Screening for texturing Leuconostoc and genomics behind polysaccharide production

Area of Science:

• Food Microbiology
• Biotechnology
• Fermentation Science

Background:

• Polysaccharide synthesis by Leuconostoc species can improve the texture of fermented food products.
• Screening Leuconostoc strains for their ability to produce polysaccharides and modify food texture is crucial for food innovation.

Purpose of the Study:

• To screen a large collection of Leuconostoc strains for polysaccharide synthesis and texturing capabilities in milk.
• To identify specific strains, particularly Leuconostoc mesenteroides, with potential for improving food texture and potentially sweetness.

Main Methods:

• Screening of 249 Leuconostoc strains for homo-polysaccharide production.
• Evaluation of texturing capabilities of selected strains in a milk-based system.
• Genetic analysis to identify the presence of genes for both homo-polysaccharide (HoPS) and hetero-polysaccharide (HePS) synthesis.
• Milk acidification experiments with added sucrose to assess sucrose depletion and fructose release.

Main Results:

• Six Leuconostoc mesenteroides strains exhibited superior texturing properties in milk.
• These six strains possessed the genetic capacity for both HoPS and HePS synthesis.
• One strain demonstrated texture enhancement in milk even without added sucrose, indicating potential HePS synthesis via the Wzy-dependent pathway.
• All six selected strains depleted sucrose and released fructose during milk acidification experiments with added sucrose.

Conclusions:

• Selected Leuconostoc mesenteroides strains are effective in enhancing the texture of fermented products like milk.
• These strains have the genetic potential for synthesizing both HoPS and HePS.
• The ability to utilize sucrose and release fructose suggests a dual role in texture and potential sweetness enhancement in food applications.