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Biotechnological production of lactic acid integrated with potato wastewater treatment by Rhizopus arrhizus
Author(s) -
Huang Li Ping,
Jin Bo,
Lant Paul,
Zhou Jiti
Publication year - 2003
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.877
Subject(s) - rhizopus arrhizus , rhizopus oryzae , lactic acid , food science , rhizopus , hydrolysis , starch , fermentation , chemistry , biochemistry , biology , bacteria , lipase , genetics , enzyme
This paper describes a feasibility study of a for lactic acid production integrated with are treatment of wastewater from an industrial starch plant. Rhizopus oryzae two strains, Rhizopus arrhizus and Rhizopus oligosporus were tested with respect to their capability to carry out simultaneous saccharification and fermentation to lactic acid using potato wastewater. Rhizopus arrhizus DAR 36017 was identified as a suitable strain that demonstrated a high capacity for starch saccharification and lactic acid synthesis. The optimal conditions, in terms of pH, temperature and starch concentration, for lactic acid production were determined. The selected fungal strain grew well in a pH range from 3.0 to 7.0. The addition of CaCO 3 10 g dm −3 maintained the pH at 5.0–6.0 and significantly enhanced lactic acid production. Kinetic study revealed that almost complete starch saccharification and a lactic acid yield of 450g kg −1 could be achieved in 20 h and 28 h cultivation, respectively. The maximum lactic acid production 21 g dm −3 and mycelial biomass (1.7 g dm −3 ) were obtained at 30 °C. Besides the multiple bioproducts, total removal of suspended solids and 90% reduction of COD were achieved in a single no‐aseptic operation. Copyright © 2003 Society of Chemical Industry