Production of lactic acid from food wastes.
Conversion of food wastes into lactic acid by simultaneous saccharification and fermentation (SSF) was investigated. The process involves saccharification of the starch component in food wastes by a commercial amylolytic enzyme preparation (a mixture of amyloglucosidase, alpha-amylase, and protease) and fermentation by Lactobacillus delbrueckii. The highest observed overall yield of lactic acid in the SSF was 91% of theoretical. Lactic acid concentration as high as 80 g/L was attainable in 48 h of the SSF. The optimum operating conditions for the maximum productivity were found to be 42 degrees C and pH 6.0. Without supplementation of nitrogen-containing nutrients, the lactic acid yield in the SSF decreased to 60%: 27 g/L of lactic acid from 60 g/L of food waste. The overall performance of the SSF, however, was not significantly affected by the elimination of mineral supplements.
Kim
Kwang Il
KI
Department of Chemical Engineering, Kyungwon University, Sungnam, Korea 461-701.
Kim
Woo Kyung
WK
Seo
Deok Ki
DK
Yoo
In Sang
IS
Kim
Eun Ki
EK
Yoon
Hyon Hee
HH
D005285:Fermentation; D005502:Food; D005947:Glucose / Q000378:metabolism; D006868:Hydrolysis; D007700:Kinetics; D007723:Korea; D019344:Lactic Acid / Q000302:isolation & purification* / Q000378:metabolism; D007778:Lactobacillus / Q000254:growth & development* / Q000378:metabolism*; D012037:Refuse Disposal / Q000379:methods*; D014495:Universities; D014866:Waste Products
D014866:Waste Products; D019344:Lactic Acid; D005947:Glucose