101
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Wan C, Chen S, Wen L, Liu X, Lee DJ, Yang X. Biosynthesis, characterization and potentiality of lipopeptides produced by Bacillus flexus S1 without inductive carbon sources. RSC Adv 2016. [DOI: 10.1039/c6ra17510d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This study newly isolated a bacterial stain ofBacillus flexusS1 which had abilities of synthesizing lipopeptides without any inductive operations, and thus it could effectively save operational procedures or cost.
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Affiliation(s)
- Chunli Wan
- Department of Environmental Science and Engineering
- Fudan University
- Shanghai 200433
- China
| | - Si Chen
- Department of Environmental Science and Engineering
- Fudan University
- Shanghai 200433
- China
| | - Lei Wen
- Department of Environmental Science and Engineering
- Fudan University
- Shanghai 200433
- China
| | - Xiang Liu
- Department of Environmental Science and Engineering
- Fudan University
- Shanghai 200433
- China
| | - Duu-Jong Lee
- Department of Chemical Engineering
- National Taiwan University of Science and Technology
- Taipei 106
- Taiwan
| | - Xue Yang
- State Key Laboratory of Pollution Control and Resources Reuse
- College of Environmental Science and Engineering
- Tongji University
- Shanghai 200092
- China
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102
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Huang R, Pan M, Wan C, Shah NP, Tao X, Wei H. Physiological and transcriptional responses and cross protection of Lactobacillus plantarum ZDY2013 under acid stress. J Dairy Sci 2015; 99:1002-1010. [PMID: 26627851 DOI: 10.3168/jds.2015-9993] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 08/27/2015] [Indexed: 01/20/2023]
Abstract
Acid tolerance responses (ATR) in Lactobacillus plantarum ZDY2013 were investigated at physiological and molecular levels. A comparison of composition of cell membrane fatty acids (CMFA) between acid-challenged and unchallenged cells showed that acid adaptation evoked a significantly higher percentage of saturated fatty acids and cyclopropane fatty acids in acid-challenged than in unchallenged cells. In addition, reverse transcription-quantitative PCR analysis in acid-adapted cells at different pH values (ranging from 3.0 to 4.0) indicated that several genes were differently regulated, including those related to proton pumps, amino acid metabolism, sugar metabolism, and class I and class III stress response pathways. Expression of genes involved in fatty acid synthesis and production of alkali was significantly upregulated. Upon exposure to pH 4.5 for 2 h, a higher survival rate (higher viable cell count) of Lactobacillus plantarum ZDY2013 was achieved following an additional challenge to 40 mM hydrogen peroxide for 60 min, but no difference in survival rate of cells was found with further challenge to heat, ethanol, or salt. Therefore, we concluded that the physiological and metabolic changes of acid-treated cells of Lactobacillus plantarum ZDY2013 help the cells resist damage caused by acid, and further initiated global response signals to bring the whole cell into a state of defense to other stress factors, especially hydrogen peroxide.
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Affiliation(s)
- Renhui Huang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, P. R. China; Jiangxi-OAI Joint Research Institute, Nanchang University, 235 Nanjing Donglu, Nanchang 330047, P. R. China
| | - Mingfang Pan
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, P. R. China; Jiangxi-OAI Joint Research Institute, Nanchang University, 235 Nanjing Donglu, Nanchang 330047, P. R. China
| | - Cuixiang Wan
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, P. R. China.
| | - Nagendra P Shah
- Food and Nutritional Science, School of Biological Science, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Xueying Tao
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, P. R. China; Jiangxi-OAI Joint Research Institute, Nanchang University, 235 Nanjing Donglu, Nanchang 330047, P. R. China
| | - Hua Wei
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, P. R. China; Jiangxi-OAI Joint Research Institute, Nanchang University, 235 Nanjing Donglu, Nanchang 330047, P. R. China
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103
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Microscopic characterization of the bacterial cell envelope of Planococcus halocryophilus Or1 during subzero growth at −15 °C. Polar Biol 2015. [DOI: 10.1007/s00300-015-1826-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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104
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Yu H, Meng X, Aflakpui FWK, Luo L. A salt-induced butA gene of Tetragenococcus halophilus confers salt tolerance to Escherichia coli by heterologous expression of its dual copies. ANN MICROBIOL 2015. [DOI: 10.1007/s13213-015-1160-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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105
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Zhang Y, Carpenter CE, Broadbent JR, Luo X. Influence of habituation to inorganic and organic acid conditions on the cytoplasmic membrane composition of Listeria monocytogenes. Food Control 2015. [DOI: 10.1016/j.foodcont.2015.02.039] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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106
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Liu C, Luo Q, Tu Y, Wang G, Liu Y, Xie Y. Drug-carrier interaction analysis in the cell penetrating peptide-modified liposomes for doxorubicin loading. J Microencapsul 2015; 32:745-54. [PMID: 26299658 DOI: 10.3109/02652048.2015.1073390] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Doxorubicin (DOX) is widely used as an antitumor model drug in liposomes because of its high encapsulation efficiency. The cell-penetrating peptide (CPP) has potential applications in drug delivery systems. However, we discovered that the encapsulation efficiency of DOX decreased with increasing modification density of CPP on liposomes. To explore the interaction mechanisms of CPP-modified liposomes (CPPL) for DOX loading, X-ray diffraction, Fourier transform infrared spectroscopy and Raman spectroscopy were utilised, and theoretical calculations based on molecular dynamics simulation were performed. Results showed that the monomeric intermolecular interaction between CPP and DOX, in which the guanidinium group of CPP was parallel to the planar aromatic chromophore of DOX, depending on the cation-pi interaction and hydrogen bonds, weakened the tendency of DOX transporting into the internal medium from the liposomal external medium. Analysis of the interaction between CPP and DOX at the molecular level provided theoretical guidance for the further development of CPPL.
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Affiliation(s)
- Chang Liu
- a Department of Pharmaceutics, State Key Laboratory of Natural and Biomimetic Drugs , School of Pharmaceutical Sciences, Peking University , Beijing , People's Republic of China and
| | - Qi Luo
- b Soft Matter Research Center and Department of Chemistry, Zhejiang University , Hangzhou , Zhejiang , People's Republic of China
| | - YingFeng Tu
- a Department of Pharmaceutics, State Key Laboratory of Natural and Biomimetic Drugs , School of Pharmaceutical Sciences, Peking University , Beijing , People's Republic of China and
| | - GuiLing Wang
- a Department of Pharmaceutics, State Key Laboratory of Natural and Biomimetic Drugs , School of Pharmaceutical Sciences, Peking University , Beijing , People's Republic of China and
| | - YingChun Liu
- b Soft Matter Research Center and Department of Chemistry, Zhejiang University , Hangzhou , Zhejiang , People's Republic of China
| | - Ying Xie
- a Department of Pharmaceutics, State Key Laboratory of Natural and Biomimetic Drugs , School of Pharmaceutical Sciences, Peking University , Beijing , People's Republic of China and
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107
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System-level understanding of the potential acid-tolerance components of Acidithiobacillus thiooxidans ZJJN-3 under extreme acid stress. Extremophiles 2015; 19:1029-39. [DOI: 10.1007/s00792-015-0780-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 08/03/2015] [Indexed: 10/23/2022]
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108
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Horner IJ, Kraut ND, Hurst JJ, Rook AM, Collado CM, Atilla-Gokcumen GE, Maziarz EP, Liu XM, Merchea MM, Bright FV. Effects of Polyhexamethylene Biguanide and Polyquaternium-1 on Phospholipid Bilayer Structure and Dynamics. J Phys Chem B 2015; 119:10531-42. [DOI: 10.1021/acs.jpcb.5b07162] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Ian J. Horner
- Department
of Chemistry, Natural Sciences Complex, SUNY-Buffalo, Buffalo, New York 14260-3000, United States
| | - Nadine D. Kraut
- PPG Industries
Inc., 440 College Park Dr., Monroeville, Pennsylvania 15146, United States
| | - Jerod J. Hurst
- Department
of Chemistry, Natural Sciences Complex, SUNY-Buffalo, Buffalo, New York 14260-3000, United States
| | - Alyssa M. Rook
- Department
of Chemistry, Natural Sciences Complex, SUNY-Buffalo, Buffalo, New York 14260-3000, United States
| | - Crystal M. Collado
- Department
of Chemistry, Natural Sciences Complex, SUNY-Buffalo, Buffalo, New York 14260-3000, United States
| | - G. Ekin Atilla-Gokcumen
- Department
of Chemistry, Natural Sciences Complex, SUNY-Buffalo, Buffalo, New York 14260-3000, United States
| | - E. Peter Maziarz
- Pfizer Consumer
Healthcare, 1211 Sherwood Ave., Richmond, Virginia 23220, United States
| | - X. Michael Liu
- Pfizer Consumer
Healthcare, 1211 Sherwood Ave., Richmond, Virginia 23220, United States
| | | | - Frank V. Bright
- Department
of Chemistry, Natural Sciences Complex, SUNY-Buffalo, Buffalo, New York 14260-3000, United States
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109
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Membrane fluidity-related adaptive response mechanisms of foodborne bacterial pathogens under environmental stresses. Food Res Int 2015. [DOI: 10.1016/j.foodres.2015.03.016] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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110
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Detection of acid and hop shock induced responses in beer spoiling Lactobacillus brevis by MALDI-TOF MS. Food Microbiol 2015; 46:501-506. [DOI: 10.1016/j.fm.2014.09.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 08/27/2014] [Accepted: 09/28/2014] [Indexed: 11/24/2022]
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111
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The antibacterial activity of ceramsite coated by silver nanoparticles in micropore. Appl Biochem Biotechnol 2015; 176:267-76. [PMID: 25820386 DOI: 10.1007/s12010-015-1572-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 03/12/2015] [Indexed: 10/23/2022]
Abstract
In the present study, ceramsite was combined with silver nanoparticles (AgNPs) to fabricate a new nanocomposite for water disinfection. The ceramsite was prepared by fly ash, straw ash, and cement. AgNPs were synthesized using polyvinylpyrrolidone (PVP) as the capping agent. The nanocomposite was prepared by self-aggregation of AgNPs on the surface of the ceramsite. AgNPs capped with PVP can form a thin film on the surface of micropore in ceramsite. The nanocomposite can inhibit bacteria growth and induce damage of the cell membrane of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Therefore, the nanocomposite is a new material which can be used for disinfection in drinking water.
