Method for Collecting Air-Water Interface Microbes Suitable for Subsequent Microscopy and Molecular Analysis in both Research and Teaching Laboratories

Henk, Margaret C.

doi:10.1128/aem.70.4.2486-2493.2004

Cited by 19 publications

(15 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Bacteria with greater hydrophobic character are more strongly attracted to this interface. 17 A surfactant such as sodium dodecyl sulfate (SDS) efficiently removes bacteria adhered to surfaces 18 and increases the negative charge at the interface. 19 Since surfactants are also strongly attracted to the air-water interface our hypothesis was that SDS would preferentially occupy the air-water interface of the bubbles by displacing the bacteria, effectively decreasing the bacteria concentration within the diffusion length of singlet oxygen (~150 nm).…”

Section: Resultsmentioning

confidence: 99%

“…Previous studies have shown that bacteria, 14,15 as well as particles 17 accumulate at the air-water interface due to wetting properties and surface charges of the particulate surfaces. Bacteria with hydrophobic wetting properties and low zeta potentials are especially strongly attracted to the gas-liquid interface, minimizing the overall energy of the system.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Bacterial Inactivation by a Singlet Oxygen Bubbler: Identifying Factors Controlling the Toxicity of ¹O₂ Bubbles

Bartusik

Aebisher

Lyons

et al. 2012

Environ. Sci. Technol.

View full text Add to dashboard Cite

A microphotoreactor device was developed to generate bubbles (sized: 1.4 mm diameter, 90 μL) containing singlet oxygen at levels toxic to bacteria and fungus. As singlet oxygen decays rapidly to triplet oxygen, the bubbles leave behind no waste or by-products other than O2. From a comparative study in deaerated, air saturated, and oxygenated solutions, it was reasoned that the singlet oxygen bubbles inactivate Escherichia coli and Aspergillus fumigatus, mainly by an oxygen gradient inside and outside of the bubble such that singlet oxygen is solvated and diffuses through the aqueous solution until it reacts with the target organism. Thus, singlet oxygen bubble toxicity was inversely proportional to the amount of dissolved oxygen in solution. In a second mechanism, singlet oxygen interacts directly with E. coli that accumulate at the gas-liquid interface although this mechanism operates at a rate approximately 10 times slower. Due to encapsulation in the gaseous core of the bubble and a 0.98 ms lifetime, the bubbles can traverse relatively long 0.39 mm distances carrying 1O2 far into the solution; by comparison the diffusion distance of 1O2 fully solvated in H2O is much shorter (~150 nm). Bubbles that reached the outer air/water interface contained no 1O2. The mechanism by which 1O2 deactivated organisms was explored through the addition of detergent molecules and Ca2+ ions. Results indicate that the preferential accumulation of E. coli at the air-water interface of the bubble leads to enhanced toxicity of bubbles containing 1O2. The singlet oxygen device offers intriguing possibilities for creating new types of disinfection strategies based on photodynamic (1O2) bubble carriers.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Bacterial Inactivation by a Singlet Oxygen Bubbler: Identifying Factors Controlling the Toxicity of ¹O₂ Bubbles

Bartusik

Aebisher

Lyons

et al. 2012

Environ. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…The surface microlayer (SML) is a ubiquitous feature in aquatic environments (Henk, 2004) and represents the interface between the hydrosphere and the atmosphere, being operationally defined as the uppermost millimeter of the water column (Liss & Duce, 1997). Several physical and biological processes, including simple diffusion, turbulent mixing, rising bubbles, in situ primary production, convection and upwelling of underlying waters (UW) (Liss & Duce, 1997), contribute to the enrichment of organic and inorganic nutrients as well as microorganisms at this interface.…”

Section: Introductionmentioning

confidence: 99%

Relation between bacterial activity in the surface microlayer and estuarine hydrodynamics

Santos

Coelho

et al. 2011

FEMS Microbiology Ecology

View full text Add to dashboard Cite

Bacterial communities of the surface microlayer (SML) of the estuary Ria de Aveiro (Portugal) were characterized in terms of abundance and activity during a 2-year survey at two sites with distinct hydrodynamic properties (marine and brackish water zones). The hydrodynamic conditions were simulated using a bidimensional numerical model and related to the microbiological observations. The pattern of variation of bacterial biomass productivity (BBP) was distinct between the two sampling sites. At the outer site, BBP was significantly lower at the SML, whereas at the inner site, it was significantly enhanced at the SML. Although the total bacterial abundance was similar in the SML and underlying water (UW), the fraction of cells attached to particles was significantly higher at the SML (two to three times). The integration of microbiological results with environmental and hydrological variables shows that strong currents in the marine zone promote the vertical mixing, inhibiting the establishment of an SML bacterial community distinct from that of UW. In contrast, in the brackish water zone, lower current velocities provide conditions for enhancing the bacterial activity in the enriched SML. Estuarine dynamics influence the distribution and activity of microorganisms at the SML and in the water column, with anticipated impacts for the carbon cycle in the estuarine environment.

