共查询到20条相似文献,搜索用时 203 毫秒
1.
John A. Finlay Michael P. Schultz Gemma Cone Maureen E. Callow James A. Callow 《Biofouling》2013,29(4):401-411
Laboratory assessment of the adhesion of diatoms to non-toxic fouling-release coatings has tended to focus on single cells rather than the more complex state of a biofilm. A novel culture system based on open channel flow with adjustable bed shear stress values (0–2.4?Pa) has been used to produce biofilms of Navicula incerta. Biofilm development on glass and polydimethylsiloxane elastomer (PDMSe) showed a biphasic relationship with bed shear stress, which was characterised by regions of biofilm stability and instability reflecting cohesion between cells relative to the adhesion to the substratum. On glass, a critical shear stress of 1.3–1.4?Pa prevented biofilm development, whereas on PDMS, biofilms continued to grow at 2.4?Pa. Studies of diatom biofilms cultured on zwitterionic coatings using a bed shear stress of 0.54?Pa showed lower biomass production and adhesion strength on poly(sulfobetaine methacrylate) compared to poly(carboxybetaine methacrylate). The dynamic biofilm approach provides additional information to supplement short duration laboratory evaluations. 相似文献
2.
Stacy Sommer Abdullah Ekin Shane J. Stafslien Justin Daniels Lyndsi J. VanderWal 《Biofouling》2013,29(8):961-972
Siloxane–polyurethane fouling-release (FR) coatings based on aminopropyl terminated poly(dimethylsiloxane) (PDMS) macromers were prepared and characterized for FR performance via laboratory biological assays. These systems rely on self-stratification, resulting in a coating with a siloxane-rich surface and polyurethane bulk. Previously, these coating systems have used PDMS with multiple functional groups which react into the polyurethane bulk. Here, aminopropyl terminated PDMS macromers were prepared, where a single amine group anchors the PDMS in the coating. Coatings were prepared with four molecular weights (1000, 5000, 10,000, and 15,000 g mol?1) and two levels of PDMS (5% and 10%). High water contact angles and low surface energies were observed for the coatings before and after water immersion, along with low pseudobarnacle removal forces. Laboratory bioassays showed reduced biofilm retention of marine bacteria, good removal of diatoms from coatings with low molecular weight PDMS, high removal of algal sporelings (young plants), and low removal forces of live barnacles. 相似文献
3.
Matthew G. Watson Andrew J. Scardino Liliana Zalizniak Jeff Shimeta 《Biofouling》2013,29(9-10):709-720
Ciliate assemblages are often overlooked, but ubiquitous components of microbial biofilms which require a better understanding. Ciliate, diatom and bacterial colonisation were evaluated on two fouling-release (FR) coatings, viz. Intersleek 970 and Hempasil X3, and two biocidal antifouling (AF) coatings, viz. Intersmooth 360 and Interspeed 5640, in Port Phillip Bay, Australia. A total of 15 genera were identified during the 10 week deployment. Intersleek 970 displayed the most rapid fouling by ciliates, reaching 63.3(± 5.9) cells cm?2. After 10 weeks, all four coatings were extensively fouled. However, the toxicity of the AF coatings still significantly inhibited microbial fouling compared to the FR coatings. On all treatments, colonies of sessile peritrichs dominated the ciliate assemblage in the early stage of succession, but as the biofilm matured, vagile ciliates exerted more influence on the assemblage structure. The AF coatings showed selective toxic effects, causing significant differences in the ciliate species assemblages among the treatments. 相似文献
4.
Gilles Brackman Tom Defoirdt Carol Miyamoto Peter Bossier Serge Van Calenbergh Hans Nelis Tom Coenye 《BMC microbiology》2008,8(1):149
Background
To date, only few compounds targeting the AI-2 based quorum sensing (QS) system are known. In the present study, we screened cinnamaldehyde and substituted cinnamaldehydes for their ability to interfere with AI-2 based QS. The mechanism of QS inhibition was elucidated by measuring the effect on bioluminescence in several Vibrio harveyi mutants. We also studied in vitro the ability of these compounds to interfere with biofilm formation, stress response and virulence of Vibrio spp. The compounds were also evaluated in an in vivo assay measuring the reduction of Vibrio harveyi virulence towards Artemia shrimp. 相似文献5.
