Melibiose transport system in Lactobacillus plantarum

Area of Science:

• Microbiology
• Molecular Biology
• Biochemistry

Background:

• Lactobacillus plantarum ATCC 8014 exhibits temperature-dependent growth on melibiose.
• Melibiose transport and alpha-galactosidase activity are crucial for utilizing this disaccharide.

Purpose of the Study:

• To investigate the temperature sensitivity of melibiose utilization in Lactobacillus plantarum.
• To elucidate the mechanisms of melibiose transport and alpha-galactosidase induction.

Main Methods:

• Comparative growth studies at different temperatures (30°C vs. 37°C).
• Isolation and characterization of a lactose-negative mutant (NTG 21).
• Enzyme assays for alpha-galactosidase activity and transport studies.

Main Results:

• L. plantarum ATCC 8014 and its mutant NTG 21 show impaired melibiose transport and alpha-galactosidase induction at 37°C compared to 30°C.
• The lactose transport system partially facilitates melibiose uptake in the wild-type strain.
• Enzyme induction is temperature-sensitive, specifically affecting the induction process rather than inducer uptake or enzyme stability.

Conclusions:

• Melibiose utilization in L. plantarum is regulated by a temperature-sensitive induction mechanism.
• Distinct pathways exist for lactose and melibiose transport, although some overlap occurs.
• Understanding these temperature-dependent processes is vital for optimizing microbial applications.