Related Experiment Video
Updated: Nov 20, 2025
04:40
The Cultivation, Growth, and Viability of Lactic Acid Bacteria: A Quality Control Perspective
Published on: June 16, 2022
8.8K
A weak post-acidification Lactobacillus helveticus UV mutant with improved textural properties
Chengran Guan1, Xuan Chen1, Ruifeng Zhao1
1Key Lab of Dairy Biotechnology and Safety Control College of Food Science and Technology Yangzhou University Yangzhou China.
Food Science & Nutrition
|January 21, 2021
Summary
Researchers developed a new strain of Lactobacillus helveticus (L. helveticus sh2-5-66) with weak postacidification properties. This mutant improves milk texture, rheology, and flavor, offering enhanced dairy product quality.
Area of Science:
- Food Microbiology
- Dairy Science
- Bacteriology
Background:
- Postacidification in fermented dairy products can negatively impact texture and flavor.
- Lactobacillus helveticus (L. helveticus) strains are important in cheese production.
- H+-ATPase activity is linked to the postacidification capabilities of L. helveticus.
Purpose of the Study:
- To develop a mutant of L. helveticus SH2-1 exhibiting weak postacidification and improved texturing.
- To investigate the relationship between H+-ATPase activity and postacidification in L. helveticus.
- To evaluate the stability and impact of the mutant strain on fermented milk properties.
Main Methods:
- Screening of 80 UV-mutagenized L. helveticus strains.
- Detection of H+-ATPase activity to identify weak postacidification mutants.
- Fermentation of milk with the selected mutant strain (L. helveticus sh2-5-66).
- Analysis of pH, acidity, textural, and rheological properties of fermented milk.
- Assessment of genetic stability over 100 generations and evaluation of co-culture effects.
Main Results:
- A weak postacidification mutant, L. helveticus sh2-5-66, was successfully derived.
- L. helveticus sh2-5-66 fermented milk had a higher pH (0.57 units) and lower acidity (57.1 °T) compared to the wild type.
- The mutant strain demonstrated genetic stability over 100 generations.
- Fermented milk produced with L. helveticus sh2-5-66 showed enhanced texture, rheology, and flavor during storage.
- Co-culturing with Streptococcus thermophilus st447 further improved these characteristics.
Conclusions:
- H+-ATPase activity is a key factor in controlling postacidification in L. helveticus.
- The L. helveticus sh2-5-66 mutant offers a viable solution for reducing postacidification issues in dairy fermentation.
- This mutant strain contributes to improved sensory and textural attributes of fermented dairy products, with potential for further enhancement through co-culturing.
