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activities of oxidative enzymes in mycoplasmas.the activities of several oxidoreductases were measured in three fermentative and two nonfermentative mycoplasma species that were grown under aerobic or anaerobic conditions. acholeplasma laidlawii mg, mycoplasma hyorhinis gdl, and mycoplasma pneumoniae fh had very high apparent activities of pyruvate dehydrogenase and pyruvate dehydrogenase complex compared with the activities of mammalian fibroblasts or human platelet-enriched preparations, while mycoplasma salivarium vv and mycoplasma arthri ...19873571159
comparison of two methods for detection of mollicutes (mycoplasmatales and acholeplasmatales) in cell cultures in the netherlands.a total of 1949 cell cultures was tested for contamination with mollicutes by cultivation on and in mycoplasma media, 25.7% of the cell cultures was positive, 243 strains of mycoplasma hyorhinis were isolated. furthermore, mainly m. arginini and m. orale were detected, less often acholeplasma laidlawii, m. fermentans and m. pneumoniae. optimal conditions for isolation were discussed. about one third of 217 hybridoma cultures and two third of 57 myeloma cultures proved to be contaminated, all wit ...19872444156
molecular characterization of mycoplasma genitalium species-specific and cross-reactive determinants: identification of an immunodominant protein of m. genitalium.species-specific proteins of mycoplasma genitalium as well as proteins cross-reactive with m. pneumoniae have been identified using monoclonal antibodies generated against these mycoplasmas in enzyme-linked immunosorbent assays (elisa) and western blot analyses. specificity of the antibodies was examined using m. hominis, m. orale m. salivarium and acholeplasma laidlawii. a 140-kda (kilodalton) protein of m. genitalium that appeared to be immunodominant in mice was also shown by radioimmunopreci ...19872444561
immunological cross-reactivity of a mycoplasma pneumoniae membrane-associated protein antigen with mycoplasma genitalium and acholeplasma laidlawii.a murine monoclonal antibody, oc2f5, reacts with a mycoplasma pneumoniae antigen with an approximate mr of 43,000. this antigen is trypsin and proteinase k sensitive and partitions in the detergent phase of a triton x-114 solution. the monoclonal antibody cross-reacts with an antigen from both mycoplasma genitalium and acholeplasma laidlawii with a similar molecular weight. this cross-reactivity should be considered in the development of m. pneumoniae antigen detection systems based on the use o ...19872447119
[dependence of membrane protein turnover in mycoplasma cells on the age of the culture].to understand the molecular mechanisms of damages appearing in biological membranes in the process of cellular aging, changes in the rate of catabolic processes in mycoplasma cells have been studied. this study has revealed that the aging of acholeplasma laidlawii culture is accompanied by a decrease in the activity of such catabolic enzymes as dna-ase, rna-ase, cathepsin d and beta-glucosidase. a considerable increase in the duration of the half-life of membrane proteins has been registered, wh ...19873113136
transposition of gram-positive transposon tn916 in acholeplasma laidlawii and mycoplasma pulmonis.mycoplasma genetics has been limited by a lack of genetic tools such as selectable markers, methods to transfer dna, and suitable vectors for cloning. studies were undertaken to examine the potential of using the streptococcal transposon tn916 as a mycoplasma genetic tool. the escherichia coli plasmid pam120, which contains tn916, was transformed into acholeplasma laidlawii and mycoplasma pulmonis. transposition of tn916 into the mycoplasma chromosome apparently occurred by an excision-insertion ...19873029869
lipid modulation of the activity and temperature dependence of the purified (na+ + mg2+)-atpase from acholeplasma laidlawii b membranes.the influence of lipid composition on the activity and temperature dependence of the purified (na+ + mg2+)-atpase from acholeplasma laidlawii b membranes has been investigated. the reconstituted enzyme requires liquid-crystalline lipid for full activity. however, phosphatidylcholines with fatty acids varying considerably in chemical structure and chain length all support comparable levels of activity at temperatures above their gel to liquid-crystalline phase transition temperatures, indicating ...19872959635
mycoplasma species in chicken flocks with different management systems.chicken flocks hatched together but reared under different management systems were examined for mycoplasmas over a two-year period. on the farm a multiple-age flocks were reared in close contact. this farm had not been depopulated for over 15 years. on farms b, c and d single-age flocks were reared and the farms were depopulated every year. on farm a 218 birds from 20 flocks were tested: mycoplasmas were isolated from 202 (92.7%). on farms b, c and d 289 birds from seven flocks were tested: myco ...198718766648
animal viruses are able to fuse with prokaryotic cells. fusion between sendai or influenza virions and mycoplasma.sendai and influenza virions are able to fuse with mycoplasmata. virus-mycoplasma fusion was demonstrated by the use of fluorescently labeled intact virions and fluorescence dequenching, as well as by electron microscopy. a high degree of fusion was observed upon incubation of both virions with mycoplasma gallisepticum or mycoplasma capricolum. significantly less virus-cell fusion was observed with acholeplasma laidlawii, whose membrane contains relatively low amounts of cholesterol. the require ...19882826447
characterization of sodium transport in acholeplasma laidlawii b cells and in lipid vesicles containing purified a. laidlawii (na+-mg2+)-atpase by using nuclear magnetic resonance spectroscopy and 22na tracer techniques.the active transport of sodium ions in live acholeplasma laidlawii b cells and in lipid vesicles containing the (na+-mg2+)-atpase from the plasma membrane of this microorganism was studied by 23na nuclear magnetic resonance spectroscopic and 22na tracer techniques, respectively. in live a. laidlawii b cells, the transport of sodium was an active process in which metabolic energy was harnessed for the extrusion of sodium ions against a concentration gradient. the process was inhibited by low temp ...19882973459
presence of anaplerotic reactions and transamination, and the absence of the tricarboxylic acid cycle in mollicutes.cell extracts of the fermentative mollicutes acholeplasma laidlawii b-pg9, acholeplasma morum s2, mycoplasma capricolum 14, mycoplasma gallisepticum s6, mycoplasma pneumoniae fh, mycoplasma hyopneumoniae j and m. genitalium g-37, and the non-fermentative mycoplasma hominis pg-21, mycoplasma hominis 1620 and mycoplasma bovigenitalium pg-11 were examined for 39 cytoplasmic enzyme activities associated with the tricarboxylic acid (tca) cycle, transamination, anaplerotic reactions and other enzyme a ...19883141576
