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Yue Y, Wang S, Lv X, Wang C, Xu B, Ping L, Guo J, Li X, Evivie SE, Liu F, Li B, Huo G. Analysis of the complete genome sequence of Lactobacillus delbrueckii ssp. bulgaricus with post-acidification capacity and its influence on yogurt in storage. J Dairy Sci 2021; 105:1058-1071. [PMID: 34802736 DOI: 10.3168/jds.2021-20999] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 10/12/2021] [Indexed: 11/19/2022]
Abstract
In recent years, yogurt has been one of the most popular fermented dairy products and is sold worldwide. In this study, pH and titrated acid changes of 4 strains of Lactobacillus delbrueckii ssp. bulgaricus fermented milk during storage were detected. The difference between L. bulgaricus KLDS1.1011 and KLDS1.0207 was significant, with the latter exhibiting reduced acidity levels. Therefore, we determined the complete genome sequence of the 2 strains. Then the expression of specific genes and common genes related to glucose metabolism and proteolysis of L. bulgaricus KLDS1.1011 and KLDS1.0207 were detected by quantitative real-time reverse-transcription PCR. Analysis indicated that the key enzymes in glycometabolism and proteolysis of L. bulgaricus KLDS1.1011 were significantly different than those of L. bulgaricus KLDS1.0207. The contents of lactose and glucose decreased during storage of L. bulgaricus fermented milk, as determined by HPLC, and the contents of lactic acid and galactose increased, with L. bulgaricus KLDS1.1011 increasing less. With skim milk as a raw material, L. bulgaricus KLDS1.1011, KLDS1.0207, and Streptococcus thermophilus S1 were used as fermentation strains to yield yogurt at 42°C, and sensory evaluation was compared with yogurt fermented by commercial starter cultures. Yogurt from L. bulgaricus KLDS1.1011 was the highest-rated. Therefore, the study may provide guidelines for the development of yogurt starters.
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Affiliation(s)
- Yingxue Yue
- Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin 150030, PR China
| | - Song Wang
- Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin 150030, PR China
| | - Xiuli Lv
- Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin 150030, PR China
| | - Chengfeng Wang
- Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin 150030, PR China
| | - Baofeng Xu
- Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin 150030, PR China
| | - Lijun Ping
- Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin 150030, PR China
| | - Jiayao Guo
- Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin 150030, PR China
| | - Xuetong Li
- Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin 150030, PR China
| | - Smith Etareri Evivie
- Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin 150030, PR China; Food College, Northeast Agricultural University, Harbin 150030, PR China; Department of Food Science and Human Nutrition, Faculty of Agriculture, University of Benin, Benin City 300001, Edo State, Nigeria; Department of Animal Science, Faculty of Agriculture, University of Benin, Benin City 300001, Edo State, Nigeria
| | - Fei Liu
- Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin 150030, PR China; Food College, Northeast Agricultural University, Harbin 150030, PR China
| | - Bailiang Li
- Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin 150030, PR China; Food College, Northeast Agricultural University, Harbin 150030, PR China.
| | - Guicheng Huo
- Key Laboratory of Dairy Science, Ministry of Education, Northeast Agricultural University, Harbin 150030, PR China; Food College, Northeast Agricultural University, Harbin 150030, PR China.
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Culture media based on effluent derived from soy protein concentrate production for Lacticaseibacillus paracasei 90 biomass production: statistical optimisation, mineral characterization, and metabolic activities. Antonie van Leeuwenhoek 2021; 114:2047-2063. [PMID: 34609626 DOI: 10.1007/s10482-021-01660-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 09/11/2021] [Indexed: 10/20/2022]
Abstract
The waste and by-products of the soybean industry could be an economic source of nutrients to satisfy the high nutritional demands for the cultivation of lactic acid bacteria. The aims of this work were to maximize the biomass production of Lacticaseibacillus paracasei 90 (L90) in three culture media formulated from an effluent derived from soy protein concentrate production and to assess the effects these media have on the enzymatic activity of L90, together with their influence on its fermentation profile in milk. The presence of essential minerals and fermentable carbohydrates (sucrose, raffinose, and stachyose) in the effluent was verified. L90 reached high levels of microbiological counts (∼ 9 log cfu mL-1) and dry weight (> 1 g L-1) on the three optimized media. Enzymatic activities (lactate dehydrogenase and β-galactosidase) of L90, and its metabolism of lactose and citric acid, as well as lactic acid and pyruvic acid production in milk, were modified depending on the growth media. The ability of the L90 to produce the key flavour compounds (diacetyl and acetoin) was maintained or improved by growing in the optimized media in comparison with MRS.
