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1.
Summary Determination of the primary structure of the peptidoglycan of 8 strains of Peptococcus showed that 4 different peptidoglycan types occur. P. prevotii ATCC 9321 and P. grigoroffii H40/10 contain the l-Lys-d-Glu type with glycine in position 1 of the peptide subunit. P. variabilis ATCC 14955 and H 39/5, P. activus H22/12 and P. anaerobius H/7 show the l-Lys-Gly type with glycine in position 1 of the peptide subunit. P. aerogenes ATCC 14963 contains the l-Orn-d-Glu type and P. saccharolyticus ATCC 14953 the l-Lys-Gly4, l-Ser1type. The occurrence of these different peptidoglycan types is a valuable criterion for the classification of peptococci. The following conclusions were made: P. saccharolyticus had to be excluded from Peptococcus. P. variabilis and P. anaerobius can be united within one species, whereas P. prevotii ATCC 9321 and P. aerogenes ATCC 14963 can not be included in one species as has been suggested before. P. grigoroffii H40/10 and P. activus H22/12 were wrongly classified.  相似文献   

2.
The cell wall composition, the configuration of lactic acid produced from glucose under anaerobic conditions, the occurrence of fructose-1,6-diphosphate (FDP) activatedl-lactate dehydrogenase (l-LDH), and the esterase pattern were determined from more than 80 strains of coagulase-positive staphylococci isolated from man and animal. Strains isolated from man, swine, bovines and hares form a rather homogencous group. They exhibit a similar cell wall composition, produce predominantlyd,l-lactate and have a characteristic and simple esterase pattern. Coagulasepositive staphylococci isolated from dogs, horses, minks and pigeons are quite distinct from typicalStaphylococcus aureus strains. They exhibit a different cell wall composition, produce onlyl-lactate, possess anl-LDH which is specifically activated by FDP, and have a quite complex esterase pattern.List of Abbreviations BBP bromphenol blue - FDP fructose-1,6-diphosphate - d-LDH d-lactate dehydrogenase - l-LDH l-lactate dehydrogenase - NAD nicotinamide adenine dinucleotide  相似文献   

3.
Anionic phosphate-containing cell wall polymers of bacilli are represented by teichoic acids and poly(glycosyl 1-phosphates). Different locations of phosphodiester bonds in the main chain of teichoic acids as well as the nature and combination of the constituent structural elements underlie their structural diversity. Currently, the structures of teichoic acids of bacilli can be classified into three types, viz. poly(polyol phosphates) with glycerol or ribitol as the polyol; poly(glycosylpolyol phosphates), mainly glycerol-containing polymers; and poly(acylglycosylglycerol phosphate), in which the components are covalently linked through glycosidic, phosphodiester, and amide bonds. In addition to teichoic acids, poly(glycosyl 1-phosphates) with mono- and disaccharide residues in the repeating units have been detected in cell walls of several Bacillus subtilis and Bacillus pumilus strains. The known structures of teichoic acids and poly(glycosyl 1-phosphates) of B. subtilis, B. atrophaeus, B. licheniformis, B. pumilus, B. stearothermophilus, B. coagulans, B. cereus as well as oligomers that link the polymers to peptidoglycan are surveyed. The reported data on the structures of phosphate-containing polymers of different strains of B. subtilis suggest heterogeneity of the species and may be of interest for the taxonomy of bacilli to allow differentiation of closely related organisms according to the “structures and composition of cell wall polymers” criterion  相似文献   

4.
The LytR-CpsA-Psr (LCP) proteins are thought to transfer bactoprenol-linked biosynthetic intermediates of wall teichoic acid (WTA) to the peptidoglycan of Gram-positive bacteria. In Bacillus subtilis, mutants lacking all three LCP enzymes do not deposit WTA in the envelope, while Staphylococcus aureus Δlcp mutants display impaired growth and reduced levels of envelope phosphate. We show here that the S. aureus Δlcp mutant synthesized WTA yet released ribitol phosphate polymers into the extracellular medium. Further, Δlcp mutant staphylococci no longer restricted the deposition of LysM-type murein hydrolases to cell division sites, which was associated with defects in cell shape and increased autolysis. Mutations in S. aureus WTA synthesis genes (tagB, tarF, or tarJ2) inhibit growth, which is attributed to the depletion of bactoprenol, an essential component of peptidoglycan synthesis (lipid II). The growth defect of S. aureus tagB and tarFJ mutants was alleviated by inhibition of WTA synthesis with tunicamycin, whereas the growth defect of the Δlcp mutant was not relieved by tunicamycin treatment or by mutation of tagO, whose product catalyzes the first committed step of WTA synthesis. Further, sortase A-mediated anchoring of proteins to peptidoglycan, which also involves bactoprenol and lipid II, was not impaired in the Δlcp mutant. We propose a model whereby the S. aureus Δlcp mutant, defective in tethering WTA to the cell wall, cleaves WTA synthesis intermediates, releasing ribitol phosphate into the medium and recycling bactoprenol for peptidoglycan synthesis.  相似文献   

