In this study, an advanced biorefinery technology that uses mixed bakery waste has been developed to
produce L-lactic acid using an adaptively evolved Thermoanaerobacterium aotearoense LA1002-G40 in a
non-sterilized system. Under these conditions, mixed bakery waste was directly hydrolysed by
Aspergillus awamori and Aspergillus oryzae, resulting in a nutrient-rich hydrolysate containing 83.6 g/L
glucose, 9.5 g/L fructose and 612 mg/L free amino nitrogen. T. aotearoense LA1002-G40 was evaluated
and then adaptively evolved to grow in this nutrient-rich hydrolysate. Using a 5-L fermenter, the overall
lactic acid production from mixed bakery waste was 0.18 g/g with a titer, productivity and yield of 78.5 g/
L, 1.63 g/L/h and 0.85 g/g, respectively. This is an innovative procedure involving a complete bioconversion
process for L-lactic acid produced from mixed bakery waste under non-sterilized conditions. The
proposed process could be potentially applied to turn food waste into L-lactic acid in an economically
feasible way.