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Bustos AY, Taranto MP, Gerez CL, Agriopoulou S, Smaoui S, Varzakas T, Enshasy HAE. Recent Advances in the Understanding of Stress Resistance Mechanisms in Probiotics: Relevance for the Design of Functional Food Systems. Probiotics Antimicrob Proteins 2024:10.1007/s12602-024-10273-9. [PMID: 38829565 DOI: 10.1007/s12602-024-10273-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2024] [Indexed: 06/05/2024]
Abstract
In recent years, more and more scientific community, food producers, and food industry show increased interest in functional foods containing probiotics, which is a big challenge. The consumption of probiotics in the context of a balanced diet through the consumption of functional foods or through the intake of pharmaceutical preparations has proven to contribute to the improvement of human health, even contributing to the prevention of diseases. In order for probiotics to be considered suitable for consumption, they must contain a minimum concentration of viable cells, namely, at least 107 colony forming units of beneficial microbes per gram. Ensuring the viability of bacterial cells until the moment of consumption is the overriding priority of functional probiotic food manufacturers. Probiotic bacteria are subject to stress conditions not only during food manufacturing but also during gastrointestinal passage, which limit or even compromise their functionality. This paper first examines all the stressful conditions faced by probiotic cells in their production stages and related to the conditions present in the bioreactor fermentation and drying processes as well as factors related to the food matrix and storage. The stress situations faced by probiotic microorganisms during the gastrointestinal transit especially during stomach and intestinal residence are also analyzed. In order to understand the adaptation mechanisms of probiotic bacteria to gastrointestinal stress, intrinsic and adaptive mechanisms identified in probiotic strains in response to acid stress and to bile and bile acid stress are analyzed. In addition, improvement strategies for multiple stress tolerance of lactic acid bacteria through directions dealing with stress, accumulation of metabolites, use of protectants, and regulation of technological parameters are examined. Finally, the definition of postbiotics, inanimate microorganisms and/or their components conferring health benefits, is also introduced. Postbiotics include cell lysates, enzymes, and cell wall fragments derived from probiotic bacteria and may represent an alternative to the use of probiotics, when they do not tolerate stressful conditions.
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Affiliation(s)
- Ana Yanina Bustos
- Centro de Investigación en Biofísica Aplicada y Alimentos (CIBAAL/UNSE-CONICET), RN 9-Km 1125, (4206), Santiago del Estero, Argentina
- Facultad de Agronomía y Agroindustrias (FAyA), Universidad Nacional de Santiago del Estero, Av. Belgrano Sur 1912, (4200), Santiago del Estero, Argentina
- Facultad de Humanidades, Ciencias Sociales y de La Salud (FHU), Universidad Nacional de Santiago del Estero, Av. Belgrano Sur 1912, (4200), Santiago del Estero, Argentina
| | - María Pía Taranto
- Centro de Referencia Para Lactobacilos (CONICET-CERELA), Chacabuco 145, (4000), San Miguel de Tucumán, Argentina
| | - Carla Luciana Gerez
- Centro de Referencia Para Lactobacilos (CONICET-CERELA), Chacabuco 145, (4000), San Miguel de Tucumán, Argentina
| | - Sofia Agriopoulou
- Department of Food Science and Technology, University of the Peloponnese, 24100, Antikalamos Messinia, Kalamata, Greece
| | - Slim Smaoui
- Laboratory of Microbial Biotechnology and Engineering Enzymes (LMBEE), Center of Biotechnology of Sfax (CBS), University of Sfax, Road of Sidi Mansour Km 6, P.O. Box 1177, 3018, Sfax, Tunisia
| | - Theodoros Varzakas
- Department of Food Science and Technology, University of the Peloponnese, 24100, Antikalamos Messinia, Kalamata, Greece.
