Controlled release of protein from viable Lactococcus lactis cells

Area of Science:

• Microbiology
• Biotechnology
• Molecular Biology

Background:

• The CsiA protein in Lactococcus lactis influences cell wall integrity and causes leakage of intracellular components.
• Controlled release of intracellular molecules is crucial for various biotechnological and therapeutic applications.

Purpose of the Study:

• To engineer and optimize the CsiA protein for targeted release of biologically active compounds.
• To evaluate the efficacy of CsiA-mediated release of both endogenous and heterologous molecules.
• To assess the impact of CsiA expression on Lactococcus lactis cell viability and growth.

Main Methods:

• Investigated the effects of varying CsiA expression levels on the leakage of intracellular lactate dehydrogenase and nucleic acids.
• Utilized recombinant and nonrecombinant forms of CsiA to induce a leakage phenotype.
• Demonstrated proof-of-principle by releasing active Listeria bacteriophage endolysin LM4.

Main Results:

• Overexpression of CsiA protein leads to cell wall defects and intracellular material leakage.
• CsiA facilitated the efficient release of active heterologous endolysin LM4.
• Optimized CsiA expression allowed molecule release without compromising cell viability.

Conclusions:

• CsiA protein offers a novel, controllable lysis technology for releasing intracellular materials.
• This system has potential applications in industrial fermentation, food processing, and medical therapy.
• Controlled release of active molecules is achievable without external lytic agents.