5.
The cell wall anionic polymers of the 13 species of the Streptomyces cyaneus cluster have a similar structure and contain -glucosylated 1,5-poly(ribitol phosphate) and 1,3-poly(glycerol phosphate). In the degree of glucosylation of the ribitol phosphate units of their teichoic acids, the cluster members can be divided into two groups. The streptomycetes of the first group (S. afghaniensis, S. janthinus, S. purpurascens, S. roseoviolaceus, and S. violatus) are characterized by a very similar structure of their cell walls, the completely glucosylated 1,5-poly(ribitol phosphate) chains, and a high degree of DNA homology (67–88% according to literature data). The cell wall teichoic acids of the second group (S. azureus, S. bellus, S. caelestis, S. coeruleorubidus, S. curacoi, and S. violarus) differ in the degree of -glucosylation of their 1,5-poly(ribitol phosphate) chains and have a lower level of DNA homology (54–76% according to literature data). Two streptomycetes of the cluster (S. cyaneus and S. hawaiiensis) are genetically distant from the other cluster members but have the same composition and structure of the cell wall teichoic acids as the second-group streptomycetes. The data obtained confirm the genetic relatedness of the S. cyaneus cluster members and suggest that the structure of the cell wall teichoic acids may serve as one of the taxonomic criteria of the species-level status of streptomycetes.  相似文献   

6.
We studied the growth characteristics and oxidative capacities of Acetobacter aceti IFO 3281 in batch and chemostat cultures. In batch culture, glycerol was the best growth substrate and growth on ethanol occurred only after 6 days delay, although ethanol was rapidly oxidized to acetic acid. In continuous culture, both glycerol and ethanol were good growth substrates with similar characteristics. Resting cells in a bioreactor oxidized ribitol to l-ribulose with a maximal specific rate of 1.2 g g–1 h–1). The oxidation of ribitol was inhibited by ethanol but not by glycerol. Biomass yield (YSX; C-mmol/C-mmol) on ethanol and glycerol was low (0.21 and 0.17, respectively). In the presence of ribitol the yield was somewhat higher (0.25) with ethanol but lower (0.13) with glycerol, with respectively lower and higher CO2 production. In chemostat cultures the oxidation rate of ribitol was unaffected by ethanol or glycerol. Cell-free extract oxidized ethanol very slowly but not ribitol; the oxidative activity was located in the cell membrane fraction. Enzymatic activities of some key metabolic enzymes were determined from steady-state chemostat with ethanol, glycerol, or ethanol/glycerol mixture as a growth limiting substrate. Based on the measured enzyme activities, metabolic pathways are proposed for ethanol and glycerol metabolism.  相似文献   

7.
Summary Cell walls of Schizochytrium aggregatum and Thraustochytrium sp. were mechanically isolated and subjected to chemical analysis. On a dry weight basis the cell walls contain 21–36% carbohydrate and 30–43% protein. The principal sugar (>95%) of the Schizochytrium wall is l-galactose, while the Thraustochytrium cell wall contains l-galactose, d-galactose and xylose with l-galactose predominating. Ultrastructurally the cell walls of both organisms consist of a laminated structure which yields thin, flexible, nearly circular scales (0.5–1.1 in diameter) upon sonic disintegration. Structures presumed to be developing wall scales are found within cisternae of the Golgi apparatus in both organisms. The chemical composition and method of formation of the cell wall in these two protists is distinctly different from that found in the Saprolegniales (Oomycetes), the group with which these organisms have hitherto been aligned.  相似文献   