show abstract

“…To confirm and extend the results from the tube assay, V. vulnificus phase variants were grown statically in HI broth in six-well culture plates at 30°C for up to 6 h, and the resulting biofilms that formed at the air-broth interface were harvested by their attachment upon contact to collodion-coated glass coverslips as described previously (10) and viewed by differential interference contrast microscopy. Figure 5 shows that while the rugose strains BG(R) and ABZ1(R) (Fig.…”

mentioning

confidence: 99%

High-Frequency Phase Variation of Vibrio vulnificus 1003: Isolation and Characterization of a Rugose Phenotypic Variant

Grau¹,

Henk²,

Pettis

2005

J Bacteriol

Self Cite

View full text Add to dashboard Cite

The marine bacterium Vibrio vulnificus is a human pathogen that can spontaneously switch between virulent opaque and avirulent translucent phenotypes. Here, we document an additional form, the rugose variant, which produces copious biofilms and which may contribute both to pathogenicity of V. vulnificus and to its survival under adverse environmental conditions.Vibrio vulnificus is a marine bacterium that can cause human disease and has been implicated as the cause of over 95% of the deaths related to seafood consumption in the United States (13,25). Infection usually occurs through the ingestion of raw oysters or by contact of an open wound with contaminated seawater. Susceptible individuals include those with liver disease, immune dysfunction, or elevated serum iron levels. When a susceptible individual consumes raw oysters contaminated with V. vulnificus, the result can be a rapidly fulminating septicemia, with mortality occurring in over 50% of cases (13,25).Some V. vulnificus isolates produce a polysaccharide capsule (3) which gives the colonies a smooth, mucoid, opaque phenotype. It has been reported that the capsule is a major virulence factor, presumably protecting the bacterium from the host immune system (23, 32). In culture, many opaque (O) strains spontaneously produce translucent (T) variants (28, 35). Opaque strains have been shown to be virulent in a mouse model, while translucent strains were avirulent in this model (23,32,35). Several studies have shown that capsular polysaccharide (CPS) expression varies between opaque and translucent strains as well as among different translucent strains (i.e., suggesting there are different degrees of translucence) (28,29,32). Transposon insertions have been shown to produce completely acapsular translucent strains (28,29,35).Opaque strains of V. vulnificus have been reported to switch spontaneously to the translucent phenotype at frequencies of 10 Ϫ5 to 10 Ϫ4 when the cells were grown in rich medium (12,29,32). If grown in a peptone-based yet more-defined medium, the switch occurs at a higher frequency, with over 60% of the colonies exhibiting the translucent phenotype (23). The reverse switch, from translucent to opaque, has been reported to occur at frequencies of 9.2 ϫ 10 Ϫ3 (29), less than 10 Ϫ4 (32), or not at all (12, 23). We have previously observed that opaque strains will spontaneously yield translucent variants much more often than the reverse. However, the translucent-to-opaque switch did occur on rare occasions when strains were routinely subcultured in heart infusion broth at 37°C and then left to stand at room temperature for several days before plating and incubation of plates at 37°C (unpublished results).Vibrio cholerae, the etiological agent of cholera, is a close relative of V. vulnificus. Although the O1 strains of V. cholerae produce no CPS, they have been responsible for the first six pandemics of cholera. The current, seventh pandemic has been caused not only by O1 strains but also by O139 strains, which do produce CPS (19). In additio...

show abstract

Method for Collecting Air-Water Interface Microbes Suitable for Subsequent Microscopy and Molecular Analysis in both Research and Teaching Laboratories

Cited by 19 publications

References 22 publications

Bacterial Inactivation by a Singlet Oxygen Bubbler: Identifying Factors Controlling the Toxicity of ¹O₂ Bubbles

Bacterial Inactivation by a Singlet Oxygen Bubbler: Identifying Factors Controlling the Toxicity of ¹O₂ Bubbles

Relation between bacterial activity in the surface microlayer and estuarine hydrodynamics

High-Frequency Phase Variation of Vibrio vulnificus 1003: Isolation and Characterization of a Rugose Phenotypic Variant

Contact Info

Product

Resources

About

Method for Collecting Air-Water Interface Microbes Suitable for Subsequent Microscopy and Molecular Analysis in both Research and Teaching Laboratories

Cited by 19 publications

References 22 publications

Bacterial Inactivation by a Singlet Oxygen Bubbler: Identifying Factors Controlling the Toxicity of 1O2 Bubbles

Bacterial Inactivation by a Singlet Oxygen Bubbler: Identifying Factors Controlling the Toxicity of 1O2 Bubbles

Relation between bacterial activity in the surface microlayer and estuarine hydrodynamics

High-Frequency Phase Variation of Vibrio vulnificus 1003: Isolation and Characterization of a Rugose Phenotypic Variant

Contact Info

Product

Resources

About

Bacterial Inactivation by a Singlet Oxygen Bubbler: Identifying Factors Controlling the Toxicity of ¹O₂ Bubbles

Bacterial Inactivation by a Singlet Oxygen Bubbler: Identifying Factors Controlling the Toxicity of ¹O₂ Bubbles