DNA base composition of yellowErwinia strains

DNA base composition, expressed as % GC, was determined in 34 strains of yellow-pigmentedErwinia-like organisms from plant, animal and human origin. Organisms calledErwinia herbicola (Graham and Hodgkiss, 1967) have a % GC in the narrow range 55.0 to 56.5, with the exception of strain G 146 which has 58.6% GC. They include the formerBacterium herbicola, Erwinia lathyri, Bacterium typhi flavum and the Muraschi isolates,Erwinia milletiae with 55.8 % falls within the % GC range of theHerbicola group,Erwinia ananas is at the lower end of the group with 54.8 ± 0.4 % GC andErwinia uredovora still lower at 53.7 ± 0.7 % GC. These data and the compositional distribution of the DNA fragments do not exclude the inclusion of these organisms into the genusErwinia.     

Differentiation of Erwinia Species in the "Herbicola" Group by Class Analysis of Cellular Fatty Acids

Profiles of cellular fatty acids of Erwinia herbicola, E. ananas, E. stewartü and E. uredovora , comprising the Herbicola group in the genus Erwinia , contained 7 major components accounting for 90–95% of total fatty acids, and,30 minor components, each less than 1% of the total. The major components and their average percentage ranges in cells on King's medium B at 28°C for 1 days were: 12:0 (3.5–4.5%), 14:0 (3.6–4.3%), 16:0 (28.1–35.7%), 16:1 (17.5–24.2%), 18:1 (13.9–31.9%), 3-OH 14:0 (4.6–7.2%) and cyclopropane 17:0 (trace levels in E. stewartii , 5.0–6.7% in other species). Fatty acid composition changed as a function of physiological age of the cells. The regression coefficient ( b ) as a function of age for percentage of saturated even- and oddcarbon, straight-chain fatty acids (Classes A and B) was either negative or not significant for E. ananas and positive for the other species. A series of dichotomous steps was constructed based on fatty acid algorithms to differentiate all four species.     

Molecular cloning of an ice nucleation gene from Erwinia ananas and its expression in Escherichia coli

Abstract An approximately 7 kbp genomic DNA fragment was cloned from an ice nucleation-active (ina) strain of Erwinia ananas and defined as to its restriction enzyme site. When the DNA fragment was introduced into E. coli MM294, a potent ice nucleation activity was expressed. Both 0.7 kbp truncation from the 5'-end and 1.7 kbp truncation from the 3'-end were also effective in expressing the ice nucleation activity in E. coli . Therefore, the resulting DNA fragment of approximately 5 kbp was considered to be an ina gene and named ina A. It existed as a unique gene in this strain of E. ananas . No corresponding ina gene existed in an ice nucleation-inactive strain of E. milletiae .     

Nitrogen Fixation in a Biotype of Erwinia herbicola Resembling Escherichia coli

Two nitrogen-fixing members of the Enterobacteriaceae have been isolated from paper mill process water and compost. Although they closely resembled Escherichia coli , detailed biochemical characterization of these and 7 other isolates established that they should be assigned to a biotype of Erwinia herbicola . They may be distinguished from E. coli by their lack of amino acid decarboxylase activity, their ability to utilize cellobiose and malonate and to ferment cellobiose and amygdalin. In one of them, the capacity to fix nitrogen, ferment cellobiose and utilize malonate was resistant to the effects of ethidium bromide, acridine orange and sodium dodecyl sulphate, and the ability to utilize cellobiose could not be transferred on to E. coli or Salmonella typhi . It is therefore concluded that these characters are not carried on transferable plasmids. Forty-eight strains of E. coli of varying origin were examined for acetylene reducing activity and all were found to be negative. It is concluded that hitherto no naturally occurring strains of E. coli have been shown to fix nitrogen.     

Erwinia herbicola isolates from alfalfa plants may play a role in nodulation of alfalfa by Rhizobium meliloti

Erwinia herbicola was isolated from roots of plants derived from surface-sterilized seeds of all alfalfa varieties that were tested. Some of these E. herbicola strains affected nodulation by certain strains of Rhizobium meliloti. In previously published work we presented the isolation of slow-and fast-nodulating variants from a single culture of R. meliloti 102F51. In the absence of E. herbicola, the slow-nodulating variant induced the formation of nodules on alfalfa as rapidly as the faster-nodulating strain. The rates of nodulation by the faster-nodulating variant were the same in the presence and absence of E. herbicola. All of the previously reported slower-nodulating strains derived from R. meliloti 102F51 nodulated more rapidly on sterilized plants than in the presence of certain E. herbicola isolates.     

Zwittermicin A-producing strains of Bacillus cereus from diverse soils.

