaneous saccharification and fermentation of cellulose into lactic acidBiotechnology Letters, 1999
- Use of Wastewater Sludge as a Raw Material for Production of l-Lactic AcidEnvironmental Science & Technology, 1998
- Production of ethanol from recycled paper sludge using cellulase and yeast, Kluveromyces marxianusBiomass and Bioenergy, 1997
- Biochemical Engineering Analysis of Critical Process Factors in the Biomass-to-Ethanol TechnologyBiotechnology Progress, 1997
- Membrane-mediated extractive fermentation for lactic acid production from cellulosic biomassApplied Biochemistry and Biotechnology, 1997
- Simultaneous hydrolysis and fermentation of pulp mill primary clarifier sludgeThe Canadian Journal of Chemical Engineering, 1994
- Fuel Ethanol from Cellulosic BiomassScience, 1991
- Simultaneous saccharification and fermentation of cellulose to lactic acidBiotechnology & Bioengineering, 1991
- Surface deactivation of cellulase and its preventionEnzyme and Microbial Technology, 1982