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Bioconversion of Inositol Isomers by Enzymes and Microbial Fermentation
Hyelyeon HWANG,Eunju KIM,Ho Jae LEE,Chang Hee JEONG,Tae Woon KIM,Sung Wook HONG 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.10
Inositol is a vitamin-like substance and found in foods such as fruits, beans, grains, and nuts. Inositol can be found in many isomers. The isomer D-chiro-inositol is a postreceptor signaling molecule of insulin action. However, the studies have documented that inositol in the ice plant (Delosperma) consist mainly of myo-inositol form, which is very low in biological utilization efficiency. The objective of this study was to investigate the optimal processing conditions for conversion of inositol into D-chiro-inositol form in the ice plant and to improve the biological utilization by enzyme treatment and fermentation. To convert inositol into D-chiro-inositol form, 0.5% (v/v) enzyme complexes(viscozyme, and celluclast), which consists of glucanase, xylanase, cellulase and hemicellulase was treated at 50℃ for 4h. In addition, fermentation was performed using an inositol 2-dehydrogenase producing strain, which was identified as Bacillus subtilis, Lacticaseibacillus casei, and L. paracasei by 16S rDNA analysis. The contents of D-chiro-inositol was significantly increased by enzyme treatment and fermentation in the ice plant. The results suggest that these methods to convert inositol to D-chiro-inositol can be applied for the use of ice plant processing as functional food biomaterial.
Hyelyeon Hwang,Ho Jae Lee,Mi-Ai Lee,Hyejin Sohn,You Hyun Chang,Sung Gu Han,Jong Youn Jeong,Sung Ho Lee,Sung Wook Hong 한국축산식품학회 2020 한국축산식품학회지 Vol.40 No.4
Synthetic nitrite is considered an undesirable preservative for meat products; thus, controlling synthetic nitrite concentrations is important from the standpoint of food safety. We investigated 1,000 species of microorganisms from various kimchi preparations for their potential use as a starter culture for the production of nitrites. We used 16S rRNA gene sequence analysis to select a starter culture with excellent nitrite and nitric oxide productivity, which we subsequently identified as Staphylococcus hominis subspecies hominis WiKim0113. That starter culture was grown in NaCl (up to 9%; w/v) at 10℃-40℃; its optimum growth was observed at 30℃ at pH 4.0-10.0. It exhibited nonproteolytic activity and antibacterial activity against Clostridium perfringens, a bacterium that causes food poisoning symptoms. Analysis of Staphylococcus hominis subspecies hominis WiKim0113 with an API ZYM system did not reveal the presence of β-glucuronidase, and tests of the starter culture on 5% (v/v) sheep blood agar showed no hemolytic activity. Our results demonstrated the remarkable stability of coagulasenegative Staphylococcus hominis subspecies hominis WiKim0113, especially in strain negative for staphylococcal enterotoxins and sensitive to clinically relevant antibiotics. Moreover, Staphylococcus hominis subspecies hominis WiKim0113 exhibited a 45.5% conversion rate of nitrate to nitrite, with nitrate levels reduced to 25% after 36 h of culturing in the minimal medium supplemented with nitrate (200 ppm). The results clearly demonstrated the safety and utility of Staphylococcus hominis subspecies hominis WiKim0113, and therefore its suitability as a starter culture.
