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Zhang H, Ye T, Fengmin L, Zhang X, Wang J, Wei X, Neo YP, Liu H, Fang H. Strategies to Enhance l-Isoleucine Synthesis by Modifying the Threonine Metabolism Pathway in Escherichia coli. ACS OMEGA 2024; 9:10276-10285. [PMID: 38463329 PMCID: PMC10918650 DOI: 10.1021/acsomega.3c07619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 01/23/2024] [Accepted: 01/30/2024] [Indexed: 03/12/2024]
Abstract
l-threonine as an important precursor substance of l-isoleucine and improving its accumulation in Escherichia coli became an important idea to construct a chassis strain with high l-isoleucine production. Meanwhile, the effect of l-threonine metabolic pathway disruption in E. coli for the improved production of l-isoleucine remains unrevealed. In the present study, a mutant strain of E. coli was engineered by inactivating specific metabolic pathways (e.g., Δtdh, ΔltaE, and ΔyiaY) that were associated with l-threonine metabolism but unrelated to l-isoleucine synthesis. This was done with the aim to reduce the breakdown of l-threonine and, thereby, increase the production of l-isoleucine. The results obtained demonstrated a 72.3% increment in l-isoleucine production from 4.34 to 7.48 g·L-1 in the mutant strain compared with the original strain, with an unexpected 10.3% increment in bacterial growth as measured at OD600. Transcriptome analysis was also conducted on both the mutant strain NXU102 and the original strain NXU101 in the present study to gain a comprehensive understanding of their physiological attributes. The findings revealed a notable disparity in 1294 genes between the two strains, with 658 genes exhibiting up-regulation and 636 genes displaying down-regulation. The activity of tricarboxylic acid (TCA) cycle-related genes was found to decrease, but oxidative phosphorylation-related genes were highly up-regulated, which explained the increased activity of the mutant strain. For instance, l-lysine catabolism-related genes were found to be up-regulated, which reconfigured the carbon flow into the TCA cycle. The augmentation of acetic acid degradation pathway-related genes assisted in the reduction in acetic acid accumulation that could retard cell growth. Notably, substantial up-regulation of the majority of genes within the aspartate pathway could potentially account for the increased production of l-isoleucine in the present study. In this paper, a chassis strain with an l-isoleucine yield of 7.48 g·L-1 was successfully constructed by cutting off the threonine metabolic pathway. Meanwhile, transcriptomic analysis revealed that the cutting off of the threonine metabolic pathway induced perturbation of genes related to the pathways associated with the synthesis of l-isoleucine, such as the tricarboxylic acid cycle, glycolysis, and aspartic acid pathway.
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Affiliation(s)
- HaoJie Zhang
- Ningxia Key Laboratory for Food Microbial-Applications Technology and Safety Control, School of Food Science and Engineering, Ningxia University, Yinchuan 750021, China
| | - Tong Ye
- Ningxia Key Laboratory for Food Microbial-Applications Technology and Safety Control, School of Food Science and Engineering, Ningxia University, Yinchuan 750021, China
| | - Liu Fengmin
- Ningxia Key Laboratory for Food Microbial-Applications Technology and Safety Control, School of Food Science and Engineering, Ningxia University, Yinchuan 750021, China
| | - Xiangjun Zhang
- School of Life Science, Ningxia University, Yinchuan 750021, China
- Ningxia Key Laboratory for Food Microbial-Applications Technology and Safety Control, School of Food Science and Engineering, Ningxia University, Yinchuan 750021, China
| | - Jipeng Wang
- Ningxia Key Laboratory for Food Microbial-Applications Technology and Safety Control, School of Food Science and Engineering, Ningxia University, Yinchuan 750021, China
| | - Xiaobo Wei
- Ningxia Key Laboratory for Food Microbial-Applications Technology and Safety Control, School of Food Science and Engineering, Ningxia University, Yinchuan 750021, China
| | - Yun Ping Neo
- School of Biosciences, Faculty of Health and Medical Sciences, Taylor's University, Subang Jaya, Selangor 47500, Malaysia
| | - Huiyan Liu
- Ningxia Key Laboratory for Food Microbial-Applications Technology and Safety Control, School of Food Science and Engineering, Ningxia University, Yinchuan 750021, China
| | - Haitian Fang
- Ningxia Key Laboratory for Food Microbial-Applications Technology and Safety Control, School of Food Science and Engineering, Ningxia University, Yinchuan 750021, China
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Li P, Mei J, Xie J. The regulation of carbon dioxide on food microorganisms: A review. Food Res Int 2023; 172:113170. [PMID: 37689923 DOI: 10.1016/j.foodres.2023.113170] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 06/16/2023] [Accepted: 06/17/2023] [Indexed: 09/11/2023]
Abstract