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112
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Relationship between acid tolerance and cell membrane in Bifidobacterium, revealed by comparative analysis of acid-resistant derivatives and their parental strains grown in medium with and without Tween 80. Appl Microbiol Biotechnol 2015; 99:5227-36. [DOI: 10.1007/s00253-015-6447-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 01/10/2015] [Accepted: 01/29/2015] [Indexed: 02/06/2023]
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113
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Kanno M, Tamaki H, Mitani Y, Kimura N, Hanada S, Kamagata Y. pH-induced change in cell susceptibility to butanol in a high butanol-tolerant bacterium, Enterococcus faecalis strain CM4A. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:69. [PMID: 25904984 PMCID: PMC4405824 DOI: 10.1186/s13068-015-0251-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 04/02/2015] [Indexed: 05/09/2023]
Abstract
BACKGROUND Though butanol is considered as a potential biofuel, its toxicity toward microorganisms is the main bottleneck for the biological butanol production. Recently, butanol-tolerant bacteria have been proposed as alternative butanol production hosts overcoming the end product inhibition. One remaining key issue to be addressed is how physicochemical properties such as pH and temperature affect microbial butanol tolerance during cultivation and fermentation. RESULTS We investigated the pH effect on butanol tolerance of a high butanol-tolerant bacterium, Enterococcus faecalis strain CM4A. The strain grew over a broad pH range (pH 4.0 to 12.0) and preferred alkaline pH (pH 8.0 and 10.0) in the absence of butanol. However, in the presence of butanol, strain CM4A grew better under acidic and neutral pH conditions (pH 6.0 and 6.8). Membrane fatty acid analysis revealed that the cells exposed to butanol exhibited increased cyclopropane and saturated fatty acids, which contribute to butanol tolerance of the strain by decreasing membrane fluidity, more evidently at acidic and neutral pH than at alkaline pH. Meanwhile, the strain grown under alkaline pH without butanol increased short chain fatty acids, which is involved in increasing membrane fluidity for alkaline adaptation. Such a change was not observed in the cells grown under alkaline pH with butanol. These results suggested that strain CM4A simultaneously exposed to butanol and alkali stresses was not likely able to properly adjust membrane fluidity due to the opposite response to each stress and thereby showed low butanol tolerance under alkaline pH. Indeed, the cells exposed to butanol at alkaline pH showed an irregular shape with disrupted membrane structure under transmission electron microscopy observation, which also indicated the impact of butanol and alkali stresses on functioning of cellular membrane. CONCLUSION The study clearly demonstrated the alkaline pH-induced increase of cell susceptibility to butanol in the tested strain. Our findings indicate the non-negligible impact of pH on microbial butanol tolerance, providing a new insight into efficient butanol production.
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Affiliation(s)
- Manabu Kanno
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566 Japan
| | - Hideyuki Tamaki
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566 Japan
| | - Yasuo Mitani
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566 Japan
| | - Nobutada Kimura
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566 Japan
| | - Satoshi Hanada
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566 Japan
| | - Yoichi Kamagata
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8566 Japan
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114
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Dai X, An J, Wang Y, Wu Z, Zhao Y, Guo Q, Zhang X, Li C. Antibacterial amphiphiles based on ε-polylysine: synthesis, mechanism of action, and cytotoxicity. RSC Adv 2015. [DOI: 10.1039/c5ra10393b] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
To combat antibiotic-resistant bacteria, an amphiphile based on ε-polylysine was synthesized via an alkylation reaction. The positively charged amphiphile could adsorb bacterial membranes, disrupt them and subsequently kill the bacteria.
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Affiliation(s)
- Xiaomei Dai
- Key Laboratory of Functional Polymer Materials of Ministry of Education
- Institute of Polymer Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Jinxia An
- Key Laboratory of Functional Polymer Materials of Ministry of Education
- Institute of Polymer Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Yanan Wang
- Key Laboratory of Functional Polymer Materials of Ministry of Education
- Institute of Polymer Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Zhongming Wu
- The Ministry of Health Key Laboratory of Hormone and Development
- Metabolic Diseases Hospital
- Tianjin Medical University
- Tianjin 300070
- China
| | - Yu Zhao
- Key Laboratory of Functional Polymer Materials of Ministry of Education
- Institute of Polymer Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Qianqian Guo
- Key Laboratory of Functional Polymer Materials of Ministry of Education
- Institute of Polymer Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Xinge Zhang
- Key Laboratory of Functional Polymer Materials of Ministry of Education
- Institute of Polymer Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Chaoxing Li
- Key Laboratory of Functional Polymer Materials of Ministry of Education
- Institute of Polymer Chemistry
- Nankai University
- Tianjin 300071
- China
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115
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Heredia RM, Boeris PS, Biasutti MA, López GA, Paulucci NS, Lucchesi GI. Coordinated response of phospholipids and acyl components of membrane lipids in Pseudomonas putida A (ATCC 12633) under stress caused by cationic surfactants. MICROBIOLOGY-SGM 2014; 160:2618-2626. [PMID: 25280753 DOI: 10.1099/mic.0.081943-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The present study assessed the role of membrane components of Pseudomonas putida A (ATCC 12633) under chemical stress conditions originated by treatment with tetradecyltrimethylammonium bromide (TTAB), a cationic surfactant. We examined changes in fatty acid composition and in the fluidity of the membranes of cells exposed to TTAB at a specific point of growth as well as of cells growing with TTAB. The addition of 10-50 mg TTAB l(-1) promoted an increase in the saturated/unsaturated fatty acid ratio. By using fluorescence polarization techniques, we found that TTAB exerted a fluidizing effect on P. putida A (ATCC 12633) membranes. However, a complete reversal of induced membrane fluidification was detected after 15 min of incubation with TTAB. Consistently, the proportion of unsaturated fatty acids was lower in TTAB-treated cells as compared with non-treated cells. In the presence of TTAB, the content of phosphatidylglycerol increased (120 %), whilst that of cardiolipin decreased (60 %). Analysis of the fatty acid composition of P. putida A (ATCC 12633) showed that phosphatidylglycerol carried the major proportion of saturated fatty acids (89 %), whilst cardiolipin carried an elevated proportion of unsaturated fatty acids (18 %). The increase in phosphatidylglycerol and consequently in saturated fatty acids, together with a decrease in cardiolipin content, enabled greater membrane resistance, reversing the fluidizing effect of TTAB. Therefore, results obtained in the present study point to changes in the fatty acid profile as an adaptive response of P. putida A (ATCC 12633) cells to stress caused by a cationic surfactant.
