Enhanced lactic acid production from the anaerobic co-digestion of swine manure with apple or potato waste via ratio adjustment

Valorization of municipal organic waste into purified lactic acid

“…The bakery waste batch fermentation resulted in a higher LA productivity of 2.4 g/L/h with Bacillus coagulans as fermenting strain with a titer of 62 g/L (Alexandri et al, 2020) compared with potato/apple derived starch (Li et al, 2021b;Lian et al, 2020). When lucerne green juice hydrolysate was added replacing yeast extract a 6 h lag phase took place but no significant change occurred in the LA titer demonstrating that it was useful as nitrogen supplement.…”

“…Food waste recently tested for LA fermentation are for a large extend starch related such as potato (Lian et al, 2020;Pradhan et al, 2021), wheat (Pradhan et al, 2021), apples (Lian et al, 2020) and bakery waste (Alexandri et al, 2020). The fermentation into LA requires enzymatic hydrolysis of the soluble polysaccharides into monosaccharides usind α-glucosidase while the soluble proteins are hydrolyzed with protease.…”

“…The anaerobic co-digestion studied by Lian et al, (2020) using swine manure as inoculum could be done without enzyme addition for both apple and potato waste. The apple waste gave a higher LA concentration (28 g/L) than the potato waste (8.9 g/L) but the productivity was low (0.16 g/L/h).…”

“…The apple waste gave a higher LA concentration (28 g/L) than the potato waste (8.9 g/L) but the productivity was low (0.16 g/L/h). The use of a mixed community explained the low productivity with formation of side products such as butyric acid and acetic acid (Lian et al, 2020).…”

Towards a Circular Economy of Plastics: An Evaluation of the Systematic Transition to a New Generation of Bioplastics

“…Its high manufacturing cost must be reduced in order to produce more bioplastics. Several works in the literature have reported the use of lignocellulosic wastes and food-derived wastes, such as spent coffee grounds [ 150 ], fruit wastes [ 149 , 151 , 152 ], alfalfa silages [ 153 ], and corn cobs [ 154 ] ( Table 2 ). Despite PLA being extensively adopted, it still has drawbacks such as its cost and its structural breakability and fragility.…”