evaluation of three methods for curing hybridomas from mycoplasma contamination.hybridomas are as susceptible to mycoplasma contamination as animal cell cultures. two in vitro methods and one in vivo passage into mice were compared for efficiency of curing hybridomas from mycoplasma contaminations. four contaminated clones were treated with the combined action of 5-bromouracil (5-brura) and the hoechst 33258 followed by photosensitization. the other in vitro method involved the use of bm-cycline. the success of overcoming the mycoplasma contamination was dependent on the le ...19882453449
[mechanism of the action of 12,13-epoxytrichothecenes on macromolecular synthesis in mollicutes]. 19882471043
[the identification of restriction fragments containing rrna genes and construction of a gene bank of acholeplasma laidlawii pg8]. 19882471045
[self-inactivation of nadh-oxidase from mycoplasma cells during reaction].the feasibility of self-inactivation of nadh-oxidase by plasma membranes of acholeplasma laidlawii cells was investigated. it was demonstrated that the rate of nadh oxidation in a flow reactor upon stirring diminishes with time. this decrease of the reaction rate is not coupled with the presence in the reaction mixture of the reaction products--nad+ and h2o2, and is irreversible. in the absence of nadh the enzyme activity is unaffected. the data obtained suggest that nadh-oxidase is inactivated ...19883358960
distinction of species and strains of mycoplasmas (mollicutes) by genomic dna fingerprints with an rrna gene probe.genomic fingerprints of acholeplasma laidlawii, mycoplasma hominis, and mycoplasma pneumoniae strains were obtained by southern blot hybridization of the digested mycoplasmal dnas with an rrna gene probe. the hybridization patterns revealed genotypic heterogeneity among a. laidlawii and m. hominis strains and a remarkable degree of homogeneity among m. pneumoniae strains isolated from pneumonia patients during a 10-year period. genomic fingerprints with the rrna gene probe can thus serve as indi ...19883384931
electroporation-mediated transfection of acholeplasma laidlawii with mycoplasma virus l1 and l3 dna.in contrast to mycoplasma virus l1 and l2 circular dna, mycoplasma virus l3 linear dna is not biologically active in polyethylene glycol-mediated transfection. electroporation of acholeplasma laidlawii, however, leads to plaque formation after incubation with l3 dna. the efficiency of electroporation-mediated transfection is 1/10 that of polyethylene glycol-mediated transfection as estimated with l1 dna. trypsin treatment of cells before dna addition increases the efficiency of dna uptake.19883392773
[isolation, chromatographic characteristics and subunit structure of the dna-dependent rna-polymerase of acholeplasma laidlawii pg-8]. 19883249581
purification of membrane proteins in sds and subsequent renaturation.a prerequisite for the purification of any protein to homogeneity is that the protein is not non-specifically associated with other proteins especially during the final stage(s) of the fractionation procedure. this requirement is not so often fulfilled when nonionic detergents (for instance triton x-100) are used for solubilization of membrane proteins. the reason is that these detergents are not efficient enough to prevent the protein of interest from forming aggregates with other proteins upon ...19882833310
infrared spectroscopic studies of acholeplasma laidlawaii b membranes. comparison of the gel to liquid-crystal phase transition in intact cells and isolated membranes.the physical state of the membrane lipids in the plasma membranes of intact, live acholeplasma laidlawii b cells was probed by fourier-transform infrared spectroscopy and compared with that in isolated membranes. infrared spectra of live a. laidlawii b cells, enriched biosynthetically in the presence of avidin, with saturated deuterated and unsaturated non-deuterated fatty acids have been recorded at a variety of temperatures. the results indicate that within the temperature range of the gel to ...19883208762
the effect of variations in growth temperature, fatty acid composition and cholesterol content on the lipid polar head-group composition of acholeplasma laidlawii b membranes.we have systematically investigated the effect of variations in growth temperature, fatty acid composition and cholesterol content on the membrane lipid polar headgroup composition of acholeplasma laidlawii b. two important lipid compositional parameters have been determined from such an analysis. the first parameter studied was the ratio of the two major neutral glycolipids of this organism, monoglucosyldiacylglycerol (mgdg) and diglucosyldiacylglycerol (dgdg). as the former lipid prefers to ex ...19883191126
acholeplasma laidlawii b-pg9 adenine-specific purine nucleoside phosphorylase that accepts ribose-1-phosphate, deoxyribose-1-phosphate, and xylose-1-phosphate.an adenylate-specific purine nucleoside phosphorylase (purine nucleoside:orthophosphate ribosyltransferase, ec12.4.2.1) (pnp) was isolated from a cytoplasmic fraction of acholeplasma laidlawii b-pg9 and partially purified (820-fold). this partially purified pnp could only ribosylate adenine and deribosylate adenosine and deoxyadenosine. the a. laidlawii partially purified pnp could not use hypoxanthine, guanine, uracil, guanosine, deoxyguanosine, or inosine as substrates, but could use ribose-1- ...19883123458
survey of mycoplasma infections in cell cultures and a comparison of detection methods.a total of 1424 cell cultures was assayed for mycoplasmas by microbiological culture and fluorescent dna staining. of these cultures, 412 (29%) were infected with mycoplasmas. the most frequently occurring mycoplasma species were mycoplasma orale (34%), m. hyorhinis (26%), m. arginini (21%), m. fermentans (13%) and acholeplasma laidlawii (5%). a few isolates each of m. hominis, m. pulmonis and m. bovis were also detected. when detection methods were compared, microbiological culture produced fal ...19883146169
identification of mycoplasma hyopneumoniae in formalin-fixed porcine lung, using an indirect immunoperoxidase method.an indirect immunoperoxidase staining technique was evaluated for detection of mycoplasma hyopneumoniae in formalin-fixed, paraffin-embedded porcine lung. lungs from swine with induced (n = 4) or naturally occurring m hyopneumoniae infection (n = 31) were examined grossly, by light and immunofluorescent microscopy, and by an indirect immunoperoxidase test, using antibody raised in swine against m hyopneumoniae as the primary antibody. organisms stained by the indirect immunoperoxidase method wer ...19883056138
