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Thakur S, Singh A, Sharma R, Aurora R, Jain SK. Biosurfactants as a Novel Additive in Pharmaceutical Formulations: Current Trends and Future Implications. Curr Drug Metab 2020; 21:885-901. [PMID: 33032505 DOI: 10.2174/1389200221666201008143238] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/09/2020] [Accepted: 08/13/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND Surfactants are an important category of additives that are used widely in most of the formulations as solubilizers, stabilizers, and emulsifiers. Current drug delivery systems comprise of numerous synthetic surfactants (such as Cremophor EL, polysorbate 80, Transcutol-P), which are associated with several side effects though used in many formulations. Therefore, to attenuate the problems associated with conventional surfactants, a new generation of surface-active agents is obtained from the metabolites of fungi, yeast, and bacteria, which are termed as biosurfactants. OBJECTIVES In this article, we critically analyze the different types of biosurfactants, their origin along with their chemical and physical properties, advantages, drawbacks, regulatory status, and detailed pharmaceutical applications. METHODS 243 papers were reviewed and included in this review. RESULTS Briefly, Biosurfactants are classified as glycolipids, rhamnolipids, sophorolipids, trehalolipids, surfactin, lipopeptides & lipoproteins, lichenysin, fatty acids, phospholipids, and polymeric biosurfactants. These are amphiphilic biomolecules with lipophilic and hydrophilic ends and are used as drug delivery vehicles (foaming, solubilizer, detergent, and emulsifier) in the pharmaceutical industry. Despite additives, they have some biological activity as well (anti-cancer, anti-viral, anti-microbial, P-gp inhibition, etc.). These biomolecules possess better safety profiles and are biocompatible, biodegradable, and specific at different temperatures. CONCLUSION Biosurfactants exhibit good biomedicine and additive properties that can be used in developing novel drug delivery systems. However, more research should be driven due to the lack of comprehensive toxicity testing and high production cost which limits their use.
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Affiliation(s)
- Shubham Thakur
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, 143005, India
| | - Amrinder Singh
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, 143005, India
| | - Ritika Sharma
- Sri Sai College of Pharmacy, Badhani, Pathankot, 145001, India
| | - Rohan Aurora
- The International School Bangalore, Karnataka, 562125, India
| | - Subheet Kumar Jain
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, 143005, India
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Campodonico MA, Vaisman D, Castro JF, Razmilic V, Mercado F, Andrews BA, Feist AM, Asenjo JA. Acidithiobacillus ferrooxidans's comprehensive model driven analysis of the electron transfer metabolism and synthetic strain design for biomining applications. Metab Eng Commun 2016; 3:84-96. [PMID: 29468116 PMCID: PMC5779729 DOI: 10.1016/j.meteno.2016.03.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 12/16/2015] [Accepted: 03/14/2016] [Indexed: 10/28/2022] Open
Abstract
Acidithiobacillus ferrooxidans is a gram-negative chemolithoautotrophic γ-proteobacterium. It typically grows at an external pH of 2 using the oxidation of ferrous ions by oxygen, producing ferric ions and water, while fixing carbon dioxide from the environment. A. ferrooxidans is of great interest for biomining and environmental applications, as it can process mineral ores and alleviate the negative environmental consequences derived from the mining processes. In this study, the first genome-scale metabolic reconstruction of A. ferrooxidans ATCC 23270 was generated (iMC507). A total of 587 metabolic and transport/exchange reactions, 507 genes and 573 metabolites organized in over 42 subsystems were incorporated into the model. Based on a new genetic algorithm approach, that integrates flux balance analysis, chemiosmotic theory, and physiological data, the proton translocation stoichiometry for a number of enzymes and maintenance parameters under aerobic chemolithoautotrophic conditions using three different electron donors were estimated. Furthermore, a detailed electron transfer and carbon flux distributions during chemolithoautotrophic growth using ferrous ion, tetrathionate and thiosulfate were determined and reported. Finally, 134 growth-coupled designs were calculated that enables Extracellular Polysaccharide production. iMC507 serves as a knowledgebase for summarizing and categorizing the information currently available for A. ferrooxidans and enables the understanding and engineering of Acidithiobacillus and similar species from a comprehensive model-driven perspective for biomining applications.