This review presents a survey of two extremely important technologies about CO2 with the effectiveness of controlling microorganisms - atmospheric pressure CO2-based modified atmosphere packaging (MAP) and high pressure CO2 non-thermal pasteurization (HPCD). CO2-based MAP is effectively in delaying the lag and logarithmic phases of microorganisms by replacing the surrounding air, while HPCD achieved sterilization by subjecting food to either subcritical or supercritical CO2 for some time in a continuous, batch or semi-batch way. In addition to the advantages of healthy, eco-friendly, quality-preserving, effective characteristic, some challenges such as the high drip loss and packaging collapse associated with higher concentration of CO2, the fuzzy mechanisms of oxidative stress, the unproven specific metabolic pathways and biomarkers, etc., in CO2-based MAP, and the unavoidable extraction of bioactive compounds, the challenging application in solid foods with higher efficiency, the difficult balance between optimal sterilization and optimal food quality, etc., in HPCD still need more efforts to overcome. The action mechanism of CO2 on microorganisms, researches in recent years, problems and future perspectives are summarized. When dissolved in solution medium or cellular fluids, CO2 can form carbonic acid (H2CO3), and H2CO3 can further dissociate into bicarbonate ions (HCO3-), carbonate (CO32-) and hydrogen cations (H+) ionic species following series equilibria. The action mode of CO2 on microorganisms may be relevant to changes in intracellular pH, alteration of proteins, enzyme structure and function, alteration of cell membrane function and fluidity, and so on. Nevertheless, the effects of CO2 on microbial biofilms, energy metabolism, protein and gene expression also need to be explored more extensively and deeply to further understand the action mechanism of CO2 on microorganisms.
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Affiliation(s)
- Peiyun Li
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China; National Experimental Teaching Demonstration Center for Food Science and Engineering Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Center of Aquatic Product Processing and Preservation, Shanghai 201306, China; Shanghai Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation, Shanghai 201306, China.
| | - Jun Mei
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China; National Experimental Teaching Demonstration Center for Food Science and Engineering Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Center of Aquatic Product Processing and Preservation, Shanghai 201306, China; Shanghai Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation, Shanghai 201306, China.
| | - Jing Xie
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China; National Experimental Teaching Demonstration Center for Food Science and Engineering Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Center of Aquatic Product Processing and Preservation, Shanghai 201306, China; Shanghai Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation, Shanghai 201306, China; Collaborative Innovation Center of Seafood Deep Processing, Ministry of Education, Dalian 116034, China.
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Li T, Zuo X, Zhang S, Kong Q. Inactivation of antibiotic resistant bacteria from stormwater runoff using UVA/LED and its potential risks. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2022; 86:2963-2973. [PMID: 36515199 DOI: 10.2166/wst.2022.384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Recently, increasing attention has been paid to antibiotic resistance in stormwater runoff. However, there is no available literature about the control of antibiotic resistant bacteria (ARB) through 365 nm ultraviolet light-emitting diode (UVA/LED). In this study, batch experiments were conducted to investigate ARB inactivation kinetics, effects of light intensity and water matrix (including suspended solid (SS) concentration, initial pH and bacteria concentration), and potential transmission risks after UVA/LED irradiation. Results showed that ARB inactivation efficiencies reached 6.31 log reduction at 8 mW/cm2 (86 J/cm2) of UVA/LED for 180 min. ARB inactivation efficiencies increased with the increase of light intensity, and showed a linear relationship. ARB inactivation decreased with increasing SS levels, and the largest inactivation efficiencies was 3.56 log reduction at 50 mg/L of SS. Initial pH had slight effect on ARB inactivation through UVA/LED irradiation. A low initial bacteria concentration (105 CFU/mL) was not necessarily associated with good ARB inactivation (3.59 log reduction). After UVA/LED irradiation, ARB was hardly detected during 12 hr of dark repair, and the transfer frequency of kanamycin resistance gene was increased to 5.43 × 10-4. These suggested that the application of UVA/LED to inactivate ARB in stormwater runoff was feasible and desirable in this study.
