Microbial communities of printing paper machines

Abstract

The microbial content of printing paper machines, running at a temperature of 45-50 degrees C and at pH 4.5-5, was studied. Bacteria were prevalent colonizers of the machine wet end and the raw materials. A total of 390 strains of aerobic bacteria were isolated and 86% of these were identified to genus and species by biochemical, chemotaxonomic and phylogenetic methods. The most common bacteria found at the machine wet end were Bacillus coagulans and other Bacillus species, Burkholderia cepacia, Ralstonia pickettii, and in pink slimes, accumulating in the wire area and press section, species of Deinococcus, aureobacterium and Brevibacterium. Paper-making chemicals also contained species of Aureobacterium, B. cereus, B. licheniformis, B. sphaericus, Bordetella, Hydrogenophaga, Klebsiella pneumoniae, Pantoea agglomerans, Pseudomonas stutzeri, Staphylococcus and sometimes other enteric bacteria, but these did not colonize the process water. Yeasts and moulds were not present in significant numbers. A total of 131 strains were tested for their potential to degrade paper-making raw materials; 91 strains were found to have degradative activity, mainly species of Burkholderia and Ralstonia, Sphingomonas and Bacillus, and enterobacteria produced enzymes which degraded paper-making chemicals. Stainless steel adhering strains occurred in slimes and wire water and were identified as Burkholderia cepacia, B. coagulans and Deinococcus geothermalis. Coloured slimes were formed on the machine by species of Deinococcus, Acinetobacter and Methylobacterium (pink), Aureobacterium, Pantoea and Ralstonia (yellowish) and Microbulbifer-related strains (brown). The impact of the strains and species found in the printing paper machine community on the technical quality of paper, machine operation, and as a potential biohazard (Hazard Group 2 bacteria), is discussed.

Colanic acid is an exopolysaccharide common to many enterobacteria isolated from paper-machine slimes

“…Almost all (16/18) of the isolates were members of the family Enterobacteriaceae with Enterobacter and Klebsiella (Raoultella) as the most frequently represented genera. Enterobacter, Klebsiella and Citrobacter species are common in soil, healthy and decaying wood and in plants and also appear to be normal inhabitants in many paper machines [2,24,25,33,47]. According to a Canadian study, these bacteria grew continuously in many of the mills studied with the most likely growth areas being paper machines, biofilms on machinery and piping and the primary clarifier [15].…”

“…Polysaccharide-producing enterobacteria were found especially in the Finnish mill B and in the Spanish mill, slimy bacteria belonging to, e.g. genera Acinetobacter, Aureobacterium, Bacillus, Brevundimonas, Deinococcus, Methylobacterium, Paenibacillus and Pseudomonas have previously been identified from various other mills [24,34,47].…”

Fluorescent in situ hybridization and flow cytometry as tools to evaluate the treatments for the control of slime-forming enterobacteria in paper mills

“…Investigations into the slime-forming bacteria (SFB) of pulp, paper and board mills showed that the primary slime producers worldwide were members of Enterobacteriaceae with Enterobacter cloacae, Enterobacter aerogenes, Pantoea agglomerans, Klebsiella pneumoniae and Raoultella spp., as the most frequently species isolated (Sanborn, 1944;Neilson & Sparell, 1976;Väisänen et al, 1998;Blanco, 2003;Gauthier et al, 2000;Gauhier & Archibald, 2001;Beuchamp et al, 2006;Rättö et al, 2006).…”

Comparison of the Bacterial Microbiota in a Bale of Collected Cardboard Determined by 454 Pyrosequencing and Clone Library

“…Clearly, 454 pyrosequencing revealed a much more diverse bacterial community than clone library. Bacteria, mostly Firmicutes and Proteobacteria, are introduced to the paper mill through contaminated cellulosic raw material, fresh incoming water and paper-making chemicals [2] [5]. Physical conditions in the paper mill range from basic to acidic pH, ambient and high temperatures, aerobic and anaerobic environments, etc.…”

“…Culturable bacterial population diversity has been studied in the fiber slurry [5]- [7], white water [5] [8], biofilms [6] [9] [10], and the final recycled products [11] by 16S rRNA gene sequences. In addition, biofilms were also studied by microscopy [5] [9] [10] [12], physiological and biochemical characterization [9] [10] [12], and fatty acids analysis [10] [12]. Unculturable bacterial population diversity has been determined in the fiber slurry [13] [14], white water [14] and biofilms [13]- [15] by 16S rRNA gene sequences.…”