evaluation of a digitonin disk assay to discriminate between acholeplasma and mycoplasma isolates from bovine milk.a study was undertaken to evaluate effectiveness of a digitonin disk inhibition test to discriminate between acholeplasma laidlawii and mycoplasma sp. isolated from bovine milk. the test measured zone diameters of growth inhibition surrounding a digitonin-containing disk on solid medium. zones of inhibition for 20 isolates of a. laidlawii, ranging from 8-14 mm, did not overlap those of 261 isolates of mycoplasma sp., ranging from 16 to 38 mm. examination of variation in zone diameters for m. bov ...19892912675
determination of microbial genome sizes by two-dimensional denaturing gradient gel electrophoresis.in two-dimensional denaturing gradient gel electrophoresis, dna is digested with a restriction endonuclease and the resulting dna fragments are separated as a function of size by conventional agarose gel electrophoresis. following this first dimension electrophoresis, the fragment distribution is placed at the top of a denaturing gradient slab gel and electrophoresis is carried out parallel to the gradient direction. this second dimension separation is a complex function of the base sequence of ...19892786189
characterization of phospholipase a2 of mycoplasma species.as phospholipases of mycoplasma species may play a role in the pathogenesis of respiratory tract and urogenital tract diseases mycoplasma mycoides and acholeplasma laidlawii were examined as to the production of phospholipase a2 (pla) and attempts were made to purify and characterize it. both species produced pla. the purified enzyme was found to be heat-labile, active at alkaline ph, revealing a single band in polyacrylamide gel electrophoresis. metal ions such as calcium and barium, increased ...19892691360
the influence of membrane lipid composition and physical properties of membrane structure and function in acholeplasma laidlawii. 19892669829
development and application of monoclonal antibodies for the detection of cell infecting mycoplasmas.two hybridoma cell lines producing monoclonal antibodies (mabs) to mycoplasmas were established by fusion of mouse myeloma and spleen cells obtained from mice immunized with whole cell mycoplasma pneumoniae antigens. the mabs designated as myc-4 and myc-9 bound to a single m. pneumoniae protein band with approximate molecular weights of 150,000. in dot-eia both mabs reacted with ten mycoplasma spp., two serovars of ureaplasma urealyticum and acholeplasma laidlawii. the mabs have great potential ...19892513356
inactivation of the vascular permeability-increasing activity of bradykinin by mycoplasmas.mycoplasma pneumoniae, m. genitalium, m. fermentans, m. hominis, m. salivarium, m. orale, ureaplasma urealyticum and acholeplasma laidlawii inactivated the vascular permeability-increasing activity of bradykinin when the mixture of bradykinin and mycoplasma cells was injected after incubation at 37 degrees c for 1 h. cell components responsible for inactivation of the activity of bradykinin were found to be arginine-specific aminopeptidase and carboxypeptidase.19892515097
a cation/proton antiport activity in acholeplasma laidlawii.sealed membrane vesicles of acholeplasma laidlawii were obtained by controlled lysis of carotenoid-rich intact cells. an imposed delta ph was created by loading membrane vesicles or intact acholeplasma laidlawii cells with 0.25 m nh4cl and diluting them into 0.25 m choline chloride. the passive efflux of nh3 from the membrane vesicles or cells resulted in the creation of a delta ph (inside acid) that could be visualized by the quenching of the fluorescence of the weak base acridine orange. where ...19892544484
release of mycoplasmavirus l1 upon transfection of acholeplasma laidlawii with homologous and heterologous viral dna.this communication reports on the release of mycoplasmavirus l1 after infection of acholeplasma laidlawii with purified l3 virus. release also occurred after transfection with certain restriction fragments from mv-l3 and mv-l1 genomes. since circular molecules are efficiently taken up in polyethylene glycol-mediated transfection, inducing fragments were applied cloned in e. coli plasmids. release was also observed after electroporation of cells incubated with mv-l1 replicative intermediate dna a ...19892552957
[detection certainty of the contamination of bull sperm with mycoplasma].tests for presence of mycoplasmas were conducted on 20 insemination bulls known as mycoplasma spreaders, with 5 sperm pellet batches of 20 pellets each being investigated for each animal. mycoplasma contamination was positively recorded from 83 of the above 100 batches. mycoplasma (m.) bovigenitalium, m. californicum. m. arginini, m. bovirhinis, and acholeplasma laidlawii were typed by means of indirect immunofluorescent technique, which confirmed the presence also in the gdr of mycoplasma speci ...19892619465
[the inactivation of mycoplasmas and bacteria in calf serum by 60co gamma rays].reported in this paper is the use of 60co gamma radiation to inactivate mycoplasmas in calf serum, newborn calf serum, and fetal calf serum. a dose of 3 kgy, independent of dose rate, was found to be sufficient for inactivation in the above sera of several mycoplasmas, including acholeplasma laidlawii, mycoplasma (m.) orale, m. arginini, m. hyorhinis, and m. bovis. the critical dose proved to be at 2 kgy. no difference was found to exist between the above species in susceptibility to irradiation ...19892619478
[binding of oligodeoxyribonucleotides by mycoplasma rna polymerase related to gene promotors of various microorganisms]. 19892663405
[development of specific technics for the prevention of mycoplasma infections in swine].four experimental series were run in 2 experiments with 44 unweaned piglets to test non-inactivated vaccine from ts-mutant m-60 of mycoplasma (m.) arginini and from attenuated strains of ch-2 m. hyorhinis, ep-29 m. hyosynoviae, m. suipneumoniae, and b-1 acholeplasma laidlawii. similar deviations of clinical and immunological parameters were recorded from piglets inoculated with the above vaccine and infected with pathogenic mycoplasma cultures. these deviations, however, were less strongly prono ...19892619458
[the "in vitro" effect of antibiotics on mycoplasmas under conditions of the preparation of bull sperm].bull sperm was experimentally contaminated with mycoplasma (m.) bovis, m. bovigenitalium, and acholeplasma laidlawii (10(5) colony-forming units/ml sperm). antibiotics were tested for their effectiveness under conditions of preparation of sperm for artificial insemination, primarily for their capability of killing all mycoplasma by the end of sperm equilibration (cooling to +4 degrees c within 5 h). mycoplasma decontamination was achievable only by means of nourseothricin and lincospectin, in a ...19892619467
studies on the purified, lipid-reconstituted (na+ + mg2+)-atpase from acholeplasma laidlawii b membranes. dependence of enzyme activity on lipid headgroup and hydrocarbon chain structure.the purified (na+ + mg2+)-atpase from acholeplasma laidlawii b membranes was successfully reconstituted with a number of different phospho- and glycolipids, and the ability of these lipids to support the function of this enzyme was evaluated by their ability to increase the specific activity of the purified enzyme and by their ability to restore its lipid-phase state-dependent properties which were lost during purification. the incorporation of this atpase into liposomes composed of the endogeno ...19892526120
