Viability plays an important role in the beneficial microbes (probiotics) to produce health benefits. However, this idea has been changed after the invention of the term "paraprobiotics," indicating that non-viable microbes could produce health benefits similar to those produced by live probiotics. Occasionally, it might be dangerous to administer live probiotics to people with weak immunity. In such cases, ingestion of paraprobiotics could be a potential alternative. The definition of paraprobiotics refers to the use of inactivated (non-viable) microbial cells or cell fractions to provide health benefits to the consumer. Paraprobiotics have attracted much attention because of their long shelf life, safety, and beneficial effects, such as modulation of immunity, modification of biological responses, reduction of cholesterol, anti-inflammatory, and antiproliferative properties. These features indicate that paraprobiotics may play a vital role in improving the health of the consumer by enhancing particular physiological functions, even though the exact underlying mechanisms have not yet been completely elucidated. In this mini-review, we briefly discuss the historical backgrounds of paraprobiotics and evidence of their health-promoting effects, prophylactic, and therapeutic properties.

We previously identified β-sitosterol (BS) as one of the most abundant compounds found in Korean red ginseng oil. BS is a widely prevalent vegetable-derived phytosterol with many known health benefits. Here, we investigated the efficacy of BS against Brucella (B.) abortus infection. BS showed no effect on bacterial growth but attenuated internalization, intracellular survival and MAPKs-linked intracellular signaling in RAW264.7 cells. BS treatment in cells is also associated with increased nitrite concentration during infection at 24 h. Slightly enhanced resistance to B. abortus infection was observed in mice orally given BS, which could be mediated by induced production of proinflammatory cytokines. Taken together, our study demonstrates the contribution of BS treatment against B. abortus infection although further investigation is encouraged to maximize its beneficial effects against intracellular infection.

Consumption of anti-inflammatory nutraceuticals may help treat or prevent inflammation-related illnesses such as diabetes, cardiovascular disease, and cancer. This study evaluated the effect of Croton hirtus L'Hér extract (CHE) on lipopolysaccharide (LPS)-induced nitric oxide (NO) production and nuclear factor kappa-B (NF-κB) signaling cascades. CHE significantly suppressed LPS-induced NO production and inducible nitric oxide synthase (iNOS) expression in RAW264.7 macrophages, although cyclooxygenase (COX)-2 expression was not affected. CHE also suppressed LPS-induced IκB kinase (IKK), IκB, and p65 phosphorylation in RAW264.7 cells. Western blot and immunofluorescence assays of cytosol and nuclear p65 and the catalytic subunit of NF-κB showed that CHE suppressed LPS-induced p65 translocation from the cytosol to the nucleus. CHE also suppressed LPS-induced Interleukin (IL)-6 and tumor necrosis factor (TNF)-α production in RAW264.7 cells. These results suggest that CHE prevents NO-mediated inflammation by suppressing NF-κB and inflammatory cytokines.

For control of brucellosis in small ruminants, attenuated B. melitensis Rev1 is used but it can be virulent for animals and human. Based on these aspects, it is essential to identify potential immunogens to avoid these problems in prevention of brucellosis. The majority of OMPs in the Omp25/31 family have been studied because these proteins are relevant in maintaining the integrity of the outer membrane but their implication in the virulence of the different species of this genus is not clearly described. Therefore, in this work we studied the role of Omp31 on virulence by determining the residual virulence and detecting lesions in spleen and testis of mice inoculated with the B. melitensis LVM31 mutant strain. In addition, we evaluated the conferred protection in mice immunized with the mutant strain against the challenge with the B. melitensis Bm133 virulent strain. Our results showed that the mutation of omp31 caused a decrease in splenic colonization without generating apparent lesions or histopathological changes apparent in both organs in comparison with the control strains and that the mutant strain conferred similar protection as the B. melitensis Rev1 vaccine strain against the challenge with B. melitensis Bm133 virulent strain. These results allow us to conclude that Omp31 plays an important role on the virulence of B. melitensis in the murine model, and due to the attenuation shown by the strain, it could be considered a vaccine candidate for the prevention of goat brucellosis.

