Hydroxypropyl β-cyclodextrin improving multiple stresses tolerance of Lactococcus lactis subsp. lactis.

Area of Science:

• Food Microbiology
• Industrial Biotechnology
• Probiotic Research

Background:

• Lactiplantibacillus lactis (L. lactis) is a key industrial starter for dairy and meat fermentation, valued as a probiotic.
• Industrial processes expose L. lactis to stresses like heat, salt, cold, and hydrogen peroxide, impacting its growth and survival.
• Trehalose is a known protectant, but its efficacy under multiple stresses requires comparison.

Purpose of the Study:

• To investigate the protective effects of hydroxypropyl β-cyclodextrin (HP β-CD) on L. lactis against multiple industrial stresses.
• To compare the protective efficacy of HP β-CD with trehalose.
• To elucidate the potential protective mechanism of HP β-CD on L. lactis cell structure.

Main Methods:

• L. lactis cultures were subjected to heat, NaCl, cold, and H2O2 stresses.
• Cell growth was assessed using OD600 measurements and spot plating.
• Cell structure integrity was examined via scanning electron microscopy and fluorescence spectroscopy.

Main Results:

• HP β-CD significantly improved L. lactis growth and tolerance under all tested stress conditions.
• HP β-CD demonstrated superior protective effects compared to trehalose.
• Microscopic and spectroscopic analyses indicated that HP β-CD interacts with L. lactis cells, protecting their structure.

Conclusions:

• HP β-CD is a potential protective agent for L. lactis in industrial food applications.
• HP β-CD offers enhanced protection against multiple stresses compared to trehalose.
• Further research is needed to fully understand the protective mechanisms of HP β-CD on L. lactis.