Abstract:
:Conjugal plasmid transfer was examined on the phylloplane of bean (Phaseolus vulgaris) and related to the spatial distribution pattern and metabolic activity of the bacteria. The donor (Pseudomonas putida KT2442) harbored a derivative of the TOL plasmid, which conferred kanamycin resistance and had the gfp gene inserted downstream of a lac promoter. A chromosomal insertion of lacIq prevented expression of the gfp gene. The recipient (P. putida KT2440) had a chromosomal tetracycline resistance marker. Thus, transconjugants could be enumerated by plating and visualized in situ as green fluorescent cells. Sterile bean seedlings were inoculated with donors and recipients at densities of approximately 10(5) cells per cm2. To manipulate the density and metabolic activity (measured by incorporation of [3H]leucine) of the inoculated bacteria, plants were grown at various relative humidities (RH). At 100% RH, the transconjugants reached a density of 3 x 10(3) CFU/cm2, corresponding to about one-third of the recipient population. At 25% RH, numbers of transconjugants were below the detection limit. Immediately after inoculation onto the leaves, the per-cell metabolic activity of the inocula increased by up to eight times (100% RH), followed by a decrease to the initial level after 96 h. The metabolic activity of the bacteria was not rate limiting for conjugation, and no correlation between the two parameters was observed. Apparently, leaf exudates insured that the activity of the bacteria was above a threshold value for transfer to occur. Transconjugants were primarily observed in junctures between epidermal cells and in substomatal cavities. The distribution of the transconjugants was similar to the distribution of indigenous bacteria on nonsterile leaves. Compared to polycarbonate filters, with cell densities equal to the overall density on the leaves, transfer ratios on leaves were up to 30 times higher. Thus, aggregation of the bacteria into microhabitats on the phylloplane had a great stimulatory effect on transfer.
journal_name
Appl Environ Microbioljournal_title
Applied and environmental microbiologyauthors
Normander B,Christensen BB,Molin S,Kroer Ndoi
10.1128/AEM.64.5.1902-1909.1998subject
Has Abstractpub_date
1998-05-01 00:00:00pages
1902-9issue
5eissn
0099-2240issn
1098-5336journal_volume
64pub_type
杂志文章abstract::A modification of the Adler capillary assay was used to evaluate the chemotactic responses of several denitrifiers to nitrate and nitrite. Strong positive chemotaxis was observed to NO(3) and NO(2) by soil isolates of Pseudomonas aeruginosa, Pseudomonas fluorescens, and Pseudomonas stutzeri, with the peak response occ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.49.1.109-114.1985
更新日期:1985-01-01 00:00:00
abstract::Ninety-nine Campylobacter coli isolates were examined by bacterial restriction endonuclease DNA analysis (BRENDA) with HindIII. Isolates from poultry from the same environment had identical patterns, patterns of isolates carried by suckling piglets were generally the same as those of isolates recovered from their dams...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.48.3.545-549.1984
更新日期:1984-09-01 00:00:00
abstract::The ability of various subsets of poultry intestinal microbiota to protect turkeys from colonization by Campylobacter jejuni was investigated. Community subsets were generated in vivo by inoculation of day-old poults with the cecal contents of a Campylobacter-free adult turkey, followed by treatment with one antimicro...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00678-10
更新日期:2010-12-01 00:00:00
abstract::Three common food pathogenic microorganisms were exposed to treatments simulating those used in food processing. Treated cell suspensions were then analyzed for reduction in growth by plate counting. Flow cytometry (FCM) and fluorescence-activated cell sorting (FACS) were carried out on treated cells stained for membr...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00323-11
更新日期:2011-07-01 00:00:00
abstract::The effects of pulsed electric field (PEF) treatment and processing factors on the inactivation kinetics of Listeria innocua NCTC 11289 were investigated by using a pilot plant PEF unit with a flow rate of 200 liters/h. The electric field strength, pulse length, number of pulses, and inlet temperature were the most si...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.65.12.5364-5371.1999
更新日期:1999-12-01 00:00:00
abstract::The structure and stability of the dominant lactic acid bacterium population were assessed during wheat flour sourdough type I propagation by using singly nine strains of Lactobacillus sanfranciscensis. Under back-slopping propagation with wheat flour type 0 F114, cell numbers of presumptive lactic acid bacteria varie...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01524-08
更新日期:2009-02-01 00:00:00
abstract::The metabolism of aflatoxin B1 to aflatoxins M1 and Q1 by rat liver microsomes from animals pretreated with polychlorinated or polybrominated biphenyl congeners depended on the structure of the halogenated biphenyl inducers. Microsomes from rats treated with phenobarbital (PB) or halogenated biphenyls that exhibit PB-...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.49.4.882-886.1985
更新日期:1985-04-01 00:00:00
abstract::Epilithic bacteria were isolated nonselectively from riverbed stones and examined by gel zymography for their ability to produce alkylsulfatase (AS) enzymes and thus to metabolize alkyl sulfate surfactants such as sodium dodecyl sulfate. The percentages of AS+ isolates from stone epilithon at five sites from the sourc...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.54.2.555-560.1988
更新日期:1988-02-01 00:00:00
abstract::A molecular method based on restriction fragment length polymorphism (RFLP) of PCR-amplified fragments of the 23S rRNA gene was designed to rapidly identify Listeria strains to the species level. Two fragments (S1, 460 bp, and S2, 890 bp) were amplified from boiled DNA. S2 was cut with the restriction enzymes XmnI or ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/aem.69.11.6386-6392.2003
更新日期:2003-11-01 00:00:00
abstract::A glycosyltransferase, involved in the synthesis of cyclic maltosylmaltose [CMM; cyclo-{-->6)-alpha-D-Glcp(1-->4)-alpha-D-Glcp(1-->6)-alpha-D-Glcp(1-->4)-alpha-D-Glcp(1-->}] from starch, was purified to homogeneity from the culture supernatant of Arthrobacter globiformis M6. The CMM-forming enzyme had a molecular mass...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.72.2.1065-1071.2006
更新日期:2006-02-01 00:00:00
abstract::Short sequence repeats (SSRs) with a potential variable number of tandem repeat (VNTR) loci were identified in the genome of the citrus pathogen Xylella fastidiosa and used for typing studies. Although mono- and dinucleotide repeats were absent, we found several intermediate-length 7-, 8-, and 9-nucleotide repeats, wh...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/aem.67.9.4091-4095.2001
更新日期:2001-09-01 00:00:00
abstract::Seven different sources of inocula that included sediments, contaminated soils, groundwater, process effluent, and sludge were used to establish enrichment cultures of denitrifying bacteria on benzene, toluene, and xylenes in the absence of molecular oxygen. All of the enrichment cultures demonstrated complete depleti...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.57.2.450-454.1991
更新日期:1991-02-01 00:00:00
abstract::Group I strains of Clostridium botulinum are known to degrade arginine by the arginine deiminase pathway. We have found that C. botulinum Okra B consumed a level of arginine (20 g/liter) higher than the basal requirement for growth (3 g/liter). Arginine was probably the preferred source of nitrogen for biosynthesis bu...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.58.7.2334-2337.1992
更新日期:1992-07-01 00:00:00
abstract::Salmonella enterica is an animal and zoonotic pathogen of worldwide importance. Salmonella serovars that differ in their host and tissue tropisms exist. Cattle are an important reservoir of human nontyphoidal salmonellosis, and contaminated bovine peripheral lymph nodes enter the food chain via ground beef. The relati...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.02262-17
更新日期:2018-01-31 00:00:00
abstract::beta-D-Galactosidase (EC 3.2.1.23) was extracted from Streptococcus thermophilus grown in deproteinized cheese whey. Cultural conditions optimum for maximum enzyme production were pH 7.0, 40 degrees C, and 24 h. Proteose peptone (2.0%, wt/vol) and corn steep liquor (2.8%, wt/vol) were highly stimulatory, increasing th...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.34.2.185-188.1977
更新日期:1977-08-01 00:00:00
abstract::[This corrects the article on p. 931 in vol. 46.]. ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.47.5.1193-1193.1984
更新日期:1984-05-01 00:00:00
abstract::Oxidative stress causes transient actin cytoskeleton depolarization and also provokes vacuole fragmentation in wild-type cells. Under conditions of oxidative stress induced by hydrogen peroxide, the Slt2 protein is required to repolarize the actin cytoskeleton and to promote vacuole fusion. In this study, we show that...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01692-13
更新日期:2013-10-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.33.4.955-962.1977
更新日期:1977-04-01 00:00:00