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Affiliation(s)
- Romina Marisa Heredia
- Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CPX5804BYA Río Cuarto, Córdoba, Argentina
| | - Paola Sabrina Boeris
- Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CPX5804BYA Río Cuarto, Córdoba, Argentina
| | - María Alicia Biasutti
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CPX5804BYA Río Cuarto, Córdoba, Argentina
| | - Gastón Alberto López
- Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CPX5804BYA Río Cuarto, Córdoba, Argentina
| | - Natalia Soledad Paulucci
- Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CPX5804BYA Río Cuarto, Córdoba, Argentina
| | - Gloria Inés Lucchesi
- Departamento de Biología Molecular, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CPX5804BYA Río Cuarto, Córdoba, Argentina
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116
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Mei L, Lu Z, Zhang X, Li C, Jia Y. Polymer-Ag nanocomposites with enhanced antimicrobial activity against bacterial infection. ACS APPLIED MATERIALS & INTERFACES 2014; 6:15813-21. [PMID: 25170799 DOI: 10.1021/am502886m] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Herein, a nontoxic nanocomposite is synthesized by reduction of silver nitrate in the presence of a cationic polymer displaying strong antimicrobial activity against bacterial infection. These nanocomposites with a large concentration of positive charge promote their adsorption to bacterial membranes through electrostatic interaction. Moreover, the synthesized nanocomposites with polyvalent and synergistic antimicrobial effects can effectively kill both Gram-positive and Gram-negative bacteria without the emergence of bacterial resistance. Morphological changes obtained by transmission electron microscope observation show that these nanocomposites can cause leakage and chaos of intracellular contents. Analysis of the antimicrobial mechanism confirms that the lethal action of nanocomposites against the bacteria started with disruption of the bacterial membrane, subsequent cellular internalization of the nanoparticles, and inhibition of intracellular enzymatic activity. This novel antimicrobial material with good cytocompatibility promotes healing of infected wounds in diabetic rats, and has a promising future in the treatment of other infectious diseases.
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Affiliation(s)
- Lin Mei
- Key Laboratory of Functional Polymer Materials of Ministry Education, Institute of Polymer Chemistry, Nankai University , Tianjin 300071, China
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117
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Louesdon S, Charlot-Rougé S, Tourdot-Maréchal R, Bouix M, Béal C. Membrane fatty acid composition and fluidity are involved in the resistance to freezing of Lactobacillus buchneri R1102 and Bifidobacterium longum R0175. Microb Biotechnol 2014; 8:311-8. [PMID: 24981007 PMCID: PMC4353344 DOI: 10.1111/1751-7915.12132] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 04/07/2014] [Accepted: 04/29/2014] [Indexed: 11/29/2022] Open
Abstract
Determinations of membrane fatty acid composition and fluidity were used together with acidification activity and viability measurements to characterize the physiological state after freezing of Lactobacillus buchneri R1102 and Bifidobacterium longum R0175 cells harvested in the exponential and stationary growth phases. For both strains, lower membrane fluidity was achieved in cells harvested in the stationary growth phase. This change was linked to a lower unsaturated-to-saturated fatty acid ratio for both strains and a higher cyclic-to-saturated fatty acid ratio for L. buchneri R1102 alone. These membrane properties were linked to survival and to maintenance of acidification activity of the cells after freezing, which differed according to the strain and the growth phase. Survival of B. longum R0175 was increased by 10% in cells with low membrane fluidity and high relative saturated fatty acid contents, without any change in acidification activity. Acidification activity was more degraded (70 min) in L. buchneri R1102 cells displaying low membrane fluidity and high saturated and cyclic fatty acid levels. Finally, this study showed that membrane modifications induced by the growth phase differed among bacterial strains in terms of composition. By lowering membrane fluidity, these modifications could be beneficial for survival of B. longum R0175 during the freezing process but detrimental for maintenance of acidification activity of L. buchneri R1102.
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Affiliation(s)
- Séverine Louesdon
- UMR 782 Génie et Microbiologie des Procédés Alimentaires, AgroParisTech - INRA, Thiverval-Grignon, 78850, France; Laboratoire Procédés Bactéries, Lallemand SAS, Blagnac Cedex, 31702, France
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118
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Olchowik-Grabarek E, Swiecicka I, Andreeva-Kovaleskaya Z, Solonin A, Bonarska-Kujawa D, Kleszczyńska H, Mavlyanov S, Zamaraeva M. Role of Structural Changes Induced in Biological Membranes by Hydrolysable Tannins from Sumac Leaves (Rhus typhina L.) in their Antihemolytic and Antibacterial Effects. J Membr Biol 2014; 247:533-40. [DOI: 10.1007/s00232-014-9664-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 04/09/2014] [Indexed: 01/03/2023]
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119
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Maulucci G, Troiani D, Eramo SLM, Paciello F, Podda MV, Paludetti G, Papi M, Maiorana A, Palmieri V, De Spirito M, Fetoni AR. Time evolution of noise induced oxidation in outer hair cells: role of NAD(P)H and plasma membrane fluidity. Biochim Biophys Acta Gen Subj 2014; 1840:2192-202. [PMID: 24735797 DOI: 10.1016/j.bbagen.2014.04.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 03/25/2014] [Accepted: 04/07/2014] [Indexed: 01/24/2023]
Abstract
BACKGROUND Noise exposure impairs outer hair cells (OHCs). The common basis for OHC dysfunction and loss by acoustic over-stimulation is represented by reactive oxygen species (ROS) overload that may affect the membrane structural organization through generation of lipid peroxidation. METHODS Here we investigated in OHC different functional zones the mechanisms linking metabolic functional state (NAD(P)H intracellular distribution) to the generation of lipid peroxides and to the physical state of membranes by two photon fluorescence microscopy. RESULTS In OHCs of control animals, a more oxidized NAD(P)H redox state is associated to a less fluid plasma membrane structure. Acoustic trauma induces a topologically differentiated NAD(P)H oxidation in OHC rows, which is damped between 1 and 6h. Peroxidation occurs after ~4h from noise insult, while ROS are produced in the first 0.2h and damage cells for a period of time after noise exposure has ended (~7.5h) when a decrease of fluidity of OHC plasma membrane occurs. OHCs belonging to inner rows, characterized by a lower metabolic activity with respect to other rows, show less severe metabolic impairment. CONCLUSIONS Our data indicate that plasma membrane fluidity is related to NAD(P)H redox state and lipid peroxidation in hair cells. GENERAL SIGNIFICANCE Our results could pave the way for therapeutic intervention targeting the onset of redox umbalance.
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Affiliation(s)
| | - Diana Troiani
- Istituto di Fisiologia, Università Cattolica (UCSC), Roma, Italy.
| | | | - Fabiola Paciello
- Dipartimento di Scienze Chirurgiche per le patologie della testa e del collo, Università Cattolica (UCSC), Roma, Italy
| | | | - Gaetano Paludetti
- Dipartimento di Scienze Chirurgiche per le patologie della testa e del collo, Università Cattolica (UCSC), Roma, Italy
| | | | | | | | | | - Anna Rita Fetoni
- Dipartimento di Scienze Chirurgiche per le patologie della testa e del collo, Università Cattolica (UCSC), Roma, Italy
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Louesdon S, Charlot-Rougé S, Juillard V, Tourdot-Maréchal R, Béal C. Osmotic stress affects the stability of freeze-dried Lactobacillus buchneri R1102 as a result of intracellular betaine accumulation and membrane characteristics. J Appl Microbiol 2014; 117:196-207. [PMID: 24661271 DOI: 10.1111/jam.12501] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Revised: 03/06/2014] [Accepted: 03/14/2014] [Indexed: 11/27/2022]
Abstract
AIMS To help cells to better resist the stressful conditions associated with the freeze-drying process during starter production, we investigated the effect of various osmotic conditions on growth, survival and acidification activity of Lactobacillus buchneri R1102, after freeze-drying and during storage for 3 months at 25°C. METHODS AND RESULTS High survival rates during freeze-drying, but not during storage, were obtained when 0·1 mol l(-1) KCl was added at the beginning of fermentation, without any change in membrane properties and betaine accumulation. This condition made it possible to maintain a high acidification rate throughout the process. In contrast, the addition of 0·6 mol l(-1) KCl concentrations at the beginning of fermentation led to a high survival rate during storage that was related to high intracellular betaine levels, low membrane fluidity and high cycC19:0 concentrations. However, these modifications induced the degradation of acidification activity during storage. When a moderate stress was applied by combining 0·1 mol l(-1) KCl at the beginning and 0·6 mol l(-1) KCl at the end of fermentation, betaine accumulated in the cells without any membrane alteration, allowing them to maintain high acidification activity and survival rate during storage. CONCLUSION Specific osmotic conditions during fermentation induced intracellular betaine accumulation and modifications of membrane character-istics, thus affecting stress resistance of Lact. buchneri R1102. A slight osmotic stress made it possible to maintain a high acidification activity, whereas a high osmotic stress at the end of fermentation led to the preservation of cell survival during freeze-dried storage. SIGNIFICANCE AND IMPACT OF THE STUDY This study revealed that the survival and preservation of acidification activity of freeze-dried Lact. buchneri R1102 during starter production can be improved by using appropriate osmotic conditions.