the anaplerotic phosphoenolpyruvate carboxylase of the tricarboxylic acid cycle deficient acholeplasma laidlawii b-pg9.phosphoenolpyruvate carboxylase (ec 4.1.1.31) (pep-c) was purified approximately 770-fold from the mollicute acholeplasma laidlawii b-pg9. the partially purified pep-c required phosphoenolpyruvate (pep) and mncl2 at ph 7.4 or mgcl2 at ph 8.6 for optimal activity. the product is oxaloacetate as detected by a malate dehydrogenase indicator system. the kma (pep variable) was 0.66 mm and the kmb (bicarbonate variable) was 1.02 mm. at low bicarbonate concentrations (0.5 mm), pep-c activity was stimul ...19892614382
[optimization of physico-chemical parameters of reaction media for determining the activity of rna-polymerases of mollicutes].rna-polymerases of mollicutes differ considerably from certain species of bacteria in the temperature optimum of the activity manifestation. the activity of mollicute enzymes is considerably higher in the presence of manganese ions than in the presence of magnesium ions. they differ from escherichia coli transcriptase in this character but are similar to the rna-polymerase of lactic bacteria, hypothetic ancestors of acholeplasm. sensitivity of rna-polymerases to metals may be one of arguments ex ...19892668709
virus-like infectious agent (vlia) is a novel pathogenic mycoplasma: mycoplasma incognitus.the newly recognized pathogenic virus-like infectious agent (vlia), originally reported in patients with aids but also known to be pathogenic in previously healthy non-aids patients and in non-human primates, was cultured in cell-free conditions using a modified sp-4 medium and classified as a member of the order mycoplasmatales, class mollicutes. the infectious microorganism is tentatively referred to as mycoplasma incognitus. m. incognitus has the unique biochemical properties of utilizing glu ...19892817215
mollicutes dna polymerases: characterization of a single enzyme from mycoplasma mycoides and ureaplasma urealyticum and of three enzymes from acholeplasma laidlawii.the dna polymerase activity of different members of mollicutes was studied. a single dna polymerase was found in mycoplasma mycoides and ureaplasma urealyticum, type species of the genera mycoplasma and ureaplasma, and was compared with the previously described mycoplasma orale enzyme. most of their properties were comparable; an immunological relationship was demonstrated between m. orale and m. mycoides enzymes by immunoblotting. in contrast to these results, three different dna polymerases we ...19892694245
transformation of acholeplasma laidlawii with streptococcal plasmids pva868 and pva920.one limitation with studying mycoplasma genetics is the lack of cloning vectors. studies were undertaken to determine whether streptococcal plasmids could replicate in acholeplasma laidlawii, for the purpose of identifying potential vectors. plasmids pva868 and pva920 contain the same origin of replication and tetracycline resistance determinant. pva920 also contains an erythromycin resistance determinant not present in pva868. a. laidlawii was transformed with plasmids pva868 (13.7 kb) and pva9 ...19892740454
nucleotide sequence of tryptophan trna gene in acholeplasma laidlawii. 19892762159
effects of age, environmental temperature and relative humidity on the colonization of the nose and trachea of calves by mycoplasma spp.nasal and tracheal swabs sequentially collected from three groups of eight calves between the ages of 1 and 98 days indicated that the nose and trachea were colonized by mycoplasma spp. during the first weeks of life. over 92% of all calves harboured mycoplasma spp. in their noses when they were 2 weeks old, the rate of recovery falling gradually thereafter. the peak period of recovering mycoplasmas from the noses and tracheas of calves was at 6 weeks old. m. bovirhinis, m. arginini and acholepl ...19902224487
pathogenicity of acholeplasma laidlawii for the goat udder. 19902375734
cholesterol accumulation in plasma membrane and changes of membrane enzyme activity of acholeplasma laidlawii cells during culture ageing.the data presented in this report show that the microviscosity of the plasma membrane and the cholesterol/phospholipid molar ratio of its lipid bilayer increases during ageing of acholeplasma laidawii cultures. at the same time the age changes of other lipid components content do not correlate with the change of membrane viscosity. it is also shown that membrane enzyme activities of mycoplasma cell decrease with age. these results confirm the membrane hypothesis of ageing according to which incr ...19902232909
enhancement of cytotoxicity of active macrophages by mycoplasma: role of mycoplasma-associated induction of tumor necrosis factor-alpha (tnf-alpha) in macrophages.tumor necrosis factor-alpha (tnf-alpha)-inducing activity of several mycoplasmas including mycoplasma pneumoniae, a causative agent in human respiratory infectious diseases, was investigated. purified peritoneal macrophages from balb/c mice markedly enhanced their cytotoxic activity to meth a cells, when cultured with either viable or non-viable mycoplasmas. the supernatants of the macrophage culture with mycoplasmas, m. pneumoniae and acholeplasma laidlawii, showed the potent cytotoxic activity ...19902352496
cholesterol oxidation on fluorocarbon emulsion surface leads to the formation of 7-peroxycholesterol.formation of biologically active oxidized derivatives of cholesterol as a result of its oxidation on the surface of fluorocarbon emulsions was studied. a single product of cholesterol oxidation, 7-peroxycholesterol, was found. it was shown that 7-peroxycholesterol and its derivative 7-keto-cholesterol inhibit the rosette formation between human t-lymphocytes and sheep erythrocytes. these substances exert a strong cytostatic action on the growth of procaryotic and eucaryotic cell cultures. thus, ...19902365071
the stereospecificities of seven dehydrogenases from acholeplasma laidlawii. the simplest historical model that explains dehydrogenase stereospecificity.stereospecificities are reported for seven dehydrogenases from acholeplasma laidlawii, an organism from an evolutionarily distinct branch of life which has not previously been studied from a stereochemical point of view. three of the activities examined (alcohol dehydrogenase, lactate dehydrogenase, and alanine dehydrogenase) catalyze the transfer of the pro-r (a) hydrogen from nadh. four other activities (3-hydroxy-3-methylglutaryl-coa reductase, glyceraldehyde-3-phosphate dehydrogenase, glucos ...19902365693
