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Roy P, Gahlawat VK, Saravanan C, Singh BP. Enhancing bioflavor production by solid-state fermentation using Kluyveromyces marxianus and l-phenylalanine. J Basic Microbiol 2023; 63:75-91. [PMID: 36336635 DOI: 10.1002/jobm.202200503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/06/2022] [Accepted: 10/15/2022] [Indexed: 11/09/2022]
Abstract
This study includes the utilization of sweet lemon peel (SLP) and sugarcane bagasse (SB) in solid-state fermentation using Kluyveromyces marxianus for bioflavor compounds production adopting response surface methodology. The major flavor compounds, 2-phenylethanol (2-PE) and 2-phenylethyl acetate (2-PEA) were quantified using gas chromatography-mass spectrometry with and without adding any supplements. Quantification of flavor compounds indicated that without adding any accessory in the substrate, the concentration of 2-PE using SLP and SB was 0.15 ± 0.003 mg/g and 0.14 ± 0.002 mg/g, respectively. Whereas 2-PEA concentration using SLP and SB was observed as 0.01 ± 0.008 mg/g and 0.02 ± 0.001 mg/g, respectively. The addition of l-phenylalanine (l-phe) in the substrates showed 30%-75% enhancement in the production of 2-PE and 2-PEA. The present study indicates that the K. marxianus is a potential microbial cell factory for the production of 2-PE and 2-PEA with the addition of synthetic l-phe having a plethora of applications in food and pharmaceutical industries.
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Affiliation(s)
- Priyanka Roy
- Department of Basic and Applied Sciences, National Institute of Food Technology Entrepreneurship and Management, Sonipat, Haryana, India
| | - Vijay K Gahlawat
- Department of Basic and Applied Sciences, National Institute of Food Technology Entrepreneurship and Management, Sonipat, Haryana, India
| | - Chakkaravarthi Saravanan
- Department of Basic and Applied Sciences, National Institute of Food Technology Entrepreneurship and Management, Sonipat, Haryana, India
| | - Bhim P Singh
- Department of Agriculture and Environment Sciences, National Institute of Food Technology Entrepreneurship and Management, Sonipat, Haryana, India
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2
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Zhang XY, Li B, Huang BC, Wang FB, Zhang YQ, Zhao SG, Li M, Wang HY, Yu XJ, Liu XY, Jiang J, Wang ZP. Production, Biosynthesis, and Commercial Applications of Fatty Acids From Oleaginous Fungi. Front Nutr 2022; 9:873657. [PMID: 35694158 PMCID: PMC9176664 DOI: 10.3389/fnut.2022.873657] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 03/31/2022] [Indexed: 12/18/2022] Open
Abstract
Oleaginous fungi (including fungus-like protists) are attractive in lipid production due to their short growth cycle, large biomass and high yield of lipids. Some typical oleaginous fungi including Galactomyces geotrichum, Thraustochytrids, Mortierella isabellina, and Mucor circinelloides, have been well studied for the ability to accumulate fatty acids with commercial application. Here, we review recent progress toward fermentation, extraction, of fungal fatty acids. To reduce cost of the fatty acids, fatty acid productions from raw materials were also summarized. Then, the synthesis mechanism of fatty acids was introduced. We also review recent studies of the metabolic engineering strategies have been developed as efficient tools in oleaginous fungi to overcome the biochemical limit and to improve production efficiency of the special fatty acids. It also can be predictable that metabolic engineering can further enhance biosynthesis of fatty acids and change the storage mode of fatty acids.
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Affiliation(s)
- Xin-Yue Zhang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Bing Li
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Bei-Chen Huang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Feng-Biao Wang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Yue-Qi Zhang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Shao-Geng Zhao
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Min Li
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Hai-Ying Wang
- Key Laboratory of Sustainable Development of Polar Fishery, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Xin-Jun Yu
- Key Laboratory of Bioorganic Synthesis of Zhejiang Province, College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Xiao-Yan Liu
- Jiangsu Key Laboratory for Biomass-Based Energy and Enzyme Technology, Huaiyin Normal University, Huaian, China
| | - Jing Jiang
- School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, China
| | - Zhi-Peng Wang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, China
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Martínez-Avila O, Llenas L, Ponsá S. Sustainable polyhydroxyalkanoates production via solid-state fermentation: Influence of the operational parameters and scaling up of the process. FOOD AND BIOPRODUCTS PROCESSING 2022. [DOI: 10.1016/j.fbp.2021.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Bioproduction of 2-Phenylethanol through Yeast Fermentation on Synthetic Media and on Agro-Industrial Waste and By-Products: A Review. Foods 2022; 11:foods11010109. [PMID: 35010235 PMCID: PMC8750221 DOI: 10.3390/foods11010109] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/23/2021] [Accepted: 12/27/2021] [Indexed: 11/17/2022] Open
Abstract
Due to its pleasant rosy scent, the aromatic alcohol 2-phenylethanol (2-PE) has a huge market demand. Since this valuable compound is used in food, cosmetics and pharmaceuticals, consumers and safety regulations tend to prefer natural methods for its production rather than the synthetic ones. Natural 2-PE can be either produced through the extraction of essential oils from various flowers, including roses, hyacinths and jasmine, or through biotechnological routes. In fact, the rarity of natural 2-PE in flowers has led to the inability to satisfy the large market demand and to a high selling price. Hence, there is a need to develop a more efficient, economic, and environmentally friendly biotechnological approach as an alternative to the conventional industrial one. The most promising method is through microbial fermentation, particularly using yeasts. Numerous yeasts have the ability to produce 2-PE using l-Phe as precursor. Some agro-industrial waste and by-products have the particularity of a high nutritional value, making them suitable media for microbial growth, including the production of 2-PE through yeast fermentation. This review summarizes the biotechnological production of 2-PE through the fermentation of different yeasts on synthetic media and on various agro-industrial waste and by-products.
