Valorization of Agri-Food Waste via Fermentation: Production of l-lactic Acid as a Building Block for the Synthesis of Biopolymers

• Main Authors: Giovanni Dedenaro, Stefania Costa, Irene Rugiero, Paola Pedrini, Elena Tamburini
• Format: Article
• Language: English
• Published: MDPI AG 2016-11-01
• Series: Applied Sciences
• Subjects: lactic acid fermentation; LAB strains; L. casei; L. farciminis; pear pomace; ricotta cheese whey
• Online Access: http://www.mdpi.com/2076-3417/6/12/379

Global interest towards lactic acid production has recently significantly increased because lactic acid can be used as raw material for the production of polylactic acid (PLA), a polymer used in biodegradable plastics for its special, environmentally-friendly properties. However, the high production costs have hindered the large-scale application of PLA due to the high price of lactic acid. Here we evaluated the potential of pear pomace and ricotta cheese whey (RCW) as a low-cost source of nutrients for lactic acid fermentation of Lactobacillus casei and Lactobacillus farciminis in microaerophilic conditions and mild sterility. After an initial lab-scale screening of 19 lactic acid bacteria (LAB) strains to select the highest producer of lactic acid, we reported the 1L-batch scale-up to test process efficiency and productivity of the most promising LAB strains. Batch fermentation of a 25:75 mixture of pear pomace and RCW, respectively, reached an overall yield factor of 90% and a volumetric productivity of 0.42 g/L·h.