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Affiliation(s)
- S Louesdon
- UMR 782 Génie et Microbiology des Procédés Alimentaires, AgroParisTech - INRA, Thiverval-Grignon, France; Laboratoire Procédés Bactéries, Lallemand SAS, Blagnac Cedex, France
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Zhu B, Xia X, Xia N, Zhang S, Guo X. Modification of Fatty acids in membranes of bacteria: implication for an adaptive mechanism to the toxicity of carbon nanotubes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:4086-4095. [PMID: 24579825 DOI: 10.1021/es404359v] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We explored whether bacteria could respond adaptively to the presence of carbon nanotubes (CNTs) by investigating the influence of CNTs on the viability, composition of fatty acids, and cytoplasmic membrane fluidity of bacteria in aqueous medium for 24 h exposure. The CNTs included long single-walled carbon nanotubes (L-SWCNTs), short single-walled carbon nanotubes (S-SWCNTs), short carboxyl single-walled carbon nanotubes (S-SWCNT-COOH), and aligned multiwalled carbon nanotubes (A-MWCNTs). The bacteria included three common model bacteria, Staphyloccocus aureus (Gram-positive), Bacillus subtilis (Gram-positive), and Escherichia coli (Gram-negative), and one polybrominated diphenyl ether degrading strain, Ochrobactrum sp. (Gram-negative). Generally, L-SWCNTs were the most toxic to bacteria, whereas S-SWCNT-COOH showed the mildest bacterial toxicity. Ochrobactrum sp. was more susceptible to the toxic effect of CNTs than E. coli. Compared to the control in the absence of CNTs, the viability of Ochrobactrum sp. decreased from 71.6-81.4% to 41.8-70.2%, and E. coli from 93.7-104.0% to 67.7-91.0% when CNT concentration increased from 10 to 50 mg L(-1). The cytoplasmic membrane fluidity of bacteria increased with CNT concentration, and a significant negative correlation existed between the bacterial viabilities and membrane fluidity for E. coli and Ochrobactrum sp. (p < 0.05), indicating that the increase in membrane fluidity induced by CNTs was an important factor causing the inactivation of bacteria. In the presence of CNTs, E. coli and Ochrobactrum sp. showed elevation in the level of saturated fatty acids accompanied with reduction in unsaturated fatty acids, compensating for the fluidizing effect of CNTs. This demonstrated that bacteria could modify their composition of fatty acids to adapt to the toxicity of CNTs. In contrast, S. aureus and B. subtilis exposed to CNTs increased the proportion of branched-chain fatty acids and decreased the level of straight-chain fatty acids, which was also favorable to counteract the toxic effect of CNTs. This study suggests that the bacterial tolerances to CNTs are associated with both the adaptive modification of fatty acids in the membrane and the physicochemical properties of CNTs. This is the first report about the physiologically adaptive response of bacteria to CNTs, and may help to further understand the ecotoxicological effects of CNTs.
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Affiliation(s)
- Baotong Zhu
- School of Environment, Beijing Normal University, State Key Laboratory of Water Environment Simulation/Key Laboratory of Water and Sediment Sciences of Ministry of Education , Beijing 100875, People's Republic of China
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Screening and characterization of Sphingomonas sp. mutant for welan gum biosynthesis at an elevated temperature. Bioprocess Biosyst Eng 2014; 37:1849-58. [DOI: 10.1007/s00449-014-1159-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 02/16/2014] [Indexed: 11/24/2022]
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Broadbent JR, Oberg TS, Hughes JE, Ward RE, Brighton C, Welker DL, Steele JL. Influence of polysorbate 80 and cyclopropane fatty acid synthase activity on lactic acid production by Lactobacillus casei ATCC 334 at low pH. ACTA ACUST UNITED AC 2014; 41:545-53. [DOI: 10.1007/s10295-013-1391-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 12/04/2013] [Indexed: 11/30/2022]
Abstract
Abstract
Lactic acid is an important industrial chemical commonly produced through microbial fermentation. The efficiency of acid extraction is increased at or below the acid’s pKa (pH 3.86), so there is interest in factors that allow for a reduced fermentation pH. We explored the role of cyclopropane synthase (Cfa) and polysorbate (Tween) 80 on acid production and membrane lipid composition in Lactobacillus casei ATCC 334 at low pH. Cells from wild-type and an ATCC 334 cfa knockout mutant were incubated in APT broth medium containing 3 % glucose plus 0.02 or 0.2 % Tween 80. The cultures were allowed to acidify the medium until it reached a target pH (4.5, 4.0, or 3.8), and then the pH was maintained by automatic addition of NH4OH. Cells were collected at the midpoint of the fermentation for membrane lipid analysis, and media samples were analyzed for lactic and acetic acids when acid production had ceased. There were no significant differences in the quantity of lactic acid produced at different pH values by wild-type or mutant cells grown in APT, but the rate of acid production was reduced as pH declined. APT supplementation with 0.2 % Tween 80 significantly increased the amount of lactic acid produced by wild-type cells at pH 3.8, and the rate of acid production was modestly improved. This effect was not observed with the cfa mutant, which indicated Cfa activity and Tween 80 supplementation were each involved in the significant increase in lactic acid yield observed with wild-type L. casei at pH 3.8.
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Affiliation(s)
- J R Broadbent
- grid.53857.3c 0000000121858768 Department of Nutrition, Dietetics, and Food Science Utah State University 8700 Old Main Hill 84322-8700 Logan UT USA
| | - T S Oberg
- grid.53857.3c 0000000121858768 Department of Nutrition, Dietetics, and Food Science Utah State University 8700 Old Main Hill 84322-8700 Logan UT USA
| | - J E Hughes
- grid.53857.3c 0000000121858768 Department of Biology Utah State University Logan UT USA
| | - R E Ward
- grid.53857.3c 0000000121858768 Department of Nutrition, Dietetics, and Food Science Utah State University 8700 Old Main Hill 84322-8700 Logan UT USA
| | - C Brighton
- grid.53857.3c 0000000121858768 Department of Nutrition, Dietetics, and Food Science Utah State University 8700 Old Main Hill 84322-8700 Logan UT USA
| | - D L Welker
- grid.53857.3c 0000000121858768 Department of Biology Utah State University Logan UT USA
| | - J L Steele
- grid.14003.36 0000000099041312 Department of Food Science University of Wisconsin Madison USA
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Wu C, Huang J, Zhou R. Progress in engineering acid stress resistance of lactic acid bacteria. Appl Microbiol Biotechnol 2013; 98:1055-63. [DOI: 10.1007/s00253-013-5435-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2013] [Revised: 11/24/2013] [Accepted: 11/25/2013] [Indexed: 11/24/2022]
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125
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An oleaginous bacterium that intrinsically accumulates long-chain free Fatty acids in its cytoplasm. Appl Environ Microbiol 2013; 80:1126-31. [PMID: 24296497 DOI: 10.1128/aem.03056-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Medium- and long-chain fatty acids are present in organisms in esterified forms that serve as cell membrane constituents and storage compounds. A large number of organisms are known to accumulate lipophilic materials as a source of energy and carbon. We found a bacterium, designated GK12, that intrinsically accumulates free fatty acids (FFAs) as intracellular droplets without exhibiting cytotoxicity. GK12 is an obligatory anaerobic, mesophilic lactic acid bacterium that was isolated from a methanogenic reactor. Phylogenetic analysis based on 16S rRNA gene sequences showed that GK12 is affiliated with the family Erysipelotrichaceae in the phylum Firmicutes but is distantly related to type species in this family (less than 92% similarity in 16S rRNA gene sequence). Saturated fatty acids with carbon chain lengths of 14, 16, 18, and 20 were produced from glucose under stress conditions, including higher-than-optimum temperatures and the presence of organic solvents that affect cell membrane integrity. FFAs were produced at levels corresponding to up to 25% (wt/wt) of the dry cell mass. Our data suggest that FFA accumulation is a result of an imbalance between excess membrane fatty acid biosynthesis due to homeoviscous adaptation and limited β-oxidation activity due to anaerobic growth involving lactic acid fermentation. FFA droplets were not further utilized as an energy and carbon source, even under conditions of starvation. A naturally occurring bacterium that accumulates significant amounts of long-chain FFAs with noncytotoxicity would provide useful strategies for microbial biodiesel production.
