• Journal of Microbiology and Biotechnology
• /
• v.31 no.10
• /
• pp.1366-1372
• /
• 2021

Bacterial nanocellulose (BNC) is a biocompatible material with a lot of potential. To make BNC commercially feasible, improvements in its production and surface qualities must be made. Here, we investigated the in situ fermentation and generation of BNC by addition of different cellulosic substrates such as Avicel and carboxymethylcellulose (CMC) and using Komagataeibacter sp. SFCB22-18. The addition of cellulosic substrates improved BNC production by a maximum of about 5 times and slightly modified its structural properties. The morphological and structural properties of BNC were investigated by using Fourier transform-infrared spectroscopy (FT-IR), scanning electron microscopy and X-ray diffraction. Furthermore, a type-A cellulose-binding protein derived from Clostridium thermocellum, CtCBD3, was used in a novel biological analytic approach to measure the surface crystallinity of the BNC. Because Avicel and CMC may adhere to microfibrils during BNC synthesis or crystallization, cellulose-binding protein could be a useful tool for identifying the crystalline properties of BNC with high sensitivity.

• Journal of Dairy Science and Biotechnology
• /
• v.37 no.1
• /
• pp.49-56
• /
• 2019

Vulvovaginal candidiasis is a major urogenital infection in women. Lactobacilli are important in maintaining vaginal health. In the present study, the effect of heat adaptation at $47{\sim}52^{\circ}C$ prior to heat stress at $60^{\circ}C$ in improving the viability of Lactobacillus salivarius MG242 was examined. L. salivarius MG242 has antifungal effects against Candida albicans. Heat-adapted cells had a higher survival rate than non-adapted cells during the subsequent heat stress. When chloramphenicol was added during the adaptation process, heat tolerance was abolished, suggesting the involvement of de novo protein synthesis with the heat adaptation of L. salivarius MG242 strain. Exopolysaccharide quantification and scanning election microscopy did not reveal any appreciable changes during heat adaptation. The antifungal activity of L. salivarius MG242 against C. albicans was maintained during the heat adaptation. These results suggest that heat adaptation can be applied for the development of probiotic products using L. salivarius MG242 to improve its stress tolerance during processing.

• Journal of Applied Biological Chemistry
• /
• v.62 no.2
• /
• pp.137-141
• /
• 2019

At concentrations with little or no cytotoxicity, C. arvensis extract indicates the ability of high DPPH radical scavenging, inhibited tyrosinase activity, and decreased melanin content. The treatment of B16F10 cells with C. arvensis extract suppressed the protein expression of tyrosinase a dose-dependent manner. These results suggest that C. arvensis extract inhibits melanin synthesis by inhibiting tyrosinase expression and tyrosinase activity. In addition, C. arvensis extract showed antimicrobial activities against bacteria and yeast. These results indicate that C. arvensis extract may serve as nutraceutical and cosmeceutical agents.

• Journal of Korean Biological Nursing Science
• /
• v.24 no.2
• /
• pp.77-85
• /
• 2022

Purpose: Aging process comes with cognitive impairment due to decreased neuronal cell number, activity, and neuronal circuit. Alteration of inhibitory neurons contributes to cognitive impairment in normal aging and is responsible for disrupting the excitation/inhibition balance by reducing the synthesis of gamma-aminobutyric acid (GABA). Morus nigra (Mulberry) is a natural physiologically active substance that has been proven to have anti-oxidant, anti-diabetic, and anti-inflammatory effects through many studies. This study aimed to evaluate the effects of the mulberry extract (ME) on cognitive function through anti-oxidant enzyme and GABAergic neuronal activity in aged rat brain. Methods: Sprague Dawley rats were randomly assigned as the young group (8 weeks, n= 8), aging group (67 weeks, n= 8), and aging+ mulberry extract group (67 weeks, n= 8). The aging+ mulberry extract group was orally administered 500 mg/kg/d mulberry extract for 6 weeks. Results: The aging+ mulberry extract group improved spatial and short-term memory. The antioxidant potential of ME increased the expression of superoxide dismutase-1 (SOD-1) and decreased inducible nitric oxide synthase (iNOS). Also, the aging+ mulberry extract group significantly increased the expression of GABAergic interneuron in hippocampus cornu ammonis1 (CA1) compared to the aging group. Conclusion: The number of GABAergic inhibitory interneurons was deceased and memory functions in the aging process, but those symptoms were improved and restored by mulberry extract administration.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.5
• /
• pp.1075-1080
• /
• 2004

