Characterization of dextran-producing Leuconostoc strains.

Area of Science:

• Microbiology
• Bacteriology

Background:

• Leuconostoc species are crucial in industrial applications, particularly for dextran production.
• Distinguishing between physiologically similar Leuconostoc strains is challenging but important for research and industry.

Purpose of the Study:

• To characterize Leuconostoc strains based on antibiotic susceptibility, carbohydrate fermentation, sucrase activity, and plasmid content.
• To establish reliable methods for differentiating dextran-producing Leuconostoc strains.

Main Methods:

• Antibiotic susceptibility testing was performed on Leuconostoc strains.
• Carbohydrate fermentation profiles were analyzed, specifically for melibiose and raffinose.
• Sucrase enzyme activity patterns were examined using polyacrylamide gel electrophoresis.
• Plasmid DNA content was analyzed in the characterized strains.

Main Results:

• All tested Leuconostoc strains exhibited resistance to sulphathiazole, trimethoprim, and vancomycin.
• Strains were divisible into two groups based on their ability to ferment melibiose and raffinose.
• Six Leuconostoc strains contained plasmids.
• Unique sucrase activity patterns were observed in many strains when analyzed by gel electrophoresis.

Conclusions:

• The combined data on antibiotic resistance, fermentation, enzyme activity, and plasmid profiles provide a robust method for distinguishing Leuconostoc strains.
• These characterization techniques are valuable for identifying and differentiating dextran-producing Leuconostoc, aiding their effective use in research and industrial settings.