8.
A Gram-positive, motile, endospore-forming and rod-shaped halophilic bacterial strain MSS-155 (KCTC 3788 and KCCM 41687) was isolated from a marine solar saltern of the Yellow Sea in Korea and was subjected to a polyphasic taxonomic study. This organism grew at temperature of 10.0–42.0°C with an optimum of 35°C. Strain MSS-155 grew optimally in the presence of 10% NaCl and did not grow in the absence of NaCl. The cell wall peptidoglycan type of strain MSS-155 was A4 based on l-Orn-d-Asp. Strain MSS-155 was also characterized chemotaxonomically by having menaquinone-7 (MK-7) as the predominant isoprenoid quinone and anteiso-C15:0 as the major fatty acid. The DNA G+C content was 44.0 mol%. Phylogenetic analysis based on 16S rDNA sequences showed that strain MSS-155 falls within the radiation of the cluster comprising Halobacillus species. Levels of 16S rDNA sequence similarity between strain MSS-155 and the type strains of four Halobacillus species were in the range 97.6–98.8%. Strain MSS-155 exhibited levels of DNA-DNA relatedness of 6.2–11.2% to the type strains of Halobacillus species described previously. On the basis of phenotypic properties, phylogeny, and genomic data, strain MSS-155 should be placed in the genus Halobacillus as a member of a novel species, for which we propose the name Halobacillus locisalis sp. nov.Communicated by W.D. Grant  相似文献   

9.
S ummary . The isolation of an antibacterial α-globulin from the sera of humans as well as selected animal species has been reported. While antibacterial agent (ABA) reduced the respiration of intact cells by 55%, the anti-respiratory effect was increased to 67% and 85% for spheroplasts and L-forms, respectively. Studies indicated that neither cell wall nor peptidoglycan could absorb ABA quickly enough to inhibit its membrane damaging effects. Although the ribitol teichoic acid-free mutant Staphylococcus aureus H52A5 was not susceptible to ABA, the lack of ribitol teichoic acid may have altered structurally the cell wall so that ABA access to the cell membrane was precluded. The activity of ABA was neutralized by prior exposure of staphylococci to exogenous coagulase, presumably by masking unknown receptor sites for ABA on the cell surface. In our studies with cell wall deficient organisms, we could not demonstrate coagulase reversal of ABA activity.  相似文献   

10.
Investigations of cell wall teichoic acid structures of various staphylococci were carried out by a rapid method based on the gas-liquid chromatographic separation of products obtained after treatment of phenol-extracted cells with 70% hydrofluoric acid. In most of the strains teichoic acids of the poly(glycerolphosphate) and/or poly(ribitolphosphate) type were found. Teichoic acids of the poly(glycerolphosphate-N-acetylglucosaminephosphate) type and polymers consisting of N-acetylglucosaminephosphate were present in few strains.The results obtained by the rapid chemical screening method were compared with data obtained by serological analysis of teichoic acid structures using specific antisera and the lectin wheat germ agglutinin. Teichoic acid components occurring in low concentrations could only be detected with the chemical and not with the serological method. A number of strains of species of the genus Staphylococcus have been studied using these rapid methods. With a few exceptions, the teichoic acid structure proved to be a constant marker within a given species.Abbreviations used CIE counnter immunoelectrophoresis - GalNAc N-acetylgalactosamine - Glc glucose - GlcNAc N-acetylglucosamine - Gro glycerol - Rit ribitol  相似文献   

11.
Cultures ofBacillus subtilis in balanced growth exhibited a constant rate of turnover of peptidoglycan for 2.5–3.5 generations. Turnover was measured by determining the retention of a labeled precursor of peptidoglycan. When fluorescein-conjugated concanavalin A was used to monitor the fate of cell surface teichoic acid, label disappeared from the cylinders more rapidly than from caps and septa. The results suggest that cell wall poles are partially resistant to turnover.  相似文献   