Dextransucrase (DSRB742) from Leuconostoc mesenteroides NRRL B-742CB is a glucosyltransferase that catalyzes the synthesis of dextran using sucrose, or the synthesis of oligosaccharides when acceptor molecules, like maltose, are present. The DSRB742 gene (dsrB742) was cloned and the properties were characterized. In order to identify critical amino acid residues, the DSRB742 amino acid sequence was aligned with glucosyltransferase sequences, and three amino acid residues reported as sucrose binding amino acids in Streptococcus glucosyltransferases were selected for site-directed mutagenesis experiments. Asp-533, Asp-536, and His-643 were independently replaced with Ala or Asn. D533A and D536A dextransucrases showed reduced dextran synthesis activities, 2.3% and 40.8% of DSRB742 dextransucrase, respectively, and D533N, D536N, H643A, end H643N dextransucrases showed complete suppression of dextran synthesis activities altogether. Additionally, D536N dextransucrase showed complete suppression of oligosaccharide synthesis activities. However, modifications at Asp-533 or at His-643 retained acceptor reaction activities in the range of 8.4% to 21.3% of DSRB742 acceptor reaction activity. Thus at least two carboxyl groups of Asp-533 and Asp-536, and His-643 as a proton donor, are essential for the catalysis process.

• Journal of Applied Biological Chemistry
• /
• v.57 no.4
• /
• pp.365-371
• /
• 2014

In the present study, we investigated the biological activities of Xylosma congesta leaf ethanol extract (XCO) using a variety of in vitro and cell culture model systems for anti-melanogenic, anti-wrinkle, anti-inflammatory and anti-oxidant activities. First, XCO markedly inhibited ${\alpha}$-melanocyte stimulating hormone-stimulated melanin synthesis in B16F10 cells. Secondly, XCO marginally induced procollagen synthesis in CCD-986SK cells. Thirdly, XCO dose-dependently suppressed lipopolysaccharide-induced nitric oxide (NO) production in RAW 264.7 cells. XCO did not affect cell viability at different concentrations used in this study, indicating that XCO-mediated inhibition of melanin, procollagen and NO synthesis is not mediated by cytotoxicity. Finally, XCO was found to exert anti-oxidant effect. Taken together, these findings demonstrate for the first time that XCO possesses anti-melanogenic, anti-wrinkle, anti-inflammatory and anti-oxidant activities, and suggest further evaluation and development of XCO as a functional supplement or cosmetic that may be useful for whitening skin, reducing wrinkles and treating inflammatory responses.

• Microbiology and Biotechnology Letters
• /
• v.44 no.3
• /
• pp.285-292
• /
• 2016

In the present study, we evaluated the in vitro wound-healing properties of two types of rice cell extracts (RCEs; prepared using ethanol and pressurized hot water extraction methods), using human dermal fibroblasts and keratinocytes. The effects of the RCEs (at 25–100 μg/ml) on cytotoxicity and cell migration were assessed. Both RCEs were not cytotoxic to the two cell types, instead increasing their proliferation by up to 25% in a dose-dependent manner compared with the controls. Furthermore, both RCEs significantly enhanced the migratory ability of the two cell types (fibroblast, 230–450%; keratinocyte, 170–350%). Additionally, we examined the effect of the RCEs on type I collagen synthesis, which is important in the wound reconstruction process. The RCEs significantly increased collagen type I mRNA and protein levels to a degree comparable to that induced by vitamin C. These results suggest the RCEs to be candidate materials for use in promoting wound healing, through their actions of increasing cell migration and accelerating wound re-epithelialization.