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Isolation of butanol- and isobutanol-tolerant bacteria and physiological characterization of their butanol tolerance. Appl Environ Microbiol 2013; 79:6998-7005. [PMID: 24014527 DOI: 10.1128/aem.02900-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Despite their importance as a biofuel production platform, only a very limited number of butanol-tolerant bacteria have been identified thus far. Here, we extensively explored butanol- and isobutanol-tolerant bacteria from various environmental samples. A total of 16 aerobic and anaerobic bacteria that could tolerate greater than 2.0% (vol/vol) butanol and isobutanol were isolated. A 16S rRNA gene sequencing analysis revealed that the isolates were phylogenetically distributed over at least nine genera: Bacillus, Lysinibacillus, Rummeliibacillus, Brevibacillus, Coprothermobacter, Caloribacterium, Enterococcus, Hydrogenoanaerobacterium, and Cellulosimicrobium, within the phyla Firmicutes and Actinobacteria. Ten of the isolates were phylogenetically distinct from previously identified butanol-tolerant bacteria. Two relatively highly butanol-tolerant strains CM4A (aerobe) and GK12 (obligate anaerobe) were characterized further. Both strains changed their membrane fatty acid composition in response to butanol exposure, i.e., CM4A and GK12 exhibited increased saturated and cyclopropane fatty acids (CFAs) and long-chain fatty acids, respectively, which may serve to maintain membrane fluidity. The gene (cfa) encoding CFA synthase was cloned from strain CM4A and expressed in Escherichia coli. The recombinant E. coli showed relatively higher butanol and isobutanol tolerance than E. coli without the cfa gene, suggesting that cfa can confer solvent tolerance. The exposure of strain GK12 to butanol by consecutive passages even enhanced the growth rate, indicating that yet-unknown mechanisms may also contribute to solvent tolerance. Taken together, the results demonstrate that a wide variety of butanol- and isobutanol-tolerant bacteria that can grow in 2.0% butanol exist in the environment and have various strategies to maintain structural integrity against detrimental solvents.
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Influence of freezing stress on morphological alteration and biofilm formation by Listeria monocytogenes: relationship with cell surface hydrophobicity and membrane fluidity. Arch Microbiol 2013; 195:705-15. [DOI: 10.1007/s00203-013-0921-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 07/23/2013] [Accepted: 08/17/2013] [Indexed: 12/25/2022]
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Royce LA, Liu P, Stebbins MJ, Hanson BC, Jarboe LR. The damaging effects of short chain fatty acids on Escherichia coli membranes. Appl Microbiol Biotechnol 2013; 97:8317-27. [PMID: 23912117 PMCID: PMC3757260 DOI: 10.1007/s00253-013-5113-5] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Revised: 07/08/2013] [Accepted: 07/09/2013] [Indexed: 12/19/2022]
Abstract
Carboxylic acids are an attractive biorenewable chemical. However, like many other fermentatively produced compounds, they are inhibitory to the biocatalyst. An understanding of the mechanism of toxicity can aid in mitigating this problem. Here, we show that hexanoic and octanoic acids are completely inhibitory to Escherichia coli MG1655 in minimal medium at a concentration of 40 mM, while decanoic acid was inhibitory at 20 mM. This growth inhibition is pH-dependent and is accompanied by a significant change in the fluorescence polarization (fluidity) and integrity. This inhibition and sensitivity to membrane fluidization, but not to damage of membrane integrity, can be at least partially mitigated during short-term adaptation to octanoic acid. This short-term adaptation was accompanied by a change in membrane lipid composition and a decrease in cell surface hydrophobicity. Specifically, the saturated/unsaturated lipid ratio decreased and the average lipid length increased. A fatty acid-producing strain exhibited an increase in membrane leakage as the product titer increased, but no change in membrane fluidity. These results highlight the importance of the cell membrane as a target for future metabolic engineering efforts for enabling resistance and tolerance of desirable biorenewable compounds, such as carboxylic acids. Knowledge of these effects can help in the engineering of robust biocatalysts for biorenewable chemicals production.
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Affiliation(s)
- Liam A. Royce
- Department of Chemical and Biological Engineering, Iowa State University, 3051 Sweeney Hall, Ames, IA 50011 USA
| | - Ping Liu
- Interdepartmental Microbiology Program, Iowa State University, Ames, IA 50011 USA
| | - Matthew J. Stebbins
- Department of Chemical and Biological Engineering, Iowa State University, 3051 Sweeney Hall, Ames, IA 50011 USA
| | - Benjamin C. Hanson
- Department of Chemical and Biological Engineering, Iowa State University, 3051 Sweeney Hall, Ames, IA 50011 USA
| | - Laura R. Jarboe
- Department of Chemical and Biological Engineering, Iowa State University, 3051 Sweeney Hall, Ames, IA 50011 USA
- Interdepartmental Microbiology Program, Iowa State University, Ames, IA 50011 USA
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Ma Y, Wang Z, Zhao W, Lu T, Wang R, Mei Q, Chen T. Enhanced bactericidal potency of nanoliposomes by modification of the fusion activity between liposomes and bacterium. Int J Nanomedicine 2013; 8:2351-60. [PMID: 23847417 PMCID: PMC3700910 DOI: 10.2147/ijn.s42617] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background Pseudomonas aeruginosa represents a good model of antibiotic resistance. These organisms have an outer membrane with a low level of permeability to drugs that is often combined with multidrug efflux pumps, enzymatic inactivation of the drug, or alteration of its molecular target. The acute and growing problem of antibiotic resistance of Pseudomonas to conventional antibiotics made it imperative to develop new liposome formulations to overcome these mechanisms, and investigate the fusion between liposome and bacterium. Methods The rigidity, stability and charge properties of phospholipid vesicles were modified by varying the cholesterol, 1,2-dioleoyl-sn-glycero-3-phosphatidylethanolamine (DOPE), and negatively charged lipids 1,2-dimyristoyl-sn-glycero-3-phosphoglycerol sodium salt (DMPG), 1,2-dimyristoyl-sn-glycero-3-phopho-L-serine sodium salt (DMPS), 1,2-dimyristoyl-sn-glycero-3-phosphate monosodium salt (DMPA), nature phosphatidylserine sodium salt from brain and nature phosphatidylinositol sodium salt from soybean concentrations in liposomes. Liposomal fusion with intact bacteria was monitored using a lipid-mixing assay. Results It was discovered that the fluid liposomes-bacterium fusion is not dependent on liposomal size and lamellarity. A similar degree of fusion was observed for liposomes with a particle size from 100 to 800 nm. The fluidity of liposomes is an essential pre-request for liposomes fusion with bacteria. Fusion was almost completely inhibited by incorporation of cholesterol into fluid liposomes. The increase in the amount of negative charges in fluid liposomes reduces fluid liposomes-bacteria fusion when tested without calcium cations due to electric repulsion, but addition of calcium cations brings the fusion level of fluid liposomes to similar or higher levels. Among the negative phospholipids examined, DMPA gave the highest degree of fusion, DMPS and DMPG had intermediate fusion levels, and PI resulted in the lowest degree of fusion. Furthermore, the fluid liposomal encapsulated tobramycin was prepared, and the bactericidal effect occurred more quickly when bacteria were cultured with liposomal encapsulated tobramycin. Conclusion The bactericidal potency of fluid liposomes is dramatically enhanced with respect to fusion ability when the fusogenic lipid, DOPE, is included. Regardless of changes in liposome composition, fluid liposomes-bacterium fusion is universally enhanced by calcium ions. The information obtained in this study will increase our understanding of fluid liposomal action mechanisms, and help in optimizing the new generation of fluid liposomal formulations for the treatment of pulmonary bacterial infections.
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Affiliation(s)
- Yufan Ma
- Key Laboratory for Space Bioscience and Biotechnology, School of Life Sciences, Northwestern Polytechnical University, Xi'an, Shaanxi, People's Republic of China
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Diakogiannis I, Berberi A, Siapi E, Arkoudi-Vafea A, Giannopoulou L, Mastronicolis SK. Growth and membrane fluidity of food-borne pathogen Listeria monocytogenes in the presence of weak acid preservatives and hydrochloric acid. Front Microbiol 2013; 4:152. [PMID: 23785360 PMCID: PMC3682119 DOI: 10.3389/fmicb.2013.00152] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 05/29/2013] [Indexed: 12/04/2022] Open
Abstract
This study addresses a major issue in microbial food safety, the elucidation of correlations between acid stress and changes in membrane fluidity of the pathogen Listeria monocytogenes. In order to assess the possible role that membrane fluidity changes play in L. monocytogenes tolerance to antimicrobial acids (acetic, lactic, hydrochloric acid at low pH or benzoic acid at neutral pH), the growth of the bacterium and the gel-to-liquid crystalline transition temperature point (T m) of cellular lipids of each adapted culture was measured and compared with unexposed cells. The T m of extracted lipids was measured by differential scanning calorimetry. A trend of increasing T m values but not of equal extent was observed upon acid tolerance for all samples and this increase is not directly proportional to each acid antibacterial action. The smallest increase in T m value was observed in the presence of lactic acid, which presented the highest antibacterial action. In the presence of acids with high antibacterial action such as acetic, hydrochloric acid or low antibacterial action such as benzoic acid, increased T m values were measured. The T m changes of lipids were also correlated with our previous data about fatty acid changes to acid adaptation. The results imply that the fatty acid changes are not the sole adaptation mechanism for decreased membrane fluidity (increased T m). Therefore, this study indicates the importance of conducting an in-depth structural study on how acids commonly used in food systems affect the composition of individual cellular membrane lipid molecules.