Bacillus cereus UW85 produces a novel aminopolyol antibiotic, zwittermicin A, that contributes to the ability of UW85 to suppress damping-off of alfalfa caused by Phytophthora medicaginis. UW85 produces a second antibiotic, provisionally designated antibiotic B, which also contributes to suppression of damping-off but has not been structurally defined yet and is less potent than zwittermicin A. The purpose of this study was to isolate genetically diverse strains of B. cereus that produce zwittermicin A and suppress disease. We found that most isolates of B. cereus that were sensitive to phage P7 or inhibited the growth of Erwinia herbicola produced zwittermicin A; therefore, phage typing and E. herbicola inhibition provided indirect, but rapid screening tests for identification of zwittermicin A-producing isolates. We used these tests to screen a collection of 4,307 B. cereus and Bacillus thuringiensis isolates obtained from bacterial stock collections and from diverse soils collected in Honduras, Panama, Australia, The Netherlands, and the United States. A subset of the isolates screened by the P7 sensitivity and E. herbicola inhibition tests were assayed directly for production of zwittermicin A, leading to the identification of 57 isolates that produced zwittermicin A; 41 of these isolates also produced antibiotic B. Eight isolates produced antibiotic B but not zwittermicin A. The assay for phage P7 sensitivity was particularly useful because of its simplicity and rapidity and because 22 of the 23 P7-sensitive isolates tested produced zwittermicin A. However, not all zwittermicin A-producing isolates were sensitive to P7, and the more labor-intensive E. herbicola inhibition assay identified a larger proportion of the zwittermicin A producers.(ABSTRACT TRUNCATED AT 250 WORDS)     

一株新的溶磷草生欧文氏菌的分离、鉴定及其溶磷效果的初步研究

从湖南、湖北、云南等地磷矿开采场的土壤样品中筛选到一株溶磷能力较强的菌株P21,结合生理生化指标和16S rDNA序列分析鉴定其属于草生欧文氏菌菠萝变种(Erwinia herbicola var.ananas).该菌能溶解磷酸三钙、羟基磷灰石、磷酸铁、磷酸锌,其中对磷酸三钙和羟基磷灰石的每升液体培养基溶磷量(P2O5)分别高达1206.20mg、529.67mg.溶磷菌草生欧文氏菌菠萝变种P21对产地不同的8种磷矿石溶解能力不同,对云南晋宁和昆阳、四川雅安、江苏锦屏等地磷矿石有较强的溶解能力,每升液体培养基溶磷量分别为96.64mg、78.46mg、67.07mg、65.24mg,对其它产地的磷矿石溶解能力较差.实验表明,培养液的pH下降与溶磷菌P21的溶磷量无直接关系.     

Microbial metabolism of amino alcohols. Metabolism of ethanolamine and 1-aminopropan-2-ol in species of Erwinia and the roles of amino alcohol kinase and amino alcohol O-phosphate phospho-lyase in aldehyde formation

1. Growth of Erwinia carotovora N.C.P.P.B. 1280 on media containing 1-aminopropan-2-ol compounds or ethanolamine as the sole N source resulted in the excretion of propionaldehyde or acetaldehyde respectively. The inclusion of (NH(4))(2)SO(4) in media prevented aldehyde formation. 2. Growth, microrespirometric and enzymic evidence implicated amino alcohol O-phosphates as aldehyde precursors. An inducibly formed ATP-amino alcohol phosphotransferase was partially purified and found to be markedly stimulated by ADP, unaffected by NH(4) (+) ions and more active with ethanolamine than with 1-aminopropan-2-ol compounds. Amino alcohol O-phosphates were deaminated by an inducible phospho-lyase to give the corresponding aldehydes. This enzyme, separated from the kinase during purification, was more active with ethanolamine O-phosphate than with 1-aminopropan-2-ol O-phosphates. Activity of the phospho-lyase was unaffected by a number of possible effectors, including NH(4) (+) ions, but its formation was repressed by the addition of (NH(4))(2)SO(4) to growth media. 3. E. carotovora was unable to grow with ethanolamine or 1-aminopropan-2-ol compounds as sources of C, the production of aldehydes during utilization as N sources being attributable to the inability of the microbe to synthesize aldehyde dehydrogenase. 4. Of seven additional strains of Erwinia examined similar results were obtained only with Erwinia ananas (N.C.P.P.B. 441) and Erwinia milletiae (N.C.P.P.B. 955).     

Erwinia herbicola isolates from alfalfa plants may play a role in nodulation of alfalfa by Rhizobium meliloti.

Erwinia herbicola was isolated from roots of plants derived from surface-sterilized seeds of all alfalfa varieties that were tested. Some of these E. herbicola strains affected nodulation by certain strains of Rhizobium meliloti. In previously published work we presented the isolation of slow-and fast-nodulating variants from a single culture of R. meliloti 102F51. In the absence of E. herbicola, the slow-nodulating variant induced the formation of nodules on alfalfa as rapidly as the faster-nodulating strain. The rates of nodulation by the faster-nodulating variant were the same in the presence and absence of E. herbicola. All of the previously reported slower-nodulating strains derived from R. meliloti 102F51 nodulated more rapidly on sterilized plants than in the presence of certain E. herbicola isolates.     

