The Beneficial Role of Lactobacillus paracasei subsp. paracasei NTU 101 in the Prevention of Atopic Dermatitis.

Atopic dermatitis (AD) is a recurrent allergic disease characterized by symptoms such as itching, redness, swelling, dryness, scaling skin, inflammation, and tissue damage. The underlying pathogenesis of AD remains unclear. Steroid drugs are commonly used in the clinical treatment of AD; however, their long-term use may lead to associated complications. Numerous studies have indicated that probiotics could modulate the immune system, enhance immune function, or suppress excessive immune responses. In this study, Lactobacillus paracasei subsp. paracasei NTU 101 (NTU 101) was orally administered for a duration of 4 weeks, followed by the induction of AD using ovalbumin (OVA) in a mouse model. The skin condition of the stimulated site was observed during the induction period. Subsequently, the serum immunoglobulin E (IgE) content, splenocyte T cell typing, and skin histological interpretation were examined to evaluate the efficacy of NTU 101 in alleviating AD symptoms in allergen-exposed animals. The findings indicated that administering NTU 101 beforehand effectively alleviated skin symptoms in animals with AD. It reduced the infiltration of inflammatory cells in skin tissue sections, and compared to the OVA group, there was a significant reduction in the thickening of the epidermal cell layer (decreased from 89.0 ± 20.2 µM to 48.6 ± 16.0 µM) and dermis layer (decreased from 310.3 ± 69.0 µM to 209.7 ± 55.5 µM). Moreover, the proportion of regulatory T (Treg) cells and T helper 2 (Th2) cells in splenocytes significantly increased, while the proportions of T helper 1 (Th1) and T helper 17 (Th17) cells did not differ. It is speculated that the potential mechanism by which NTU 101 prevents AD involves increasing the expression of Forkhead box protein P3 (FOXP3) and promoting Treg cell maturation, thereby alleviating allergic reaction symptoms associated with AD.

Laser-Induced NanoKneading (LINK): Deformation of Patterned Azopolymer Nanopillar Arrays via Photo-Fluidization.

Ordered arrays of polymer nanostructures have been widely investigated because of their promising applications such as solar-cell devices, sensors, and supercapacitors. It remains a great challenge, however, to manipulate the shapes of individual nanostructures in arrays for tailoring specific properties. In this study, an effective strategy to prepare anisotropic polymer nanopillar arrays via photo-fluidization is presented. Azobenzene-containing polymers (azopolymers) are first infiltrated into the nanopores of ordered anodic aluminum oxide (AAO) templates. After the removal of the AAO templates using weak bases, azopolymer nanopillar arrays can be prepared. Upon exposure of linearly polarized lights, azobenzene groups in the azopolymers undergo trans-cis-trans photoisomerization, causing mass migration and elongation of the nanopillar along with the polarization directions. As a result, anisotropic nanopillar arrays can be fabricated, of which the deformation degrees are controlled by the illumination times. Furthermore, patterned nanopillar arrays can also be constructed with designed photomasks. This work presents a practical and versatile strategy to fabricate arrays of anisotropic nanostructures for future technical applications.

Doubly bonded E13═P and B═E15 molecules and their reactions with H2, acetonitrile, benzophenone, and 2,3-dimethylbutadiene.

The bonding properties and the potential energy surfaces for the chemical reactions of doubly bonded compounds that have the >E13═E15< pattern are studied using density functional theory (M06-2X/Def2-SVPD). Nine molecules, >E13═P< (E13 = B, Al, Ga, In, and Tl) and >B═E15< (E15 = N, P, As, Sb, and Bi), are used as model reactants in this work. Four types of chemical reactions, H2 addition, acetonitrile, benzophenone [2 + 2] cycloadditions, and dimethylbutadiene [4 + 2] cycloaddition, are used to study the chemical reactivity of these inorganic, ethylene-like molecules. The results of these theoretical analyses show that only the >B═P< molecule has a weak B═P double bond, while the >Al═P< , >Ga═P< , >In═P< , >Tl═P< , >B═N< , >B═As<, >B═Sb<, and >B═Bi< compounds are best described as having a strong single σ bond, instead of a traditional p-p π bond. The theoretical results also show that the singlet-triplet energy gap can be used to determine the relative reactivity of these doubly bonded molecules. According to these theoretical investigations, it is predicted that the order of reactivity is as follows: B═P > Al═P > Ga═P > In═P > Tl═P and B═N ≪ B═P < B═As < B═Sb < B═Bi. The conclusions drawn are consistent with the available experimental observations.

Safety and mutagenicity evaluation of Vigiis 101 powder made from Lactobacillus paracasei subsp. paracasei NTU 101.

The aim of the present work was to assess the genotoxic activity and the potential for toxicity upon repeated dosing of "Vigiis 101" powder, a probiotic consisting of dried bacteria Lactobacillus paracasei subsp. paracasei NTU 101. Results of the Ames test in Salmonella typhimurium strains TA1537, TA98, TA100, TA102, and TA1535 showed that Vigiis 101 (⩽5 mg per plate) was not mutagenic. We used experiments on ICR mice to evaluate the genotoxicity of Vigiis 101. Compared to the control, high-dose Vigiis 101 administration (16.72 g per kg of body weight) did not cause significant changes either in the number of reticulocytes or in the percentage (occurrence) of micronucleated reticulocytes. A mammalian chromosomal aberration test showed that the number of Chinese hamster ovary cells with abnormal chromosomes was <4% after Vigiis 101 treatment (maximal concentration was 5 mg/ml). A 28-day oral toxicity assay in Wistar rats was performed to assess the no-observed-adverse-effect level of Vigiis 101. Compared to the control, high-dose Vigiis 101 administration (5000 mg/kg/day) had no effects on mortality and body weight and did not cause toxicopathological lesions. Taken together, these results show that Vigiis 101 has no significant mutagenic or toxic effects.