The symbiotic nature of the relationship between algae and marine bacteria is well-studied among the complex microbial interactions. The mutual profit between algae and bacteria occurs via nutrient and vitamin exchange. It is necessary to analyze the genome sequence of a bacterium to predict its symbiotic relationships. In this study, the genome of a marine bacterium, Pseudoruegeria sp. M32A2M, isolated from the south-eastern isles (GeoJe-Do) of South Korea, was sequenced and analyzed. A draft genome (91 scaffolds) of 5.5 Mb with a DNA G+C content of 62.4% was obtained. In total, 5,101 features were identified from gene annotation, and 4,927 genes were assigned to functional proteins. We also identified transcription core proteins, RNA polymerase subunits, and sigma factors. In addition, full flagella-related gene clusters involving the flagellar body, motor, regulator, and other accessory compartments were detected even though the genus Pseudoruegeria is known to comprise non-motile bacteria. Examination of annotated KEGG pathways revealed that Pseudoruegeria sp. M32A2M has the metabolic pathways for all seven vitamin Bs, including thiamin (vitamin B1), biotin (vitamin B7), and cobalamin (vitamin B12), which are necessary for symbiosis with vitamin B auxotroph algae. We also identified gene clusters for seven secondary metabolites including ectoine, homoserine lactone, beta-lactone, terpene, lasso peptide, bacteriocin, and non-ribosomal proteins.

Interferon (IFN)-λ plays an essential role in mucosal cells which exhibit strong antiviral activity. Lactobacillus plantarum (L. plantarum) has substantial application potential in the food and medical industries because of its probiotic properties. Alphacoronaviruses, especially porcine epidemic diarrhea virus (PEDV) and transmissible gastroenteritis virus (TGEV), cause high morbidity and mortality in piglets resulting in economic loss. Co-infection by these two viruses is becoming increasingly frequent. Therefore, it is particularly important to develop a new drug to prevent diarrhea infected with mixed viruses in piglets. In this study, we first constructed an anchored expression vector with CWA (C-terminal cell wall anchor) on L. plantarum. Second, we constructed two recombinant L. plantarum strains that anchored IFN-λ3 via pgsA (N-terminal transmembrane anchor) and CWA. Third, we demonstrated that both recombinant strains possess strong antiviral effects against coronavirus infection in the intestinal porcine epithelial cell line J2 (IPEC-J2). However, recombinant L. plantarum with the CWA anchor exhibited a more powerful antiviral effect than recombinant L. plantarum with pgsA. Consistent with this finding, Lb.plantarum-pSIP-409-IFN-λ3-CWA enhanced the expression levels of IFN-stimulated genes (ISGs) (ISG15, OASL, and Mx1) in IPEC-J2 cells more than did recombinant Lb.plantarum-pSIP-409-pgsA'-IFN-λ3. Our study verifies that recombinant L. plantarum inhibits PEDV and TGEV infection in IPEC-J2 cells, which may offer great potential for use as a novel oral antiviral agent in therapeutic applications for combating porcine epidemic diarrhea and transmissible gastroenteritis. This study is the first to show that recombinant L. plantarum suppresses PEDV and TGEV infection of IPEC-J2 cells.