12.
The cell wall of Actinoplanes philippinesis VKM Ac-647 harbours several carbohydrate-containing anionic polymers. (1) The main polymer of the wall is of a poly(glycosylglycerol phosphate) nature. Its monomeric units — O--d-mannopyranosyl-(14)--d-galactopyranosyl-(11)-glycerol monophosphates — are connected by phosphodiester bonds involving the hydroxyl groups at glycerol C3 and galactose C6. There also are chains without mannosyl substitutents. The teichoic acid structure has been established by chemical analysis and with 1H and 13C NMR spectroscopy. This is the first finding of a teichoic acid with mannosyl residues in a bacterial cell wall. (2) The phosphorylated mannan contains mannose and 2-O-methylmannose. Its core chain has -1,2; -1,3; and -1,6 substitutions as revealed by 13C NMR spectroscopy.The peptide unit of the peptidoglycan contains no l-alanine, instead of which position 1 is occupied by glycine; and diaminopimelic acid is represented, besides its meso- (or DD) form, by small amounts of its LL isomer.Abbreviations Gro glycerol - Gro2P glycerol-2 phosphate - APT attached-proton-test - Ptot total content of phosphorus - Plab phosphorus mineralized in 7 min at 100°C - PNA phosphorus of nucleic acids - Pstab stable phosphorus - T trace amounts  相似文献   

13.
During L-lactic acid fermentation by Rhizopus oryzae, increasing the phosphate level in the fermentation medium from 0.1 g l–1 to 0.6 g l–1 KH2PO4 reduced the maximal concentration of L-lactic acid and fumaric acid from 85 g l–1 to 71 g l–1 and from 1.36 g l–1 to 0.18 g l–1, respectively; and it decreased the fermentation time from 72 h to 52 h. Phosphate at 0.40 g l–1 KH2PO4 was suitable for both minimizing fumaric acid accumulation and benefiting L-lactic acid production.  相似文献   

14.
Zusammenfassung Von L. plantarum und L. inulinus wurden die Zellwände isoliert und durch Inkubation mit Trypsin gereinigt. Durch Extraktion mit TES und Formamid konnte das Murein (Peptidoglycan) bis zu rund 85% der Trockenmasse angereichert werden. Die Zellwände von L. plantarum enthielten rund 30% Teichonsäure des Ribit-Typs, die von L. inulinus waren frei von Teichonsäure.Im Hydrolysat der teichonsäurefreien Zellwände ergaben sich folgende aufbzw. abgerundete Molverhältnisse Mur: GlNH2:Glu:DAPl-Alad-Ala=1:1:1:1:1:0,5. Außerdem waren 2 Mole Ammoniak enthalten, was das Vorliegen von Glu und DAP als Amide anzeigt. Die durch Hemmung mit d-Cycloserin angereicherte unvollständige Mureinvorstufe hatte ein Molverhältnis von UDP:Murl-Ala:Glu:DAP=1:1:1:1:1.Nach Dinitrophenylierung der Zellwand ließen sich rund 50% der gesamten DAP als mono-DNP-DAP nachweisen. Die Hydrazinolyse der Zellwand zum Nachweis C-terminaler Aminosäuren ergab 4% freies DAP und 0,8% freies Alanin.Durch die Analyse der in Partialhydrolysaten der Zellwand auftretenden Peptide konnte die folgende Aminosäuresequenz des an die Muraminsäure gebundenen Tetrapeptides bestimmt werden: l-Ala-d-Glu-l-Lys-d-Ala. Im Murein ist vermutlich nur etwa die Hälfte der Muraminsäure mit einem Tetrapeptid, die andere Hälfte mit einem Tripeptid, dessen d-Alanin fehlt, substituiert.Die Quervernetzung erfolgt zwischen der 2. Aminogruppe der DAP und der Carboxylgruppe des d-Alanins eines benachbarten Tetrapeptids.
The amino acid sequence of the DAP-containing murein of Lactobacillus plantarum and Lactobacillus inulinus
Summary Cell walls of L. plantarum and L. inulinus were isolated and purified by incubation with trypsin. After extraction with TCA and formamide, 85% of the dry weight consists of murein (peptidoglycan).The cell walls of L. plantarum contained about 30% teichoic acid (ribit-type), whereas no teichoic acid was present in the cell walls of L. inulinus.The quantitative determination of amino sugars and amino acids in the hydrolysate of the cell walls showed the following molar ratios: Mur: Gl-NH2:Glu:DAP l-Alad-Ala=1:1:1:1:1:0.5. In addition, 2 mols of NH3 were found per mol of glutamic acid, indicating, that DAP as well as glutamic acid are present as amides.The UDP-activated cell wall precursor which was accumulated by inhibiting the cells by d-cycloserine showed the following molar ratios: UDP:Murl-Ala: Glu:DAP=1:1:1:1:1.After dinitrophenylation and hydrolysation of the cell wall 50% of the DAP were present as mono-DNP-DAP. Hydrozinolysis of the cell wall yielded 4% free DAP and 0.8% free alanine. This shows that only a very small amount of these amino acids are C-terminal in the whole murein.The analysis of various peptides from acid partial hydrolysates of the cell wall indicates the following amino acid sequence of the tetrapeptides attached to muramic acid: l-Ala-d-Glu-meso-DAP-d-Ala. Only half of the muramic acid molecules are substituted by tetrapeptides, while the other half carries a tripeptide in which the terminal d-alanine is missing.The cross-linking of the muropeptides is achieved by a peptide-bond between the second amino group of DAP and the carboxylgroup of the d-alanine of an adjacent muropeptide.
  相似文献   