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Development of a Continuous System for 2-Phenylethanol Bioproduction by Yeast on Whey Permeate-Based Medium. Molecules 2021; 26:molecules26237388. [PMID: 34885969 PMCID: PMC8658864 DOI: 10.3390/molecules26237388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 11/26/2021] [Accepted: 12/01/2021] [Indexed: 11/16/2022] Open
Abstract
2-Phenylethanol (2-PE) is an alcohol with a rosy scent and antimicrobial activity, and therefore, it is widely used in the food and cosmetic industries as an aroma and preservative. This work was aimed to draw up a technology for 2-PE bioproduction on whey permeate, which is waste produced by the dairy industry, rich in lactase and proteins. Its composition makes it a harmful waste to dispose of; however, with a properly selected microorganism, it could be converted to a value-added product. Herein, two yeast Kluyveromyces marxianus strains and one Kluyveromyces lactis, isolated from dairy products, were tested for 2-PE production, firstly on standard media and then on whey permeate based media in batch cultures. Thereafter, the 2-PE bioproduction in a continuous system in a 4.8 L bioreactor was developed, and subsequently, the final product was recovered from culture broth. The results showed that the yield of 2-PE production increased by 60% in the continuous culture compared to batch culture. Together with a notable reduction of chemical oxygen demand for whey permeate, the present study reports a complete, effective, and environmentally friendly strategy for 2-PE bioproduction with a space-time yield of 57.5 mg L-1 h-1.
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Solieri L. The revenge of Zygosaccharomyces yeasts in food biotechnology and applied microbiology. World J Microbiol Biotechnol 2021; 37:96. [PMID: 33969449 DOI: 10.1007/s11274-021-03066-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 04/28/2021] [Indexed: 12/01/2022]
Abstract
Non-conventional yeasts refer to a huge and still poorly explored group of species alternative to the well-known model organism Saccharomyces cerevisiae. Among them, Zygosaccharomyces rouxii and the sister species Zygosaccharomyces bailii are infamous for spoiling food and beverages even in presence of several food preservatives. On the other hand, their capability to cope with a wide range of process conditions makes these yeasts very attractive factories (the so-called "ZygoFactories") for bio-converting substrates poorly permissive for the growth of other species. In balsamic vinegar Z. rouxii is the main yeast responsible for converting highly concentrated sugars into ethanol, with a preference for fructose over glucose (a trait called fructophily). Z. rouxii has also attracted much attention for the ability to release important flavor compounds, such as fusel alcohols and the derivatives of 4-hydroxyfuranone, which markedly contribute to fragrant and smoky aroma in soy sauce. While Z. rouxii was successfully proposed in brewing for producing low ethanol beer, Z. bailii is promising for lactic acid and bioethanol production. Recently, several research efforts exploited omics tools to pinpoint the genetic bases of distinctive traits in "ZygoFactories", like fructophily, tolerance to high concentrations of sugars, lactic acid and salt. Here, I provided an overview of Zygosaccharomyces industrially relevant phenotypes and summarized the most recent findings in disclosing their genetic bases. I suggest that the increasing number of genomes available for Z. rouxii and other Zygosaccharomyces relatives, combined with recently developed genetic engineering toolkits, will boost the applications of these yeasts in biotechnology and applied microbiology.
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Affiliation(s)
- L Solieri
- Department of Life Sciences, University of Modena and Reggio Emilia, Via Amendola 2, 42122, Reggio Emilia, Italy.
