Detection and characterization of lactose-utilizing Lactococcus spp. in natural ecosystems

Area of Science:

• Microbiology
• Environmental Science
• Food Science

Background:

• Lactose-utilizing Lactococcus species are crucial in dairy industries.
• Their survival and prevalence in non-dairy environments remain largely uncharacterized.
• Understanding environmental niches is key for novel starter culture development.

Purpose of the Study:

• To investigate the presence and characteristics of Lactococcus species in non-dairy environments.
• To identify potential novel strains for starter culture applications.
• To compare environmental isolates with industrial starter cultures.

Main Methods:

• Polymerase chain reaction (PCR) amplification and 16S rRNA sequencing for identification.
• Genus- and species-specific probes for Lactococcus detection.
• Phenotypic characterization (arginine hydrolysis, citrate fermentation, protease and bacteriocin production).
• PCR verification of specific genes (citP, prtP, nisA, nisZ).

Main Results:

• Lactococci were successfully isolated from diverse non-dairy sources including soil, effluent water, and cattle skin.
• Environmental Lactococcus lactis strains exhibited varied phenotypic properties, differing from industrial strains.
• Absence of citP-related sequences and varied arginine hydrolysis were noted in environmental isolates.

Conclusions:

• Most industrial Lactococcus strains do not survive well in non-dairy environments.
• Natural environmental niches harbor Lactococcus strains with unique characteristics.
• These environmental isolates represent a valuable resource for developing novel dairy starter cultures.