Biofilm ecology: On-line methods bring new insights into mic and microbial biofouling 总被引:1,自引:0,他引:1
Microbial biofilms were formed on coupons with defined coatings in once-through laminar flow fields of controlled bulk-phase composition and shear. Dilute media were utilized to select for biofilm growth. The formation, succession, and stability of the biofilms were monitored with non-destructive on-line methods (fluorescence, bioluminescence, attenuated total reflectance Fourier transform infrared spectrometry [ATR-FTIR] and electrochemical impedance spectroscopy) and by high resolution destructive analysts (viable and direct counts and phospholipid fatty acid signature methods) at the termination of the experiments. Biofilms of reproducible composition can be formed and the order of inoculation of multi-component biofilms affects their composition at harvest. The corrosion rates of mild steel depended on the biofilm composition but not the attached biomass. Examination of biofilms with the scanning vibrating electrode in a microscope field showed effects of heterogeneity in biofilm structure which promoted localized anodic activity. Pseudomonas stains were engineered to contain the lux gene cassette as a "reporter"; and the formation of the exopolymer alginate was shown not to promote attachment of the strain or secondary colonization by Vibrio. Examination of mutants forming different alginate structures showed differential attachment and biofilm structure. Studies of mutants of lipopolysaccharide structure showed differential attachment to substrata. Specific antifouling and fouling-release coatings showed a wide range of attachment and release properties as well as sublethal toxicity. 相似文献
6.
Partha Majumdar Elizabeth Lee Nehal Patel Kaley Ward Shane J. Stafslien Justin Daniels 《Biofouling》2013,29(3):185-200
Polysiloxane coatings containing chemically-bound (“tethered”) quaternary ammonium salt (QAS) moieties were investigated for potential application as environmental-friendly coatings to control marine biofouling. A combinatorial/high-throughput approach was applied to the investigation to enable multiple variables to be probed simultaneously and efficiently. The variables investigated for the moisture-curable coatings included QAS composition, ie alkyl chain length, and concentration as well as silanol-terminated polysiloxane molecular weight. A total of 75 compositionally unique coatings were prepared and characterized using surface characterization techniques and biological assays. Biological assays were based on two different marine microorganisms, a bacterium, Cellulophaga lytica and a diatom, Navicula incerta, as well as a macrofouling alga, Ulva. The results of the study showed that all three variables influenced coating surface properties as well as antifouling (AF) and fouling-release (FR) characteristics. The incorporation of QAS moieties into a polysiloxane matrix generally resulted in an increase in coating surface hydrophobicity. Characterization of coating surface morphology revealed a heterogeneous, two-phase morphology for many of the coatings investigated. A correlation was found between water contact angle and coating surface roughness, with the contact angle increasing with increasing surface roughness. Coatings based on the QAS moiety containing the longest alkyl chain (18 carbons) displayed the highest micro-roughness and, thus, the most hydrophobic surfaces. With regard to AF and FR properties, coatings based on the 18 carbon QAS moieties were very effective at inhibiting C. lytica biofilm formation and enabling easy removal of Ulva sporelings (young plants) while coatings based on the 14 carbon QAS moities were very effective at inhibiting biofilm growth of N. incerta. 相似文献
7.