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Affiliation(s)
- Miguel A Campodonico
- Centre for Biotechnology and Bioengineering, CeBiB, University of Chile, Beauchef 850, Santiago, Chile
| | - Daniela Vaisman
- Centre for Biotechnology and Bioengineering, CeBiB, University of Chile, Beauchef 850, Santiago, Chile
| | - Jean F Castro
- Centre for Biotechnology and Bioengineering, CeBiB, University of Chile, Beauchef 850, Santiago, Chile
| | - Valeria Razmilic
- Centre for Biotechnology and Bioengineering, CeBiB, University of Chile, Beauchef 850, Santiago, Chile
| | - Francesca Mercado
- Centre for Biotechnology and Bioengineering, CeBiB, University of Chile, Beauchef 850, Santiago, Chile
| | - Barbara A Andrews
- Centre for Biotechnology and Bioengineering, CeBiB, University of Chile, Beauchef 850, Santiago, Chile
| | - Adam M Feist
- Department of Bioengineering, University of California, 9500 Gilman Drive # 0412, San Diego, La Jolla, CA 92093, USA
| | - Juan A Asenjo
- Centre for Biotechnology and Bioengineering, CeBiB, University of Chile, Beauchef 850, Santiago, Chile
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An overview of techniques for the characterization and quantification of microbial colonization on stone monuments. ANN MICROBIOL 2014. [DOI: 10.1007/s13213-014-0956-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Sand W. The influence of four detergents on the substrate oxidation by thiobacillus ferrooxidans. ACTA ACUST UNITED AC 2008. [DOI: 10.1080/09593338509384362] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Abstract
Evidence is discussed for roles of cardiolipins in oxidative phosphorylation mechanisms that regulate State 4 respiration by returning ejected protons across and over bacterial and mitochondrial membrane phospholipids, and that regulate State 3 respiration through the relative contributions of proteins that transport protons, electrons and/or metabolites. The barrier properties of phospholipid bilayers support and regulate the slow proton leak that is the basis for State 4 respiration. Proton permeability is in the range 10(-3)-10(-4) cm s-1 in mitochondria and in protein-free membranes formed from extracted mitochondrial phospholipids or from stable synthetic phosphatidylcholines or phosphatidylethanolamines. The roles of cardiolipins in proton conductance in model phospholipid membrane systems need to be assessed in view of new findings by Hübner et al. [313]: saturated cardiolipins form bilayers whilst natural highly unsaturated cardiolipins form nonlamellar phases. Mitochondrial cardiolipins apparently participate in bilayers formed by phosphatidylcholines and phosphatidylethanolamines. It is not yet clear if cardiolipins themselves conduct protons back across the membrane according to their degree of fatty acyl saturation, and/or modulate proton conductance by phosphatidylcholines and phosphatidylethanolamines. Mitochondrial cardiolipins, especially those with high 18:2 acyl contents, strongly bind many carrier and enzyme proteins that are involved in oxidative phosphorylation, some of which contribute to regulation of State 3 respiration. The role of cardiolipins in biomembrane protein function has been examined by measuring retained phospholipids and phospholipid binding in purified proteins, and by reconstituting delipidated proteins. The reconstitution criterion for the significance of cardiolipin-protein interactions has been catalytical activity; proton-pumping and multiprotein interactions have yet to be correlated. Some proteins, e.g., cytochrome c oxidase are catalytically active when dimyristoylphosphatidylcholine replaces retained cardiolipins. Cardiolipin-protein interactions orient membrane proteins, matrix proteins, and on the outerface receptors, enzymes, and some leader peptides for import; activate enzymes or keep them inactive unless the inner membrane is disrupted; and modulate formation of nonbilayer HII-phases. The capacity of the proton-exchanging uncoupling protein to accelerate thermogenic respiration in brown adipose tissue mitochondria of cold-adapted animals is not apparently affected by the increased cardiolipin unsaturation; this protein seems to take over the protonophoric role of cardiolipins in other mitochondria. Many in vivo influences that affect proton leakage and carrier rates selectively alter cardiolipins in amount per mitochondrial phospholipids, in fatty acyl composition and perhaps in sidedness; other mitochondrial membrane phospholipids respond less or not at all.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- F L Hoch
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor
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8
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Nicolaus B, Trincone A, Esposito E, Vaccaro MR, Gambacorta A, De Rosa M. Calditol tetraether lipids of the archaebacterium Sulfolobus solfataricus. Biosynthetic studies. Biochem J 1990; 266:785-91. [PMID: 2109600 PMCID: PMC1131208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Lipids from the archaebacterium Sulfolobus solfataricus are based on 72-membered macrocyclic tetraethers made up from two C40 diol units differently cyclized and either two glycerol moieties or one glycerol moiety and a unique branched-chain nonitol named calditol (glycerodialkylnonitol tetraethers, GDNTs). To elucidate the biosynthesis of calditol and related tetraethers, labelled precursors, [U-14C,1(3)-3H]glycerol, [U-14C,2-3H]glycerol, D-[1-14C,6-3H]glucose, D-[6-14C,1-3H]glucose, D-[1-14C,2-3H]glucose, D-[1-14C,6-3H]fructose and D-[1-14C]galactose, were fed to S. solfataricus. Without regard to stereochemistry or phosphorylation, incorporation experiments provided evidence that the biosynthesis of calditol occurs via an aldolic condensation between dihydroxyacetone and fructose, through a 2-oxo derivative of calditol as an intermediate. The latter is in turn reduced and then alkylated to yield the GDNTs. The biogenetic origins of both glycerol and C40 isoprenoid moieties of GDNTs are also discussed.