Serological difference betweenErwinia herbicola strains of plant and human origin

FiftyErwinia herbicola isolates obtained from host plants were examined in an agglutination reaction with antiserum prepared againstE. ananas (E. herbicola) strain CCM 2407 antigen of plant origin and with antiserum prepared againstEnterobacter agglomerans strain CNCTC M 269 antigen of human origin. In tests with strain CCM 2407 antiserum, 56% isolates showed a positive reaction, while in tests with strain CNCTC M 269 antiserum only 14 % isolates showed a positive reaction. AmongE. herbicola isolates which showed a positive reaction with CCM 2407 antiserum 18 % showed a positive reaction with the CNCTC M 269 antiserum too. Our results confirmed the serological heterogeneity ofE. herbicola population. In spite of the difference in the origin of the two antigens used for the preparation of antisera (plant, human; Japan, Czech Republic) our results indicate that some of ourE. herbicola strains andE. agglomerans strain CNCTC M 269 are serologically identical.     

Genetic Transfer of Episomic Elements Among Erwinia Species and Other Enterobacteria: F′lac+

The episomic element F'lac(+) was transferred, probably by conjugation, from Escherichia coli to Lac(-) strains of Erwinia herbicola, Erwinia amylovora, and Erwinia chrysanthemi (but not to several other Erwinia spp. In preliminary trials). The lac genes in the exconjugants of the Erwinia spp. showed varying degrees of stability depending on the strain (stable in E. herbicola strains Y46 and Y74 and E. amylovora strain EA178, but markedly unstable in E. chrysanthemi strain EC16). The lac genes and the sex factor (F) were eliminated from the exconjugants by treatment with acridine orange, thus suggesting that both lac and F are not integrated in the Erwinia exconjugants. All of the tested Lac(+) exconjugants of E. herbicola strains Y46 and Y74 and E. amylovora strain EA178, but not of E. chrysanthemi strain EC 16, were sensitive to the F-specific phage M13. The heterogenotes (which harbored F'lac(+)) of E. herbicola strains Y46 and Y74, E. amylovora strain EA178, and E. chrysanthemi strain EC16 were able to transfer lac genes by conjugation to strains of E. herbicola, E. amylovora, E. chrysanthemi, Escherichia coli, and Shigella dysenteriae. The frequency of such transfer from Lac(+) exconjugants of Erwinia spp. was comparable to that achieved by using E. coli F'lac(+) as donors, thus indicating the stability, expression, and restriction-and-modification properties of the sex factor (F) in Erwinia spp.     

Erwinia aphidicola,a new species isolated from pea aphid,Acyrthosiphon pisum

Five strains of Gram-negative, oxidase-negative, facultatively anaerobic, fermentative, motile, rod-shaped bacterium with the general characteristics of the family Enterobacteriaceae were isolated from the gut of multiple specimens of the pea aphid. All the strains caused aphid mortality when ingested by insects via a synthetic diet. The results of biochemical tests showed that these strains are most related to Erwinia herbicola and Pantoea agglomerans. According to DNA-DNA hybridization, the five strains showed more than 96% relatedness to each other, indicating that these organisms are members of a single species. These strains were most closely related to Erwinia herbicola (22% DNA relatedness). Phenotypic differentiation of these strains from Erwinia herbicola, which was also detected from aphid gut, was based on negative reactions in tests of yellow pigment production, gelatin liquefaction, acid production from inulin, starch and dulcitol, and positive acid production from melibiose, inositol, cellobiose and glycerol. On the basis of these data, the name Erwinia aphidicola is proposed for the new organism. The type strain is strain X 001 (=IAM 14479).     

UV-induced formation of filamentous forms in bacteria of Erwinia genus

Cells of 56 pectolytic Erwinia strains of different origin tested are prone to filamentation after UV-irradiation. The fact makes one possible to consider them natural fil+ organisms. Bacteria E. herbicola (9 strains) that are unable to synthesize pectatelyases are not transformed into filaments after NV-irradiation. The function of fil+ genes is recA-dependent in bacteria E. chrysanthemi ENA49 and is phenotypically analogous to fil+ gene function in E. coli B or lon- mutation in E. coli K12.     

