Polysaccharide-producing bacteria isolated from paper machine slime deposits

Area of Science:

• Microbiology
• Industrial Biotechnology
• Biochemistry

Background:

• Slime deposits in paper mills pose significant challenges, impacting operational efficiency and product quality.
• Effective control strategies often require understanding the microbial communities and their secreted products, particularly polysaccharides.
• Enzymatic methods offer a sustainable alternative to traditional chemical treatments.

Purpose of the Study:

• To isolate and identify polysaccharide-producing bacteria from paper mill slime.
• To characterize the polysaccharides produced by selected bacterial isolates.
• To lay the groundwork for developing novel enzymatic slime control methods.

Main Methods:

• Isolation of bacteria from paper mill slime samples.
• Cultivation of bacteria and polysaccharide production in liquid culture.
• Identification of bacterial isolates using ribotyping, 16S rDNA sequencing, physiological tests, and fatty acid analysis.
• Characterization of produced polysaccharides.

Main Results:

• Twenty-seven polysaccharide-producing bacterial isolates were obtained.
• Nine isolates were selected for further characterization, belonging to seven genera.
• Four species were identified: Bacillus cereus, Brevundimonas vesicularis, Klebsiella pneumoniae, and Paenibacillus stellifer.
• Polysaccharide yields ranged from 0.07 to 1.20 g L(-1), with B. vesicularis producing the highest amount.
• The produced polysaccharides were heteropolysaccharides composed of various sugars and uronic acids.

Conclusions:

• Bacterial isolates from paper mill slime produce diverse heteropolysaccharides.
• Specific bacterial species, such as B. vesicularis and K. pneumoniae, show potential for high polysaccharide yield.
• The characterization of these polysaccharides is crucial for developing targeted enzymatic slime control strategies.