摘要:

Attachment of microorganisms to metal surfaces was investigated in a nutrient enriched pristine arctic river. Biofilms were characterised in terms of bacterial population size and metabolic activity. Metals were placed in the river at an untreated and a phosphate + nitrate enriched site. After 25 days, poorly developed bacterial films were formed on stainless steel and titanium surfaces at the control site. However, at the enriched site thick algal/bacterial films developed on both of these metals, as shown by scanning and transmission electron microscopy. The bacteria in these films were highly active, with high levels of polyhydroxy alkanoic acid synthesis. Even after 25 days, adhesion was minimal on copper alloy surfaces at both sites. The data are discussed in relation to the pristine nature of this river system and the implications for eutrophic rivers.

ISSN:0892-7014    

DOI:10.1080/08927018909378118

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Corrosion of steel (SIS 1146) by two marine isolates,Serratia marcescensEF190 and aPseudomonassp. S9 was investigated by weight loss measurements of metal coupons placed in static batch cultures. Cell suspensions with and without nutrients were compared with cell free extracts of cultures and uninoculated controls. Adhesion of cells to the metal surface was quantified microscopically.

ISSN:0892-7014    

DOI:10.1080/08927018909378119

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Bacteria are attracted to surfaces. Their surface adhesion, with subsequent binary fission and exopolymer production, leads to the formation of biofilms. Such biofilms consist of bacterial cells in a matrix of their own exopolysaccharide glycocalyces. In addition to the bulk fluid and the surface, biofilms constitute a third physical phase. The close proximity of the bacterial cells in the biofilm matrices assists the formation of metabolically dependent consortia. The chemical and physical activities of these microbial communities produces a heterogeneous system at the colonised surface. Metabolites, produced at specific points on the surface, can lead to the development of effective anodes and cathodes at adjoining locations on the surface. In this way the fouling of a surface by bacterial biofilm development facilitates focal attack on that surface. This pit formation is characteristic of bacterial surface activities as diverse as dental decay and metal corrosion. In this review, we examine bacterial adhesion, biofilm formation and several instances of focal bacterial attack on colonised surfaces. However, pathogenic biofilms and the fouling of biological surfaces, with the exception of caries formation, is outside the scope of this paper.

ISSN:0892-7014    

DOI:10.1080/08927018909378120

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A monitoring cell (moncell) has been developed for the diagnosis and monitoring of biofouling and other problematic processes in groundwater systems. The device, relatively simple in design and application, is proving to be a useful tool, particularly for engineers who are not always aware of the processes occurring within their systems. All too often the yields from water supply boreholes and irrigation tubewells can decline without initially causing due concern. Yield decline can result from the clogging of parts of the system, (e.g. the screen, filter, pump, pipework) due to biofilm growth, chemical/biochemical deposition, and/or particle migration. Being unaware of the problem, or the nature of the problem, for too long a period can often lead to complete failure of the system. Early diagnosis is essential for optimum operation, maintenance and if necessary rehabilitation of the system. Trials with the moncell suggest that it could be used in other enclosed flow systems where a simple visual monitoring and diagnostic aid would prove useful.

ISSN:0892-7014    

DOI:10.1080/08927018909378121

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The use of biocide is an important method in the control of biofouling in industrial processes. The efficacy of the biocide is influenced by various factors such as the type, concentration and mode of application of the biocide. Studies were carried out using ‘Clorox’, which contains sodium hypochlorite, in controlling biofilm development in laboratory scale biofilm reactors. The reactors were operated at a 10‐day hydraulic retention time (HRT) at 28°C, with mixing at 500 rpm. The initial inoculum was obtained from a cooling tower, and growth was maintained using Characklis Medium (Trulear & Characklis, 1982). There appears to be an inverse relationship between biocide concentration and biofilm thickness. Applying the biocide in sub doses showed less of an effect in controlling the biofilm than application of biocide in one dose. Application of biocide at different phases of biofilm growth showed no significant difference. Temperatures of 38°C and above increase the effect of the biocide.

ISSN:0892-7014    

DOI:10.1080/08927018909378122

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0892-7014    

DOI:10.1080/08927018909378123

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0892-7014    

DOI:10.1080/08927018909378117

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor