Abstract:
:Bacterial plasmolytic response to osmotic stress was evaluated as a physical indicator of membrane integrity and hence cellular viability. Digital image analysis and either low-magnification dark-field, high-magnification phase-contrast, or confocal laser microscopy, in conjunction with pulse application of a 1.5 M NaCl solution, were used as a rapid, growth-independent method for quantifying the viability of attached biofilm bacteria. Bacteria were considered viable if they were capable of plasmolysis, as quantified by changes in cell area or light scattering. When viable Salmonella enteritidis biofilm cells were exposed to 1.5 M NaCl, an approximately 50% reduction in cell protoplast area (as determined by high-magnification phase-contrast microscopy) was observed. In contrast, heat- and formalin-killed S. enteritidis cells were unresponsive to NaCl treatment. Furthermore, the mean dark-field cell area of a viable, sessile population of Pseudomonas fluorescens cells (approximately 1,100 cells) increased by 50% as a result of salt stress, from 1,035 +/- 162 to 1,588 +/- 284 microns2, because of increased light scattering of the condensed, plasmolyzed cell protoplast. Light scattering of ethanol-killed control biofilm cells underwent little change following salt stress. When the results obtained with scanning confocal laser microscopy and a fluorescent viability probe were compared with the accuracy of plasmolysis as a viability indicator, it was found that the two methods were in close agreement. Used alone or in conjunction with fluorochemical probes, physical indicators of membrane integrity provided a rapid, direct, growth-independent method for determining the viability of biofilm bacteria known to undergo plasmolysis, and this method may have value during efficacy testing of biocides and other antimicrobial agents when nondestructive time course analyses are required.
journal_name
Appl Environ Microbioljournal_title
Applied and environmental microbiologyauthors
Korber DR,Choi A,Wolfaardt GM,Caldwell DEdoi
10.1128/AEM.62.11.3939-3947.1996subject
Has Abstractpub_date
1996-11-01 00:00:00pages
3939-47issue
11eissn
0099-2240issn
1098-5336journal_volume
62pub_type
杂志文章abstract::Despite the increasing knowledge of Synechococcus spp. and their co-occurring cyanophages in oceanic and coastal water, little is known about their abundance, distribution, and interactions in the Chesapeake Bay estuarine ecosystem. A 5-year interannual survey shows that Synechococcus spp. and their phages are persist...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00267-11
更新日期:2011-11-01 00:00:00
abstract::Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) has been used to identify bacteria based upon protein signatures. This research shows that while some different proteins are produced by vegetative bacteria when they are cultured in different growth media, positive identificat...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.71.1.58-64.2005
更新日期:2005-01-01 00:00:00
abstract::The routine production and storage of frozen doughs are still problematic. Although commercial baker's yeast is highly resistant to environmental stress conditions, it rapidly loses stress resistance during dough preparation due to the initiation of fermentation. As a result, the yeast loses gassing power significantl...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/aem.68.10.4780-4787.2002
更新日期:2002-10-01 00:00:00
abstract::Cyanobacterial blooms are potential health hazards in water supply reservoirs. This paper reports analyses of a cyanobacterial bloom by use of PCR-based methods for direct detection and identification of strains present and determination of their toxigenicity. Serial samples from Malpas Dam, in the New England region ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/aem.68.12.6070-6076.2002
更新日期:2002-12-01 00:00:00
abstract::A method was developed to follow bacterial nitrate reduction in freshwater sediments by using common high-performance liquid chromatographic equipment. The low detection limit (14 pmol) of the method enabled us to study concentration profiles and reaction kinetics under natural conditions. Significant nitrate concentr...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.53.2.217-223.1987
更新日期:1987-02-01 00:00:00
abstract::Two Acanthamoeba species, fed at three temperatures, expelled vesicles containing living Legionella pneumophila cells. Vesicles ranged from 2.1 to 6.4 microns in diameter and theoretically could contain several hundred bacteria. Viable L. pneumophila cells were observed within vesicles which had been exposed to two co...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.64.1.279-286.1998
更新日期:1998-01-01 00:00:00
abstract::Cell extracts of Clostridium thermohydrosulfuricum, an anaerobic bacterium which ferments starch into ethanol at 65 degrees C, contained both pullulanase and glucoamylase activities. The general physiochemical and catalytic properties of these enzyme activities were compared. Pullulanase and glucoamylase activities we...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.49.5.1168-1173.1985
更新日期:1985-05-01 00:00:00
abstract::A basal (BC) medium devoid of added carbohydrates, a complete (CC) medium containing nine carbohydrates were developed for enumerating rumen bacteria. The colony counts on the BC medium were 85 to 100% of those obtained on the CC medium. These colonies were pinpoint size (less than or equal to mm in diameter) but incr...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.39.4.709-719.1980
更新日期:1980-04-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.62.3.1084-1088.1996
更新日期:1996-03-01 00:00:00
abstract::The ability of Streptococcus species to selectively adhere to the oral epithelial cells of newborns was studied in vitro. On day 1 of life, mucosal cells from normal infants demonstrated selective attraction for the natural distribution of streptococci that would soon colonize these surfaces. Streptococcus salivarius ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.32.4.494-497.1976
更新日期:1976-10-01 00:00:00
abstract::Under anoxic conditions, most methoxylated mononuclear aromatic compounds are degraded by bacteria, with catechol being formed as an important intermediate. On the basis of our experiments with the sulfate-reducing bacterium Desulfobacterium sp. strain Cat2, we describe for the first time the enzymatic activities invo...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.60.9.3396-3400.1994
更新日期:1994-09-01 00:00:00
