Whole genome sequences of Lactococcus lactis KCKM 0851 isolated from green onion kimchi.

Lactococcus lactis KCKM 0851 isolated from green onion kimchi is a probiotic candidate and can be used as a starter culture for kimchi and dairy products. The whole-genome data of this strain will help us understand its genetics and metabolic characteristics.

Draft genome sequence of Lactiplantibacillus plantarum KCKM 0106, isolated from mustard leaf kimchi.

Lactiplantibacillus plantarum KCKM 0106, isolated from mustard leaf kimchi, demonstrates probiotic properties, such as acid tolerance and adhesion to intestinal epithelial cells. We present the draft genome sequence of L. plantarum KCKM 0106, comprising 3,328,662 bp and 44.4% GC content.

Influence of Isolation Temperature on Isolating Diverse Lactic Acid Bacteria from Kimchi and Cultural Characteristics of Psychrotrophs.

Kimchi is a traditional Korean fermented vegetable that is stored and fermented at low temperatures. However, kimchi lactic acid bacteria (LAB) are typically isolated under mesophilic conditions, which may be inappropriate for isolating the diverse LAB. Therefore, this study investigated the suitable conditions for isolating various LAB from kimchi. Here, LAB were isolated from four kimchi samples using MRS, PES, and LBS media and varying isolation temperatures (30, 20, 10, and 5°C). Then, MRS was selected as the suitable medium for LAB isolation. A comparison of culture-dependent and culture-independent approaches indicated that 5°C was not a suitable isolation temperature. Thus, the number and diversity of LAB were determined at 30, 20, and 10°C using 12 additional kimchi samples to elucidate the effect of isolation temperature. With the exception of two samples, most samples did not substantially differ in LAB number. However, Leuconostoc gelidum, Leuconostoc gasicomitatum, Leuconostoc inhae, Dellaglioa algida, Companilactobacillus kimchiensis, Leuconostoc miyukkimchii, Leuconostoc holzapfelii, and Leuconostoc carnosum were isolated only at 10 and 20°C. The growth curves of these isolates, except Leu. holzapfelii and Leu. carnosum, showed poor growth at 30°C. This confirmed their psychrotrophic characteristics. In Weissella koreensis, which was isolated at all isolation temperatures, there was a difference in the fatty acid composition of membranes between strains that could grow well at 30°C and those that could not. These findings can contribute to the isolation of more diverse psychrotrophic strains that were not well isolated under mesophilic temperatures.

Sustainable Production of Shinorine from Lignocellulosic Biomass by Metabolically Engineered Saccharomyces cerevisiae.

Mycosporine-like amino acids (MAAs) have been used in cosmetics and pharmaceuticals. The purpose of this work was to develop yeast strains for sustainable and economical production of MAAs, especially shinorine. First, genes involved in MAA biosynthetic pathway from Actinosynnema mirum were introduced into Saccharomyces cerevisiae for heterologous shinorine production. Second, combinatorial expression of wild and mutant xylose reductase was adopted in the engineered S. cerevisiae to facilitate xylose utilization in the pentose phosphate pathway. Finally, the accumulation of sedoheptulose 7-phosphate (S7P) was attempted by deleting transaldolase-encoding TAL1 in the pentose phosphate pathway to increase carbon flux toward shinorine production. In fed-batch fermentation, the engineered strain (DXdT-M) produced 751 mg/L shinorine in 71 h. Ultimately, 54 mg/L MAAs was produced by DXdT-M from rice straw hydrolysate. The results suggest that shinorine production by S. cerevisiae might be a promising process for sustainable production and industrial applications.

Anti-inflammatory and anti-pathogenic potential of Lacticaseibacillus rhamnosus IDCC 3201 isolated from feces of breast-fed infants.

OBJECTIVE: We investigated the anti-inflammatory and anti-pathogenic activities of Lacticaseibacillus rhamnosus IDCC 3201 isolated from the feces of breast-fed infants. METHODS: Cell viability, nitric oxide (NO) production, and expression of inflammatory markers by L. rhamnosus IDCC 3201 were quantitatively analyzed in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. The antibacterial and antifungal activities of L. rhamnosus IDCC 3201 against various pathogens were also investigated. RESULTS: Treatment of LPS-induced macrophages with cell-free supernatant of L. rhamnosus IDCC 3201 significantly decreased the expression levels of tumor necrosis factor (TNF-α) and interleukin-6 (IL-6). Nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) levels also significantly decreased in LPS-induced macrophages. Phenotypically, the treatment of L. rhamnosus IDCC 3201 reduced the production of nitric oxide (NO) in LPS-induced macrophages. Furthermore, L. rhamnosus IDCC 3201 was proven to have potent inhibitory activities against various pathogens responsible for inflammatory responses in the gastrointestinal tract (i.e., Bacillus cereus, Enterococcus faecalis, Staphylococcus aureus, and Salmonella Typhimurium), respiratory system (i.e., Streptococcus pneumoniae), and vagina (i.e., Candida albicans). CONCLUSION: L. rhamnosus IDCC 3201 has anti-inflammatory activity in terms of decreased expression of cytokines, inflammation-inducible enzymes in LPS-induced macrophages, and anti-pathogenic activity.

Safety evaluation of Lactococcus lactis IDCC 2301 isolated from homemade cheese.

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 ß-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.

Expression of keratin 10 in rat organ surface primo-vascular tissues.

The primo-vascular system is described as the anatomical structure corresponding to acupuncture meridians and has been identified in several tissues in the body, but its detailed anatomy and physiology are not well understood. Recently, the presence of keratin 10 (Krt10) in primo-vascular tissue was reported, but this finding has not yet been confirmed. In this study, we compared Krt10 expression in primo-vascular tissues located on the surface of rat abdominal organs with Krt10 expression on blood and lymphatic vessels. Krt10 protein (approximately 56.5 kDa) was evaluated by western blot analysis and immunohistochemistry. Krt10 (IR) in the primo-node was visualized as patchy spots around each cell or as a follicle-like structure containing a group of cells. Krt10 IR was also identified in vascular and lymphatic tissues, but its distribution was diffuse over the extracellular matrix of the vessels. Thus Krt10 protein was expressed in all three tissues tested, but the expression pattern of Krt10 in primo-vascular tissue differed from those of blood and lymphatic vascular tissues, suggesting that structural and the regulatory roles of Krt10 in primo-vascular system are different from those in blood and lymphatic vessels.