| | - Hesham Ali El Enshasy
- Institute of Bioproduct Development (IBD), Universiti Teknologi Malaysia (UTM), 81310, Johor, Malaysia
- Faculty of Chemical and Energy Engineering, Universiti Teknologi Malaysia (UTM), 81310, Johor, Malaysia
- City of Scientific Research and Technology Applications (SRTA), New Borg Al Arab, 21934, Egypt
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Yao S, Tu R, Jin Y, Zhou R, Wu C, Qin J. Improvement of the viability of Tetragenococcus halophilus under acidic stress by forming the biofilm cell structure based on RNA-Seq and iTRAQ analyses. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2024; 104:3559-3569. [PMID: 38147410 DOI: 10.1002/jsfa.13240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 12/22/2023] [Accepted: 12/23/2023] [Indexed: 12/28/2023]
Abstract
BACKGROUND Tetragenococcus halophilus is a halophilic lactic acid bacterium (LAB) isolated from soya sauce moromi. During the production of these fermented foods, acid stress is an inevitable environmental stress. In our previous study, T. halophilus could form biofilms and the cells in the biofilms exhibited higher cell viability under multiple environmental stresses, including acid stress. RESULTS In this study, the effect of preformed T. halophilus biofilms on cell survival, cellular structure, intracellular environment, and the expression of genes and proteins under acid stress was investigated. The result showed that acid stress with pH 4.30 for 1.5 h reduced the live T. halophilus cell count and caused cellular structure damage. However, T. halophilus biofilm cells exhibited greater cell survival under acid stress than the planktonic cells, and biofilm formation reduced the damage of acid stress to the cell membrane and cell wall. The biofilm cells maintained a higher level of H+ -ATPase activity and intracellular ammonia concentration after acid stress. The RNA-Seq and iTRAQ technologies revealed that the genes and proteins associated with ATP production, the uptake of trehalose and N-acetylmuramic acid, the assembly of H+ -ATPase, amino acid biosynthesis and metabolism, ammonia production, fatty acid biosynthesis, CoA biosynthesis, thiamine production, and acetoin biosynthesis might be responsible for the stronger acid tolerance of T. halophilus biofilm cells together. CONCLUSION These findings further explained the mechanisms that allowed LAB biofilm cells to resist environmental stress. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Shangjie Yao
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Rongkun Tu
- Luzhou Lao Jiao Co., Ltd., Luzhou, China
| | - Yao Jin
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Rongqing Zhou
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Chongde Wu
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
| | - Jiufu Qin
- College of Biomass Science and Engineering, Sichuan University, Chengdu, China
- Key Laboratory of Leather Chemistry and Engineering, Ministry of Education, Sichuan University, Chengdu, China
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Sibanda T, Marole TA, Thomashoff UL, Thantsha MS, Buys EM. Bifidobacterium species viability in dairy-based probiotic foods: challenges and innovative approaches for accurate viability determination and monitoring of probiotic functionality. Front Microbiol 2024; 15:1327010. [PMID: 38371928 PMCID: PMC10869629 DOI: 10.3389/fmicb.2024.1327010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 01/15/2024] [Indexed: 02/20/2024] Open
Abstract
Bifidobacterium species are essential members of a healthy human gut microbiota. Their presence in the gut is associated with numerous health outcomes such as protection against gastrointestinal tract infections, inflammation, and metabolic diseases. Regular intake of Bifidobacterium in foods is a sustainable way of maintaining the health benefits associated with its use as a probiotic. Owing to their global acceptance, fermented dairy products (particularly yogurt) are considered the ideal probiotic carrier foods. As envisioned in the definition of probiotics as "live organisms," the therapeutic functionalities of Bifidobacterium spp. depend on maintaining their viability in the foods up to the point of consumption. However, sustaining Bifidobacterium spp. viability during the manufacture and shelf-life of fermented dairy products remains challenging. Hence, this paper discusses the significance of viability as a prerequisite for Bifidobacterium spp. probiotic functionality. The paper focuses on the stress factors that influence Bifidobacterium spp. viability during the manufacture and shelf life of yogurt as an archetypical fermented dairy product that is widely accepted as a delivery vehicle for probiotics. It further expounds the Bifidobacterium spp. physiological and genetic stress response mechanisms as well as the methods for viability retention in yogurt, such as microencapsulation, use of oxygen scavenging lactic acid bacterial strains, and stress-protective agents. The report also explores the topic of viability determination as a critical factor in probiotic quality assurance, wherein, the limitations of culture-based enumeration methods, the challenges of species and strain resolution in the presence of lactic acid bacterial starter and probiotic species are discussed. Finally, new developments and potential applications of next-generation viability determination methods such as flow cytometry, propidium monoazide-quantitative polymerase chain reaction (PMA-qPCR), next-generation sequencing, and single-cell Raman spectroscopy (SCRS) methods are examined.
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Affiliation(s)
- Thulani Sibanda
- Department of Consumer and Food Sciences, University of Pretoria, Pretoria, South Africa
- Department of Applied Biology and Biochemistry, National University of Science and Technology, Bulawayo, Zimbabwe
- Department of Biology, National of University of Lesotho, Maseru, Lesotho
| | - Tlaleo Azael Marole
- Department of Consumer and Food Sciences, University of Pretoria, Pretoria, South Africa
| | | | - Mapitsi S. Thantsha
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Elna M. Buys
- Department of Consumer and Food Sciences, University of Pretoria, Pretoria, South Africa
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Zhang G, He M, Xiao L, Jiao Y, Han J, Li C, Miller MJ, Zhang L. Milk fat globule membrane protects Bifidobacterium longum ssp. infantis ATCC 15697 against bile stress by modifying global transcriptional responses. J Dairy Sci 2024; 107:91-104. [PMID: 37678788 DOI: 10.3168/jds.2023-23591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 07/17/2023] [Indexed: 09/09/2023]
Abstract
The milk fat globule membrane (MFGM) can protect probiotic bacteria from bile stress. However, its potential mechanism has not been reported. In this study, the viability, morphology and gene transcriptional response of Bifidobacterium longum ssp. infantis ATCC 15697 (BI_15697) stressed by bile salts with or without MFGM were investigated. It was shown that MFGM alleviated the reduction in BI_15697 population induced by 0.2% porcine bile stress and restored the population to the control levels. MFGM ameliorated the shrunken, fragmented appearance and irregular morphology of BI_15697 and maintained cell integrity disrupted by bile stress. RNA-sequencing results showed that MFGM increased transport of glucose and raffinose and decreased that of branched-chain amino acids (BCAA) in the presence of bile salts. MFGM stimulated the expression of genes involved in the synthesis of raffinose in galactose metabolism and the metabolism of BCAA, suggesting that MFGM stimulated the accumulation of raffinose and BCAA in the presence of bile. In addition, MFGM stimulated the expression of 2 bile efflux transporters under bile stress. Together, the multifactorial response helps BI_15697 excrete bile salts and maintain cellular integrity in response to bile stress. This study proposes a mechanism for the protection of BI_15697 against bile salt stress by MFGM, thereby providing a molecular basis for its application in incorporation of probiotics.
