Safety evaluation of Lactococcus lactis IDCC 2301 isolated from homemade cheese

Abstract

For applications of microorganisms as probiotics in the food industry, safety evaluation has increasingly become important to ensure the health of consumers. Although people have been using various lactic acid bacteria for different purposes, some studies have reported that certain lactic acid bacteria exhibit properties of virulence and produce toxic compounds. Thus, it is necessary to examine the characteristics associated with lactic acid bacteria that are safe for use as probiotics. This research aimed to assess the safety of Lactococcus lactis IDCC 2301 isolated from homemade cheese using in vitro and in vivo assays, including antibiotic resistance, hemolytic activity, toxin production, infectivity, and metabolic activity in immune‐compromised animal species. The results demonstrated that the strain was susceptible to nine antibiotics suggested by the European Food Safety Authority (EFSA). Whole‐genome analysis revealed that L. lactis IDCC 2301 neither has toxigenic genes nor harbors antibiotic resistance. Moreover, L. lactis IDCC 2301 showed neither hemolytic nor β‐glucuronidase activity. Furthermore, none of the D‐lactate and biogenic amines were produced by L. lactis IDCC 2301. Finally, it was demonstrated that there was no toxicity and mortality using single‐dose oral toxicity tests in rats. These results indicate that L. lactis IDCC 2301 can be safely used as probiotics for human consumption.

Potential of Bifidobacteriumlactis IDCC 4301 isolated from breast milk‐fed infant feces as a probiotic and functional ingredient

“…The antibiotic sensitivity of BL was investigated based on the EFSA recommendations (Kim et al, 2021 ; Rychen et al, 2018 ). Nine antibiotics (ampicillin, vancomycin, gentamicin, kanamycin, streptomycin, erythromycin, clindamycin, tetracycline, and chloramphenicol), which are typically used to treat enterococcal infections, were tested.…”

Lactic Acid Bacteria in Dairy Foods: Prime Sources of Antimicrobial Compounds

“…Recent studies have shed light on the safety evaluation of LAB strains, adding depth to the theoretical framework. For instance, Kim et al [96] focused on the safety evaluation of L. lactis IDCC 2301, a strain isolated from homemade cheese. Utilizing both in vitro and in vivo assays, they evaluated aspects such as antibiotic resistance and potential toxin production.…”

Lactococcus lactis in Dairy Fermentation—Health-Promoting and Probiotic Properties

“…Safety assessment of L. lactis on the susceptibility to antibiotics is based on the testing of the antibiotics listed in EFSA scientific opinion and commonly used for the treatment of enterococcal infections [92,93]. The cutoff values (µg mL −1 ) indicated in EFSA include ampicillin (2 µg mL −1 ), clindamycin (1 µg mL −1 ), chloramphenicol (8 µg mL −1 ), erythromycin (1 µg mL −1 ), gentamicin (32 µg mL −1 ), kanamycin (64 µg mL −1 ), streptomycin (32 µg mL −1 ), tetracycline (4 µg mL −1 ), and vancomycin (4 µg mL −1 ).…”

“…However, Lactoccocus, as well as other LAB species, is considered as not possessing or showing weak lipase activity [15,157,318,323]. Also, L. lactis isolated from dairy products does not show any esterase activity outside the cell [15,93,318]; however, environmental L. lactis strains have opposite traits [157]. Lactate dehydrogenase is another Lactococcus-utilized enzyme, which is responsible for carbon source conversion to L-lactate from pyruvate.…”