title: Valorisation of mixed bakery waste in non-sterilized fermentation for L-lactic acid production by an evolved Thermoanaerobacterium sp. strain.
abstract: 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 83.6g/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.
authors.affiliation: Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China; School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Yang
authors.affiliation: Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China.
authors.forename: Muzi
authors.initials: M
authors.lastname: Zhu
authors.affiliation: Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China.
authors.forename: Xiongliang
authors.initials: X
authors.lastname: Huang
authors.affiliation: School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong.
authors.forename: Carol Sze Ki
authors.initials: CS
authors.lastname: Lin
authors.affiliation: Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China.
authors.forename: Jufang
authors.initials: J
authors.lastname: Wang
authors.affiliation: Guangdong Key Laboratory of Fermentation and Enzyme Engineering, School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, China. Electronic address: shuangli@scut.edu.cn.
authors.forename: Shuang
authors.initials: S
authors.lastname: Li
mesh_terms: D001230:Aspergillus; D001420:Bacteria, Aerobic; D019149:Bioreactors; D005285:Fermentation; D005502:Food; D005947:Glucose; D006868:Hydrolysis; D019344:Lactic Acid / Q000096:biosynthesis*; D009584:Nitrogen; D046950:Thermoanaerobacterium / Q000378:metabolism*; D014866:Waste Products
chemical_list: D014866:Waste Products; D019344:Lactic Acid; D005947:Glucose; D009584:Nitrogen
keywords: Adaptive evolution; Food waste; Fungal hydrolysis; Non-sterilized fermentation; l-lactic acid