• Journal of Microbiology and Biotechnology
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• v.26 no.6
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• pp.1018-1025
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• 2016

Probiotics are considered as the best effective alternatives to antibiotics. The aim of this study was to characterize the probiotic potential of lactobacilli for use in swine farming by using in vitro evaluation methods. A total of 106 lactic acid bacterial isolates, originating from porcine feces, were first screened for the capacity to survive stresses considered important for putative probiotic strains. Sixteen isolates showed notable acid and bile resistance, antibacterial activity, and adherence to intestinal porcine epithelial cells (IPEC-1). One isolate, LR1, identified as Lactobacillus reuteri, was selected for extensive study of its probiotic and functional properties in IPEC-1 cell models. L. reuteri LR1 exhibited good adhesion to IPEC-1 cells and could inhibit the adhesion of enterotoxigenic Escherichia coli (ETEC) to IPEC-1 cells. L. reuteri LR1 could also modulate transcript and protein expression of cytokines involved in inflammation in IPEC-1 cells; the Lactobacillus strain inhibited the ETEC-induced expression of proinflammatory transcripts (IL-6 and TNF-α) and protein (IL-6), and increased the level of anti-inflammatory cytokine (IL-10). Measurement of the permeation of FD-4 showed that L. reuteri LR1 could maintain barrier integrity in monolayer IPEC-1 cells exposed to ETEC. Immunolocalization experiments showed L. reuteri LR1 could also prevent ETEC-induced tight junction ZO-1 disruption. Together, these results indicate that L. reuteri LR1 exhibits desirable probiotic properties and could be a potential probiotic for use in swine production.

• Journal of the Korean Applied Science and Technology
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• v.38 no.6
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• pp.1383-1392
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• 2021

It has been reported that emodin, a major pharmacologically active ingredient of herbal medicines such as Polygonum cuspidatum, Polygonum multiflorum, Rheum palmatum, and Aloe vera, is effective in antioxidant, antibacterial, anti-inflammatory, anticancer, and liver protection. In this study, to investigate the potential of emodin to be used as a skin disease and functional material, the activity related to the improvement of inflammation and skin barrier function was confirmed. To observe the anti-inflammatory effect on HaCaT cells, which are human keratinocytes, cytokine inhibition was confirmed by ELISA kit and protein expression by western blot. In HaCaT cells activated with TNF-α (10 ng/mL)/IFN-γ (10 ng/mL), emodin was treated with each concentration (5, 10, 20, 40) µM. As a result, It was confirmed that the production amount of TNF-α, IL-1β and IL-6 decreased as the concentration of emodin increased. In the experimental results on the expression levels of inflammation-related proteins iNOS and COX-2, it was confirmed that 48% of iNOS and 29% of COX-2 were inhibited compared to control at a concentration of 20 µM of emodin. As an indicator of skin barrier function improvement, the mRNA expression level of filaggrin, involucrin, and loricirn and the production amount of filaggrin, involucrin, and loricirn were confirmed. and excellent results were obtained with an emodin concentration-dependent increase. In particular, filaggrin, which was produced twice as much as the control at a concentration of 20 µM, is a protein involved in the formation of NMF, a natural moisturizing factor, and is known to play an important role in moisturizing the stratum corneum. In conclusion, it was confirmed that emodin can be used as a material for improving inflammation and improving skin barrier function, which is part of the potential for use as a skin disease and functional material. It is believed that if additional research is performed in the future, the scope of its application can be further expanded.

• Journal of Life Science
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• v.34 no.7
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• pp.465-475
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• 2024

Lactiplantibacillus plantarum K9 is a probiotic strain that can be utilized from various bioactive substances isolated from Protaetia brevitarsis seulensis larvae. In this study, a genetic analysis of L. plantarum K9 revealed the existence of a bacterial chromosome and three plasmids. The glycolysis pathway and pentose phosphate pathway were examined for their normal functioning via an analysis of the core metabolic pathways of L. plantarum K9. Since the key enzymes, fluctose-1,6-bisphospatase (EC: 3.1.3.11) and 6-phosphogluconate dehydratase (EC: 4.2.1.12)/2-keto-deoxy-6-phosphogluconate (KDPG) aldolase (EC: 4.2.1.55), of gluconeogenesis and the ED pathway were not identified from the L. plantarum K9 genome, we suggest that gluconeogenesis and the ED pathway are not performed in L. plantarum K9. Additionally, while some enzymes, related to fumarate and malate biosyntheses, involved in the TCA cycle were identified from L. plantarum K9, the enzymes associated with the remaining TCA cycle were absent, indicating that the TCA cycle cannot proceed. Meanwhile, based on our findings, we propose that the oxidative electron transport system performs class IIB-type (bd-type) electron transfer. In summary, we assert that L. plantarum K9 performs homolactic fermentation, executes gluconeogenesis and the pentose phosphate pathway, and carries out energy metabolism through the class IIB-type oxidative electron transport system. Therefore, we suggest that L. plantarum K9 has relatively high lactic acid production, and that it has excellent antibacterial activity, as a result, compared to other lactic acid bacterial strains. Moreover, we speculate that L. plantarum K9 has an oxidative electron transport capability, indicating that it is highly resistant to oxygen and suggesting that it has fine cultivation characteristics, which collectively make it highly suitable for use as a probiotic.