Effect of Total Solid Content and Pretreatment on the Production of Lactic Acid from Mixed Culture Dark Fermentation of Food Waste
Food waste landfilling causes environmental degradation, and this work assesses a sustainable food valorization technique. In this study, food waste is converted into lactic acid in a batch assembly by dark fermentation without pH control and without the addition of external inoculum at 37 °C. The effect of total solid (TS), enzymatic, and aeration pretreatment was investigated on liquid product concentration and product yield. The maximum possible TS content was 34% of enzymatic pretreated waste and showed the highest lactic acid concentration of 52 g/L, with a lactic acid selectivity of 0.6 glactic/gtotalacids. The results indicated that aeration pretreatment does not significantly improve product concentration or yield. Non-pretreated waste in a 29% TS system showed a lactic acid concentration of 31 g/L. The results showed that enzymatic pretreated waste at TS of 34% results in the highest production of lactic acid.
KeywordsMixed culture fermentation Food waste Carboxylic acid Lactic acid Enzymatic pretreatment Total solid content Biorefinery
The authors would like to acknowledge the financial support of the Masdar Institute of Science and Technology, to help fulfill the vision of the late President Sheikh Zayed Bin Sultan Al Nahyan for sustainable development and empowerment of the United Arab Emirates and humankind, funding project 2GBIONRG (12KAMA4). A. Yousuf would like to acknowledge the Masdar Institute of Science and Technology Student Support Grant: SS2014-000003. The authors would like to acknowledge Dr. Glenda El Gamal for reviewing the manuscript’s English.
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