Sokolova A Cilz N Daniels J Stafslien SJ Brewer LH Wendt DE Bright FV Detty MR 《Biofouling》2012,28(5):511-523
Five non-biocidal xerogel coatings were compared to two commercial non-biocidal coatings and a silicone standard with respect to antifouling (AF)/fouling-release (FR) characteristics. The formation and release of biofilm of the marine bacterium Cellulophaga lytica, the attachment and release of the microalga Navicula incerta, and the fraction removal and critical removal stress of reattached adult barnacles of Amphibalanus amphitrite were evaluated in laboratory assays. Correlations of AF/FR performance with surface characteristics such as wettability, surface energy, elastic modulus, and surface roughness were examined. Several of the xerogel coating compositions performed well against both microfouling organisms while the commercial coatings performed less well toward the removal of microalgae. Reattached barnacle adhesion as measured by critical removal stress was significantly lower on the commercial coatings when compared to the xerogel coatings. However, two xerogel compositions showed release of 89-100% of reattached barnacles. These two formulations were also tested in the field and showed similar results. 相似文献
8.
Benjamin A.S. Van Mooy Laura R. Hmelo Helen F. Fredricks Justin E. Ossolinski Byron E. Pedler Daniel J. Bogorff 《Biofouling》2014,30(2):223-236
The accumulation of microbial biofilms on ships’ hulls negatively affects ship performance and efficiency while also playing a role in the establishment of even more detrimental hard-fouling communities. However, there is little quantitative information on how the accumulation rate of microbial biofilms is impacted by the balance of the rates of cell settlement, in situ production (ie growth), dispersal to surrounding waters and mortality induced by grazers. These rates were quantified on test panels coated with copper-based antifouling (AF) or polymer-based fouling-release (FR) coatings by using phospholipids as molecular proxies for microbial biomass. The results confirmed the accepted modes of efficacy of these two types of coatings. In a more extensive set of experiments with only the FR coatings, it was found that seasonally averaged cellular production rates were 1.5 ± 0.5 times greater than settlement and the dispersal rates were 2.7 ± 0.8 greater than grazing. The results of this study quantitatively describe the dynamic balance of processes leading to the accumulation of microbial biofilm on coatings designed for ships’ hulls. 相似文献
9.
Iram Liaqat Robert Thomas Bachmann Anjum Nasim Sabri Robert G. J. Edyvean 《Current microbiology》2010,61(2):148-156
Dental unit water line (DUWL) contamination by opportunistic pathogens has its significance in nosocomial infection of patients,
health care workers, and life-threatening infections to immunocompromized persons. Recently, the quorum sensing (QS) system
of DUWL isolates has been found to affect their biofilm-forming ability, making it an attractive target for antimicrobial
therapy. In this study, the effect of two quorum-sensing inhibitory compounds (patulin; PAT, penicillic acid; PA) and EDTA
on planktonic growth, AI-2 signalling and in vitro biofilm formation of Pseudomonas aeruginosa, Achromobacter xylosoxidans and Achromobacter sp. was monitored. Vibrio harveyi BB170 bioassay and crystal violet staining methods were used to detect the AI-2 monitoring and biofilm formation in DUWL
isolates, respectively. The V. harveyi BB170 bioassay failed to induce bioluminescence in A. xylosoxidans and Achromobacter sp., while P. aeruginosa showed AI-2 like activity suggesting the need of some pretreatments prior to bioassay. All strains were found to form biofilms
within 72 h of incubation. The QSIs/EDTA combination have isolate-specific effects on biofilm formation and in some cases
it stimulated biofilm formation as often as it was inhibited. However, detailed information about the anti-biofilm effect
of these compounds is still lacking. 相似文献
10.