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Affiliation(s)
- Ting Li
- School of Chemistry and Materials Science, Nanjing University of Information Science & Technology, Nanjing, 210044, China
| | - XiaoJun Zuo
- Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China E-mail:
| | - SongHu Zhang
- Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China E-mail:
| | - QingGang Kong
- School of Chemistry and Materials Science, Nanjing University of Information Science & Technology, Nanjing, 210044, China
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Murrieta-Dueñas R, Serrano-Rubio J, López-Ramírez V, Segovia-Dominguez I, Cortez-González J. Prediction of microbial growth via the hyperconic neural network approach. Chem Eng Res Des 2022. [DOI: 10.1016/j.cherd.2022.08.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Katsini L, Bhonsale S, Akkermans S, Roufou S, Griffin S, Valdramidis V, Misiou O, Koutsoumanis K, Muñoz López CA, Polanska M, Van Impe JF. Quantitative methods to predict the effect of climate change on microbial food safety: A needs analysis. Trends Food Sci Technol 2022. [DOI: 10.1016/j.tifs.2021.07.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Ban S, Chen L, Fu S, Wu Q, Xu Y. Modelling and predicting population of core fungi through processing parameters in spontaneous starter (Daqu) fermentation. Int J Food Microbiol 2021; 363:109493. [PMID: 34953345 DOI: 10.1016/j.ijfoodmicro.2021.109493] [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: 03/19/2021] [Revised: 10/12/2021] [Accepted: 11/22/2021] [Indexed: 11/26/2022]
Abstract
Traditional fermented foods are usually produced by spontaneous fermentation with multiple microorganisms. Environmental factors play important roles in microbial succession. However, it is still unclear how the processing parameters regulate the microbiota during fermentation. Here, we reveal the effects of processing parameters on the core microbiota in spontaneous fermentation of Chinese liquor starter. Rhizopus, Pichia, Wickerhamomyces, Saccharomycopsis, Aspergillus and Saccharomyces were identified as core microbiota using amplicon sequencing and metaproteomics analysis. Fermentation moisture gradually decreased from 34.8% to 14.2%, and fermentation temperature varied between 17.0 °C and 35.3 °C during the fermentation. Mantel test showed that fermentation moisture (P < 0.001) and fermentation temperature (P < 0.05) significantly affected the core microbiota. Moreover, structural equation modelling analysis indicated that fermentation moisture (P < 0.001) and fermentation temperature (P < 0.001) were respectively influenced by the processing parameters, room humidity and room temperature. The succession of Rhizopus, Pichia, Wickerhamomyces, Saccharomycopsis and Aspergillus were significantly affected by room humidity (P < 0.05), and the succession of Saccharomyces was significantly affected by room temperature (P < 0.001). Further, models were constructed to predict the population of core microbiota by room humidity and room temperature, using Gaussian process regression and linear regression (P < 0.05). This work would be beneficial for regulating microorganisms via controlling processing parameters in spontaneous food fermentations.