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Šelo G, Planinić M, Tišma M, Tomas S, Koceva Komlenić D, Bucić-Kojić A. A Comprehensive Review on Valorization of Agro-Food Industrial Residues by Solid-State Fermentation. Foods 2021; 10:foods10050927. [PMID: 33922545 PMCID: PMC8146281 DOI: 10.3390/foods10050927] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 12/18/2022] Open
Abstract
Agro-food industrial residues (AFIRs) are generated in large quantities all over the world. The vast majority of these wastes are lignocellulosic wastes that are a source of value-added products. Technologies such as solid-state fermentation (SSF) for bioconversion of lignocellulosic waste, based on the production of a wide range of bioproducts, offer both economic and environmental benefits. The versatility of application and interest in applying the principles of the circular bioeconomy make SSF one of the valorization strategies for AFIRs that can have a significant impact on the environment of the wider community. Important criteria for SSF are the selection of the appropriate and compatible substrate and microorganism, as well as the selection of the optimal process parameters for the growth of the microorganism and the production of the desired metabolites. This review provides an overview of the management of AFIRs by SSF: the current application, classification, and chemical composition of AFIRs; the catalytic function and potential application of enzymes produced by various microorganisms during SSF cultivation on AFIRs; the production of phenolic compounds by SSF; and a brief insight into the role of SSF treatment of AFIRs for feed improvement and biofuel production.
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Fermentation of Agri-Food Waste: A Promising Route for the Production of Aroma Compounds. Foods 2021; 10:foods10040707. [PMID: 33810435 PMCID: PMC8066995 DOI: 10.3390/foods10040707] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/21/2021] [Accepted: 03/22/2021] [Indexed: 12/13/2022] Open
Abstract
Food waste and byproducts are generated along the entire food processing and storage chain. The large amount of waste deriving from the whole process represents not only a great economic loss but also an important ethical and environmental issue in terms of failure to recycle potentially reusable materials. New, clear strategies are needed to limit the amount of waste produced and, at the same time, promote its enhancement for further conversion and application to different industrial fields. This review gives an overview of the biological approaches used so far to exploit agri-food wastes and byproducts. The application of solid-state fermentation by different microorganisms (fungi, yeasts, bacteria) to produce several value-added products was analyzed, focusing on the exploitation of lactic acid bacteria as workhorses for the production of flavoring compounds.
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Martínez-Avila O, Muñoz-Torrero P, Sánchez A, Font X, Barrena R. Valorization of agro-industrial wastes by producing 2-phenylethanol via solid-state fermentation: Influence of substrate selection on the process. WASTE MANAGEMENT (NEW YORK, N.Y.) 2021; 121:403-411. [PMID: 33445113 DOI: 10.1016/j.wasman.2020.12.036] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 12/07/2020] [Accepted: 12/29/2020] [Indexed: 06/12/2023]
Abstract
2-phenylethanol (2-PE) is a value-added compound widely used in industry due to its rose-like odor and antibacterial properties that can be bioproduced using wastes as raw materials. This study presents the valorization of nine agro-industrial wastes as potential substrates for 2-PE production using an isolated 2-PE producer Pichia kudriavzevii, and the solid-state fermentation (SSF) technology as an alternative approach. The assessed substrates comprised wastes of varied traits such that each of them provided different characteristics to the fermentation. Thus, by using a principal component analysis (PCA), it was possible to identify the most significant characteristics associated with the substrates affecting the 2-PE production. Results show that L-phenylalanine biotransformation was more efficient than de novo synthesis for producing 2-PE. Besides, from the evaluated set, the maximum 2-PE production was achieved with red apple pomace, reaching 1.7 and 25.2 mg2PE per gram of used waste through de novo and L-phenylalanine biotransformation, respectively. In that scenario, volumetric productivity and precursor yield were 39.6 mg2PE L-1h-1 and 0.69 g2PE per gram of L-phenylalanine added, respectively. From the PCA, it was identified that the reducing sugars content of the substrate, the air-filled porosity of the bed and the L-phenylalanine availability were the most critical parameters (associated with the substrates) influencing the microbial activity and 2-PE production. These results suggest that the desirable traits a solid media needs for promoting 2-PE production via SSF could be reached by using a combination of wastes in a synergistic approach.
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Affiliation(s)
- Oscar Martínez-Avila
- Composting Research Group, Department of Chemical, Biological and Environmental Engineering. Escola d'Enginyeria, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain.
| | - Patricia Muñoz-Torrero
- Composting Research Group, Department of Chemical, Biological and Environmental Engineering. Escola d'Enginyeria, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain
| | - Antoni Sánchez
- Composting Research Group, Department of Chemical, Biological and Environmental Engineering. Escola d'Enginyeria, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain.
| | - Xavier Font
- Composting Research Group, Department of Chemical, Biological and Environmental Engineering. Escola d'Enginyeria, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain.
| | - Raquel Barrena
- Composting Research Group, Department of Chemical, Biological and Environmental Engineering. Escola d'Enginyeria, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193 Barcelona, Spain.