Kamila Myszka Katarzyna Czaczyk Marcin T. Schmidt Anna M. Olejnik 《World journal of microbiology & biotechnology》2007,23(11):1605-1612
The purpose of these investigations was to evaluate the influence of limited nutrient availability in the culture medium on
Proteus vulgaris biofilm formation on surfaces of stainless steel. The relationship between the P. vulgaris adhesion to the abiotic surfaces, the cellular ATP levels, cell surface hydrophobicity and changes in the profiles of extracellular
proteins and lipopolysaccharides was examined. In all experimental variants the starvation conditions induced the bacterial
cells to adhere to the surfaces of stainless steel. Higher ATP content and lower cell surface hydrophobicity of P. vulgaris cells was observed upon nutrient-limited conditions. Under starvation conditions a reduction in the levels of extracellular
low molecular weight proteins was noticed. High molecular weight proteins formed the conditioning layer on stainless steel
plates, making the bacteria adhesion process more favorable. The production of low molecular weight carbohydrates promoted
more advanced stages of P. vulgaris biofilm formation process on the surfaces of stainless steel upon starvation. 相似文献
11.
Shane J. Stafslien Stacy Sommer Rajan Bodkhe Robert Pieper Justin Daniels 《Biofouling》2016,32(8):949-968
A series of eight novel siloxane-polyurethane fouling-release (FR) coatings were assessed for their FR performance in both the laboratory and in the field. Laboratory analysis included adhesion assessments of bacteria, microalgae, macroalgal spores, adult barnacles and pseudobarnacles using high-throughput screening techniques, while field evaluations were conducted in accordance with standardized testing methods at three different ocean testing sites over the course of six-months exposure. The data collected were subjected to statistical analysis in order to identify potential correlations. In general, there was good agreement between the laboratory screening assays and the field assessments, with both regimes clearly distinguishing the siloxane-polyurethane compositions comprising monofunctional poly(dimethyl siloxane) (PDMS) (m-PDMS) as possessing superior, broad-spectrum FR properties compared to those prepared with difunctional PDMS (d-PDMS). Of the seven laboratory screening techniques, the Cellulophaga lytica biofilm retraction and reattached barnacle (Amphibalanus amphitrite) adhesion assays were shown to be the most predictive of broad-spectrum field performance. 相似文献
12.
13.
Michael R. Hibbs Bernadette A. Hernandez-Sanchez Justin Daniels Shane J. Stafslien 《Biofouling》2013,29(7):613-624
A series of polysulfone and polyacrylate-based zwitterionic coatings were prepared on epoxy-primed aluminum substrata and characterized for their antifouling (AF) and fouling-release (FR) properties towards marine bacteria, microalgae and barnacles. The zwitterionic polymer coatings provided minimal resistance against bacterial biofilm retention and microalgal cell attachment, but facilitated good removal of attached microbial biomass by exposure to water-jet apparatus generated hydrodynamic shearing forces. Increasing the ion content of the coatings improved the AF properties, but required a stronger adhesive bond to the epoxy-primed aluminum substratum to prevent coating swelling and dissolution. Grafted poly(sulfobetaine) (gpSBMA), the most promising zwitterionic coating identified from microfouling evaluations, enabled the removal of four out of five barnacles reattached to its surface without incurring damage to their baseplates. This significant result indicated that gpSBMA relied predominately on its surface chemistry for its FR properties since it was very thin (~1–2 µm) relative to commercial coating standards (>200 µm). 相似文献
14.
Fouling-release (FR) coatings minimise the adhesion strength of fouling organisms. This study describes improved technologies to control the settlement and adhesion of the important fouling organism Mytilus galloprovincialis by incorporating the nanofillers titanium dioxide (TiO2) and carbon nanotubes (CNTs) in polydimethylsiloxane (PDMS) matrices. The incorporation of TiO2 prevented larval settlement when photoactivated with UV light, even at the lowest concentration of the nanofiller (3.75 wt%). Notably, there was 100% mortality of pediveligers exposed to photoactivated TiO2. However, plantigrades initially settled to photoactivated TiO2, but their adhesion strength was significantly reduced on these surfaces in comparison to blank PDMS. In addition, plantigrades had high mortality after 6 h. In contrast to the enhanced antifouling and FR properties of PDMS incorporating TiO2, the incorporation of CNTs had no effect on the settlement and adhesion of M. galloprovincialis. 相似文献
15.