Transfer among Erwinia spp. and other enterobacteria of antibiotic resistance carried on R factors

Antibiotic resistance carried on R factors was transferred by conjugation from Escherichia coli B/r and Shigella flexneri 1a to Erwinia spp. Tetracycline resistance (TetR) carried on R factor R100 drd-56 was transferred from E. coli B/r to strains of Erwinia amylovora, E. aroideae, E. atroseptica, E. chrysanthemi, E. cytolytica, E. dissolvens, E. herbicola, E. nigrifluens, and E. nimipressuralis, but not to strains of Erwinia carotovora, E. carnegieana, E. dieffenbachiae, E. oleraceae, and E. quercina. Multiple antibiotic resistance (chloramphenicol, streptomycin, tetracycline; ChlR-StrR-TetR) carried on R factor SR1 was transferred from a clinical isolate of S. flexneri 1a to strains of E. aroideae, E. chrysanthemi, E. herbicola, and E. nigrifluens, but not to strains of other Erwinia spp. The frequency of this transfer was low with receptive cultures of Erwinia spp. and E. coli (F(-) strain). Antibiotic resistance in the exconjugants showed varying degrees of stability in the presence or absence of acridine orange, depending on the strain tested. The frequencies of segregation to drug susceptibility in the presence of acridine orange, though low, suggest that the elements exist as plasmids in the majority of the Erwinia exconjugants. Multiple antibiotic resistance (ChlR-StrR-TetR) was found to segregate into various resistance classes (ChlR-StrR, StrR-TetR, TetR, StrR, and none) in these exconjugants. The exconjugants of E. amylovora, E. herbicola, and E. nigrifluens, to which R100 drd-56 was transferred from E. coli B/r, were sensitive to the male (F)-specific phage M13. There was a positive correlation between the susceptibility of exconjugants to the F-specific phage M13 and their ability to transfer R100 drd-56 to the recipient cultures of Escherichia coli, Erwinia herbicola, Salmonella typhimurium, and Shigella dysenteriae. Exceptions were, however, noted with Erwinia dissolvens and E. nimipressuralis exconjugants harboring R100 drd-56; these exconjugants, although not susceptible to M13, transferred R100 drd-56 to the recipient cultures. The frequency of transfer of R100 drd-56 and the levels of resistance to tetracycline in Erwinia exconjugants were found to differ markedly depending upon the strain employed. Transfer of multiple antibiotic resistance (ChlR-StrR-TetR) from Erwinia exconjugants was not obtained in preliminary trials with an E. coli F(-) strain as the recipient culture.     

丝裂霉素C对Erwinia herbicola表达及运转冰核活性蛋白方式的影响

利用添加丝裂霉素C(MMC)于不同培养基中,并在不同培养条件下对草生欧文氏菌10025A(E．herbicola 10025A)诱导培养,首次证实该菌表达冰核活性蛋白的活性及运转分泌冰核活性蛋白方式是不同。研究结果显示,MMC的加入可以提高细菌培养物的冰核活性,该现象可以解释为MMC对E．herbicola的作用能够激活细胞SOS应急系统的反应,诱导细胞合成部分参与修复DNA损伤的酶和蛋白因子,达到对E．herbicola诱导表达冰核蛋白通过高尔基体形成小液泡,向膜外分泌的方式,同时对E．herbicola细胞分裂后的形态也发生明显的影响。这对研究细胞在恶劣环境的生存机制以及获取该条件下的蛋白具有重要的意义,对低温生物的研究也将产生积极地影响。     

Release of cell-free ice nuclei by Erwinia herbicola.

Several ice-nucleating bacterial strains, including Erwinia herbicola, Pseudomonas fluorescens, and Pseudomonas syringae isolates, were examined for their ability to shed ice nuclei into the growth medium. Only E. herbicola isolates shed cell-free ice nuclei active at -2 to -10 degrees C. These cell-free nuclei exhibited a freezing spectrum similar to that of ice nuclei found on whole cells, both above and below -5 degrees C. Partially purified cell-free nuclei were examined by density gradient centrifugation, chemical and enzymatic probes, and electron microscopy. Ice-nucleating activity in these cell-free preparations was associated with outer membrane vesicles shed by cells and was sensitive to protein-modifying reagents.     

Taxonomic studies on Corynebacterium beticola (Abdou)

Morphological, physiological and chemical studies were performed on the type strain of Corynebacterium beticola in an attempt to clarify its taxonomy. The results indicate that Corynebacterium beticola is a Gram negative, facultatively anaerobic bacterium which should be assigned to the genus Erwinia as Erwinia herbicola .     

云南植物上冰核活性细菌鉴定

从云南植物上分离到９２株冰核活性细菌,并进行了鉴定。其中菠萝欧文氏菌６１株,占６６．３％;草生欧文氏菌２株,占２．２％;丁香假单胞菌２１株,占２２．８％;黄瓜角斑病菌２株,占２．２％;菜豆荚斑假单胞菌６株,占６．５％。云南省冰核活性细菌的优势种类是菠萝欧文氏菌,其次是丁香假单胞菌类。