A bacterial strain, designated B301^T and isolated from raw chicken meat obtained from a local market in Korea, was characterized and identified using a polyphasic taxonomic approach. Cells were gram-negative, non-motile, obligate-aerobic coccobacilli that were catalase-positive and oxidase-negative. The optimum growth conditions were 30℃, pH 7.0, and 0% NaCl in tryptic soy broth. Colonies were round, convex, smooth, and cream-colored on tryptic soy agar. Strain B301^T has a genome size of 3,102,684 bp, with 2,840 protein-coding genes and 102 RNA genes. The 16S rRNA gene analysis revealed that strain B301^T belongs to the genus Acinetobacter and shares highest sequence similarity (97.12%) with A. celticus ANC 4603^T and A. sichuanensis WCHAc060041^T. The average nucleotide identity and digital DNA-DNA hybridization values for closely related species were below the cutoff values for species delineation (95-96% and 70%, respectively). The DNA G+C content of strain B301^T was 37.0%. The major respiratory quinone was Q-9, and the cellular fatty acids were primarily summed feature 3 (C_16:1 ω6c/C_16:1 ω7c), C_16:0, and C_18:1 ω9c. The major polar lipids were phosphatidylethanolamine, diphosphatidyl-glycerol, phosphatidylglycerol, and phosphatidyl-serine. The antimicrobial resistance profile of strain B301^T revealed the absence of antibiotic-resistance genes. Susceptibility to a wide range of antimicrobials, including imipenem, minocycline, ampicillin, and tetracycline, was also observed. The results of the phenotypic, chemotaxonomic, and phylogenetic analyses indicate that strain B301^T represents a novel species of the genus Acinetobacter, for which the name Acinetobacter pullorum sp. nov. is proposed. The type strain is B301^T (=KACC 21653^T = JCM 33942^T).

A quantitative real-time polymerase chain reaction (QPCR) was applied to estimate biokinetic coefficients of Clostridium cadaveris and Clostridium sporogenes, which utilize protein as carbon source. Experimental data on changes in peptone concentration and 16S rRNA gene copy numbers of C. cadaveris and C. sporogenes were fitted to model. The fourth-order Runge-Kutta approximation with non-linear least squares analysis was employed to solve the ordinary differential equations to estimate biokinetic coefficients. The maximum specific growth rate (μ_max), half-saturation concentration (K_s), growth yield (Y), and decay coefficient (K_d) of C. cadaveris and C.sporogenes were 0.73 ± 0.05 and 1.35 ± 0.32 h^-1, 6.07 ± 1.52 and 5.67 ± 1.53 g/l, 2.25 ± 0.75 × 10¹⁰ and 7.92 ± 3.71 × 10⁹ copies/g, 0.002 ± 0.003 and 0.002 ± 0.001 h^-1, respectively. The theoretical specific growth rate of C. sporogenes always exceeded that of C. cadaveris at peptone concentration higher than 3.62 g/l. When the influent peptone concentration was 5.0 g/l, the concentration of C.cadaveris gradually decreased to the steady value of 2.9 × 10¹⁰ copies/ml at 4 h Hydraulic retention time (HRT), which indicates a 67.1% reduction of the initial population, but the wash out occurred at HRTs of 1.9 and 3.2 h. The 16S rRNA gene copy numbers of C. sporogenes gradually decreased to steady values ranging from 1.1 × 10¹⁰ to 2.9 × 10¹⁰ copies/ml. C. sporogenes species was predicted to wash out at an HRT of 1.6 h.

Sporotrichosis is a chronic and subacute mycosis causing epidemiological outbreaks involving sick cats and humans in southeastern Brazil. The systemic disease prevails in cats and in humans, with the symptoms restricted to the skin of immunocompetent individuals. Under these conditions, the prolonged treatment of animals and cases of recurrence justify the discovery of new treatments for sporotrichosis. This work addresses the antifungal activity of silver salts of Keggin-type heteropolyacid salts (Ag-HPA salts) such as Ag₃[PW₁₂O₄₀], Ag₆[SiW₁₀V₂O₄₀], Ag₄[SiW₁₂O₄₀] and Ag₃[PMo₁₂O₄₀] and interactions with the antifungal drugs itraconazole (ITC), terbinafine (TBF) and amphotericin B (AMB) on the yeast and mycelia forms of Sporothrix spp. Sporothrix spp. yeast cells were susceptible to Ag-HPA salts at minimum inhibitory concentration (MIC) values ranging from 8 to 128 ㎍/ml. Interactions between Ag₃[PW₁₂O₄₀] and Ag₃[PMo₁₂O₄₀] with itraconazole and amphotericin B resulted in higher antifungal activity with a reduction in growth and melanization. Treated cells showed changes in cell membrane integrity, vacuolization, cytoplasm disorder, and membrane detachment. Promising antifungal activity for treating sporotrichosis was observed for the Ag-HPA salts Ag₃[PMo₁₂O₄₀] and Ag₃[PW₁₂O₄₀], which have a low cost, high yield and activity at low concentrations. However, further evaluation of in vivo tests is still required.