S L Percival J S Knapp D S Wales R G J Edyvean 《Journal of industrial microbiology & biotechnology》1999,22(3):152-159
There is considerable interest in both Europe and the USA in the effects of microbiological fouling on stainless steels in
potable water. However, little is known about the formation and effects of biofilms, on stainless steel in potable water environments,
particularly in turbulent flow regimes. Results are presented on the development of biofilms on stainless steel grades 304
and 316 after exposure to potable water at velocities of 0.32, 0.96 and 1.75 m s−1. Cell counts on slides of stainless steel grades 304 and 316 with both 2B (smooth) and 2D (rough) finishes showed viable
and total cell counts were higher at the higher flow rates of 0.96 and 1.75 m s−1, compared to a flow rate of 0.32 m s−1. Extracellular polysaccharide levels were not significantly different (P< 0.05) between each flow rate on all stainless steel surfaces studied. higher levels were found at the higher water velocities.
the biofilm attached to stainless steel was comprised of a mixed bacterial flora including Acinetobacter sp, Pseudomonas spp, Methylobacterium sp, and Corynebacterium/Arthrobacter spp. Epifluorescence microscopy provided evidence of rod-shaped bacteria and the formation of stands, possibly of extracellular
material attached to stainless steel at high flow rates but not at low flow rates.
Received 04 February 1998/ Accepted in revised form 12 February 1999 相似文献
16.
Mattila K Weber A Salkinoja-Salonen MS 《Journal of industrial microbiology & biotechnology》2002,28(5):268-279
Paper machine biofilms formed in situ on stainless steel surfaces were studied. A robust flow cell was fitted to side stream (1.8 m s−1) of the spray water circuit of a paper machine. This on-site tool allowed for assessing the efficacy of antifoulants and
the adequacy of steel polishing under mill conditions. A rapid fluorescence-based assay was developed to quantify the biomass
of shallow biofilms on machine steel. The fluorescence matched the ATP content measured for the same biofilms. Electrolytic
polishing reduced the tendency of biofouling of 500 grit surface steel. Biofilm grew under machine conditions as clusters
on the steels, showing uniformly coccoid, filaments or short rods; only one cell type in each cluster. The biofilm clusters
excluded latex beads of 0.02 μm with hydrophilic or with hydrophobic surfaces from penetrating more than three to four layers
of cells. Under the high hydraulic flow at the machine (1.8 m s−1), the biofilm grew in 7 days 6–10 μm thick. The high flow rate guided the shape of the biofilm clusters emerging after the
primary attachment of cells. Adhered individual bacteria were the platform on steel to which solids such as paper machine
fines then accumulated. Journal of Industrial Microbiology & Biotechnology (2002) 28, 268–279 DOI: 10.1038/sj/jim/7000242
Received 04 October 2001/ Accepted in revised form 14 January 2002 相似文献
17.
Jin-Long Yang Yi-Feng Li Xing-Pan Guo Xiao Liang Yue-Feng Xu De-Wen Ding 《Biofouling》2016,32(7):763-777
This study investigated the effect of carbon nanotubes (CNTs) and titanium dioxide (TiO2) incorporated in PDMS on biofilm formation and plantigrade settlement of Mytilus coruscus. TiO2 increased bacterial density, and CNTs also increased bacterial density but reduced diatom density in biofilms after 28 days. Further analysis was conducted between bacterial communities on glass, PDMS, CNTs (0.5 wt%) and TiO2 (7.5 wt%). ANOSIM analysis revealed significant differences (R > 0.9) between seven, 14, 21 and 28 day-old bacterial communities. MiSeq sequencing showed that CNTs and TiO2 impacted the composition of 28 day-old bacterial communities by increasing the abundance of Proteobacteria and decreasing the abundance of Bacteroidetes. The maximum decreased settlement rate in 28 day-old biofilms on CNTs and TiO2 was > 50% in comparison to those on glass and PDMS. Thus, CNTs and TiO2 incorporated in PDMS altered the biomass and community composition of biofilms, and subsequently decreased mussel settlement. 相似文献
18.