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Affiliation(s)
- Ioannis Diakogiannis
- Food Chemistry Laboratory, Department of Chemistry, University of AthensAthens, Greece
| | - Anita Berberi
- Food Chemistry Laboratory, Department of Chemistry, University of AthensAthens, Greece
| | - Eleni Siapi
- Institute of Biology, Medicinal Chemistry and Biotechnology, National Hellenic Research FoundationAthens, Greece
| | | | - Lydia Giannopoulou
- Food Chemistry Laboratory, Department of Chemistry, University of AthensAthens, Greece
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Mykytczuk NCS, Foote SJ, Omelon CR, Southam G, Greer CW, Whyte LG. Bacterial growth at -15 °C; molecular insights from the permafrost bacterium Planococcus halocryophilus Or1. THE ISME JOURNAL 2013; 7:1211-26. [PMID: 23389107 PMCID: PMC3660685 DOI: 10.1038/ismej.2013.8] [Citation(s) in RCA: 174] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 12/04/2012] [Accepted: 12/23/2012] [Indexed: 11/08/2022]
Abstract
Planococcus halocryophilus strain Or1, isolated from high Arctic permafrost, grows and divides at -15 °C, the lowest temperature demonstrated to date, and is metabolically active at -25 °C in frozen permafrost microcosms. To understand how P. halocryophilus Or1 remains active under the subzero and osmotically dynamic conditions that characterize its native permafrost habitat, we investigated the genome, cell physiology and transcriptomes of growth at -15 °C and 18% NaCl compared with optimal (25 °C) temperatures. Subzero growth coincides with unusual cell envelope features of encrustations surrounding cells, while the cytoplasmic membrane is significantly remodeled favouring a higher ratio of saturated to branched fatty acids. Analyses of the 3.4 Mbp genome revealed that a suite of cold and osmotic-specific adaptive mechanisms are present as well as an amino acid distribution favouring increased flexibility of proteins. Genomic redundancy within 17% of the genome could enable P. halocryophilus Or1 to exploit isozyme exchange to maintain growth under stress, including multiple copies of osmolyte uptake genes (Opu and Pro genes). Isozyme exchange was observed between the transcriptome data sets, with selective upregulation of multi-copy genes involved in cell division, fatty acid synthesis, solute binding, oxidative stress response and transcriptional regulation. The combination of protein flexibility, resource efficiency, genomic plasticity and synergistic adaptation likely compensate against osmotic and cold stresses. These results suggest that non-spore forming P. halocryophilus Or1 is specifically suited for active growth in its Arctic permafrost habitat (ambient temp. ∼-16 °C), indicating that such cryoenvironments harbor a more active microbial ecosystem than previously thought.
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Affiliation(s)
- Nadia C S Mykytczuk
- Department of Natural Resource Sciences, McGill University, Montreal, Quebec, Canada.
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Bergmann S, David F, Clark W, Wittmann C, Krull R. Membrane fluidity of halophilic ectoine-secreting bacteria related to osmotic and thermal treatment. Bioprocess Biosyst Eng 2013; 36:1829-41. [PMID: 23653110 DOI: 10.1007/s00449-013-0957-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 04/12/2013] [Indexed: 11/30/2022]
Abstract
In response to sudden decrease in osmotic pressure, halophilic microorganisms secrete their accumulated osmolytes. This specific stress response, combined with physiochemical responses to the altered environment, influence the membrane properties and integrity of cells, with consequent effects on growth and yields in bioprocesses, such as bacterial milking. The aim of this study was to investigate changes in membrane fluidity and integrity induced by environmental stress in ectoine-secreting organisms. The halophilic ectoine-producing strains Alkalibacillus haloalkaliphilus and Chromohalobacter salexigens were treated hypo- and hyper-osmotically at several temperatures. The steady-state anisotropy of fluorescently labeled cells was measured, and membrane integrity assessed by flow cytometry and ectoine distribution. Strong osmotic downshocks slightly increased the fluidity of the bacterial membranes. As the temperature increased, the increasing membrane fluidity encouraged more ectoine release under the same osmotic shock conditions. On the other hand, combined shock treatments increased the number of disintegrated cells. From the ectoine release and membrane integrity measurements under coupled thermal and osmotic shock conditions, we could optimize the secretion conditions for both bacteria.
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Affiliation(s)
- Sven Bergmann
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Gaußstraße 17, 38106, Braunschweig, Germany,
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133
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Kaszycki P, Walski T, Hachicho N, Heipieper HJ. Biostimulation by methanol enables the methylotrophic yeasts Hansenula polymorpha and Trichosporon sp. to reveal high formaldehyde biodegradation potential as well as to adapt to this toxic pollutant. Appl Microbiol Biotechnol 2013; 97:5555-64. [DOI: 10.1007/s00253-013-4796-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 02/17/2013] [Accepted: 02/19/2013] [Indexed: 11/27/2022]
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134
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Lai L, Lin C, Xiao CQ, Xu ZQ, Han XL, Fu L, Li DW, Mei P, Jiang FL, Guo QL, Liu Y. Adhesion of quantum dots-induced membrane damage of Escherichia coli. J Colloid Interface Sci 2013; 389:61-70. [DOI: 10.1016/j.jcis.2012.09.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 09/01/2012] [Accepted: 09/03/2012] [Indexed: 11/30/2022]
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135
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Chadeau E, Dumas E, Adt I, Degraeve P, Noël C, Girodet C, Oulahal N. Assessment of the mode of action of polyhexamethylene biguanide against Listeria innocua by Fourier transformed infrared spectroscopy and fluorescence anisotropy analysis. Can J Microbiol 2012; 58:1353-61. [PMID: 23210992 DOI: 10.1139/w2012-113] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Polyhexamethylene biguanide (PHMB) is a cationic biocide. The antibacterial mode of action of PHMB (at concentrations not exceeding its minimal inhibitory concentration) upon Listeria innocua LRGIA 01 was investigated by Fourier transformed infrared spectroscopy and fluorescence anisotropy analysis. Fourier transformed infrared spectra of bacteria treated with or without PHMB presented some differences in the lipids region: the CH(2)/CH(3) (2924 cm(-1)/2960 cm(-1)) band areas ratio significantly increased in the presence of PHMB. Since this ratio generally reflects membrane phospholipids and membrane microenvironment of the cells, these results suggest that PHMB molecules interact with membrane phospholipids and, thus, affect membrane fluidity and conformation. To assess the hypothesis of PHMB interaction with L. innocua membrane phospholipids and to clarify the PHMB mode of action, we performed fluorescence anisotropy experiments. Two probes, 1,6-diphenyl-1,3,5-hexatriene (DPH) and its derivative 1-[4-(trimethyl-amino)-phenyl]-6-phenylhexa-1,3,5-triene (TMA-DPH), were used. DPH and TMA-DPH incorporate inside and at the surface of the cytoplasmic membrane, respectively. When PHMB was added, an increase of TMA-DPH fluorescence anisotropy was observed, but no changes of DPH fluorescence anisotropy occurred. These results are consistent with the hypothesis that PHMB molecules perturb L. innocua LRGIA 01 cytoplasmic membrane by interacting with the first layer of the membrane lipid bilayer.
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Affiliation(s)
- Elise Chadeau
- Université de Lyon, Université Lyon 1 - ISARA Lyon, Bioingénierie et Dynamique Microbienne aux Interfaces Alimentaires, IUT Lyon 1 site de Bourg en Bresse - Technopole Alimentec, rue Henri de Boissieu, 01000 Bourg en Bresse, France
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Puspita ID, Kamagata Y, Tanaka M, Asano K, Nakatsu CH. Are uncultivated bacteria really uncultivable? Microbes Environ 2012; 27:356-66. [PMID: 23059723 PMCID: PMC4103542 DOI: 10.1264/jsme2.me12092] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Accepted: 06/20/2012] [Indexed: 11/16/2022] Open
Abstract
Many strategies have been used to increase the number of bacterial cells that can be grown from environmental samples but cultivation efficiency remains a challenge for microbial ecologists. The difficulty of cultivating a fraction of bacteria in environmental samples can be classified into two non-exclusive categories. Bacterial taxa with no cultivated representatives for which appropriate laboratory conditions necessary for growth are yet to be identified. The other class is cells in a non-dividing state (also known as dormant or viable but not culturable cells) that require the removal or addition of certain factors to re-initiate growth. A number of strategies, from simple to high throughput techniques, are reviewed that have been used to increase the cultivation efficiency of environmental samples. Some of the underlying mechanisms that contribute to the success of these cultivation strategies are described. Overall this review emphasizes the need of researchers to first understand the factors that are hindering cultivation to identify the best strategies to improve cultivation efficiency.