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Affiliation(s)
- Gongsheng Zhang
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, Harbin 150030, China
| | - Mingxue He
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, Harbin 150030, China
| | - Lihong Xiao
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, Harbin 150030, China
| | - Yuehua Jiao
- Center of Drug Safety Evaluation, Heilongjiang University of Chinese Medicine, Harbin 150040, China
| | - Jianchun Han
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, Harbin 150030, China; Heilongjiang Green Food Science Research Institute, Harbin 150030, China.
| | - Chun Li
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, Harbin 150030, China; Center of Drug Safety Evaluation, Heilongjiang University of Chinese Medicine, Harbin 150040, China
| | - Michael J Miller
- Department of Food Science and Human Nutrition, University of Illinois Urbana-Champaign, Urbana, IL 61801
| | - Lili Zhang
- Key Laboratory of Dairy Science, Ministry of Education, College of Food Science, Northeast Agricultural University, Harbin 150030, China.
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Wu S, Ji J, Carole NVD, Yang J, Yang Y, Sun J, Ye Y, Zhang Y, Sun X. Combined metabolomics and transcriptomics analysis reveals the mechanism of antibiotic resistance of Salmonella enterica serovar Typhimurium after acidic stress. Food Microbiol 2023; 115:104328. [PMID: 37567621 DOI: 10.1016/j.fm.2023.104328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 06/10/2023] [Accepted: 06/16/2023] [Indexed: 08/13/2023]
Abstract
Drug-resistant Salmonella is widely distributed in the meat production chain, endangering food safety and public health. Acidification of meat products during processing can induce acid stress, which may alter antibiotic resistance. Our study investigated the effects of acid stress on the antibiotic resistance and metabolic profile of Salmonella Typhimurium, and explored the underlying mechanisms using metabolomic and transcriptomic analysis. We found that acid-stressed 14028s was more sensitive to small molecule hydrophobic antibiotics (SMHA) while more resistant to meropenem (MERO). Metabolomic analysis revealed that enhanced sensitivity to SMHA was correlated with increased purine metabolism and tricarboxylic acid cycle. Transcriptomic analysis revealed the downregulation of chemotaxis-related genes, which are also associated with SMHA sensitivity. We also found a significant downregulation of the ompF gene, which encodes a major outer membrane protein OmpF of Salmonella. The decreased expression of OmpF porin hindered the influx of MERO, leading to enhanced resistance of the bacteria to the drug. Our findings contribute to greatly improve the understanding of the relationship between Salmonella metabolism, gene expression, and changes in drug resistance after acid stress, while providing a structural framework for exploring the relationship between bacterial stress responses and antibiotic resistance.
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Affiliation(s)
- Shang Wu
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Jian Ji
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Nanfack V D Carole
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Jia Yang
- Yangzhou Center for Food and Drug Control, Yangzhou, 225000, China
| | - Yang Yang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Jiadi Sun
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Yongli Ye
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Yinzhi Zhang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, China
| | - Xiulan Sun
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Collaborative Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, China.
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Castro-López C, Romero-Luna HE, García HS, Vallejo-Cordoba B, González-Córdova AF, Hernández-Mendoza A. Key Stress Response Mechanisms of Probiotics During Their Journey Through the Digestive System: A Review. Probiotics Antimicrob Proteins 2023; 15:1250-1270. [PMID: 36001271 DOI: 10.1007/s12602-022-09981-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/17/2022] [Indexed: 11/26/2022]
Abstract
The survival of probiotic microorganisms during their exposure to harsh environments plays a critical role in the fulfillment of their functional properties. In particular, transit through the human gastrointestinal tract (GIT) is considered one of the most challenging habitats that probiotics must endure, because of the particularly stressful conditions (e.g., oxygen level, pH variations, nutrient limitations, high osmolarity, oxidation, peristalsis) prevailing in the different sections of the GIT, which in turn can affect the growth, viability, physiological status, and functionality of microbial cells. Consequently, probiotics have developed a series of strategies, called "mechanisms of stress response," to protect themselves from these adverse conditions. Such mechanisms may include but are not limited to the induction of new metabolic pathways, formation/production of particular metabolites, and changes of transcription rates. It should be highlighted that some of such mechanisms can be conserved across several different strains or can be unique for specific genera. Hence, this review attempts to review the state-of-the-art knowledge of mechanisms of stress response displayed by potential probiotic strains during their transit through the GIT. In addition, evidence whether stress responses can compromise the biosafety of such strains is also discussed.
