'Biodeterioration of limestone: role of bacterial biofilms and possible intervention strategies'

Skipper, Philip (2018) 'Biodeterioration of limestone: role of bacterial biofilms and possible intervention strategies'. PhD thesis, University of Lincoln.

'Biodeterioration of limestone: role of bacterial biofilms and possible intervention strategies'

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Item Type:Thesis (PhD)
Item Status:Live Archive


Limestone built heritage is at risk from the effects of biofilms, a microbial community encapsulated in a matrix of sugars, protein and extracellular DNA. Although biofilm research has been carried out in Mediterranean regions, few studies cover temperate Northern Europe climates, or the UK. This study concentrates on bacterial colonisation of Lincoln limestone, a highly vulnerable building material, and identifies the species, their role in biodeterioration and the efficacy of biocides against them.
As part of this study the core species which comprise the bacterial component of the limestone microbiome have been characterised for the first time; this has allowed the identification of non-core species which are significantly associated with damaged and undamaged surfaces.
Four mechanisms of biodeterioration have been identified, one previously unidentified, and isolated species have been characterised as to whether they are biodeteriorative and the mechanisms of biodeterioration that they employ. Two species, Curtobacterium flaccumfaciens and Solibacillus silvestris, have been characterised as producing biofilm matrix which actively causes biomechanical damage to the oolitic limestone structure as opposed to the passive enhancement of physical weathering which has been previously associated with biofilm matrix. Species capable of biodeterioration have also been shown to be present on both damaged and undamaged surfaces, something which has not been previously investigated.
Environmental sampling, species identification and characterisation of species for biodeterioration have all combined to identify markers of biodeterioration, ie both physical markers and biomarkers. Specifically, a surface pH of 5.5 or lower and the presence of B. licheniformis is indicative of biodeterioration with a proportionally higher level of M. luteus when comparing damaged and undamaged stone.
Finally this study brings the literature on conservation methods up to date by testing biocides which are in current usage, as many biocides in the literature are discontinued. This study is also the first in the field to show their efficacy against biofilm encapsulated bacteria and their propensity for chemically disrupting the biofilm matrix.

Keywords:Biodeterioration, Conservation, Biofilm
Subjects:C Biological Sciences > C500 Microbiology
K Architecture, Building and Planning > K250 Conservation of Buildings
C Biological Sciences > C510 Applied Microbiology
Divisions:College of Science > School of Life Sciences
ID Code:33697
Deposited On:17 Nov 2018 20:46

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