abstract::A 1,6-dichlorohexane-degrading strain of Acinetobacter sp. was isolated from activated sludge. The organism could grow with and quantitatively release halide from 1,6-dichlorohexane, 1,9-dichlorononane, 1-chloropentane, 1-chlorobutane, 1-bromopentane, ethylbromide, and 1-iodopropane. Crude extracts contained an induci...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.53.3.561-566.1987
更新日期:1987-03-01 00:00:00
abstract::The nonlinear thermal inactivation of Aspergillus niger spores in phosphate-citrate buffer was studied. The thermal inactivation pattern of the spore consisted of a shoulder, an accelerated decline, and a tail at various constant temperatures around 60 degrees C. The pattern fitted a thermotolerant subpopulation model...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.62.10.3745-3749.1996
更新日期:1996-10-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.58.3.781-785.1992
更新日期:1992-03-01 00:00:00
abstract::Azospirillum spp. were shown to utilize both straw and xylan, a major component of straw, for growth with an adequate combined N supply and also under N-limiting conditions. For most strains examined, a semisolid agar medium was satisfactory, but several strains appeared to be capable of slow metabolism of the agar. S...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.49.2.423-428.1985
更新日期:1985-02-01 00:00:00
abstract::Motile phototrophic consortia are highly regular associations in which numerous cells of green sulfur bacteria surround a flagellated colorless beta-proteobacterium in the center. To date, seven different morphological types of such consortia have been described. In addition, two immotile associations involving green ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.70.8.4821-4830.2004
更新日期:2004-08-01 00:00:00
abstract::In this study, the feasibility of fluorescence lifetime imaging (FLIM) for measurement of RNA:DNA ratios in microorganisms was assessed. The fluorescence lifetime of a nucleic acid-specific probe (SYTO 13) was used to directly measure the RNA:DNA ratio inside living bacterial cells. In vitro, SYTO 13 showed shorter fl...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01806-07
更新日期:2008-01-01 00:00:00
abstract::The effects of water activity (aw, 0.955 to 0.970), pH (4.75 to 5.75), and storage time (up to 60 days) on toxin production by Clostridium botulinum in cooked, vacuum-packed potatoes were studied by using factorial design experiments and most-probable-number methodology. Samples were inoculated with 10(3), 10(4), or 1...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.55.3.656-660.1989
更新日期:1989-03-01 00:00:00
abstract::Phormium yellow leaf (PYL) phytoplasma causes a lethal disease of the monocotyledon, New Zealand flax (Phormium tenax). The 16S rRNA genes of PYL phytoplasma were amplified from infected flax by PCR and cloned, and the nucleotide sequences were determined. DNA sequencing and Southern hybridization analysis of genomic ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.62.9.3133-3139.1996
更新日期:1996-09-01 00:00:00
abstract::PCR-based methods have been developed to rapidly screen for Legionella pneumophila in water as an alternative to time-consuming culture techniques. However, these methods fail to discriminate between live and dead bacteria. Here, we report a viability assay (viability PCR [v-PCR]) for L. pneumophila that combines ethi...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.02878-08
更新日期:2009-06-01 00:00:00
abstract::Patulin production by Penicillium griseofulvum was monitored with Sep-Pak cartridges and high-pressure liquid chromatography. Determination and quantification of this metabolite proved to be very simple, and our method saved time and a large amount of organic solvents. ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.51.1.209-210.1986
更新日期:1986-01-01 00:00:00
abstract::Prototrophic and growth factor-requiring strains of Alcaligenes spp. were used to study the effect of a protozoan, Tetrahymena pyriformis, on the degradation of p-aminobenzoate. The protozoan inhibited activity of the prototrophic bacterium by reducing its population size. For the growth factor-requiring strain of Alc...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.41.1.229-232.1981
更新日期:1981-01-01 00:00:00
abstract::Antibody against nivalenol tetraacetate (tetra-Ac-NIV) was prepared by immunization of rabbits with triacetyl-15-pimelate-NIV conjugated to bovine serum albumin. By using tritiated tetra-Ac-NIV as the test ligand, antibody titers were demonstrated as early as 4 weeks after immunization. Useful antibody for radioimmuno...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.57.4.1026-1030.1991
更新日期:1991-04-01 00:00:00