15.
Evidence is presented that the high levels of internal l-glutamic and l-aspartic acid in frog Rana esculenta red blood cells are due to the existence of a specific carrier for acidic amino acids of high affinity K m = 3 m and low capacity (Vmax) 0.4 mol l-Glu · Kg–1 dry cell mass · 10 min–1. It is Na+ dependent and the incorporation of l-glutamic acid can be inhibited by l and d-aspartate and l-cysteic acid, while d-glutamic does not inhibit. Moreover, this glutamic uptake shows a bell-shaped dependence on the external pH. All these properties show that this carrier belongs to the system X AG family. Besides the incorporation through this system, l-glutamic acid is also taken up through the ASC system, although, under physiological conditions, this transport is far less important, since it has relatively low affinity K m 39 m but high capacity (V max) 1.8 mol l-Glu · Kg–1 dry cell mass · 10 min–1.  相似文献   

16.
Whole cells ofTreponema pallidum consumed O2 with lactate in a glucose-depleted medium.d(–) Lactate caused marked stimulation of O2 uptake at a rate similar to that with glucose, whereasl(+) lactate resulted in no increase over the reduced rate observed upon glucose depletion. Lactate oxidation was specific for -hydroxy straight-chain acids of 3,4, and 5 carbons. O2 uptake during lactate oxidation proceeded independently of pyruvate oxidation and required NAD. The product of lactate oxidation was pyruvate.d(–) Lactate-stimulate O2 uptake was sensitive to chlorpromazine and resistant to amytal and cyanide. Glucose did not inhibit the oxidation of lactate as shown by the additive effect of both substrates on O2 uptake. Oxidation of glucose, but not lactate, provided energy necesary for motilibty or maintenance of virulence. A mixture of lactate isomers was formed from glucose with thel(+) isomer concentration remaining constant and thed(–) isomer concentration varying inversely with dissolved O2 concentration. The function of lactate as an oxidizable substrate is apparently quite distinct from that of glucose.  相似文献   

17.
Biochemical properties of yeast l-asparaginase   总被引:5,自引:0,他引:5  
Only a single l-asparaginase has been found in the yeast Saccharomyces cerevisiae. The enzyme is synthesized constitutively, and its functioning is not controlled by the products of its activity. The apparent Km for the yeast l-asparaginase reaction is 2.5×10–4 m. Activity is greatest at pH 8.5 and is unaffected by the ionic strength of reaction mixtures. l-Asparagine can serve as the sole nitrogen source for cell metabolism but cannot serve as the sole supply of carbon. Active l-asparaginase is necessary for the use of l-asparagine as a nitrogen donor for cell growth. This requirement suggests a possible way in which l-asparaginase-deficient strains of yeast or other organisms might easily be selected.G.E.J. was supported by U.S. Public Health Service Predoctoral Fellowship No. 5 F01 GM36,437.  相似文献   