glycosidase activities of mycoplasmas.the activities of alpha- and beta-glucosidase, beta-galactosidase and beta-n acetylglucosaminidase were assessed at acidic ph by fluorimetry using the appropriate 4-methylumbelliferyl substrate in four mycoplasma species (m. pneumoniae, m. gallisepticum, m. hominis and m. capricolum) and in acholeplasma laidlawii. the glycosidase activities were in a low range (0.1-4.2 nmole per h per mg protein) with the exception of higher activities of beta-n-acetylglucosaminidase in a. laidlawii. the enzyme ...19902119590
studies on the purified na+,mg(2+)-atpase from acholeplasma laidlawii b membranes: a differential scanning calorimetric study of the protein-phospholipid interactions.the purified na+,mg2(+)-atpase from the acholeplasma laidlawii b plasma membrane was reconstituted with dimyristoyl phosphatidylcholine and the lipid thermotropic phase behavior of the proteoliposomes formed was investigated by differential scanning calorimetry. the effect of this atpase on the host lipid phase transition is markedly dependent on the amount of protein incorporated. at low protein/lipid ratios, the presence of increasing quantities of atpase in the proteoliposomes increases the t ...19902140945
thermotropic characterization of the 2-o-acyl,polyprenyl alpha-d-glucopyranoside isolated from palmitate-enriched acholeplasma laidlawii b membranes.the thermotropic phase behavior of a monoacylated neutral glucolipid (2-o-acyl,polyprenyl alpha-d-glucopyranoside), isolated from palmitate-enriched acholeplasma laidlawii b membranes, was studied by differential scanning calorimetry, infrared spectroscopy and x-ray diffraction. when equilibrated at low temperatures, aqueous dispersions of this lipid form an ordered, crystal-like lamellar gel phase which transforms to an inverted hexagonal phase at temperatures near 65 degrees c upon heating. ho ...19902378878
mycoplasmas and acholeplasmas isolated from ducks and their possible association with pasteurellas.two hundred and sixty-three cases of clinically diseased ducks of all ages were examined for the presence of mycoplasmas. mycoplasmas and acholeplasmas belonging to more than eight serogroups were cultured from 68 of them, and comprised 12 m anatis, one m columbinasale, two m gallinaceum, two m gallinarum, nine m synoviae, three unidentified mycoplasma species, 37 acholeplasma laidlawii and one unclassified acholeplasma belonging to each of serogroups 7 and 8. they were identified by biochemical ...19902399638
differences in accumulation of radiolabeled amino acids and polyamines by mycoplasma and acholeplasma species.four species in the order mycoplasmatales, mycoplasma capricolum, mycoplasma hominis, mycoplasma arginini, and acholeplasma laidlawii, were compared for their ability to accumulate radiolabeled amino acids and polyamines. the use of a novel high-molecular-weight (hmw) medium, from which molecules of less than 12,000 molecular weight had been removed by extensive dialysis, allowed us to discern significant differences among the species in their relative accumulations of [3h]methionine and [3h]leu ...19902275861
isolation and characterization of mycoplasma virus l3 temperature-sensitive mutants.mycoplasma virus l3 virions are morphologically similar to coliphage t7, contain linear double-stranded dna of about 39 kilobase pairs, and produce a nonlytic cytocidal infection in acholeplasma laidlawii host cells. following nitrous acid mutagenesis, ninety-eight l3 temperature-sensitive (ts) mutants were isolated from a total of 57,000 plaque-forming units (pfu), using 37 degrees c as the permissive temperature and 41 degrees c as the nonpermissive temperature, with reversion frequencies of 1 ...19902277590
plasmid transformation and replica filter plating of acholeplasma laidlawii.the restriction deficient mutant 8195 of acholeplasma laidlawii strain ja1 was transformed by the promiscuous streptococcal plasmid vector pnz18 at a frequency of 4 x 10(-4)/cfu. the plasmid was maintained without structural rearrangements but was lost in the absence of a selection pressure, i.e. kanamycin or neomycin. transformed primary colonies were easily recognized due to a different colony morphology. replica filter plating, previously not obtained with mycoplasmas, was achieved using pnz1 ...19902283030
heat shock response in mycoplasmas, genome-limited organisms.we have measured the effect of heat shock on three mycoplasmas (acholeplasma laidlawii k2 and ja1 and mycoplasma capricolum kid) and demonstrated the induction of mycoplasma heat shock proteins under these conditions. increased synthesis of at least 5 heat shock proteins in a. laidlawii k2, 11 heat shock proteins in a. laidlawii ja1, and 7 heat shock proteins in m. capricolum was observed by electrophoretic analysis of proteins from heat-shocked cells in sodium dodecyl sulfate-polyacrylamide gel ...19902318804
human ureaplasmas show diverse genome sizes by pulsed-field electrophoresis.contour clamped homogeneous field (chef) agarose gel electrophoresis (age), ramped to give linear separation of dna molecules of 600-1600 kilobase pairs (kbp), was used to determine mobilities for full-sized genomic dna of the serotype standard strains of the human genital mollicutes, ureaplasma urealyticum relative to yeast chromosomal dna markers. indicated genome sizes (in kbp) were 760 for the four biotype 1 strains and 840-1140 for eleven biotype 2 strains. other estimates were: 720 for myc ...19902326188
the electrophoretic mobility of gram-negative and gram-positive bacteria: an electrokinetic analysis.the electrophoretic mobility (epm) of a variety of gram-negative and gram-positive bacteria was measured with a penkem s3000 analyser. under standard growth conditions and neutral ph all cells displayed a negative epm. the polysaccharide capsules of escherichia coli strains k1, k5, k29 and k30 generated the highest epm; to a lesser and varying degree o-antigens with charged groups and core lipopolysaccharides also contribute to the net epm. very little negative epm was measured in suspension cul ...19901696306
fast and simple procedure for the detection of cell culture mycoplasmas using a single monoclonal antibody.the detection of mycoplasmas in cell cultures is still a problem, especially in those laboratories in which the detection and identification of microorganisms is not established as a routine procedure. in our laboratory, monoclonal antibodies (mabs) have been prepared to acholeplasma laidlawii, mycoplasma hyorhinis, mycoplasma orale, mycoplasma arginini and mycoplasma salivarium. 30 mabs were obtained and one of these, designated ccm-2, was shown to bind to all five mycoplasma species. it also b ...19901697315
[the interaction of the rna-polymerases of a phytopathogenic strain of mycoplasma with oligodeoxyribonucleotides associated with gene promoter regions]. 19902090419