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Affiliation(s)
- B Nicolaus
- Istituto per la Chimica di Molecole di Interesse Biologico del Consiglio Nazionale delle Ricerche, Napoli, Italy
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Ghosh M, Mishra AK. Effect of cultural conditions on the lipid profile of Thiobacillus ferroxidas. Arch Microbiol 1985. [DOI: 10.1007/bf00411253] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Production of emulsifying agent during growth of Pseudomonas cepacia with 2,4,5-trichlorophenoxyacetic acid. Arch Microbiol 1983. [DOI: 10.1007/bf00408018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Goldfine H. Lipids of Prokaryotes–Structure and Distribution. CURRENT TOPICS IN MEMBRANES AND TRANSPORT 1982. [DOI: 10.1016/s0070-2161(08)60307-x] [Citation(s) in RCA: 77] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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12
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Langworthy TA. Lipids of Bacteria Living in Extreme Environments. CURRENT TOPICS IN MEMBRANES AND TRANSPORT 1982. [DOI: 10.1016/s0070-2161(08)60308-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Chapter 6.3 Oxidative Reactions in the Sulfur Cycle. ACTA ACUST UNITED AC 1979. [DOI: 10.1016/s0166-1116(08)71064-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Abstract
The phospholipid composition of Caulobacter crescentus CB13 and CB15 was determined. The acidic phospholipids, phosphatidylglycerol and cardiolipin, comprise approximately 87% of the total phospholipids. Neither phosphatidylethanolamine nor its precursor phosphatidylserine was detected. The outer and inner membranes of C. crescentus CB13 were separated, and phospholipid analysis revealed heterogeneity with respect to the relative amounts of phosphatidylglycerol and cardiolipin in the two membranes. As has been shown to be the case for other bacterial membranes, the concentration of cardiolipin increases and phosphatidylglycerol decreases as cell cultures enter stationary phase.
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16
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Intracytoplasmic membrane production inEscherichia coli O111a1: Phospholipid biosynthesis. Curr Microbiol 1978. [DOI: 10.1007/bf02602846] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Langworthy TA. Comparative lipid composition of heterotrophically and autotrophically grown Sulfolobus acidocaldarius. J Bacteriol 1977; 130:1326-32. [PMID: 863856 PMCID: PMC235357 DOI: 10.1128/jb.130.3.1326-1332.1977] [Citation(s) in RCA: 44] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Complex lipids from the thermoacidophilic facultative autotroph Sulfolobus acidocaldarius, as well as a strictly autotrophic isolate, were compared between cells grown on yeast extract and elemental sulfur. Lipids from both organisms grown autotrophically were nearly identical. Each contained about 15% neutral lipids, 35% glycolipids, and 50% acidic lipids. Glycolipids and acidic lipids contained C40H82-76-derived glycerol ether residues. Major glycolipids included the glycerol ether analogues of glucosyl galactosyl diglyceride (5%) and glucosyl polyol diglyceride (75%). Acidic lipids were comprised mainly of the glycerol ether analogues of phosphatidyl inositol (7%), inositolphosphoryl glucosyl polyol diglyceride (72%), and a partially characterized sulfate- and phosphate-containing derivative of glucosyl polyol diglyceride (13%). The lipids from cells grown heterotrophically were similar to those from autotrophically grown cells, except that the partially characterized acidic lipid was absent. In addition, the two glycolipids as well as the respective inositolphosphoryl derivatives were each present in nearly equal proportions.