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Dai J, Li K, Song N, Yao W, Xia H, Yang Q, Zhang X, Li X, Wang Z, Yao L, Yang S, Chen X. Zygosaccharomyces rouxii, an Aromatic Yeast Isolated From Chili Sauce, Is Able to Biosynthesize 2-Phenylethanol via the Shikimate or Ehrlich Pathways. Front Microbiol 2020; 11:597454. [PMID: 33250885 PMCID: PMC7673420 DOI: 10.3389/fmicb.2020.597454] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 10/06/2020] [Indexed: 11/26/2022] Open
Abstract
We isolated an aromatic strain of yeast (M2013310) from chili sauce. Assembly, annotation, and phylogenetic analysis based on genome sequencing, identified M2013310 as an allodiploid yeast that was closely related to Zygosaccharomyces rouxii. During fermentation, M2013310, produced an aromatic alcohol with a rose-honey scent; gas chromatography tandem mass spectrometry identified this alcohol as 2-phenylethanol. The concentration of 2-phenylethanol reached 3.8 mg/L, 1.79 g/L, and 3.58 g/L, in M3 (NH4+), M3 (NH4+ + Phe), and M3 (Phe) culture media, after 72 h of fermentation, respectively. The mRNA expression levels of ARO8 encoding aromatic aminotransferases I and ARO10 encoding phenylpyruvate decarboxylase by M2013310 in M3 (Phe) were the lowest of the three different forms of media tested. These results indicated that M2013310 can synthesize 2-phenylethanol via the Shikimate or Ehrlich pathways and the production of 2-phenylethanol may be significantly improved by the over-expression of these two genes. Our research identified a promising strain of yeast (M2013310) that could be used to improve the production of 2-phenylethanol.
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Affiliation(s)
- Jun Dai
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, College of Bioengineering, Hubei University of Technology, Wuhan, China.,ABI Group, College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan, China.,State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
| | - Ke Li
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, College of Bioengineering, Hubei University of Technology, Wuhan, China
| | - Na Song
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, College of Bioengineering, Hubei University of Technology, Wuhan, China
| | - Wanting Yao
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, College of Bioengineering, Hubei University of Technology, Wuhan, China
| | - Huili Xia
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, College of Bioengineering, Hubei University of Technology, Wuhan, China
| | - Qiao Yang
- ABI Group, College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan, China
| | - Xiaoling Zhang
- ABI Group, College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan, China
| | - Xin Li
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, College of Bioengineering, Hubei University of Technology, Wuhan, China
| | - Zhi Wang
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, College of Bioengineering, Hubei University of Technology, Wuhan, China
| | - Lan Yao
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, College of Bioengineering, Hubei University of Technology, Wuhan, China
| | - Shihui Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
| | - Xiong Chen
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, College of Bioengineering, Hubei University of Technology, Wuhan, China
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Martínez-Avila O, Sánchez A, Font X, Barrena R. 2-phenylethanol (rose aroma) production potential of an isolated pichia kudriavzevii through solid-state fermentation. Process Biochem 2020. [DOI: 10.1016/j.procbio.2020.03.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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12
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Screening of yeasts isolated from Baijiu environments for 2-phenylethanol production and optimization of production conditions. 3 Biotech 2020; 10:275. [PMID: 32537375 DOI: 10.1007/s13205-020-02267-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 05/18/2020] [Indexed: 02/01/2023] Open
Abstract
2-Phenylethanol (2-PE) with a pleasant rose-like odor is a valuable aroma compound used in many fields. 2-PE production by yeast is considered a promising alternative to chemical synthesis and extraction from natural materials. In this report, the strain YF1702 produced a significantly higher level of 2-PE when compared with other strains isolated from Baijiu-producing environments. According to morphological properties, physiological and biochemical characteristics, and 26S rDNA sequence analysis, strain YF1702 was identified as Pichia kudriavzevii. The optimal fermentation conditions of YF1702 for producing 2-PE were obtained by single-factor experiments, Plackett-Burman design, steepest ascent design, and response surface methodology. The optimal inoculation conditions for strain YF1702 were 50 g/L glucose, 6.0 g/L yeast extract, 10.7 g/L L-Phe, and 32 g/L Tween-60. The optimal fermentation conditions were pH 2.3, 26 °C, 210 rpm shaking, an inoculum size of 0.4% (v/v), and a loading volume of 25.5 mL/250 mL for 56 h. Under these optimal conditions 2-PE production by YF1702 was 5.09 g/L. This strain has the potential to increase the content of 2-PE in Baijiu production and enhance the aroma characteristics of Baijiu.
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