Analysis Of Bacterial Diversity Of Paper Machine System By16s RDNA

Bacteria growing in paper machines can cause several problems. Biofilms detaching frompaper machine surfaces may lead to holes and spots in the end product or even break the paperweb leading to expensive delays in production. The aim of this thesis was to identify bacterialspecies colonizing paper machines and to assess the role of bacteria in the formation of slime.Firstly, we explored the bacterial diversity in whitewater and slime in paper mill UPM.Total DNA were directly extracted from the whitewater and slime sample.16S rDNAs wereamplified directly from purified DNA by PCR with universally bacteria-specific rDNAprimers and cloned.61bacteria of whitewater were identified by partial sequencing of their16S rDNAs.28operational taxonomic units (OTUs) were clustered in the following phylaincluding, Proteobacteria(77.05%), Firmicutes(11.48%), Actinobacteria(4.92%), Deinococcus-Thermus(3.28%), Bacteroidetes(1.64%), Cyanobacteria(1.64%).117bacteria of slime wereidentified by partial sequencing of their16S rDNAs.55OTUs were clustered in the flowingphyla including: Proteobacteria, Firmicutes, Planctomycetes, Bacteroidetes, Chloroflexi,Actinobacteria, Verrucomicrobia, Spirochaetes, Nitrospirae. The results show a highproportion of71.79%of Proteobacteria.Bacterial diversity is high both in the whitewater andslime sample.Secondly,118bacteria were isolated from slime sample of PM1in UPM.9genuses ofbacteria were identified by16S rDNA: Exiguobacterium profundum, Bacillusweihenstephanensis, Bacillus thuringiensis, Acidovorax temperans, Diaphorobacternitroreducens, Flavobacterium cucumis, Exiguobacterium aestuarii, Bacillus korlensis,Pseudomonas jinjuensis.I tested the ability of slime formation of several bacteria in liquid LB medium. Testingconditions are as follow:37℃,150rpm for48hours.The experiments reveal that the mosteasily slime formation bacteria is Bacillus thuringiensis, flowing with Acidovorax temperans,Pseudomonas jinjuensis.The ability of fiber degradation of isolated bacteria was also tested.9of the118isolatedbacteria were selected to testing the ability of fiber degradatiaon. The results reveal that thesome of the isolated bacteria can degrade the fiber: LB7Bacillus weihenstephanensis, KB62Exiguobacterium aestuarii, this is useful for finding possible bacteria which can be used inbiomass energy.