abstract::Populations of feral pigs (Sus scrofa) may serve as an environmental reservoir of Cryptosporidium parvum oocysts and Giardia sp. cysts for source water. We conducted a cross-sectional study to determine the prevalence of and associated demographic and environmental risk factors for the shedding of C. parvum oocysts an...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.63.10.3946-3949.1997
更新日期:1997-10-01 00:00:00
abstract::In May 1999, field surveys of Lyme disease spirochetes were conducted around the Tianshan Mountains in Xinjiang Uygur Autonomous Region in northwestern People's Republic of China. Ixodes persulcatus ticks were obtained in a Tianchi Lake valley with primary forest, while the tick fauna was poor in the semidesert or at ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.67.11.5161-5165.2001
更新日期:2001-11-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.40.5.959-963.1980
更新日期:1980-11-01 00:00:00
abstract::Water samples from rivers, streams, ponds, and activated sewage were tested for the presence of bacteria which utilize 2,4-dichlorophenoxyacetic acid (2,4-D) as a sole source of carbon. Seventy percent of the attempted enrichments yielded pure cultures of 2,4-D-metabolizing bacteria. All but 1 of the 30 isolates were ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.49.5.1237-1245.1985
更新日期:1985-05-01 00:00:00
abstract::A tremorgenic mycotoxin was isolated from Penicillium paraherquei Abe ex G. Smith and identified as verruculogen. It was produced at the rate of approximately 1 mg/g of the dried fungal mycelium cultured on peptone-enriched Czapek-Dox medium at 28 degrees C. ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.32.3.441-442.1976
更新日期:1976-09-01 00:00:00
abstract::A diesel fuel-contaminated aquifer was bioremediated in situ by the injection of oxidants (O2 and NO3-) and nutrients in order to stimulate microbial activity. After 3.5 years of remediation, an aquifer sample was excavated and the material was used (i) to isolate bacterial strains able to grow on selected hydrocarbon...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.63.6.2136-2141.1997
更新日期:1997-06-01 00:00:00
abstract::In this study, we used chemostat cultures to analyze the quantitative effects of the specific growth rate and respiration on the metabolism in Lactococcus lactis CHCC2862 and on the downstream robustness of cells after freezing or freeze-drying. Under anaerobic conditions, metabolism remained homofermentative, althoug...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.02785-19
更新日期:2020-03-02 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
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更新日期:2011-06-01 00:00:00
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journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.32.2.294-297.1976
更新日期:1976-08-01 00:00:00
abstract::The role of Escherichia coli as a pathogen has been the focus of considerable study, while much less is known about it as a commensal and how it adapts to and colonizes different environmental niches within the mammalian gut. In this study, we characterize Escherichia coli organisms (n = 146) isolated from different r...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01688-12
更新日期:2012-10-01 00:00:00
abstract::The aromatic amino acids are synthesized via a common biosynthetic pathway. A tryptophan-producing mutant of Corynebacterium glutamicum was genetically engineered to produce tyrosine or phenylalanine in abundance. To achieve this, three biosynthetic genes encoding the first enzyme in the common pathway, 3-deoxy-d-arab...
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::AbiV is an abortive infection protein that inhibits the lytic cycle of several virulent phages infecting Lactococcus lactis, while a mutation in the phage gene sav confers insensitivity to AbiV. In this study, we have further characterized the effects of the bacterial AbiV and its interaction with the phage p2 protein...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.00093-10
更新日期:2010-11-01 00:00:00
abstract::Five cases of primary amoebic meningoencephalitis associated with swimming in freshwater lakes have been recorded in Florida over the past 14 years. The present study demonstrated that pathogenic Naegleria, the causative agent, is relatively widespread. Twelve of 26 lakes sampled only once yielded the amoeba. Populati...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.34.6.661-667.1977
更新日期:1977-12-01 00:00:00
abstract::A clinical isolate of Pseudomonas aeruginosa was found capable of utilizing salicylate by the salicylate hydroxylase and beta-ketoadipate pathway. ...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.41.1.312-314.1981
更新日期:1981-01-01 00:00:00
abstract::Prodigiosin (PG), a red linear tripyrrole pigment normally secreted by Serratia marcescens, has received attention for its reported immunosuppressive, antimicrobial, and anticancer properties. Although several genes have been shown to be important for prodigiosin synthesis, information on the regulatory mechanisms beh...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.02052-20
更新日期:2021-01-04 00:00:00
abstract::Tropomyosin receptor kinase A (TrkA), a receptor tyrosine kinase, is known to be associated with various diseases. Thus, TrkA has become a major drug-screening target for these diseases. Despite the fact that the production of recombinant proteins by prokaryotic hosts has advantages, such as fast growth and ease of ge...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.03112-14
更新日期:2015-02-01 00:00:00
abstract::O-antigen biosynthetic (wbf) regions for Vibrio cholerae serogroups O5, O8, and O108 were isolated and sequenced. Sequences were compared to those of other published V. cholerae O-antigen regions. These wbf regions showed a high degree of heterogeneity both in gene content and in gene order. Genes identified frequentl...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01663-10
更新日期:2011-04-01 00:00:00
abstract::The extensive use of antibiotics in hospitals and in the animal breeding industry has promoted antibiotic resistance in bacteria, which resulted in the emergence of a large number of antibiotic resistance genes in the intestinal tract of human and farmed animals. Genetic exchange of resistance genes between the two ec...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.01910-20
更新日期:2020-12-11 00:00:00
abstract::Spiroplasma citri is transmitted from plant to plant by phloem-feeding leafhoppers. In an attempt to identify mechanisms involved in transmission, mutants of S. citri affected in their transmission must be available. For this purpose, transposon (Tn4001) mutagenesis was used to produce mutants which have been screened...
journal_title:Applied and environmental microbiology
pub_type: 杂志文章
doi:10.1128/AEM.70.7.3960-3967.2004
更新日期:2004-07-01 00:00:00