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Affiliation(s)
- Indun Dewi Puspita
- Graduate School of Agriculture, Hokkaido University, N9 W9, Kita-ku, Sapporo, Hokkaido 060–8589,
Japan
| | - Yoichi Kamagata
- Graduate School of Agriculture, Hokkaido University, N9 W9, Kita-ku, Sapporo, Hokkaido 060–8589,
Japan
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 2–17 Tsukisamu-Higashi, Toyohira, Sapporo, Hokkaido 062–8517,
Japan
| | - Michiko Tanaka
- Graduate School of Agriculture, Hokkaido University, N9 W9, Kita-ku, Sapporo, Hokkaido 060–8589,
Japan
| | - Kozo Asano
- Graduate School of Agriculture, Hokkaido University, N9 W9, Kita-ku, Sapporo, Hokkaido 060–8589,
Japan
| | - Cindy H. Nakatsu
- Graduate School of Agriculture, Hokkaido University, N9 W9, Kita-ku, Sapporo, Hokkaido 060–8589,
Japan
- Department of Agronomy, Purdue University, West Lafayette, Indiana 47907,
USA
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137
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Lactobacillus casei combats acid stress by maintaining cell membrane functionality. ACTA ACUST UNITED AC 2012; 39:1031-9. [DOI: 10.1007/s10295-012-1104-2] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2011] [Accepted: 02/06/2012] [Indexed: 10/28/2022]
Abstract
Abstract
Lactobacillus casei strains have traditionally been recognized as probiotics and frequently used as adjunct culture in fermented dairy products where lactic acid stress is a frequently encountered environmental condition. We have investigated the effect of lactic acid stress on the cell membrane of L. casei Zhang [wild type (WT)] and its acid-resistant mutant Lbz-2. Both strains were grown under glucose-limiting conditions in chemostats; following challenge by low pH, the cell membrane stress responses were investigated. In response to acid stress, cell membrane fluidity decreased and its fatty acid composition changed to reduce the damage caused by lactic acid. Compared with the WT, the acid-resistant mutant exhibited numerous survival advantages, such as higher membrane fluidity, higher proportions of unsaturated fatty acids, and higher mean chain length. In addition, cell integrity analysis showed that the mutant maintained a more intact cellular structure and lower membrane permeability after environmental acidification. These results indicate that alteration in membrane fluidity, fatty acid distribution, and cell integrity are common mechanisms utilized by L. casei to withstand severe acidification and to reduce the deleterious effect of lactic acid on the cell membrane. This detailed comparison of cell membrane responses between the WT and mutant add to our knowledge of the acid stress adaptation and thus enable new strategies to be developed aimed at improving the industrial performance of this species under acid stress.
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138
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Liu X, Gai Z, Tao F, Tang H, Xu P. Carotenoids play a positive role in the degradation of heterocycles by Sphingobium yanoikuyae. PLoS One 2012; 7:e39522. [PMID: 22745775 PMCID: PMC3380023 DOI: 10.1371/journal.pone.0039522] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 05/22/2012] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Microbial oxidative degradation is a potential way of removing pollutants such as heterocycles from the environment. During this process, reactive oxygen species or other oxidants are inevitably produced, and may cause damage to DNA, proteins, and membranes, thereby decreasing the degradation rate. Carotenoids can serve as membrane-integrated antioxidants, protecting cells from oxidative stress. FINDINGS Several genes involved in the carotenoid biosynthetic pathway were cloned and characterized from a carbazole-degrading bacterium Sphingobium yanoikuyae XLDN2-5. In addition, a yellow-pigmented carotenoid synthesized by strain XLDN2-5 was identified as zeaxanthin that was synthesized from β-carotene through β-cryptoxanthin. The amounts of zeaxanthin and hydrogen peroxide produced were significantly and simultaneously enhanced during the biodegradation of heterocycles (carbazole < carbazole + benzothiophene < carbazole + dibenzothiophene). These higher production levels were consistent with the transcriptional increase of the gene encoding phytoene desaturase, one of the key enzymes for carotenoid biosynthesis. CONCLUSIONS/SIGNIFICANCE Sphingobium yanoikuyae XLDN2-5 can enhance the synthesis of zeaxanthin, one of the carotenoids, which may modulate membrane fluidity and defense against intracellular oxidative stress. To our knowledge, this is the first report on the positive role of carotenoids in the biodegradation of heterocycles, while elucidating the carotenoid biosynthetic pathway in the Sphingobium genus.
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Affiliation(s)
- Xiaorui Liu
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, People′s Republic of China
| | - Zhonghui Gai
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, People′s Republic of China
| | - Fei Tao
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, People′s Republic of China
| | - Hongzhi Tang
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, People′s Republic of China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, People′s Republic of China
- * E-mail:
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139
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Abstract
As members of the indigenous human microbiota found on several mucosal tissues, Methanobrevibacter smithii and Methanosphaera stadtmanae are exposed to the effects of antimicrobial peptides (AMPs) secreted by these epithelia. Although antimicrobial and molecular effects of AMPs on bacteria are well described, data for archaea are not available yet. Besides, it is not clear whether AMPs affect them as the archaeal cell envelope differs profoundly in terms of chemical composition and structure from that of bacteria. The effects of different synthetic AMPs on growth of M. smithii, M. stadtmanae, and Methanosarcina mazei were tested using a microtiter plate assay adapted to their anaerobic growth requirements. All three tested methanoarchaea were highly sensitive against derivatives of human cathelicidin, of porcine lysin, and a synthetic antilipopolysaccharide peptide (Lpep); however, sensitivities differed markedly among the methanoarchaeal strains. The potent AMP concentrations affecting growth were below 10 μM, whereas growth of Escherichia coli WBB01 was not affected at peptide concentrations up to 10 μM under the same anaerobic growth conditions. Atomic force microscopy and transmission electron microscopy revealed that the structural integrity of the methanoarchaeal cells is destroyed within 4 h after incubation with AMPs. The disruption of the cell envelope of M. smithii, M. stadtmanae, and M. mazei within a few minutes of exposure was verified by using LIVE/DEAD staining. Our results strongly suggest that the release of AMPs by eukaryotic epithelial cells is a potent defense mechanism targeting not only bacteria, but also methanoarchaea.
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140
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Cacas JL, Furt F, Le Guédard M, Schmitter JM, Buré C, Gerbeau-Pissot P, Moreau P, Bessoule JJ, Simon-Plas F, Mongrand S. Lipids of plant membrane rafts. Prog Lipid Res 2012; 51:272-99. [PMID: 22554527 DOI: 10.1016/j.plipres.2012.04.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Lipids tend to organize in mono or bilayer phases in a hydrophilic environment. While they have long been thought to be incapable of coherent lateral segregation, it is now clear that spontaneous assembly of these compounds can confer microdomain organization beyond spontaneous fluidity. Membrane raft microdomains have the ability to influence spatiotemporal organization of protein complexes, thereby allowing regulation of cellular processes. In this review, we aim at summarizing briefly: (i) the history of raft discovery in animals and plants, (ii) the main findings about structural and signalling plant lipids involved in raft segregation, (iii) imaging of plant membrane domains, and their biochemical purification through detergent-insoluble membranes, as well as the existing debate on the topic. We also discuss the potential involvement of rafts in the regulation of plant physiological processes, and further discuss the prospects of future research into plant membrane rafts.
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Affiliation(s)
- Jean-Luc Cacas
- Laboratoire de Biogenèse Membranaire, UMR 5200 CNRS, Université de Bordeaux, 146 Rue Léo Saignat, 33076 Bordeaux, France
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141
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Comparative lipidomic analysis of Cephalosporium acremonium insights into industrial and pilot fermentations. BIOTECHNOL BIOPROC E 2012. [DOI: 10.1007/s12257-011-0494-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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142
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de Carvalho CC. Adaptation of Rhodococcus erythropolis cells for growth and bioremediation under extreme conditions. Res Microbiol 2012; 163:125-36. [DOI: 10.1016/j.resmic.2011.11.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 11/05/2011] [Indexed: 10/15/2022]
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143
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Trevors J, Pollack G. Origin of microbial life hypothesis: A gel cytoplasm lacking a bilayer membrane, with infrared radiation producing exclusion zone (EZ) water, hydrogen as an energy source and thermosynthesis for bioenergetics. Biochimie 2012; 94:258-62. [DOI: 10.1016/j.biochi.2011.10.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2011] [Accepted: 10/05/2011] [Indexed: 10/16/2022]
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144
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Ethanol induced response in Phanerochaete chrysosporium and its role in the decolorization of triarylmethane dye. ANN MICROBIOL 2011. [DOI: 10.1007/s13213-011-0390-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022] Open
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145
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Waranusantigul P, Lee H, Kruatrachue M, Pokethitiyook P, Auesukaree C. Isolation and characterization of lead-tolerant Ochrobactrum intermedium and its role in enhancing lead accumulation by Eucalyptus camaldulensis. CHEMOSPHERE 2011; 85:584-590. [PMID: 21764101 DOI: 10.1016/j.chemosphere.2011.06.086] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Revised: 06/21/2011] [Accepted: 06/21/2011] [Indexed: 05/31/2023]
Abstract
In this study, the potential of rhizospheric bacteria in promoting the growth and Pb accumulation by the woody plant Eucalyptus camaldulensis under hydroponic conditions was investigated for the first time. Three Pb-tolerant bacteria were isolated from the rhizosphere of E. camaldulensis grown in Pb-contaminated soils in the Bo Ngam Pb mine, Thailand. Based on analysis of partial 16S rRNA gene sequence, the three isolates were identified as Microbacterium paraoxydans BN-2, Ochrobactrum intermedium BN-3, and Bacillus fusiformis BN-4. Among these strains, O. intermedium BN-3 showed the highest tolerance to not only Pb but also Cd and Zn. After growth in the presence of Pb, the membranes of O. intermedium BN-3 cells exhibited an increase in unsaturated fatty acid levels but a decrease in fluidity. In hydroponic studies, inoculation of O. intermedium BN-3 significantly increased the biomass and Pb accumulation by E. camaldulensis compared to the uninoculated control. The results suggested the role of the natural rhizospheric bacteria localized to the root surface of E. camaldulensis in promoting Pb accumulation and plant growth. Our results indicate that O. intermedium BN-3 and other indigenous rhizospheric bacteria have the potential to improve the efficiency of phytoremediation of Pb-contaminated sites.