Human carbonic anhydrase (CA) isozyme II has been used as protein target for disorder treatment including glaucoma. Current clinically used sulfonamide-based CA inhibitors can induce side effects, and so alternatives are required. This study aimed to investigate a natural CA inhibitor from Murraya paniculata. The previously developed yeast-based assay was used to screen 14 compounds isolated from M. paniculata and identified by NMR analysis for anti-human CA isozyme II (hCAII) activity. Cytotoxicity of the compounds was also tested using the same yeast-based assay but in a different cultivation condition. Two flavonoid candidate compounds, 5, 6, 7, 8, 3', 4', 5'-heptamethoxyflavone (4) and 3, 5, 7, 8, 3', 4', 5'-heptamethoxyflavone (9), showed potent inhibitory activity against hCAII with a minimal effective concentration of 10.8 and 21.5 μM, respectively, while they both exhibited no cytotoxic effect, even at the highest concentration tested (170 μM). The results from an in vitro esterase assay of the two candidates confirmed their hCAII inhibitory activity with IC₅₀ values of 24.0 and 34.3 μM, respectively. To investigate the potential inhibition mechanism of compound 4, in silico molecular docking was performed using the FlexX and SwissDock software. This revealed that compound 4 coordinated with the Zn²⁺ ion in the hCAII active site through its methoxy oxygen at a distance of 1.60 Å (FlexX) or 2.29 Å (SwissDock). The interaction energy of compound 4 with hCAII was -13.36 kcal/mol. Thus, compound 4 is a potent novel flavonoid-based hCAII inhibitor and may be useful for further anti-CAII design and development.

This study was designed to synthesize triglycerol monolaurate (TGML) with Lipozyme 435 as the catalyst, and explore its effects on the growth of Aspergillus parasiticus (A. parasiticus) and Aspergillus flavus (A. flavus) and the secretion of aflatoxin b1. The highest content of TGML (49.76%) was obtained at a molar ratio of triglycerol to lauric acid of 1.08, a reaction temperature of 84.93℃, a reaction time of 6 h and an enzyme dosage of 1.32%. After purification by molecular distillation combined with the washes with ethyl acetate and water, the purity of TGML reached 98.3%. Through characterization by electrospray-ionization mass spectrometry, infrared spectrum and nuclear magnetic resonance, the structure of TGML was identified as a linear triglycerol combined with lauroyl at the end. Finally, the inhibitory effects of TGML on the growths of A. parasiticus and A. flavus and the secretion of aflatoxin b1 were evaluated by measuring the colony diameter, the inhibition rate of mycelial growth and the content of mycotoxin in the media. The results indicated that TGML had a stronger inhibitory effects on colony growth and mycelial development of both toxic molds compared to sodium benzoate and potassium sorbate, and the secretions of toxins from A. parasiticus and A. flavus were completely suppressed when adding TGML at 10 and 5 mM, respectively. Based on the above results, TGML may be used as a substitute for traditional antifungal agents in the food industry.