evaluation of different hybridization procedures for the detection of mycoplasma contamination in cell cultures.cell culture samples were analysed for mycoplasma contaminations with two different dna probes which have been described earlier. one probe (the h900 probe), derived from the 23s rrna gene of mycoplasma hyorhinis, cross-hybridized with virtually all mycoplasmas (including the acholeplasmas). the other probe (the t2 probe), derived from a protein gene of acholeplasma laidlawii, cross-hybridized with most acholeplasmas. the two probes were compared in three different direct filter hybridization pr ...19902107395
genetic exchange of transposon and integrative plasmid markers in mycoplasma pulmonis.matings of genetically marked derivatives of mycoplasma pulmonis resulted in the exchange of chromosomal dna and the appearance of doubly marked transconjugants. transposons tn916 and tn4001, and a series of integrative plasmids derived from their cloned antibiotic resistance genes, were used to construct antibiotic-resistant mycoplasmal derivatives to examine this phenomenon at the molecular level. genetic exchange occurred on agar surfaces at frequencies ranging from 3.3 x 10(-4) to 6.4 x 10(- ...19902158966
terminal redundancy and circular permutation of mycoplasma virus l3 dna.this communication reports the physical map of mycoplasma virus l3 (mv-l3) dna derived from restriction patterns obtained by digestion with seven different restriction endonucleases. the length of the restriction map is 36,200 bp in contrast to the contour length of native mv-l3 dna molecules which is 39,400 bp as determined by electron microscopy. the difference in length of 3,200 bp (corresponding to 8.1% of the native viral dna contour length) is explained by terminal redundancy. it was possi ...19902212995
ageing of procaryotes. acholeplasma laidlawii as an object for cell ageing studies: a brief note.it was established that a. laidlawii cell viability in the stationary phase of culture development decreases according to the gompertz law. it was shown that the "stationary" ageing of a. laidlawii cells is accompanied by the lower intensity of phosphorus-containing compounds biosynthesis, decreased rate of membrane proteins synthesis and degradation and also by accumulation of dna single-strand breaks. the biochemical changes found in ageing a. laidlawii cells are similar to ageing manifestatio ...19902214893
pulse-field electrophoresis indicates full-length mycoplasma chromosomes range widely in size.full-size linear chromosomes were prepared from mycoplasmas by using gamma-irradiation to introduce one (on average) double-strand break in their circular chromosomes. chromosome sizes were estimated by pulsed-field gel electrophoresis (pfge) from the mobilities of these full-length molecules relative to dna size references. sizes estimated for ureaplasma urealyticum t960 and 16 mycoplasma species ranged from 684 kbp (m. hominis) to 1315 kbp (m. iowae). using this sample, we found no correlation ...19902216718
evidence that mycoplasmas, gram-negative bacteria, and certain gram-positive bacteria share a similar protein antigen.it was demonstrated that mycoplasmas, gram-negative bacteria, and certain gram-positive bacteria share a similar protein antigen with a molecular weight ranging from 42,000 to 48,000. western blotting (immunoblotting) with an antibody specific to a 43-kda membrane protein of mycoplasma fermentans showed the existence of this protein antigen in all mycoplasma spp. tested (14 species), acholeplasma laidlawii (1 strain), and gram-negative bacteria (8 species) but only in staphylococcus aureus of fo ...19912007558
order and dynamics in mixtures of membrane glucolipids from acholeplasma laidlawii studied by 2h nmr.the two dominant glucolipids in acholeplasma laidlawii, viz., 1,2-diacyl-3-o-(alpha-d-glucopyranosyl)-sn-glycerol (mglcdg) and 1,2-diacyl-3-o-[alpha-d-glucopyranosyl-(1----2)-o-alpha-d-glucopyranosyl ]- sn-glycerol (dglcdg), have markedly different phase behavior. mglcdg has an ability to form nonlamellar phases, whereas dglcdg only forms lamellar phases. for maintenance of a stable lipid bilayer, the polar headgroup composition in a. laidlawii is metabolically regulated in vivo, in response to ...19912036360
[the isolation and partial purification of 2 dna-dependent dna polymerases from acholeplasma laidlawii pg-8].two forms of dna-dependent dna-polymerase have been isolated and partially purified from the limited amount of biomass of cells acholeplasma laidlawii pg-8, a typical representative of genus acholeplasmataceae, as a result of successive chromatography on the columns with deae-cellulose de-52 and green a-sepharose. the first form of dna-polymerase is eluted from the ion-exchange column with nacl concentration of 0.1 m from the column with green a-sepharose of 0.27 m, while the second form-with na ...19911791778
[the rnases of the mollicute acholeplasma laidlawii pg-8: its detection and accumulation dynamics]. 19911791779
comparison of glycoproteins from ten human mycoplasma species.multiple bands of glycoprotein, rare in procaryotes, were detected in ten human mycoplasma species by staining with periodic acid-schiff (pas) reagent after sodium dodecyl sulphate-polyacrylamide gel electrophoresis (sds-page). a major contaminant formed in hayflick medium (h medium), corresponding to an apparent molecular weight of about 80 kd, was eliminated by using the organisms grown in pplo broth supplemented with pplo serum fraction (p medium), except that m. genitalium and m. pneumoniae ...19911815100
interaction of modified oligonucleotides with eukaryotic and mycoplasma cells and their fate inside the cells. 19911841342
continuous distribution of mycoplasma genome sizes.genome sizes of eleven strains of eight species of mollicutes mycoplasmataceae were investigated by pulsed-field gel electrophoresis. mycoplasma genomic sizes were determined from the sum of the sizes of fragments obtained after digestion of genomic dna with restriction endonucleases. the sizes of the fragments were determined by comparison of their electrophoretic mobilities with those of lambda dna concatemers. specific restriction endonucleases were chosen so that after digestion three to ten ...19911841633
[the thermodynamic parameters of the conformational transitions in mycoplasma dna].dna preparations have been isolated from 10 strains of phytopathogenic mycoplasms and collection culture achole plasma laidlawii pg-8. thermodynamic parameters of denaturation changes in the secondary structure (transconformation) of dna of these mycoplasms have been determined. it is shown that denaturation temperature is 82.3-83.1 degree c and enthalpy of conformational dna transitions calculated per 1 g of dry substance is 56.2-61.9 j/g. changes in the enthalpy (delta h) and entropy (delta s) ...19911861653