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Scoma A, Garrido-Amador P, Nielsen SD, Røy H, Kjeldsen KU. The Polyextremophilic Bacterium Clostridium paradoxum Attains Piezophilic Traits by Modulating Its Energy Metabolism and Cell Membrane Composition. Appl Environ Microbiol 2019; 85:e00802-19. [PMID: 31126939 PMCID: PMC6643245 DOI: 10.1128/aem.00802-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Accepted: 05/13/2019] [Indexed: 11/20/2022] Open
Abstract
In polyextremophiles, i.e., microorganisms growing preferentially under multiple extremes, synergistic effects may allow growth when application of the same extremes alone would not. High hydrostatic pressure (HP) is rarely considered in studies of polyextremophiles, and its role in potentially enhancing tolerance to other extremes remains unclear. Here, we investigated the HP-temperature response in Clostridium paradoxum, a haloalkaliphilic moderately thermophilic endospore-forming bacterium, in the range of 50 to 70°C and 0.1 to 30 MPa. At ambient pressure, growth limits were extended from the previously reported 63°C to 70°C, defining C. paradoxum as an actual thermophile. Concomitant application of high HP and temperature compared to standard conditions (i.e., ambient pressure and 50°C) remarkably enhanced growth, with an optimum growth rate observed at 22 MPa and 60°C. HP distinctively defined C. paradoxum physiology, as at 22 MPa biomass, production increased by 75% and the release of fermentation products per cell decreased by >50% compared to ambient pressure. This metabolic modulation was apparently linked to an energy-preserving mechanism triggered by HP, involving a shift toward pyruvate as the preferred energy and carbon source. High HPs decreased cell damage, as determined by Syto9 and propidium iodide staining, despite no organic solute being accumulated intracellularly. A distinct reduction in carbon chain length of phospholipid fatty acids (PLFAs) and an increase in the amount of branched-chain PLFAs occurred at high HP. Our results describe a multifaceted, cause-and-effect relationship between HP and cell metabolism, stressing the importance of applying HP to define the boundaries for life under polyextreme conditions.IMPORTANCE Hydrostatic pressure (HP) is a fundamental parameter influencing biochemical reactions and cell physiology; however, it is less frequently applied than other factors, such as pH, temperature, and salinity, when studying polyextremophilic microorganisms. In particular, how HP affects microbial tolerance to other and multiple extremes remains unclear. Here, we show that under polyextreme conditions of high pH and temperature, Clostridium paradoxum demonstrates a moderately piezophilic nature as cultures grow to highest cell densities and most efficiently at a specific combination of temperature and HP. Our results highlight the importance of considering HP when exploring microbial physiology under extreme conditions and thus have implications for defining the limits for microbial life in nature and for optimizing industrial bioprocesses occurring under multiple extremes.
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Affiliation(s)
- Alberto Scoma
- Department of Bioscience, Section of Microbiology, Aarhus University, Aarhus, Denmark
| | - Paloma Garrido-Amador
- Department of Bioscience, Section of Microbiology, Aarhus University, Aarhus, Denmark
| | | | - Hans Røy
- Department of Bioscience, Section of Microbiology, Aarhus University, Aarhus, Denmark
| | - Kasper Urup Kjeldsen
- Department of Bioscience, Section of Microbiology, Aarhus University, Aarhus, Denmark
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Li Y, Miao M, Chen X, Jiang B, Liu M, Feng B. Improving the catalytic behavior of inulin fructotransferase under high hydrostatic pressure. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2015; 95:2588-2594. [PMID: 25565432 DOI: 10.1002/jsfa.7071] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 12/08/2014] [Accepted: 12/26/2014] [Indexed: 06/04/2023]
Abstract
BACKGROUND The demand for difructose anhydride III (DFA III), a novel functional sweetener, is growing continuously. It is produced from inulin by inulin fructotransferase (IFTase). In this study, high hydrostatic pressure (HHP), as a clean technology, was first applied to further improve the catalytic efficiency of IFTase in the process. RESULTS The maximum activity of IFTase was obtained under 200 MPa at 60 °C. Meanwhile, HHP lowered the energy barrier necessary for the enzymatic reaction and decreased the volume between the reactants and the transition state. Under this condition, the optimal pH for the enzymatic reaction shifted from 5.5 to 6.0. The activity was further enhanced by 65.2% in the presence of 1.5 mol L(-1) NaCl. CONCLUSION The catalytic reaction of IFTase was performed under HHP for the first time. HHP, as a promising green technology for bioconversion, significantly accelerated the enzymatic reaction under the appropriate operational conditions.
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Affiliation(s)
- Yungao Li
- State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Ming Miao
- State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Xiangyin Chen
- State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Bo Jiang
- State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Miao Liu
- State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Biao Feng
- State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, Jiangnan University, Wuxi, Jiangsu 214122, China
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