Simultaneous Saccharification and Fermentation of L-(+)-Lactic Acid Production from Liquefied Cassava Starch by Immobilized Rhizopus oryzae in a 3 L Airlift Fermenter
Srisakul Trakarnpaiboon, Suthasinee Praneetrattananon and Vichien Kitpreechavanich* Author for corresponding; e-mail address: fsciwck@ku.ac.th
Volume: Vol.45 No.1 (January 2018)
Research Article
DOI:
Received: 15 July 2016, Revised: -, Accepted: 6 December 2016, Published: -
Citation: Trakarnpaiboon S., Praneetrattananon S. and Kitpreechavanich V., Simultaneous Saccharification and Fermentation of L-(+)-Lactic Acid Production from Liquefied Cassava Starch by Immobilized Rhizopus oryzae in a 3 L Airlift Fermenter, Chiang Mai Journal of Science, 2018; 45(1): 77-91.
Abstract
L-(+)-lactic acid production by fermentation of starchy material (low-cost agricultural products) leads to a reduction in production cost and added value of agricultural products. Rhizopus oryzae DMKU 12 was selected because it can produce the highest amount of L-(+)-lactic acid from a-amylase-treated liquefied cassava starch. L-(+)-lactic acid production by R. oryzae DMKU 12 in a shaking flask indicated that KH2PO4 and ZnSO4.7H2O significantly affected L-(+)-lactic acid production; 150 g/L of a-amylase-treated liquefied cassava starch was the concentration that maximized production. L-(+)-lactic acid of 83.7 g/L with productivity of 1.16 g/L/h was obtained by R. oryzae DMKU 12 immobilized on a 0.25 ´ 0.25 ´ 0.25 cm3 polyurethane sponge at an aeration rate of 0.75 vvm after 72 h of cultivation in a 3 L airlift fermenter. Repeated-batch culture by PUS-immobilized R. oryzae was successful at 4 cycles, with average L-(+)-lactic acid concentration and product yield of 77.7 g/L and 0.62, respectively.