Quorum sensing (QS)-mediated infections cause severe diseases in human beings. The control of infectious diseases by inhibiting QS using antipathogenic drugs is a promising approach as antibiotics are proving inefficient in treating these diseases. Marine fungal (Pestalotiopsis sydowiana PPR) extract was found to possess effective antipathogenic characteristics. The minimum inhibitory concentration (MIC) of the fungal extract against test pathogen Pseudomonas aeruginosa PAO1 was 1,000 ㎍/ml. Sub-MIC concentrations (250 and 500 ㎍/ml) of fungal extract reduced QS-regulated virulence phenotypes such as the production of pyocyanin, chitinase, protease, elastase, and staphylolytic activity in P. aeruginosa PAO1 by 84.15%, 73.15%, 67.37%, 62.37%, and 33.65%, respectively. Moreover, it also reduced the production of exopolysaccharides (74.99%), rhamnolipids (68.01%), and alginate (54.98%), and inhibited the biofilm formation of the bacteria by 90.54%. In silico analysis revealed that the metabolite of P. sydowiana PPR binds to the bacterial QS receptor proteins (LasR and RhlR) similar to their respective natural signaling molecules. Cyclo(-Leu-Pro) (CLP) and 4-Hydroxyphenylacetamide (4-HPA) were identified as potent bioactive compounds among the metabolites of P. sydowiana PPR using in silico approaches. The MIC values of CLP and 4-HPA against P. aeruginosa PAO1 were determined as 250 and 125 ㎍/ml, respectively. All the antivirulence assays were conducted at sub-MIC concentrations of CLP (125 ㎍/ml) and 4-HPA (62.5 ㎍/ml), which resulted in marked reduction in all the investigated virulence factors. This was further supported by gene expression studies. The findings suggest that the metabolites of P. sydowiana PPR can be employed as promising QS inhibitors that target pathogenic bacteria.

Deinococcus actinosclerus BM2^T (GenBank: KT448814) is a radio-resistant bacterium that is newly isolated from the soil of a rocky hillside in Seoul. As an extremophile, D. actinosclerus BM2^T may possess anti-inflammatory properties that may be beneficial to human health. In this study, we evaluated the anti-inflammatory effects of BM2U, an aqueous extract of D. actinosclerus BM2^T, on lipopolysaccharide (LPS)-mediated inflammatory responses in RAW264.7 macrophage cells. BM2U showed antioxidant capacity, as determined by the DPPH radical scavenging (IC₅₀ = 349.3 ㎍/ml) and ORAC (IC₅₀ = 50.24 ㎍/ml) assays. At 20 ㎍/ml, BM2U induced a significant increase in heme oxygenase-1 (HO-1) expression (p < 0.05). BM2U treatment (0.2-20 ㎍/ml) significantly suppressed LPS-induced increase in the mRNA expression of proinflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 (p < 0.05). BM2U treatment also suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), which are involved in the production of inflammatory mediators. BM2U treatment also inhibited the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs): JNK, ERK, and p-38 (p < 0.05). Collectively, BM2U exhibited anti-inflammatory potential that can be exploited in attenuating inflammatory responses.

Lactobacillus plantarum KU15149 was demonstrated to have probiotic behavior and functions, including antioxidant and anti-inflammatory activity. L. plantarum KU15149 obtained from homemade diced-radish kimchi has a high survival rate under artificial gastric acid (pH 2.5, 0.3% pepsin) and bile salt (0.3% oxgall) conditions. However, L. plantarum KU15149 did not produce β-glucuronidase, which is known to be a carcinogenic enzyme with resistance to several antibiotics, such as gentamycin, kanamycin, streptomycin, tetracycline, and ciprofloxacin. L. plantarum KU15149 strongly adhered to HT-29 cells and had high antioxidant activity in terms of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging and β-carotene bleaching assays. L. plantarum KU15149 also exhibited a pronounced inhibition of nitric oxide (NO) production, along with expression of nitric oxide synthase (iNOS) and cyclooxygenase -2 (COX-2) as well as pro-inflammatory cytokines, such as TNF-α, IL-1β, and IL-6, when RAW 264.7 cells were stimulated with LPS. Therefore, L. plantarum KU15149 exhibited pharmaceutical functionality as a potential probiotic.