• The Korean Journal of Pesticide Science
• /
• v.3 no.1
• /
• pp.20-28
• /
• 1999

Chloronicotinyl derivatives were synthesized by substitution of amino in 3-pyridylmethylamine with phosphite groups and their insecticidal and fungicidal activities were determined. At 500 ppm, compound 4 with methyl and butyl group in phosphonate and compound 5, 6, 7, and 8 with two butyl, 2,2,2-trifluorotehtyl, 2-ethylhexyl, phenyl, respectively, in phosphonate showed 90% insecticidal activities against brown plant-hopper (Nilaparvate lugens). These compounds showed, however, poor insecticidal activities against diamond-back moth (Plutella xylostella) and two-spotted spider mite (Tetranychus urticae) (<65%), suggesting that insecticidal activity of chloronicotinyl derivatives containing phosphorus moieties are species-dependent. Newly synthesized chloronicotinyl derivatives with halogen and/or heterocycle (compound $10{\sim}21$) did not show insecticidal activities. We also determined fungicidal activity of the synthesized chloronicotinyl derivatives against rice sheath blight (Pyricularia grisea), cucumber gray mold (Bortytis cinerea), tomato late blight (Phytophthora infestans), wheat leaf rust (Puccinia recondita), and barley powdery mildew (Erysiphe graminis). Compound 10 with butyl and 4-nitrophenyl in phosphonate at 10 ppm showed 85% fungicidal activity against rice blast, suggesting that chloronicotinyl derivatives containing phosphorus moieties could be developed as a fungicidal agent of a novel chemical structure.

• Asian-Australasian Journal of Animal Sciences
• /
• v.30 no.7
• /
• pp.957-966
• /
• 2017

Objective: To understand the dynamic structure, function, and influence on nutrient metabolism in hosts, it was crucial to assess the genetic potential of gut microbial community in yaks of different ages. Methods: The denaturing gradient gel electrophoresis (DGGE) profiles and Illumina-based metagenomic sequencing on colon contents of 15 semi-domestic yaks were investigated. Unweighted pairwise grouping method with mathematical averages (UPGMA) clustering and principal component analysis (PCA) were used to analyze the DGGE fingerprint. The Illumina sequences were assembled, predicted to genes and functionally annotated, and then classified by querying protein sequences of the genes against the Kyoto encyclopedia of genes and genomes (KEGG) database. Results: Metagenomic sequencing showed that more than 85% of ribosomal RNA (rRNA) gene sequences belonged to the phylum Firmicutes and Bacteroidetes, indicating that the family Ruminococcaceae (46.5%), Rikenellaceae (11.3%), Lachnospiraceae (10.0%), and Bacteroidaceae (6.3%) were dominant gut microbes. Over 50% of non-rRNA gene sequences represented the metabolic pathways of amino acids (14.4%), proteins (12.3%), sugars (11.9%), nucleotides (6.8%), lipids (1.7%), xenobiotics (1.4%), coenzymes, and vitamins (3.6%). Gene functional classification showed that most of enzyme-coding genes were related to cellulose digestion and amino acids metabolic pathways. Conclusion: Yaks' age had a substantial effect on gut microbial composition. Comparative metagenomics of gut microbiota in 0.5-, 1.5-, and 2.5-year-old yaks revealed that the abundance of the class Clostridia, Bacteroidia, and Lentisphaeria, as well as the phylum Firmicutes, Bacteroidetes, Lentisphaerae, Tenericutes, and Cyanobacteria, varied more greatly during yaks' growth, especially in young animals (0.5 and 1.5 years old). Gut microbes, including Bacteroides, Clostridium, and Lentisphaeria, make a contribution to the energy metabolism and synthesis of amino acid, which are essential to the normal growth of yaks.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.31 no.3
• /
• pp.27-34
• /
• 2023

In this study, various plant-based biomass are recycled into carbon materials to employ as anode materials for lithium-ion batteries. Firstly, various biomass of rice husk, chestnut, tea bag, and coffee ground are collected, washed, and ground. The carbonization process is followed under a nitrogen atmosphere at 850℃. The morphological and chemical properties of materials are investigated using FE-SEM, EDS, and FT-IR to compare the characteristic differences between various biomass. It is noticeable that biomass-derived carbon materials vary in shape and degree of carbonization depending on their precursor materials. These materials are applied as anode materials to measure the electrochemical performance. The specific capacities of rice husk-, chetnut-, tea bag-, and coffee ground-derived carbon materials are evaluated as 65.8, 80.2, 90.6, and 104.7 mAh g^-1 at 0.2C. Notably, coffee ground-based carbon exhibited the highest specific capacity owing to the difference in elemental composition and the degree of carbonization. Conclusively, this study suggests the possibility of utilizing as energy storage devices by employing various plant-based biomass into active materials for anodes.