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Affiliation(s)
- Cecilia Castro-López
- Laboratorio de Química y Biotecnología de Productos Lácteos, Centro de Investigación en Alimentación y Desarrollo A.C. (CIAD), Gustavo Enrique Astiazarán Rosas 46, Hermosillo, Sonora, 83304, México
| | - Haydee E Romero-Luna
- Instituto Tecnológico Superior de Xalapa/Tecnológico Nacional de México, Reserva Territorial s/n Sección 5, Santa Bárbara, Xalapa-Enríquez, Veracruz, 91096, México
| | - Hugo S García
- Unidad de Investigación Y Desarrollo de Alimentos, Instituto Tecnológico de Veracruz/Tecnológico Nacional de México, Miguel Ángel de Quevedo 2779, Veracruz, Veracruz, 91897, México
| | - Belinda Vallejo-Cordoba
- Laboratorio de Química y Biotecnología de Productos Lácteos, Centro de Investigación en Alimentación y Desarrollo A.C. (CIAD), Gustavo Enrique Astiazarán Rosas 46, Hermosillo, Sonora, 83304, México
| | - Aarón F González-Córdova
- Laboratorio de Química y Biotecnología de Productos Lácteos, Centro de Investigación en Alimentación y Desarrollo A.C. (CIAD), Gustavo Enrique Astiazarán Rosas 46, Hermosillo, Sonora, 83304, México
| | - Adrián Hernández-Mendoza
- Laboratorio de Química y Biotecnología de Productos Lácteos, Centro de Investigación en Alimentación y Desarrollo A.C. (CIAD), Gustavo Enrique Astiazarán Rosas 46, Hermosillo, Sonora, 83304, México.
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Novel Insights into the Molecular Mechanisms Underlying Robustness and Stability in Probiotic Bifidobacteria. Appl Environ Microbiol 2023; 89:e0008223. [PMID: 36802222 PMCID: PMC10057886 DOI: 10.1128/aem.00082-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Some probiotic bifidobacteria are highly robust and shelf-stable, whereas others are difficult to produce, due to their sensitivity to stressors. This limits their potential use as probiotics. Here, we investigate the molecular mechanisms underlying the variability in stress physiologies of Bifidobacterium animalis subsp. lactis BB-12 and Bifidobacterium longum subsp. longum BB-46, by applying a combination of classical physiological characterization and transcriptome profiling. The growth behavior, metabolite production, and global gene expression profiles differed considerably between the strains. BB-12 consistently showed higher expression levels of multiple stress-associated genes, compared to BB-46. This difference, besides higher cell surface hydrophobicity and a lower ratio of unsaturated to saturated fatty acids in the cell membrane of BB-12, should contribute to its higher robustness and stability. In BB-46, the expression of genes related to DNA repair and fatty acid biosynthesis was higher in the stationary than in the exponential phase, which was associated with enhanced stability of BB-46 cells harvested in the stationary phase. The results presented herein highlight important genomic and physiological features contributing to the stability and robustness of the studied Bifidobacterium strains. IMPORTANCE Probiotics are industrially and clinically important microorganisms. To exert their health-promoting effects, probiotic microorganisms must be administered at high counts, while maintaining their viability at the time of consumption. In addition, intestinal survival and bioactivity are important criteria for probiotics. Although bifidobacteria are among the most well-documented probiotics, the industrial-scale production and commercialization of some Bifidobacterium strains is challenged by their high sensitivity to environmental stressors encountered during manufacturing and storage. Through a comprehensive comparison of the metabolic and physiological characteristics of 2 Bifidobacterium strains, we identify key biological markers that can serve as indicators for robustness and stability in bifidobacteria.
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Abstract
Bifidobacteria naturally inhabit diverse environments, including the gastrointestinal tracts of humans and animals. Members of the genus are of considerable scientific interest due to their beneficial effects on health and, hence, their potential to be used as probiotics. By definition, probiotic cells need to be viable despite being exposed to several stressors in the course of their production, storage, and administration. Examples of common stressors encountered by probiotic bifidobacteria include oxygen, acid, and bile salts. As bifidobacteria are highly heterogenous in terms of their tolerance to these stressors, poor stability and/or robustness can hamper the industrial-scale production and commercialization of many strains. Therefore, interest in the stress physiology of bifidobacteria has intensified in recent decades, and many studies have been established to obtain insights into the molecular mechanisms underlying their stability and robustness. By complementing traditional methodologies, omics technologies have opened new avenues for enhancing the understanding of the defense mechanisms of bifidobacteria against stress. In this review, we summarize and evaluate the current knowledge on the multilayered responses of bifidobacteria to stressors, including the most recent insights and hypotheses. We address the prevailing stressors that may affect the cell viability during production and use as probiotics. Besides phenotypic effects, molecular mechanisms that have been found to underlie the stress response are described. We further discuss strategies that can be applied to improve the stability of probiotic bifidobacteria and highlight knowledge gaps that should be addressed in future studies.
