Potential Biodeteriogens of Indoor and Outdoor Surfaces (Coated With Gloss, Emulsion and Textcoat Paints)

Abstract

Potential Biodeteriogens of indoor and outdoor surfaces (coated with gloss, emulsion and text coat paints) within the University of Port Harcourt, Nigeria were investigated. Potential Biodeteriogens implicated in deterioration of painted surfaces were bacteria, fungi, microalgae and cyanobacteria. The total heterotrophic bacteria counts and total fungal counts for outdoor and indoor painted surfaces ranged from 2.8 x 10 6 to 9.00 x 10 6 cfu/g paint scrape, 1.56 x 10 4 to 6.6 x 10 4 cfu/g paint scrape; and 1.1 x 10 6 to 6.5 x 10 6 cfu/g paint scrapes, 1.31 x 10 4 to 9.8 x 10 4 cfu/g paint scrapes respectively. The result of THB and TF count expressed graphically showed surfaces with increasing order of microbial load: Gloss paints < Text coat paint < Emulsion paints. Predominant bacterial genera isolated from the surfaces include Bacillus (29.0%), Pseudomonas (22.6%), Proteus (19.4%), Serratia (16.1%), Citrobacter (6.5%), Enterobacter (3.2%) and Klebsiella (3.2%). Fungal genera isolated include: Alternaria, Aspergillus , Cladosporium , Fusarium ,Geotrichum , Gleosporium , Penicillum , Rhizopus , Saccharomyces and Stachybotrys . Fungi were the predominant biodeteriogens. Predominant microalgae isolated from the wet painted surfaces include Chorella , Characium , Closterium , Geminella , Oscillatoria , Totrogonnidium and Triceratium . Physicochemistry of various paint surfaces revealed the following: TOC (1.30 - 3.49%), Phosphate (0.39-8.82mg/100g), nitrate (4.64-187.58mg/100g), sulphate (99.78-285.00mg/100g), pH (8.55-9.59), oil and Grease (125.00-285.00mg/100g).Result showed that different consortia of biodeteriogens implicated in indoor and outdoor painted surfaces are dependent on the chemical compositions of the various paints, nature of the coating surfaces and physicochemical parameters influencing the microbial processes. Emulsion surfaces habour most potential biodeteriogens on their surfaces than the other surfaces. There were significant differences (P < 0.05) in the various potential biodeteriogens,