Kim, Seongok,Hwang, Hyelyeon,Kim, Kwang-Pyo,Yoon, Hyunjin,Kang, Dong-Hyun,Ryu, Sangryeol American Society for Microbiology 2015 Infection and immunity Vol.83 No.5
<P><I>Cronobacter</I> spp. are opportunistic pathogens that cause neonatal meningitis and sepsis with high mortality in neonates. Despite the peril associated with <I>Cronobacter</I> infection, the mechanisms of pathogenesis are still being unraveled. Hfq, which is known as an RNA chaperone, participates in the interaction with bacterial small RNAs (sRNAs) to regulate posttranscriptionally the expression of various genes. Recent studies have demonstrated that Hfq contributes to the pathogenesis of numerous species of bacteria, and its roles are varied between bacterial species. Here, we tried to elucidate the role of Hfq in <I>C. sakazakii</I> virulence. In the absence of <I>hfq</I>, <I>C. sakazakii</I> was highly attenuated in dissemination <I>in vivo</I>, showed defects in invasion (3-fold) into animal cells and survival (10<SUP>3</SUP>-fold) within host cells, and exhibited low resistance to hydrogen peroxide (10<SUP>2</SUP>-fold). Remarkably, the loss of <I>hfq</I> led to hypermotility on soft agar, which is contrary to what has been observed in other pathogenic bacteria. The hyperflagellated bacteria were likely to be attributable to the increased transcription of genes associated with flagellar biosynthesis in a strain lacking <I>hfq</I>. Together, these data strongly suggest that <I>hfq</I> plays important roles in the virulence of <I>C. sakazakii</I> by participating in the regulation of multiple genes.</P>
Evaluation of ginsenoside bioconversion of lactic acid bacteria isolated from kimchi
Boyeon Park,Hyelyeon Hwang,Jina Lee,Sung-Oh Sohn,Se Hee Lee,Min Young Jung,Hyeong In Lim,Hae Woong Park,Jong-Hee Lee 고려인삼학회 2017 Journal of Ginseng Research Vol.41 No.4
Background: Panax ginseng is a physiologically active plant widely used in traditional medicine that is characterized by the presence of ginsenosides. Rb1, a major ginsenoside, is used as the starting material for producing ginsenoside derivatives with enhanced pharmaceutical potentials through chemical, enzymatic, or microbial transformation. Methods: To investigate the bioconversion of ginsenoside Rb1, we prepared kimchi originated bacterial strains Leuconostoc mensenteroides WiKim19, Pediococcus pentosaceus WiKim20, Lactobacillus brevis WiKim47, Leuconostoc lactis WiKim48, and Lactobacillus sakei WiKim49 and analyzed bioconversion products using LC-MS/MS mass spectrometer. Results: L. mesenteroides WiKim19 and Pediococcus pentosaceus WiKim20 converted ginsenoside Rb1 into the ginsenoside Rg3 approximately five times more than Lactobacillus brevis WiKim47, Leuconostoc lactis WiKim48, and Lactobacillus sakei WiKim49. L mesenteroides WIKim19 showed positive correlation with b-glucosidase activity and higher transformation ability of ginsenoside Rb1 into Rg3 than the other strains whereas, P. pentosaceus WiKim20 showed an elevated production of Rb3 even with lack of b-glucosidase activity but have the highest acidity among the five lactic acid bacteria (LAB). Conclusion: Ginsenoside Rg5 concentration of five LABs have ranged from w2.6 mg/mL to 6.5 mg/mL and increased in accordance with the incubation periods. Our results indicate that the enzymatic activity along with acidic condition contribute to the production of minor ginsenoside from lactic acid bacteria.
