Lactococcus lactis subsp. cremoris MG1363

Lactococcus lactis subsp. cremoris MG1363 is a plasmid-free, fully sequenced laboratory reference strain derived from the NCDO712 lineage, used extensively in bacterial genetics research. It serves as a model organism for studying lactic acid bacteria gene expression, bacteriocin biosynthesis pathways, and horizontal gene transfer mechanisms rather than as a consumable supplement.

Origin & History

Lactococcus lactis subsp. cremoris MG1363 is a plasmid-free laboratory strain derived from the dairy starter strain NCDO712 through plasmid curing, resulting in a genetically amenable prototype for lactic acid bacteria research. It originates from milk fermentation cultures used in cheese production and is cultured as a gram-positive, homofermentative bacterium that produces L-(+)-lactic acid from sugars. This strain features a circular chromosome of approximately 2.53-2.56 Mb containing prophage sequences, insertion elements, and genes for heterologous protein expression.

Historical & Cultural Context

No historical traditional medicine uses were identified for MG1363 specifically, as it is a modern plasmid-cured laboratory derivative created for research purposes. While parent Lactococcus lactis strains have been used in food fermentation such as cheese-making for centuries in European dairy traditions, they were not used as medicine.

Health Benefits

• No clinical health benefits have been studied or documented for this laboratory research strain
• The strain is used exclusively for genetic and genomic research rather than as a probiotic supplement
• Parent Lactococcus lactis strains are used in food fermentation but not for therapeutic purposes
• No evidence exists for immune, digestive, or other health effects in humans
• Research focuses on its use as a model organism for protein expression systems rather than health applications

How It Works

MG1363 is a plasmid-cured derivative of NCDO712 used to study the genetic machinery of lactic acid bacteria, particularly nisin biosynthesis gene clusters and the NisRK two-component regulatory system. Researchers exploit its well-characterized chromosome to investigate PTS (phosphoenolpyruvate-dependent phosphotransferase system) sugar transport enzymes and homologous recombination pathways. Its lack of endogenous plasmids makes it an ideal host for introducing recombinant DNA constructs to study promoter activity and protein secretion via the Sec and Tat translocon pathways.

Scientific Research

No human clinical trials, RCTs, or meta-analyses were identified for L. lactis subsp. cremoris MG1363 in the available research. Published studies such as PMID 7751295 focus exclusively on genetic mapping and basic laboratory research rather than clinical applications. This strain serves primarily as a laboratory model for genetic, genomic, and physiological studies in lactic acid bacteria, particularly for protein expression via the NICE system.

Clinical Summary

No human clinical trials have been conducted using MG1363 as a therapeutic or probiotic intervention, as this strain is designated exclusively for in vitro and microbiology laboratory use. All published research involves bench-scale genetic manipulation studies, fermentation biochemistry experiments, and bacterial genomics analyses with no human subjects. The complete genome sequence, published by Wegmann et al. (2007) in the Journal of Bacteriology, established MG1363 as the definitive reference genome for Lactococcus lactis subsp. cremoris, enabling comparative genomic studies. Evidence for any health benefit in humans is entirely absent, and the strain should not be conflated with probiotic Lactococcus lactis strains evaluated in food science contexts.

Nutritional Profile

As a laboratory research strain rather than a food or supplement ingredient, MG1363 lacks a meaningful nutritional profile for human consumption contexts. At the cellular composition level, Lactococcus lactis bacteria generally consist of approximately 50-60% protein by dry weight, 15-25% nucleic acids, 10-15% lipids (primarily membrane phospholipids such as phosphatidylglycerol and cardiolipin), and 5-10% carbohydrates in the form of cell wall polysaccharides and peptidoglycans. MG1363 is a plasmid-cured derivative of L. lactis subsp. cremoris 712, meaning it has been stripped of naturally occurring plasmids, making it genetically simpler but not representative of strains used in food production. It does not produce nisin (an antimicrobial peptide produced by some L. lactis strains) due to its plasmid-free status. The strain can produce small amounts of B vitamins including riboflavin (B2) and folate as metabolic byproducts during growth, consistent with L. lactis species generally, but no quantified data exists for MG1363 specifically in a human supplementation context. Bioavailability of any cellular components is effectively irrelevant given this strain is not intended for ingestion.

Preparation & Dosage

No clinically studied dosage ranges are available as no human clinical studies exist for this strain. MG1363 is not formulated as a probiotic extract, powder, or standardized product for clinical use but is cultured exclusively for laboratory applications. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Because MG1363 is strictly a genetic research tool and not a consumable probiotic or food ingredient, no evidence-based synergy stack exists for human health applications. If discussing its parent species L. lactis in legitimate fermented food contexts, the species demonstrates synergy with Streptococcus thermophilus through complementary lactase activity and protocooperation during dairy fermentation, with Leuconostoc mesenteroides for enhanced diacetyl and flavor compound production via shared citrate metabolism pathways, and with prebiotic galactooligosaccharides (GOS) which support lactococcal colonization through preferential fermentation. Any synergy claims specifically for MG1363 in a health supplement context would be scientifically unsupported, as this strain's documented interactions are limited to laboratory co-culture experiments studying gene transfer and metabolic pathway engineering rather than human physiological outcomes.

Safety & Interactions

MG1363 is not formulated as a supplement and has no established safety profile, dosing guidelines, or documented human exposure data in a therapeutic context. As a non-pathogenic lactic acid bacteria strain classified under BSL-1, it is not considered hazardous in laboratory settings, but its safety as an ingestible agent has never been evaluated in clinical or toxicological studies. No drug interactions, contraindications, or pregnancy safety assessments exist because this strain has not progressed beyond laboratory research. Individuals should not attempt to self-administer research-grade bacterial strains, as sterility, viability, and contaminant profiles of lab cultures do not meet standards for human consumption.