search for eukaryotic motility proteins in spirochetes: immunological detection of a tektin-like protein in spirochaeta halophila.the serial endosymbiotic theory (set) for the spirochete origin of undulipodia (cilia and eukaryotic flagella) predicts that a greater number of axonemal proteins will show homology to spirochete than to other bacterial proteins. to continue testing, the set proteins associated with eukaryotic motility (tektin, centrin and calmodulin) were sought in spirochaeta halophila. western blot immunological detection techniques (for tektin and centrin) and two-dimensional gel analysis (for calmodulin) we ...19911863720
[contamination of fish tissue cell cultures by mycoplasma].the inoculated and primary cell cultures of fish (carp, salmon, and sturgeon) have been studied. acholeplasma typed as a. laidlawii in terms of its biochemical properties shown in inhibited metabolism has been isolated from 19 samples. the authors consider the source of acholeplasma-induced contamination of the cell cultures under study.19911927041
fusion of mycoplasmas: the formation of cell hybrids.poly(ethylene glycol) (peg 8000) can induce cell-cell fusion of mycoplasma capricolum cells, and it can promote the formation of intergeneric hybrids of various mycoplasma, acholeplasma and spiroplasma species. the extent of fusion was quantitatively evaluated by following the dequenching of octadecylrhodamine fluorescent label incorporated into donor cell membranes after their incubation with recipient cells. the results of dequenching experiments were confirmed by electron microscopy, as well ...19911936938
evolution of trnas and trna genes in acholeplasma laidlawii.the genes for 22 trna species from acholeplasma laidawii, belonging to the class mollicutes (mycoplasmas), have been cloned and sequenced. sixteen genes are organized in 3 clusters consisting of eleven, three and two trna genes, respectively, and the other 6 genes exist as a single gene. the arrangement of trna genes in the 11-gene, the 3-gene and the 2-gene clusters reveals extensive similarity to several parts of the 21-trna or 16-trna gene cluster in bacillus subtilis. the 11-gene cluster is ...19911722304
identification of porcine mycoplasmas using commercial enzyme assay systems. 19911760468
[the stability of the alkylating derivatives of oligodeoxyribonucleotides containing a cholesterol or phenazine radical added to the 3'-termination during their interaction with acholeplasma laidlawii pg-8].stability of alkylating derivatives of decathymidylates protected on the 3'-terminal by cholesterol and phenazine residues has been studied in the process of their interaction with cells of acholeplasma laidlawii pg-8. it is shown that the studied reagents are not split by nucleases of a. laidlawii pg-8 for the time necessary for alkylation of mycoplasma biopolymers.19911753886
chloride fluxes across acholeplasma laidlawii membranes.chloride fluxes across the cytoplasmic membrane of acholeplasma laidlawii were studied by using the chloride sensitive fluorescent dye, 6-methoxy-n-(sulfopropyl)quinolinium. chloride was found to penetrate the membrane passively. chloride flux was dependent upon the transmembrane electric potential.19911778416
mystery swine disease in the netherlands: the isolation of lelystad virus.in early 1991, the dutch pig-industry was struck by the so-called mystery swine disease. large-scale laboratory investigations were undertaken to search for the etiological agent. we focused on isolating viruses and mycoplasmas, and we tested paired sera of affected sows for antibodies against ten known pig viruses. the mycoplasmas m. hyosynoviae, m. hyopneumoniae, and acholeplasma laidlawii, and the viruses encephalomyocarditis virus and porcine enterovirus types 2 and 7 were isolated from indi ...19911835211
[the interaction of alkylating derivatives of oligodeoxyribonucleotides and their methylphosphonate analogs with mycoplasma cells].alkylating derivatives of decathymidylates and methylphosphonate analogs of oligodeoxyribonucleotides (mpao) were studied for their interaction with cells of acholeplasma laidlawii pg-8, mycoplasma capricolum california kid, m. pneumoniae fh and phytopathogenic strain (st. 118). it is shown that mpao of octa- and hexadecathymidylates as well as decathymidylates 3'-terminal modified by phenazine and cholesterol groupings are sorbed by mycoplasma cells and can penetrate inside the cells. efficienc ...19911753887
[cross reactive antigens of acholeplasma laidlawii and l-form of staphylococcus aureus].we demonstrated that the membrane of acholeplasma laidlawii pg8 and l-form of staphylococcus aureus, both of which induce cellular immunity in balb/c mice, were antigenically related each other. foodpad responses of the mice immunized with a mixture of either antigen and freund's complete adjuvant showed clearly a cross reaction when challenged with the other antigen. cross responses to incorporate 3h-thymidine to the spleen lymphocytes of the mice immunized with either antigen occurred in the p ...19911762175
the genome size of a plant-pathogenic mycoplasmalike organism resembles those of animal mycoplasmas.the genome size of a mycoplasmalike organism was determined by comparing fluorescence intensities of restriction fragments. its genome size was similar to that of mycoplasma gallisepticum and much smaller than that of acholeplasma laidlawii. although the genome size is "mycoplasmalike," other molecular data indicate a closer evolutionary relationship to a. laidlawii.19912002012
immunological properties of antibodies against mg(2+)-atpase from acholeplasma laidlawii membranes.in the present study, antibodies were raised against the mg(2+)-atpase and the immunological relationships between the enzyme and other atpase from a variety of biological membranes were determined. the anti mg(2+)-atpase antiserum inhibited 85% of the enzyme activity from a. laidlawii membranes. we demonstrate a specific selectivity of mg(2+)-atpase antiserum for antigenic determinants of the a. laidlawii membranes. immunoblot studies of a. laidlawii membrane peptides indicated labeling of five ...19911714730
isoprenoid modification of proteins distinct from membrane acyl proteins in the prokaryote acholeplasma laidlawii.isoprenylation is an important posttranslational modification that affects the activity, subunit interactions and membrane anchoring of different eukaryotic proteins. the small, cell-wall-less prokaryote acholeplasma laidlawii has more than 20 membrane acyl-proteins enriched in myristoyl and palmitoyl chains. radioactive mevalonate, a precursor to isoprenoids, was incorporated into several specific membrane proteins of 20 to 45 kda and two soluble proteins of 23-25 kda, respectively. no acyl pro ...19921616923
cloning and dna sequence of a mycoplasmal reca gene.mycoplasmas are wall-less prokaryotes phylogenetically related to gram-positive bacteria. in order to investigate dna recombination in these organisms, we have cloned the reca gene from the mycoplasma acholeplasma laidlawii. dna sequence data indicate extensive homology between the a. laidlawii reca gene and reca genes from other bacteria, particularly bacillus subtilis. the reca sequences from three a. laidlawii strains (strains ja1, k2, and 8195) were compared, and surprisingly, the gene from ...19921732213