Substitution of Asp189 residue alters the activity and thermostability of Geobacillus sp. NTU 03 lipase.

Error-prone PCR was used to create more thermoactive and/or thermostable variants of thermoalkalophilic lipases. A variant of the α6 helix (lid domain), with an 189E to V substitution at residue 189, lost its thermostability but exhibited higher activity than that of its wild-type predecessor (r03Lip). Site-saturation mutagenesis was used to explore the sequence-function relationship. Five other mutants also lost thermostability (20-40%) but exhibited enhanced thermoactivity (6.3-79-fold). The mutant E189I showed the highest activity retaining 50% activity after maintaining it at 65 °C for 24 h. In comparison to r03Lip, the mutant E189I had a higher affinity for p-nitrophenyl palmitate and p-nitrophenyl stearate (61 and 56% decreased Km) and catalytic efficiency (42-fold and 18-fold increased kcat/Km). The mutant lipase retained its tolerance to n-hexane, but had an improved transesterification activity. The results suggest that residue Glu189 plays a significant role in the thermostability and activity of this thermoalkalophilic lipase.

A "Ct contrast"-based strain-specific real-time quantitative PCR system for Lactobacilllus paracasei subsp. paracasei NTU 101.

BACKGROUND/PURPOSES: Routine cell number determination for specific Lactobacillus strain by cultivation requires at least 4-7 days. Thus rapid and specific cell number determine methods such as strain-specific quantitative PCR (qPCR) are valuable. However, qPCR method is vulnerable to difficult PCR target such as dimer/secondary structure forming sequence. METHODS: In this study, a two-component, "Ct contrast" approach was applied to strain-specific qPCR system following the development of Lactobacillus paracasei subsp. paracasei NTU 101 (NTU 101) strain-specific PCR with random amplification of polymorphic DNA (RAPD)-derived strain-specific sequences. RESULTS: The quantitative range of the NTU 101 strain-specific qPCR system was 3.0 × 101 to 3.0 × 105 copies for pure cultures, and 3.0 × 102 to 3.0 × 105 copies for multi-strain or unknown food samples. The results of spike in test and real sample testing suggested that non-specific weak background signals did not compromise test specificity, and demonstrated the potential of the NTU 101 strain-specific qPCR system in food samples. CONCLUSION: The two-component, "Ct contrast" approach is useful for qPCR discrimination when no ideal PCR target is available or the variance of the target site is unpredictable. The Ct contrast approach might provide a simple and robust solution for other challenging qPCR targets.

Proteomic insight into the effect of ethanol on citrinin biosynthesis pathway in Monascus purpureus NTU 568.

Monascus species produce several potent bioactive metabolites through polyketide secondary metabolic pathways; however, little is known of the regulation of metabolic processes in this organism. Therefore, we investigated the effect of extreme growth conditions on the production of secondary metabolites by Monascus purpureus strain NTU 568 and identified pathways that plausibly regulate the polyketide pathways by using proteomic analysis. Citrinin, a type of antibiotic, is synthesized through the polyketide pathway in M. purpureus NTU 568. We hypothesized that production of citrinin might be inhibited by ethanol. When M. purpureus NTU 568 was cultured in the medium containing 4% ethanol, the secretion of secondary metabolites was inhibited, but the dry cell weight was increased. We also found that branched chain amino acid degradation and the expression level of aldehyde dehydrogenase (ALDH) were downregulated, but proteins related to the heat shock response were induced. Furthermore, polyketide synthesis-related proteins, fatty acid synthase, epoxide hydrolase, and proteins involved in the shikimate secondary metabolic pathway were inhibited by ethanol treatment. These results suggested that reduced production of polyketide metabolites resulted not only from the expression levels of proteins in the polyketide synthesis pathway but also from reduction in the concentration of primary metabolism-generated molecules (e.g., acetyl-CoA, fatty acids) that are used as substrates for polyketide syntheses. This study provides insights into the polyketide secondary metabolism of Monascus as well as into improvement of the production of bioactive secondary metabolites in Monascus species.

Stress responses of thermophilic Geobacillus sp. NTU 03 caused by heat and heat-induced stress.

A batch culture of Geobacillus sp. NTU 03 was subjected to a rapid temperature shift for investigating the stress response. Several known heat-shock responses for protein, DNA, and cell membrane recurring were observed on two-dimensional (2D) gels. Heat caused protein and cell membrane disruption greatly affected the electron transport chain. Further, heat caused lower dissolved oxygen (DO) solubility resulting in insufficient oxygen to be electron acceptor, and the NADH could not be reoxidized. Hence, we observed seven dehydrogenase that used NADH as electron donor were downregulated on the 2D gels. In contrast, succinate dehydrogenase that used FADH(2) as electron donor was upregulated. However, this induction may simultaneously increase generation of superoxide; therefore the cellular redox state was imbalanced. We observed that superoxide dismutase (2D gel) and zinc ion ABC transporter (mRNA quantification) were upregulated, whereas ferric ion ABC transporter (2D gel and mRNA quantification) was downregulated. Increase in the reactive oxygen or nitrogen species scavenging activities were also observed. For responding the lower DO solubility, a transient activation of nitrate respiration was observed at transcriptional level. Our results support the view that both heat stress and heat-induced stress should be considered together when investigating the stress responses of thermophiles.