Biodeteriorated paints showing discolouration, loss of viscosity and foul odour have resulted in substantial economic losses in Nigeria. The present study focused on enumeration and identification of bacteria isolated from spoilt paints made in Nigeria using a non-selective nutrient agar (NA) and a semi-selective Pseudomonas Isolation Agar (PIA). The bacterial population density in a fresh paint sample was 3.0 x 103 CFU/ml while that of five samples of spoilt paint ranged from 1.0 x 103 to 1.2 x 106 CFU/ml on NA. The fresh paint had no growth on PIA while spoilt paint bacterial counts ranged from 2.0 x 103 to 8.0 x 105 CFU/ml. The most diverse colony types from the spoilt paint samples were randomly selected for purification. We subjected 9 isolates to sequencing of a portion of the 16S rRNA gene and 14 isolates to whole-cell fatty acid methyl ester profiling using the MIDI-FAME system. The most prevalently identified were Klebsiela and Providencia species. A subset of isolates were examined by transmission electron microscopy. Other detected genera included Bacillus, Brevibacillus, Lysinibacillus, and the Nocardioforms. Our results show that spoilt latex paints made in Nigeria can harbour diverse bacterial species which can cause biodeterioration.
Key words: Biodeteriorated paints, 16S rRNA, molecular methods, PCR, FAME
|