membrane protein acylation. preference for exogenous myristic acid or endogenous saturated chains in acholeplasma laidlawii.mycoplasmas are small bacteria without a cell wall, often found as surface parasites on eukaryotic cells. of the more than 200 membrane proteins from acholeplasma laidlawii resolved by two-dimensional page, 23 were covalently modified with acyl chains. these acyl proteins had lower pi values than average and were all labelled by different exogenously supplied radioactive fatty acids attached by o-ester bonds. the fatty acids were selectively incorporated in the order myristic acid (14:0) greater ...19921740134
acholeplasma laidlawii has trna genes in the 16s-23s spacer of the rrna operon.we amplified the 16s-23s rrna intergenic spacer region of acholeplasma laidlawii pg8 by polymerase chain reaction (pcr) and obtained two specific pcr products in different sizes. we have sequenced both pcr products and found that one of them has sequence homologous to the spacer trna genes in bacillus subtilis. this is the first evidence of trna genes between the 16s-23s rrna intergenic spacer regions in members of the class mollicutes.19921281149
influence of lipid composition on the orientational order in acholeplasma laidlawii strain b membranes: a deuterium nmr study.2h nmr techniques have recently been developed to determine the complete orientational order profile of lipid bilayers employing lipids containing perdeuteriated palmitic acid [lafleur, m., fine, b., sternin, e., cullis, p.r., & bloom, m. (1989) biophys. j. 56, 1037-1041]. in this work, these techniques have been applied to study order profiles in intact membranes derived from acholeplasma laidlawii strain b. it is shown that complete orientational order profiles can be readily obtained from the ...19921390762
the enzymatic synthesis of membrane glucolipids in acholeplasma laidlawii.in membranes of the prokaryote acholeplasma laidlawii, the physiological regulation of the two major membrane lipids, monoglucosyldiacylglycerol (mglcdag) and diglucosyldiacylglycerol (dglcdag), is governed by factors affecting the equilibria between lamellar and non-lamellar phases of the membrane lipids. the synthesis of the glucolipids is considered to be a two-step glucosylation: (i) dag+udp-glc----mglcdag+udp; and (ii) mglcdag+udp-glc----dglcdag+upd. this was corroborated by in vivo pulse l ...19921533160
behaviour of a glycosphingolipid with unsaturated fatty acid in phosphatidylcholine bilayers.n-(oleoyl)galactosylceramide with perdeuterated acyl chain was prepared by partial synthesis, and studied by wide line 2h-nmr in phospholipid liposomes. spectra were obtained for low glycolipid concentrations in bilayers of dimyristoyl-, distearoyl-, and 1-palmitoyl-2-oleoylphosphatidylcholines. in an attempt to isolate the effects of glycosphingolipid fatty acid cis unsaturation on glycolipid behaviour in membranes, spectral findings related to the above species were compared to literature nmr ...19921616922
[the chromatographic properties of the dna-dependent dna polymerases from acholeplasma laidlawii pg-8].the dna-dependent dna-polymerase (dna polymerase i which is not sorbed on the column with deae-cellulose, and dna-polymerase ii, which is absorbed by this column and is eluted from it by 0.3 m of nacl), have been isolated from acholeplasma laidlawii pg-8. dna-polymerase i in homogeneous state was obtained as a result of the stepwise treatment by heparin-sepharose (elution at 0.35 m of nacl) and poly-u-sepharose (elution at 0.3 m of nacl). it was presented on the electrophoregram by one polypepti ...19921584084
the effect of cholesterol and epicholesterol on the activity and temperature dependence of the purified, phospholipid-reconstituted (na+ + mg2+)-atpase from acholeplasma laidlawii b membranes.the (na+ + mg2+)-atpase purified from acholeplasma laidlawii b membranes was reconstituted into large, unilamellar vesicles formed from dimyristoylphosphatidylcholine (dmpc) and varying amounts of cholesterol or epicholesterol. the atp hydrolytic activity of the reconstituted enzyme was then determined over a range of temperatures and the phase state of the dmpc in the atpase-containing vesicles was characterized by high-sensitivity differential scanning calorimetry. in the vesicles containing o ...19921535512
membrane properties of a plant-pathogenic mycoplasmalike organism.in terms of biosystematics, the plant-pathogenic mycoplasmalike organisms (mlos) have been tentatively placed into the class mollicutes. certain physiological tests have been used to distinguish families within this class: the sterol-nonrequiring acholeplasmataceae differ from the sterol-requiring mycoplasmataceae in that the former are more resistant to lysis by digitonin and more sensitive to lysis in hypotonic salt solutions. to test mlos for these membrane properties and thus assist in their ...19921732203
identification and analysis of the genes coding for the putative pyruvate dehydrogenase enzyme complex in acholeplasma laidlawii.a monospecific antibody recognizing two membrane proteins in acholeplasma laidlawii identified a plasmid clone from a genomic library. the nucleotide sequence of the 4.6-kbp insert contained four sequential genes coding for proteins of 39 kda (e1 alpha, n terminus not cloned), 36 kda (e1 beta), 57 kda (e2), and 36 kda (e3; c terminus not cloned). the n termini of the cloned e2, e1 beta, and native a. laidlawii e2 proteins were verified by amino acid sequencing. computer-aided searches showed tha ...19921735725
breeder turkey hens seropositive and culture-negative for mycoplasma synoviae.four flocks of clinically normal turkey breeder hens were shown to have suspect and positive mycoplasma synoviae (ms) hemagglutination-inhibition (hi), enzyme-linked immunosorbent assay, and, in some cases, serum plate agglutination serology in the absence of ms isolation. in all cases, hi serology for mycoplasma gallisepticum (mg) and m. meleagridis was negative. acholeplasma laidlawii was isolated from some hens in each of these ms-seropositive culture-negative flocks. immunoblotting was used ...19921417615
evolutionary relationships of a plant-pathogenic mycoplasmalike organism and acholeplasma laidlawii deduced from two ribosomal protein gene sequences.the families within the class mollicutes are distinguished by their morphologies, nutritional requirements, and abilities to metabolize certain compounds. biosystematic classification of the plant-pathogenic mycoplasmalike organisms (mlos) has been difficult because these organisms have not been cultured in vitro, and hence their nutritional requirements have not been determined nor have physiological characterizations been possible. to investigate the evolutionary relationship of the mlos to ot ...19921556079
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