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Affiliation(s)
- Marie Schöpping
- Systems Biology, Discovery, Chr. Hansen A/S, Hørsholm, Denmark
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Ahmad A. Zeidan
- Systems Biology, Discovery, Chr. Hansen A/S, Hørsholm, Denmark
| | - Carl Johan Franzén
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
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Zhang C, Han Y, Gui Y, Wa Y, Chen D, Huang Y, Yin B, Gu R. Influence of nitrogen sources on the tolerance of Lacticaseibacillus rhamnosus to heat stress and oxidative stress. J Ind Microbiol Biotechnol 2022; 49:6693999. [PMID: 36073749 PMCID: PMC9559300 DOI: 10.1093/jimb/kuac020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 09/02/2022] [Indexed: 11/14/2022]
Abstract
It has been found that 32 genes related to nitrogen source metabolism in Lacticaseibacillus rhamnosus are downregulated under both heat stress and oxidative stress. In this study, the influence of different nitrogen sources within the growth medium on the tolerance of L. rhamnosus to heat stress and oxidative stress was investigated. Tryptone-free MRS was found to enhance the tolerance of L. rhamnosus hsryfm 1301 to heat stress and oxidative stress during the whole growth period, and this result was universal for all L. rhamnosus species analyzed. The strongest strengthening effect occurred when the OD600 value reached 2.0, at which the survival rates under heat stress and oxidative stress increased 130-fold and 40-fold, respectively. After supplementing phenylalanine, isoleucine, glutamate, valine, histidine, or tryptophan into the tryptone-free MRS, the tolerance of L. rhamnosus to heat stress and oxidative stress exhibited a sharp drop. The spray drying survival rate of L. rhamnosus hsryfm 1301 cultured in the tryptone-free MRS rose to 75% (from 30%), and the spray dried powder also performed better in the experimentally simulated gastrointestinal digestion. These results showed that decreasing the intake of amino acids is an important mechanism for L. rhamnosus to tolerate heat stress and oxidative stress. When L. rhamnosus is cultured for spray drying, the concentration of the nitrogen source's components should be an important consideration.
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Affiliation(s)
- Chenchen Zhang
- College of Food Science and Engineering, Yangzhou University, Yangzhou, P.R. China.,Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China.,Jiangsu Dairy Biotechnology Engineering Research Center, Kang Yuan Dairy Co. Ltd., Yangzhou University, Yangzhou, P.R. China.,College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, P.R. China
| | - Yuemei Han
- College of Food Science and Engineering, Yangzhou University, Yangzhou, P.R. China.,Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China
| | - Ya Gui
- College of Food Science and Engineering, Yangzhou University, Yangzhou, P.R. China.,Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China
| | - Yunchao Wa
- College of Food Science and Engineering, Yangzhou University, Yangzhou, P.R. China.,Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China
| | - Dawei Chen
- College of Food Science and Engineering, Yangzhou University, Yangzhou, P.R. China.,Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China
| | - Yujun Huang
- College of Food Science and Engineering, Yangzhou University, Yangzhou, P.R. China.,Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China
| | - Boxing Yin
- Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China.,Jiangsu Dairy Biotechnology Engineering Research Center, Kang Yuan Dairy Co. Ltd., Yangzhou University, Yangzhou, P.R. China
| | - Ruixia Gu
- College of Food Science and Engineering, Yangzhou University, Yangzhou, P.R. China.,Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China
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Bao P, Zhang Z, Liang Y, Yu Z, Xiao Z, Wang Y, Yu Y, Liu W, Chen X, Huang Z, Su Y, Chen R, Ge J. Role of the Gut Microbiota in Glucose Metabolism During Heart Failure. Front Cardiovasc Med 2022; 9:903316. [PMID: 35859583 PMCID: PMC9289393 DOI: 10.3389/fcvm.2022.903316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 05/31/2022] [Indexed: 11/29/2022] Open
Abstract
Background Blood glucose disorders are prevalent in heart failure, while the influence of the gut microbiota on this process remains unclear. Here, we used heart failure model mice and fecal microbiota transplantation (FMT) mice to evaluate the effect of the gut microbiota on the regulation of blood glucose during heart failure. Methods Thoracic aortic constriction (TAC) surgery was performed in a heart failure model, while an antibiotic cocktail was used to eliminate the microbiota to establish a germ-free (GF) model. Blood glucose, insulin, and glucagon levels were measured, and an intraperitoneal glucose tolerance test (IPGTT) was performed. 16S rRNA sequencing and metabolomics were used to evaluate the changes in gut microbiota structure and metabolism induced by TAC. Another group of FMT mice was established to observe the effect of the gut microbiota on host metabolism. Results After microbiota clearance, the glucagon concentration, the homeostasis model assessment for insulin resistance (HOMA-IR), and the area under the curve (AUC) of the IPGTT were decreased significantly in the TAC germ-free (TAC-GF) group in the third month as compared to the other groups. 16S rRNA sequencing indicated that TAC surgery affected the gut microbiota structure, and fecal metabolomics suggested that noradrenaline and adrenaline levels were higher in the TAC group than in the sham group. The FMT mice transplanted with the feces of the TAC (FMT-TAC) mice displayed a higher AUC of IPGTT, accompanied by a higher glucagon level, insulin level, and HOMA-IR than those of the mice in the other groups. The serum metabolomics of the FMT-TAC group showed that noradrenaline levels were significantly higher than those of the FMT-sham group. Conclusion The gut microbiota and its metabolism were altered during heart failure, which increased blood glucose and glucagon in the host.