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146
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Kaiser HJ, Surma MA, Mayer F, Levental I, Grzybek M, Klemm RW, Da Cruz S, Meisinger C, Müller V, Simons K, Lingwood D. Molecular convergence of bacterial and eukaryotic surface order. J Biol Chem 2011; 286:40631-7. [PMID: 21965671 DOI: 10.1074/jbc.m111.276444] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The conservation of fluidity is a theme common to all cell membranes. In this study, an analysis of lipid packing was conducted via C-laurdan spectroscopy of cell surface membranes prepared from representative species of Bacteria and Eukarya. We found that despite their radical differences in composition (namely the presence and absence of membrane-rigidifying sterol) the membrane order of all taxa converges on a remarkably similar level. To understand how this similarity is constructed, we reconstituted membranes with either bacterial or eukaryotic components. We found that transmembrane segments of proteins have an important role in buffering lipid-mediated packing. This buffering ensures that sterol-free and sterol-containing membranes exhibit similar barrier properties.
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Affiliation(s)
- Hermann-Josef Kaiser
- Max Planck Institute for Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, Dresden 01307, Germany
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147
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Glycine and its N-methylated analogues cause pH-dependent membrane damage to enterotoxigenic Escherichia coli. Amino Acids 2011; 43:245-53. [PMID: 21912862 DOI: 10.1007/s00726-011-1068-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 08/25/2011] [Indexed: 10/17/2022]
Abstract
The current study first investigates the emulsifying potential of glycine and its N-methylated derivatives N-methylglycine (sarcosine), N,N-dimethylglycine (DMG) and N,N,N-trimethylglycine (betaine) under varying pH conditions. Subsequently, the effect of these test compounds on the membrane integrity of enterotoxigenic Escherichia coli (ETEC) was evaluated. Oil in water emulsions containing each compound show that DMG is a more potent enhancer of emulsification than glycine, sarcosine and betaine under the conditions tested. Flow cytometry was used to investigate whether the emulsifying potential is associated with an effect on ETEC membrane integrity. The bacteria were exposed to each of the test compounds under varying pH conditions and membrane integrity was assessed using the LIVE/DEAD BacLight kit. Results show a membrane deteriorating effect caused by glycine, sarcosine and DMG, but not by betaine. This effect is pH- and time-dependent and has an apparent threshold at pH 9.0. Conventional plate counts confirmed concomitant changes in culturability of the membrane comprised bacteria.
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148
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Mykytczuk NCS, Trevors JT, Foote SJ, Leduc LG, Ferroni GD, Twine SM. Proteomic insights into cold adaptation of psychrotrophic and mesophilic Acidithiobacillus ferrooxidans strains. Antonie Van Leeuwenhoek 2011; 100:259-77. [DOI: 10.1007/s10482-011-9584-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Accepted: 04/29/2011] [Indexed: 11/29/2022]
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149
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The cell membrane as a major site of damage during aerosolization of Escherichia coli. Appl Environ Microbiol 2010; 77:920-5. [PMID: 21148696 DOI: 10.1128/aem.01116-10] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
This study aimed to provide data on the survival and site of damage of Escherichia coli cells following aerosolization using two different techniques, nebulization and flow focusing. Four metabolic stains were assessed for their ability to detect respiratory activities and membrane homeostasis in aerosolized E. coli cells. The degree of sublethal injury increased significantly over the 10-min period of aerosolization in E. coli cells aerosolized by using the Collison nebulizer, reaching up to 99.9% of the population. In contrast, a significantly lower proportion of the population was sublethally damaged during aerosolization using the flow-focusing aerosol generator (FFAG). Concomitantly, loss of membrane homeostasis increased at a higher rate in nebulized cells (68 to 71%) than in those aerosolized by using the FFAG (32 to 34%). The activities of respiratory enzymes decreased at increased rates in nebulized cells (27 to 37%) compared to the rates of decrease in cells aerosolized by using the FFAG (59 to 61%). The results indicate that the physiology of an aerosolized bacterium is linked to the method of aerosol generation and may affect the interpretation of a range of aerobiological phenomenon.
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150
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Bakolitsa C, Kumar A, McMullan D, Krishna SS, Miller MD, Carlton D, Najmanovich R, Abdubek P, Astakhova T, Chiu HJ, Clayton T, Deller MC, Duan L, Elias Y, Feuerhelm J, Grant JC, Grzechnik SK, Han GW, Jaroszewski L, Jin KK, Klock HE, Knuth MW, Kozbial P, Marciano D, Morse AT, Nigoghossian E, Okach L, Oommachen S, Paulsen J, Reyes R, Rife CL, Trout CV, van den Bedem H, Weekes D, White A, Xu Q, Hodgson KO, Wooley J, Elsliger MA, Deacon AM, Godzik A, Lesley SA, Wilson IA. The structure of the first representative of Pfam family PF06475 reveals a new fold with possible involvement in glycolipid metabolism. Acta Crystallogr Sect F Struct Biol Cryst Commun 2010; 66:1211-7. [PMID: 20944213 PMCID: PMC2954207 DOI: 10.1107/s1744309109022684] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Accepted: 06/12/2009] [Indexed: 11/12/2022]
Abstract
The crystal structure of PA1994 from Pseudomonas aeruginosa, a member of the Pfam PF06475 family classified as a domain of unknown function (DUF1089), reveals a novel fold comprising a 15-stranded β-sheet wrapped around a single α-helix that assembles into a tight dimeric arrangement. The remote structural similarity to lipoprotein localization factors, in addition to the presence of an acidic pocket that is conserved in DUF1089 homologs, phospholipid-binding and sugar-binding proteins, indicate a role for PA1994 and the DUF1089 family in glycolipid metabolism. Genome-context analysis lends further support to the involvement of this family of proteins in glycolipid metabolism and indicates possible activation of DUF1089 homologs under conditions of bacterial cell-wall stress or host-pathogen interactions.
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Affiliation(s)
- Constantina Bakolitsa
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
| | - Abhinav Kumar
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Daniel McMullan
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - S. Sri Krishna
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Mitchell D. Miller
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Dennis Carlton
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | | | - Polat Abdubek
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Tamara Astakhova
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Hsiu-Ju Chiu
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Thomas Clayton
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Marc C. Deller
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Lian Duan
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Ylva Elias
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Julie Feuerhelm
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Joanna C. Grant
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Slawomir K. Grzechnik
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Gye Won Han
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Lukasz Jaroszewski
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Kevin K. Jin
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Heath E. Klock
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Mark W. Knuth
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Piotr Kozbial
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
| | - David Marciano
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Andrew T. Morse
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Edward Nigoghossian
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Linda Okach
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Silvya Oommachen
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Jessica Paulsen
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Ron Reyes
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Christopher L. Rife
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Christina V. Trout
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Henry van den Bedem
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Dana Weekes
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
| | - Aprilfawn White
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
| | - Qingping Xu
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Keith O. Hodgson
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Photon Science, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - John Wooley
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Marc-André Elsliger
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Ashley M. Deacon
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Adam Godzik
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Program on Bioinformatics and Systems Biology, Burnham Institute for Medical Research, La Jolla, CA, USA
- Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA, USA
| | - Scott A. Lesley
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Protein Sciences Department, Genomics Institute of the Novartis Research Foundation, San Diego, CA, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Ian A. Wilson
- Joint Center for Structural Genomics, http://www.jcsg.org, USA
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
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