Elisa Martinelli Marianna Suffredini Antonella Glisenti Michala E. Pettitt Maureen E. Callow 《Biofouling》2013,29(5):529-541
Amphiphilic diblock copolymers, Sz6 and Sz12, consisting of a poly(dimethylsiloxane) block (average degree of polymerisation = 132) and a PEGylated-fluoroalkyl modified polystyrene block (Sz, average degree of polymerisation = 6, 12) were prepared by atom transfer radical polymerization (ATRP). Coatings were obtained from blends of either block copolymer (1–10 wt%) with a poly(dimethylsiloxane) (PDMS) matrix. The coating surface presented a simultaneous hydrophobic and lipophobic character, owing to the strong surface segregation of the lowest surface energy fluoroalkyl chains of the block copolymer. Surface chemical composition and wettability of the films were affected by exposure to water. Block copolymer Sz6 was also blended with PDMS and a 0.1 wt% amount of multiwall carbon nanotubes (CNT). The excellent fouling-release (FR) properties of these new coatings against the macroalga Ulva linza essentially resulted from the inclusion of the amphiphilic block copolymer, while the addition of CNT did not appear to improve the FR properties. 相似文献
19.
Sommer S Ekin A Webster DC Stafslien SJ Daniels J VanderWal LJ Thompson SE Callow ME Callow JA 《Biofouling》2010,26(8):961-972
Siloxane-polyurethane fouling-release (FR) coatings based on aminopropyl terminated poly(dimethylsiloxane) (PDMS) macromers were prepared and characterized for FR performance via laboratory biological assays. These systems rely on self-stratification, resulting in a coating with a siloxane-rich surface and polyurethane bulk. Previously, these coating systems have used PDMS with multiple functional groups which react into the polyurethane bulk. Here, aminopropyl terminated PDMS macromers were prepared, where a single amine group anchors the PDMS in the coating. Coatings were prepared with four molecular weights (1000, 5000, 10,000, and 15,000 g mol?1) and two levels of PDMS (5% and 10%). High water contact angles and low surface energies were observed for the coatings before and after water immersion, along with low pseudobarnacle removal forces. Laboratory bioassays showed reduced biofilm retention of marine bacteria, good removal of diatoms from coatings with low molecular weight PDMS, high removal of algal sporelings (young plants), and low removal forces of live barnacles. 相似文献
20.
Initial phases of microbial biofilm formation on opaque,innovative anti‐adhesive surfaces using a modular microfluidic system
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Katrin Wagner Sandra Friedrich Carolin Stang Thomas Bley Niels Schilling Matthias Bieda Andrés Lasagni Elke Boschke 《Engineering in Life Science》2014,14(1):76-84
Biofilms can cause numerous problems, hence it is important to understand their formation on surfaces in order to develop resistant materials and avoidance strategies. Therefore, information is required regarding adhesion processes on surfaces generally and innovative anti‐adhesive coatings in particular. Our flow cell system allows biofilms to be monitored in continuous flow conditions, without removing material for postflow imaging. The shown laminar flow ensures the maintenance of highly controlled conditions for biofilm growth. However, carried simulations of the oxygen demands of Escherichia coli cultivated as biofilms under the chosen regime indicate that conditions may become anaerobic, at least at the outlet of the flow cell, after a certain period of time. We report data on the biofouling tendencies on coatings generated with the help of direct laser interference patterning on stainless steel surfaces. Data were estimated from images acquired by fluorescence microscopy. Differences between patterned and unpatterned surfaces were not found, which is in accordance with the attachment point theory. Nevertheless, it is particularly important to elucidate in future studies the behavior of microorganisms during their attachment and the effects of variables of potentially sensitive surfaces (such as hydrophobicity, nanotopography, and charge) on their adhesion. 相似文献