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Affiliation(s)
- Shibo Ban
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Lingna Chen
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Shuangxue Fu
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China
| | - Qun Wu
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
| | - Yan Xu
- Lab of Brewing Microbiology and Applied Enzymology, Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
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Peleg M. A New Look at Models of the Combined Effect of Temperature, pH, Water Activity, or Other Factors on Microbial Growth Rate. FOOD ENGINEERING REVIEWS 2021. [DOI: 10.1007/s12393-021-09292-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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8
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Can we control microbiota in spontaneous food fermentation? – Chinese liquor as a case example. Trends Food Sci Technol 2021. [DOI: 10.1016/j.tifs.2021.02.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Kerr BJ, Curry SM, Ramirez BC. Lack of interactive effects between diet composition and acid addition with drying method on amino acid digestibility values in porcine ileal digesta. J Anim Sci 2020; 98:skaa026. [PMID: 31993632 PMCID: PMC7038183 DOI: 10.1093/jas/skaa026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 01/24/2020] [Indexed: 11/13/2022] Open
Abstract
Two experiments were conducted to determine the effect of oven drying (OD) or freeze drying (FD) on apparent ileal digestibility (AID) of AA in diets fed to pigs. In experiment 1, 15 barrows (88.4 ± 6.4 kg) were allotted to either a corn starch-soybean meal (CST), potato starch-soybean meal (PST), or corn-soybean meal (CSBM) diet, over 2 collection periods. Following collection, samples were pooled within pig and subdivided into either OD or FD, resulting in 10 observations per diet by drying-method combination. In experiment 2, 11 barrows (63.3 ± 3.8 kg) were fed a CST diet, and, following collection, samples were pooled within pig and subdivided and either adjusted to pH 4 or remain unadjusted. Subsets of these samples were then subdivided to be either FD or OD, resulting in 11 observations per pH level by drying-method combination. OD was accomplished by drying samples in a forced air oven at either 100 °C (experiment 1) or 75 °C (experiment 2). In experiment 1, there was no diet type by drying-method interactions noted for any of the AA (P > 0.10).OD resulted in a higher AID of AA compared with samples which were FD (P ≤ 0.10), for all AA except for Gly and Tyr. Averaged across all AA, AID of AA was 3.3% greater if the sample was OD compared with FD. Differences in AID of AA among the 3 diets were noted for all AA (P ≤ 0.07), except for Cys (P = 0.33), due to the fact that CST and PST diets only contained soybean meal (SBM) as an AA-providing ingredient while the CSBM diet contained both corn and SBM. Pigs fed the PST diet had greater SID for all AA compared with pigs fed the CST diet (P ≤ 0.05), except for His, Lys, Cys, and Glu. In experiment 2, there were no pH-adjustment by drying-method interactions noted on AID for any of the AA (P > 0.10). Adjusting ileal digesta to a pH of 4.0 had little effect on AID for most of the AA, except for a lowered AID of Arg, His, Lys, Trp, and Ser (P ≤ 0.10). OD resulted in a higher AID for all AA (P ≤ 0.09) except for Ile, Thr, Val, Ala, Asp, Glu, and Gly. Averaged across all AA, the increase in AID of AA was 1.7% greater if the sample was OD compared with FD. On average, OD of ileal digesta resulted in a 2.5% greater estimate of AID of AA compared with samples that were FD, and was not diet-, pH-, or AA-dependent. Because the majority of the data on AA digestibility are based on FD, a bias factor may be necessary to adjust AA digestibility data obtained on an OD-basis relative to an FD-basis for use in feed formulation.
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Affiliation(s)
- Brian J Kerr
- U.S. Department of Agriculture-Agriculture Research Service, Ames, IA
| | - Shelby M Curry
- Oak Ridge Institute for Science and Education, Oak Ridge, TN
| | - Brett C Ramirez
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA
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Pedrozo HA, Dallagnol AM, Vignolo GM, Pucciarelli AB, Schvezov CE. Mechanistically Inspired Kinetic Approach to Describe Interactions During Co‐Culture Growth of
Carnobacterium maltaromaticum
and
Listeria monocytogenes. J Food Sci 2019; 84:2592-2602. [DOI: 10.1111/1750-3841.14754] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 06/17/2019] [Accepted: 07/09/2019] [Indexed: 11/28/2022]
Affiliation(s)
- Hector A. Pedrozo
- Inst. de Materiales de Misiones (IMAM‐CONICET) Felix de Azara 1552 Posadas 3300 Misiones Argentina
- PLAPIQUI (UNS‐CONICET) Camino La Carrindanga, km. 7 8000 Bahía Blanca Argentina
| | - Andrea M. Dallagnol
- Inst. de Materiales de Misiones (IMAM‐CONICET) Felix de Azara 1552 Posadas 3300 Misiones Argentina
- Lab. de Microbiología de Alimentos y Biotecnología “Dr. Fernando O. Benassi”, Univ. Nacional de Misiones (UNaM) Ruta 12, Km 7.5 Posadas 3300 Misiones Argentina
| | - Graciela M. Vignolo
- Centro de Referencia para Lactobacilos (CERELA‐CONICET) San Miguel de Tucumán Tucumán Argentina
| | - Amada B. Pucciarelli
- Lab. de Microbiología de Alimentos y Biotecnología “Dr. Fernando O. Benassi”, Univ. Nacional de Misiones (UNaM) Ruta 12, Km 7.5 Posadas 3300 Misiones Argentina
| | - Carlos E. Schvezov
- Inst. de Materiales de Misiones (IMAM‐CONICET) Felix de Azara 1552 Posadas 3300 Misiones Argentina
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