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Wang S, Tian R, Liu B, Wang H, Liu J, Li C, Li M, Evivie SE, Li B. Effects of carbon concentration, oxygen, and controlled pH on the engineering strain Lactiplantibacillus casei E1 in the production of bioethanol from sugarcane molasses. AMB Express 2021; 11:95. [PMID: 34176008 PMCID: PMC8236424 DOI: 10.1186/s13568-021-01257-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 06/16/2021] [Indexed: 01/28/2023] Open
Abstract
Sugarcane molasses are considered a potential source for bioethanol's commercial production because of its availability and low market price. It contains high concentrations of fermentable sugars that can be directly metabolized by microbial fermentation. Heterofermentative lactic acid bacteria, especially Lactiplantibacillus casei, have a high potential to be a biocatalyst in ethanol production that they are characterized by strong abilities of carbohydrate metabolism, ethanol synthesis, and high alcohol tolerance. This study aimed to evaluate the feasibility of producing ethanol by Lactiplantibacillus casei used the ethanologen engineering strain L. casei E1 as a starter culture and cane molasses as substrate medium. The effects of environmental factors on the metabolism of L. casei E1 were analyzed by high-performance liquid chromatography (HPLC) system, and the gene expression of key enzymes in carbon source metabolism was detected using quantitative real-time PCR (RT-qPCR). Results showed that the strain could grow well, ferment sugar quickly in cane molasses. By fermenting this bacterium anaerobically at 37 °C for 36 h incubation in 5 °BX molasses when the fermenter's pH was controlled at 6.0, ethanol yield reached 13.77 g/L, and carbohydrate utilization percentage was 78.60%. RT-qPCR results verified the strain preferentially ferment glucose and fructose of molasses to ethanol at the molecular level. In addition, the metabolism of sugars, especially fructose, would be inhibited by elevating acidity. Our findings support the theoretical basis for exploring Lactic acid bacteria as a starter culture for converting sugarcane molasses into ethanol.
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Affiliation(s)
- Song Wang
- Food College, Northeast Agricultural University, Harbin, 150030, China
- Shandong Yuwang Ecological Food Industry Co., Ltd, Dezhou, 251200, Shandong, China
| | - Ran Tian
- Food College, Northeast Agricultural University, Harbin, 150030, China
| | - Buwei Liu
- Food College, Northeast Agricultural University, Harbin, 150030, China
| | - Hongcai Wang
- Shandong Yuwang Ecological Food Industry Co., Ltd, Dezhou, 251200, Shandong, China
| | - Jun Liu
- Shandong Yuwang Ecological Food Industry Co., Ltd, Dezhou, 251200, Shandong, China
| | - Chenghui Li
- Shandong Yuwang Ecological Food Industry Co., Ltd, Dezhou, 251200, Shandong, China
| | - Mingyue Li
- Shandong Yuwang Ecological Food Industry Co., Ltd, Dezhou, 251200, Shandong, China
| | - Smith Etareri Evivie
- Food College, Northeast Agricultural University, Harbin, 150030, China
- Department of Animal Science, Faculty of Agriculture, University of Benin, Benin City, 300001, Nigeria
- Department of Food Science and Human Nutrition, Faculty of Agriculture, University of Benin, Benin City, 300001, Nigeria
| | - Bailiang Li
- Food College, Northeast Agricultural University, Harbin, 150030, China.
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