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Affiliation(s)
- Pei Bao
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Zhiwei Zhang
- Reproductive Medical Center, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yixiu Liang
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Viral Heart Diseases, Department of Cardiovascular Diseases, Ministry of Public Health, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Ziqing Yu
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Viral Heart Diseases, Department of Cardiovascular Diseases, Ministry of Public Health, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Zilong Xiao
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yucheng Wang
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yong Yu
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Wen Liu
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Xueying Chen
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Zhenzhen Huang
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yangang Su
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
- *Correspondence: Yangang Su
| | - Ruizhen Chen
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
- Key Laboratory of Viral Heart Diseases, Department of Cardiovascular Diseases, Ministry of Public Health, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
- Ruizhen Chen
| | - Junbo Ge
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China
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11
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Ribosome Profiling Reveals Genome-Wide Cellular Translational Regulation in Lacticaseibacillus rhamnosus ATCC 53103 under Acid Stress. Foods 2022; 11:foods11101411. [PMID: 35626981 PMCID: PMC9140532 DOI: 10.3390/foods11101411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 11/23/2022] Open
Abstract
During fermentation and food processing, Lacticaseibacillus rhamnosus ATCC 53103 can encounter many adverse conditions, and acid stress is one of them. The purpose of the present study was to investigate the influence of acid stress on the global translational and transcriptional regulation of Lacticaseibacillus rhamnosus ATCC 53103. Two pH values (pH 6.0 vs. pH 5.0) were applied, the effects of which were studied via ribosome profiling and RNA sequencing assay. Under acid stress, many genes showed differential changes at the translational and transcriptional levels. A total of 10 genes showed different expression trends at the two levels. The expression of 337 genes—which mainly participated in the ABC transporters, amino acid metabolism, and ribosome functional group assembly pathways—was shown to be regulated only at the translational level. The translational efficiency of a few genes participating in the pyrimidine and amino acid metabolism pathways were upregulated. Ribosome occupancy data suggested that ribosomes accumulated remarkably in the elongation region of open reading frame regions under acid stress. This study provides new insights into Lacticaseibacillus rhamnosus ATCC 53103 gene expression under acid stress, and demonstrates that the bacterium can respond to acid stress with synergistic translational and transcriptional regulation mechanisms, improving the vitality of cells.
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12
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He BL, Xiong Y, Hu TG, Zong MH, Wu H. Bifidobacterium spp. as functional foods: A review of current status, challenges, and strategies. Crit Rev Food Sci Nutr 2022; 63:8048-8065. [PMID: 35319324 DOI: 10.1080/10408398.2022.2054934] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Members of Bifidobacterium are among the first microbes to colonize the human intestine naturally, their abundance and diversity in the colon are closely related to host health. Recently, the gut microbiota has been gradually proven to be crucial mediators of various metabolic processes between the external environment and the host. Therefore, the health-promoting benefits of Bifidobacterium spp. and their applications in food have gradually been widely concerned. The main purpose of this review is to comprehensively introduce general features, colonization methods, and safety of Bifidobacterium spp. in the human gut, highlighting its health benefits and industrial applications. On this basis, the existing limitations and scope for future research are also discussed. Bifidobacteria have beneficial effects on the host's digestive system, immune system, and nervous system. However, the first prerequisite for functioning is to have enough live bacteria before consumption and successfully colonize the colon after ingestion. At present, strain breeding, optimization (e.g., selecting acid and bile resistant strains, adaptive evolution, high cell density culture), and external protection technology (e.g., microencapsulation and protectants) are the main strategies to address these challenges in food application.