18.
Arabidopsis thaliana mur1 is a dwarf mutant with altered cell-wall properties, in which l-fucose is partially replaced by l-galactose in the xyloglucan and glycoproteins. We found that the mur1 mutation also affects the primary structure of the pectic polysaccharide rhamnogalacturonan II (RG-II). In mur1 RG-II a non-reducing terminal 2-O-methyl l-galactosyl residue and a 3,4-linked l-galactosyl residue replace the non-reducing terminal 2-O-methyl l-fucosyl residue and the 3,4-linked l-fucosyl residue, respectively, that are present in wild-type RG-II. Furthermore, we found that a terminal non-reducing l-galactosyl residue, rather than the previously reported d-galactosyl residue, is present on the 2-O-methyl xylose-containing side chain of RG-II in both wild type and mur1 plants. Approximately 95% of the RG-II from wild type and mur1 plants is solubilized as a high-molecular-weight (>100 kDa) complex, by treating walls with aqueous potassium phosphate. The molecular mass of RG-II in this complex was reduced to 5–10 kDa by treatment with endopolygalacturonase, providing additional evidence that RG-II is covalently linked to homogalacturonan. The results of this study provide additional information on the structure of RG-II and the role of this pectic polysaccharide in the plant cell wall.Abbreviations AIR Alcohol-insoluble residue - d-Gal d-Galactosyl - EPG Endopolygalacturonase - ESI–MS Electrospray ionization mass spectrometry - GC–MS Gas chromatography–mass spectrometry - 1H-NMR Proton nuclear magnetic resonance spectroscopy - l-Fuc l-Fucosyl - l-Gal l-Galactosyl - 2-O-MeFuc 2-O-Methyl l-fucosyl - 2-O-MeGal 2-O-Methyl l-galactosyl - 2-O-MeXyl 2-O-Methyl d-xylosyl - MWCO Molecular weight cut-off - RG-II Rhamnogalacturonan II - ppm Parts per million - RI Refractive index - SEC Size-exclusion chromatography - TFA Trifluoroacetic acid - WT Wild type  相似文献   

19.
Wall teichoic acids are anionic, phosphate-rich polymers linked to the peptidoglycan of gram-positive bacteria. In Bacillus subtilis, the predominant wall teichoic acid types are poly(glycerol phosphate) in strain 168 and poly(ribitol phosphate) in strain W23, and they are synthesized by the tag and tar gene products, respectively. Growing evidence suggests that wall teichoic acids are essential in B. subtilis; however, it is widely believed that teichoic acids are dispensable under phosphate-limiting conditions. In the work reported here, we carefully studied the dispensability of teichoic acid under phosphate-limiting conditions by constructing three new mutants. These strains, having precise deletions in tagB, tagF, and tarD, were dependent on xylose-inducible complementation from a distal locus (amyE) for growth. The tarD deletion interrupted poly(ribitol phosphate) synthesis in B. subtilis and represents a unique deletion of a tar gene. When teichoic acid biosynthetic proteins were depleted, the mutants showed a coccoid morphology and cell wall thickening. The new wall teichoic acid biogenesis mutants generated in this work and a previously reported tagD mutant were not viable under phosphate-limiting conditions in the absence of complementation. Cell wall analysis of B. subtilis grown under phosphate-limited conditions showed that teichoic acid contributed approximately one-third of the wall anionic content. These data suggest that wall teichoic acid has an essential function in B. subtilis that cannot be replaced by teichuronic acid.  相似文献   

20.
The cell walls of Actinomadura carminata INA 4281 were found to contain peptidoglycan, teichoic acid, and nonpeptidoglycan amino acids. The peptidoglycan was of the A1 type and contained a small amount of ll-DAP in addition to m-DAP. The teichoic acid was an 1,3-poly(glycerol phosphate) chain composed of about eight glycerophosphate units, two of which had a 2-acetamido-2-deoxy--d-galactopyranosyl substituent and one, a 3-O-methyl--d-galactopyranosyl-(1 3)-2-acetamido-2-deoxy--d-galactopyranosyl residue at C2 of glycerol. The structure of the polymer was identified by chemical analysis and 13C-NMR spectroscopy. The teichoic acid contained 3-O-methyl-d-galactose (madurose) — the first ever finding of this compound within a teichoic acid. The nonpeptidoglycan amino acids made up some 30% of the cell wall's dry weight, about a quarter of the amino acids being removable with sodium dodecyl sulfate. Further treatment of the cell walls with LiCl and guanidine hydrochloride caused only a small loss of the amino acids and slight changes in their molar ratio.Abbreviations Gro glycerol - GroP monophosphate glycerol - GroP2 diphosphate glycerol - Gro2P -monophosphate glycerol - PTA phosphorus of teichoic acids - PNA phosphorus of nucleic acids - TA teichoic acid  相似文献   

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