In the present study, we examined the effects of interleukin (IL)-10 expression-inducing bacteria Bifidobacterium adolescentis HP1, Lactobacillus mucosae HP2, and Weissella cibaria HP3 on high-fat diet (HFD)-induced obesity and liver steatosis in mice. Oral gavage of HP1, HP2, and HP3 reduced HFD-induced bodyweight gain, triglycerides, and total cholesterol levels in the blood and liver. They also suppressed HFD-induced colitis and the fecal δ,γ-Proteobacteria population. Of the tested bacteria, HP2, which most potently inhibited IL-10 expression, also suppressed HFD-induced bodyweight gain, liver steatosis, and colitis most effectively. These findings suggest that IL-10 expression-inducing gut bacteria can suppress obesity and liver steatosis.

The application of steroids has steadily increased thanks to their therapeutic effects. However, alternatives are required due their severe side effects; thus, studies on the activities of steroid derivatives are underway. Sugar derivatives of nandrolone, which is used to treat breast cancer, as well as cortisone and prednisone, which reduce inflammation, pain, and edema, are unknown. We linked O-glucose to nandrolone and testosterone using UDP-glucosyltransferase (UGT-1) and, then, tested their bioactivities in vitro. Analysis by NMR showed that the derivatives were 17β-nandrolone β-ᴅ-glucose and 17β-testosterone β-ᴅ-glucose, respectively. The viability was higher and cytotoxicity was evident in PC12 cells incubated with rotenone and, testosterone derivatives, compared to the controls. SH-SY5Y cells incubated with H₂O₂ and nandrolone derivatives remained viable and cytotoxicity was attenuated. Both derivatives enhanced neuronal protective effects and increased the amounts of cellular ATP.

Laccases are multicopper oxidases with important industrial value. In the study, a novel laccase gene (mco) in a Staphylococcus haemolyticus isolate is identified and heterologously expressed in Escherichia coli. Mco shares less than 40% of amino acid sequence identities with the other characterized laccases, exhibiting the maximal activity at pH 4.0 and 60℃ with 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) as a substrate. Additionally, the Mco is tolerant to a wide range of pH, heavy metal ions and many organic solvents, and it has a high decolorization capability toward textile dyes in the absence of redox mediators. The characteristics of the Mco make this laccase potentially useful for industrial applications such as textile finishing. Based on BLASTN results, mco is found to be widely distributed in both the bacterial genome and bacterial plasmids. Its potential role in oxidative defense ability of staphylococci may contribute to the bacterial colonization and survival.

Phenylalanine ammonia-lyase (PAL) catalyzes the reversible deamination of phenylalanine to cinnamic acid and ammonia. Algae have been considered as biofactories for PAL production, however, biochemical characterization of PAL and its potency for myristicin biotransformation into MMDA (3-methoxy-4, 5-methylenedioxyamphetamine) has not been studied yet. Thus, PAL from Anabaena flos-aquae and Spirulina platensis has been purified, comparatively characterized and its affinity to transform myristicin was assessed. The specific activity of purified PAL from S. platensis (73.9 μmol/mg/min) and A. flos-aquae (30.5 μmol/mg/min) was increased by about 2.9 and 2.4 folds by gel-filtration comparing to their corresponding crude enzymes. Under denaturing-PAGE, a single proteineous band with a molecular mass of 64 kDa appeared for A. flos-aquae and S. platensis PAL. The biochemical properties of the purified PAL from both algal isolates were determined comparatively. The optimum temperature of S. platensis and A. flos-aquae PAL for forward or reverse activity was reported at 30℃, while the optimum pH for PAL enzyme isolated from A. flos-aquae was 8.9 for forward and reverse activities, and S. platensis PAL had maximum activities at pH 8.9 and 8 for forward and reverse reactions, respectively. Luckily, the purified PALs have the affinity to hydroaminate the myristicin to MMDA successfully in one step. Furthermore, a successful method for synthesis of MMDA from myristicin in two steps was also established. Gas chromatography-mass spectrometry (GC-MS) analysis was conducted to track the product formation.