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Shaw N. Lipid composition as a guide to the classification of bacteria. ADVANCES IN APPLIED MICROBIOLOGY 1974; 17:63-108. [PMID: 4213752 DOI: 10.1016/s0065-2164(08)70555-0] [Citation(s) in RCA: 213] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Agate AD, Vishniac W. Changes in phospholipid composition of Thiobacillus neapolitanus during growth. ARCHIV FUR MIKROBIOLOGIE 1973; 89:247-55. [PMID: 4692631 DOI: 10.1007/bf00422205] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Agate AD, Vishniac W. Iron transport by phospholipids in a two phase system containing water and n-pentanol. Chem Phys Lipids 1972; 9:247-54. [PMID: 4360434 DOI: 10.1016/0009-3084(72)90005-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Sadler MH, Johnson EJ. A comparison of the NADH oxidase electron transport systems of two obligately chemolithotrophic bacteria. BIOCHIMICA ET BIOPHYSICA ACTA 1972; 283:167-79. [PMID: 4404938 DOI: 10.1016/0005-2728(72)90108-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Tuovinen OH, Kelly DP. Biology of Thiobacillus ferrooxidans in relation to the microbiological leaching of sulphide ores. ZEITSCHRIFT FUR ALLGEMEINE MIKROBIOLOGIE 1972; 12:311-46. [PMID: 4561082 DOI: 10.1002/jobm.3630120406] [Citation(s) in RCA: 120] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Abstract
Fatty acid spectra were made on Thiobacillus thiooxidans cultures both in the presence and absence of organic compounds. Small additions of glucose or acetate had no significant effect either on growth or fatty acid content. The addition of biotin had no stimulatory effect but did result in slight quantitative changes in the fatty acid spectrum. The predominant fatty acid was a C(19) cyclopropane acid.
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Langenbach RJ, Knoche HW. Phospholipids in the Uredospores of Uromyces phaseoli: I. Identification and Localization. PLANT PHYSIOLOGY 1971; 48:728-34. [PMID: 16657869 PMCID: PMC396937 DOI: 10.1104/pp.48.6.728] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Utilizing paper, thin layer and gas chromatography, the phospholipids of dormant and germinating spores have been isolated and identified. The identifications were based upon agreements of retardation factor values between the unknowns and reference compounds and their derivatives. Quantitative analysis of components, color reactions and specific labeling experiments were also used to support certain identifications. At least three, and usually more, criteria were used for each phospholipid that was definitively identified.The major phospholipids of Uromyces phaseoli are phosphatidylcholine and phosphatidylethanolamine. Diphosphatidylglycerol, or cardiolipin, phosphatidylinositol, and another phosphoinositide were present as minor components. In germinating spores, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, phosphatidylserine, and phosphatidic acid were detected in trace amounts. The presence of these common intermediates in the biosynthesis of phospholipids indicates that phospholipid synthesis is active during the germination process. Except for the absence of phosphatidylglycerol, the types of phospholipids present are similar to the host plant. Germ tube wall preparations were found to contain phosphatidylcholine and phosphatidylethanolamine in about the same proportion as that observed in resting spores, while the proportion of diphosphatidylglycerol was about three times higher. An unidentified phosphorous-containing lipid was also a significant component of the total phospholipids extracted from germ tube walls.
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Affiliation(s)
- R J Langenbach
- Department of Biochemistry and Nutrition, University of Nebraska, Lincoln, Nebraska 68503
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Langenbach RJ, Knoche HW. Phospholipids in the Uredospores of Uromyces phaseoli: II. Metabolism during Germination. PLANT PHYSIOLOGY 1971; 48:735-9. [PMID: 16657870 PMCID: PMC396938 DOI: 10.1104/pp.48.6.735] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The levels and types of phospholipids changed in distinct phases during the germination of (32)P-labeled uredospores of Uromyces phaseoli. During the first 20 minutes of germination, the phospholipid content dropped to 40% of the pregermination level. Between 2 and 3 hours, phospholipid levels increased to approximately 80% of the pregermination levels, and after germination for 5 hours, catabolism had reduced the (32)P-lipids to about the same level observed prior to the first anabolic phase. A second anabolic phase was observed between 5 and 10 hours of germination. Phosphatidylcholine and phosphatidylethanolamine, the major phospholipids, did not undergo anabolism and catabolism at the same rates during germination. Only small quantities of the more polar phospholipids were released to the germination media.Germinating uredospores were capable of utilizing l-methionine-methyl-(14)C, d,l-(14)C serine, (14)C-choline, and (14)C-ethanolamine for the synthesis of phospholipids. The active one-carbon units from methionine and serine appear to be involved in the methylation of phosphatidylethanolamine to form phosphatidylcholine. Preformed ethanolamine and choline may be incorporated into these two phospholipids also. Evidence for the synthesis of phosphatidylserine, which is subsequently decarboxylated to yield phosphatidylethanolamine, was obtained.