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Affiliation(s)
- Bao-Lin He
- School of Food Science and Engineering, South China University of Technology/Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, China
| | - Yong Xiong
- School of Food Science and Engineering, South China University of Technology/Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, China
| | - Teng-Gen Hu
- Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural Products Processing, Sericultural & Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Guangzhou, China
| | - Min-Hua Zong
- School of Food Science and Engineering, South China University of Technology/Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, China
| | - Hong Wu
- School of Food Science and Engineering, South China University of Technology/Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, Guangzhou, China
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13
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Caballero AM, Villagrán VAS, Serna AJ, Farrés A. Challenges in the production and use of probiotics as therapeuticals in cancer treatment or prevention. J Ind Microbiol Biotechnol 2021; 48:6356962. [PMID: 34427674 DOI: 10.1093/jimb/kuab052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 08/03/2021] [Indexed: 01/22/2023]
Abstract
Probiotics were defined as microbial strains that confer health benefits to their consumers. The concept has evolved during the last twenty years, and today metabolites produced by the strains, known as postbiotics, and even dead cells, known as paraprobiotics are closely associated to them. The isolation of commensal strains from human microbiome has led to the development of next generation probiotics. This review aims to present an overview of the developments in the area of cancer prevention and treatment, intimately related to advances in the knowledge of the microbiome role in its genesis and therapy. Strain identification and characterization, production processes, delivery strategies and clinical evaluation are crucial to translate results into the market with solid scientific support. Examples of recent tools in isolation, strain typification, quality control and development of new probiotic strains are described. Probiotics market and regulation were originally developed in the food sector, but these new strategies will impact the pharmaceutical and health sectors, requiring new considerations in regulatory frameworks.
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Affiliation(s)
- Alejandra Mejía Caballero
- Departamento de Ingeniería Celular y Biocatálisis, Insituto de Biotecnología, Universidad Nacional Autónoma de México, 62210, Cuernavaca, Morelos, México
| | - Vianey Anahi Salas Villagrán
- Departamento de Alimentos y Biotecnología, Facultad de Química, Universidad Nacional Autónoma de México, 04510 Ciudad de México, México
| | - Alaide Jiménez Serna
- Centro de Investigación y Capacitación en Gastronomía, Universidad del Claustro de Sor Juana, 06080 Ciudad de México, México
| | - Amelia Farrés
- Departamento de Alimentos y Biotecnología, Facultad de Química, Universidad Nacional Autónoma de México, 04510 Ciudad de México, México
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14
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Yang H, He M, Wu C. Cross protection of lactic acid bacteria during environmental stresses: Stress responses and underlying mechanisms. Lebensm Wiss Technol 2021. [DOI: 10.1016/j.lwt.2021.111203] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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15
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16
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Alessandri G, van Sinderen D, Ventura M. The genus bifidobacterium: From genomics to functionality of an important component of the mammalian gut microbiota running title: Bifidobacterial adaptation to and interaction with the host. Comput Struct Biotechnol J 2021; 19:1472-1487. [PMID: 33777340 PMCID: PMC7979991 DOI: 10.1016/j.csbj.2021.03.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/03/2021] [Accepted: 03/03/2021] [Indexed: 02/07/2023] Open
Abstract
Members of the genus Bifidobacterium are dominant and symbiotic inhabitants of the mammalian gastrointestinal tract. Being vertically transmitted, bifidobacterial host colonization commences immediately after birth and leads to a phase of host infancy during which bifidobacteria are highly prevalent and abundant to then transit to a reduced, yet stable abundance phase during host adulthood. However, in order to reach and stably colonize their elective niche, i.e. the large intestine, bifidobacteria have to cope with a multitude of oxidative, osmotic and bile salt/acid stress challenges that occur along the gastrointestinal tract (GIT). Concurrently, bifidobacteria not only have to compete with the myriad of other gut commensals for nutrient acquisition, but they also require protection against bacterial viruses. In this context, Next-Generation Sequencing (NGS) techniques, allowing large-scale comparative and functional genome analyses have helped to identify the genetic strategies that bifidobacteria have developed in order to colonize, survive and adopt to the highly competitive mammalian gastrointestinal environment. The current review is aimed at providing a comprehensive overview concerning the molecular strategies on which bifidobacteria rely to stably and successfully colonize the mammalian gut.