Evaluation of ginsenoside bioconversion of lactic acid bacteria isolated from kimchi
Park, Boyeon,Hwang, Hyelyeon,Lee, Jina,Sohn, Sung-Oh,Lee, Se Hee,Jung, Min Young,Lim, Hyeong In,Park, Hae Woong,Lee, Jong-Hee The Korean Society of Ginseng 2017 Journal of Ginseng Research Vol.41 No.4
Background: Panax ginseng is a physiologically active plant widely used in traditional medicine that is characterized by the presence of ginsenosides. Rb1, a major ginsenoside, is used as the starting material for producing ginsenoside derivatives with enhanced pharmaceutical potentials through chemical, enzymatic, or microbial transformation. Methods: To investigate the bioconversion of ginsenoside Rb1, we prepared kimchi originated bacterial strains Leuconostoc mensenteroides WiKim19, Pediococcus pentosaceus WiKim20, Lactobacillus brevis WiKim47, Leuconostoc lactis WiKim48, and Lactobacillus sakei WiKim49 and analyzed bioconversion products using LC-MS/MS mass spectrometer. Results: L. mesenteroides WiKim19 and Pediococcus pentosaceus WiKim20 converted ginsenoside Rb1 into the ginsenoside Rg3 approximately five times more than Lactobacillus brevis WiKim47, Leuconostoc lactis WiKim48, and Lactobacillus sakei WiKim49. L mesenteroides WIKim19 showed positive correlation with b-glucosidase activity and higher transformation ability of ginsenoside Rb1 into Rg3 than the other strains whereas, P. pentosaceus WiKim20 showed an elevated production of Rb3 even with lack of b-glucosidase activity but have the highest acidity among the five lactic acid bacteria (LAB). Conclusion: Ginsenoside Rg5 concentration of five LABs have ranged from ${\sim}2.6{\mu}g/mL$ to $6.5{\mu}g/mL$ and increased in accordance with the incubation periods. Our results indicate that the enzymatic activity along with acidic condition contribute to the production of minor ginsenoside from lactic acid bacteria.
Choi, Younho,Kim, Seongok,Hwang, Hyelyeon,Kim, Kwang-Pyo,Kang, Dong-Hyun,Ryu, Sangryeol American Society for Microbiology 2015 Infection and immunity Vol.83 No.1
<P>The aim of this study was to elucidate the function of the plasmid-borne <I>mcp</I> (methyl-accepting chemotaxis protein) gene, which plays pleiotropic roles in <I>Cronobacter sakazakii</I> ATCC 29544. By searching for virulence factors using a random transposon insertion mutant library, we identified and sequenced a new plasmid, pCSA2, in <I>C. sakazakii</I> ATCC 29544. An <I>in silico</I> analysis of pCSA2 revealed that it included six putative open reading frames, and one of them was <I>mcp</I>. The <I>mcp</I> mutant was defective for invasion into and adhesion to epithelial cells, and the virulence of the <I>mcp</I> mutant was attenuated in rat pups. In addition, we demonstrated that putative MCP regulates the motility of <I>C. sakazakii</I>, and the expression of the flagellar genes was enhanced in the absence of a functional <I>mcp</I> gene. Furthermore, a lack of the <I>mcp</I> gene also impaired the ability of <I>C. sakazakii</I> to form a biofilm. Our results demonstrate a regulatory role for MCP in diverse biological processes, including the virulence of <I>C. sakazakii</I> ATCC 29544. To the best of our knowledge, this study is the first to elucidate a potential function of a plasmid-encoded MCP homolog in the <I>C. sakazakii</I> sequence type 8 (ST8) lineage.</P>
Probiotic and Anti-Inflammatory Potential of Lactic Acid Bacteria Isolated from Kimchi
Ho Jae Lee,Chang Hee Jeong,Hyelyeon Hwang,Tae Woon Kim,Sung Wook Hong 한국식품영양과학회 2021 한국식품영양과학회 학술대회발표집 Vol.2021 No.10
27 strains of lactic acid bacteria, which were isolated from various kimchi were evaluated for their probiotic potential along with anti-inflammatory activity. Seven isolates (Lb. plantarum, Lb. paracasei, Lb. fermentum) were selected and identified by 16S rRNA gene sequence analysis. Most of isolates showed a high survival rate under gastrointestinal tract conditions such as artificial gastric juice (pH 2.5) and 0.3% bile salts, and heat treatment (40, 50, and 60˚C). Antibacterial activity showed strong inhibition against food-borne pathogenic bacteria including E. coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus. Moreover, they significantly decreased pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) and increased anti-inflammatory cytokines (IL-4, IL-10, IFN-γ) gene expression in LPS-stimulated Caco-2 cells. Further, functional properties of selected probiotics showed considerably higher anti-oxidation (DPPH and ABTS radical scavenging activity). Favorable probiotic properties of lactic acid bacteria from kimchi along with antioxidant and pro-inflammatory activity imply its potential for clinical or technological applications.