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Affiliation(s)
- R J Langenbach
- Department of Biochemistry and Nutrition, University of Nebraska, Lincoln, Nebraska 68503
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Abstract
The extracellular lipid of Thiobacillus thiooxidans is a heterogeneous mixture of phospholipid and neutral lipid, primarily free fatty acids.
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Abstract
Infection of Escherichia coli with amber mutants of phage fd, in contrast to infection with wild-type phage, leads to cell death and the proliferation of intracytoplasmic membranes observed in electron micrographs at the poles of the cells. The accumulation of membranes correlates with changes in structural phospholipids, especially a marked increase in the apparent rate of formation and total amount of cardiolipin (from 4 to 20% of total radioactive phospholipids), and a compensating decline in phosphatidylethanolamine.
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Randle CL, Albro PW, Dittmer JC. The phosphoglyceride composition of Gram-negative bacteria and the changes in composition during growth. BIOCHIMICA ET BIOPHYSICA ACTA 1969; 187:214-20. [PMID: 4898381 DOI: 10.1016/0005-2760(69)90030-7] [Citation(s) in RCA: 110] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Abstract
The lipid composition of the chemoautotroph Ferrobacillus ferrooxidans has been examined. Fatty acids represent 2% of the dry weight of the cells and 86% of the total are extractable with organic solvents. About 25% of the total fatty acids are associated with diacyl phospholipids. Polar carotenoids, the benzoquinone coenzyme Q-8, and most of the fatty acids are present in the neutral lipids. The phospholipids have been identified as phosphatidyl monomethylethanolamine (42%), phosphatidyl glycerol (23%), phosphatidyl ethanolamine (20%), cardiolipin (13%), phosphatidyl choline (1.5%), and phosphatidyl dimethylethanolamine (1%) by chromatography of the diacyl lipids, by chromatography in four systems of the glycerol phosphate esters derived from the lipids by mild alkaline methanolysis, and by chromatographic identification of the products of acid hydrolysis of the esters. No trace of phosphatidylserine (PS), glycerolphosphorylserine, or serine could be detected in the lipid extract or in derivatives of that extract. This casts some doubt on the postulated involvement of PS in iron metabolism. After growth in the presence of (14)C and (32)P, there was essentially no difference in the turnover of either isotope in the glycerolphosphate ester derived from each lipid in cells grown at pH 1.5 or 3.5.
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Abstract
The ornithine-containing lipid was separated from the other lipids of Thiobacillus thiooxidans by thin-layer chromatography. The aminolipid possesses both amide and ester linkages.
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Trudinger P. Assimilatory and Dissimilatory Metabolism of Inorganic Sulphur Compounds by Micro-Organisms. Adv Microb Physiol 1969. [DOI: 10.1016/s0065-2911(08)60367-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
Phosphatidyl glycerol, disphosphatidyl glycerol, and phosphatidyl ethanolamine were found in all of the Thiobacillus species studied. T. thioparus possessed only these phospholipids. T. intermedius, T. neapolitanus, and T. thiooxidans contained phosphatidyl-N-monomethylethanolamine, and T. novellus lipids contained phosphatidyl-N-monomethylethanolamine, phosphatidyl-N-N-dimethylethanolamine, and phosphatidyl choline, in addition to the three phospholipids common to all of the thiobacilli. Methionine was found to act as a methyl donor in the biosynthesis of the methylated forms of phosphatidyl ethanolamine. Phosphatidyl inositol was not detected in any of the organisms. Changing the nutrient medium did not result in a qualitative change in the phospholipid spectrum of the cultures.
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Abstract
As cultures of Escherichia coli progressed from the exponential growth phase to the stationary growth phase, the phospholipid composition of the cell was altered. Unsaturated fatty acids were converted to cyclopropane fatty acids, and phosphatidyl glycerol appears to have been converted to cardiolipin. With dual isotope label experiments, the kinetics of synthesis of cyclopropane fatty acid for each of the phospholipids was examined in vivo. The amount of cyclopropane fatty acid per phospholipid molecule began to increase in phosphatidyl ethanolamine at a cell density below the density at which this increase was observed in phosphatidyl glycerol or cardiolipin. The rate of this increase in phosphatidyl glycerol or in cardiolipin was faster than the rate of increase in phosphatidyl ethanolamine. After a few hours of stationary-phase growth, all the phospholipids were equally rich in cyclopropane fatty acids. It is suggested that the phospholipid alterations observed are a mechanism to protect against phospholipid degradation during stationary phase growth. Cyclopropane fatty acid synthetase activity was assayed in cultures at various stages of growth. Cultures from all growth stages examined had the same specific activity in crude extracts.
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