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Affiliation(s)
- Giulia Alessandri
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy
| | - Douwe van Sinderen
- APC Microbiome Ireland and School of Microbiology, University College Cork, Western Road, Cork, Ireland
| | - Marco Ventura
- Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy.,Microbiome Research Hub, University of Parma, Parma, Italy
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17
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Veselovsky VA, Dyachkova MS, Menyaylo EA, Polyaeva PS, Olekhnovich EI, Shitikov EA, Bespiatykh DA, Semashko TA, Kasianov AS, Ilina EN, Danilenko VN, Klimina KM. Gene Networks Underlying the Resistance of Bifidobacterium longum to Inflammatory Factors. Front Immunol 2020; 11:595877. [PMID: 33304352 PMCID: PMC7701253 DOI: 10.3389/fimmu.2020.595877] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 10/20/2020] [Indexed: 01/14/2023] Open
Abstract
As permanent residents of the normal gut microbiota, bifidobacteria have evolved to adapt to the host’s immune response whose priority is to eliminate pathogenic agents. The mechanisms that ensure the survival of commensals during inflammation and maintain the stability of the core component of the normal gut microbiota in such conditions remain poorly understood. We propose a new in vitro approach to study the mechanisms of resistance to immune response factors based on high-throughput sequencing followed by transcriptome analysis. This approach allowed us to detect differentially expressed genes associated with inflammation. In this study, we demonstrated that the presence of the pro-inflammatory cytokines IL-6 and TNFα to the growth medium of the B. longum subsp. longum GT15 strain changes the latter’s growth rate insignificantly while affecting the expression of certain genes. We identified these genes and performed a COG and a KEGG pathway enrichment analysis. Using phylogenetic profiling we predicted the operons of genes whose expression was triggered by the cytokines TNFα and IL-6 in vitro. By mapping the transcription start points, we experimentally validated the predicted operons. Thus, in this study, we predicted the genes involved in a putative signaling pathway underlying the mechanisms of resistance to inflammatory factors in bifidobacteria. Since bifidobacteria are a major component of the human intestinal microbiota exhibiting pronounced anti-inflammatory properties, this study is of great practical and scientific relevance.
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Affiliation(s)
- Vladimir A Veselovsky
- Department of Molecular Biology and Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| | - Marina S Dyachkova
- Department of Biotechnology, Vavilov Institute of General Genetics Russian Academy of Sciences, Moscow, Russia
| | - Egor A Menyaylo
- Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
| | - Polina S Polyaeva
- Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia
| | - Evgenii I Olekhnovich
- Department of Molecular Biology and Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| | - Egor A Shitikov
- Department of Molecular Biology and Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| | - Dmitry A Bespiatykh
- Department of Molecular Biology and Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| | - Tatiana A Semashko
- Department of Molecular Biology and Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| | - Artem S Kasianov
- Department of Biotechnology, Vavilov Institute of General Genetics Russian Academy of Sciences, Moscow, Russia.,Phystech School of Biological and Medical Physics, Moscow Institute of Physics and Technology (National Research University), Dolgoprudny, Russia.,Laboratory of Plant Genomics, The Institute for Information Transmission Problems of the Russian Academy of Sciences (Kharkevich Institute), Moscow, Russia
| | - Elena N Ilina
- Department of Molecular Biology and Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia
| | - Valeriy N Danilenko
- Department of Biotechnology, Vavilov Institute of General Genetics Russian Academy of Sciences, Moscow, Russia.,Faculty of Ecology, International Institute for Strategic Development of Sectoral Economics Peoples' Friendship University of Russia (RUDN University), Moscow, Russia
| | - Ksenia M Klimina
- Department of Molecular Biology and Genetics, Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, Moscow, Russia.,Department of Biotechnology, Vavilov Institute of General Genetics Russian Academy of Sciences, Moscow, Russia
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18
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Min B, Kim K, Li V, Cho S, Kim H. Changes in Cell Membrane Fatty Acid Composition of Streptococcus thermophilus in Response to Gradually Increasing Heat Temperature. J Microbiol Biotechnol 2020; 30:739-748. [PMID: 32482940 PMCID: PMC9745660 DOI: 10.4014/jmb.1912.12053] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 02/28/2020] [Indexed: 12/15/2022]
Abstract
In this study, a method of heat adaptation was implemented in an attempt to increase the upper thermal threshold of two Streptococcus thermophilus found in South Korea and identified the alterations in membrane fatty acid composition to adaptive response to heat. In order to develop heat tolerant lactic acid bacteria, heat treatment was continuously applied to bacteria by increasing temperature from 60°C until the point that no surviving cell was detected. Our results indicated significant increase in heat tolerance of heat-adapted strains compared to the wild type (WT) strains. In particular, the survival ratio of basically low heat-tolerant strain increased even more. In addition, the strains with improved heat tolerance acquired cross protection, which improved their survival ratio in acid, bile salts and osmotic conditions. A relation between heat tolerance and membrane fatty acid composition was identified. As a result of heat adaptation, the ratio of unsaturated to saturated fatty acids (UFA/SFA) and C18:1 relative concentration were decreased. C6:0 in only heatadapted strains and C22:0 in only the naturally high heat tolerant strain were detected. These results support the hypothesis, that the consequent increase of SFA ratio is a cellular response to environmental stresses such as high temperatures, and it is able to protect the cells from acid, bile salts and osmotic conditions via cross protection. This study demonstrated that the increase in heat tolerance can be utilized as a mean to improve bacterial tolerance against various environmental stresses.
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Affiliation(s)
- Bonggyu Min
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Kkotnim Kim
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Vladimir Li
- Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul 0886, Republic of Korea
| | - Seoae Cho
- C&K genomics Inc., C-1008, H businesspark, Seoul 08826, Republic of Korea
| | - Heebal Kim
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 08826, Republic of Korea
- Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul 0886, Republic of Korea
- C&K genomics Inc., C-1008, H businesspark, Seoul 08826, Republic of Korea
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