Strong Acid Resistance Research Articles

Study of TiO2-Modified Sol Coating Material in the Protection of Stone-Built Cultural Heritage

Coating materials can effectively protect stone-built cultural heritage and, as such, research into coating materials has gained comprehensive attention from researchers. The aim of this work is to prepare a TiO2-modified sol coating material (TSCM) and study its protective effects on stone-built cultural heritage. TSCM and pure TiO2 sol (p-sol, unmodified; for comparison) were applied evenly over the entire surface of stone samples. The prepared stone samples included untreated stone, stone treated with pure sol, and stone treated with TSCM. The protective effects of TSCM were evaluated by water absorption, water vapor permeability, acid resistance, and weather resistance experiments. The results show that stone treated with TSCM has excellent water absorption and water vapor permeability, strong acid resistance, and good weather resistance, compared with untreated stone or stone treated with p-sol. The acid resistance of stone treated by TSCM was 1.75 times higher than that treated with traditional coating materials. The weather resistance cycle number of stone treated by TSCM was four times higher than that treated with organic protective materials. These findings are expected to provide useful suggestions for the protection of stone-built cultural heritage.

A Novel State of Charge Estimating Scheme Based on an Air-Gap Fiber Interferometer Sensor for the Vanadium Redox Flow Battery

Real-time and remote monitoring of the state of charge (SOC) of a vanadium redox flow battery (VRFB) is technically desirable for achieving advanced compensation functions of VRFB systems. This paper, for the first time, proposes a novel SOC monitoring scheme based on an air-gap fiber Fabry–Perot interferometer (AGFFPI) sensor for the VRFB. The proposed sensing concept is based on real-time sensing of the refractive index (RI) of the positive electrolyte, which is found closely correlated to the VRFB’s SOC. The proposed SOC estimating scheme using fiber sensor has a number of merits, e.g., being precise, having lightweight, having strong acid resistance, and being easy to incorporate the state-of-the-art fiber communication technology for remote monitoring. It is found that the RI of the positive electrolyte solution exhibits distinct and linear variations in accordance with changes of the VRFB’s SOC value. Using the linear relationship between the electrolyte’s RI and SOC, a real-time SOC monitoring mechanism can be readily realized by the proposed AGFFPI. In this paper, existing SOC detecting methods for VRFB are firstly reviewed. The details concerning the proposed detecting method are then addressed. Typical experimental results are presented to verify the feasibility and effectiveness of the proposed SOC estimating scheme.

Lactobacillus reuteri Stimulates Intestinal Epithelial Proliferation and Induces Differentiation into Goblet Cells in Young Chickens.

Probiotics, such as Lactobacillus, have been proven to be effective in maintaining intestinal homeostasis. The modulatory effect of Lactobacillus on intestinal epithelial development in early life is still unclear. In this study, Lactobacillus isolates with good probiotic abilities were screened and orally administered to detect their regulatory effect on intestinal development in chickens. L. reuteri 22 was isolated from chickens and chosen for subsequent chicken experiments due to its strong acid and bile salt resistance and ability to adhere to epithelial cells. The 3-day-old chickens were orally administrated with 108 CFU L. reuteri 22 for consecutive 7 days. L. reuteri 22 increased Lgr5 mRNA expression (3.23 ± 0.40, P = 0.001) and activated the Wnt/β-catenin signaling pathway, with increasing expression of proliferating cell nuclear antigen (PCNA) (49.27 ± 9.81, P = 0.021) to support the proliferation of chicken intestinal epithelial cells. Moreover, L. reuteri 22 also inhibited the Notch signaling pathway to induce intestinal stem cell differentiation into goblet cells with increased mucin 2 (Muc-2) expression (1.72 ± 0.34, P = 0.047). L. reuteri 22 significantly enhanced lysozyme mRNA expression (2.32 ± 0.55, P = 0.019) to improve intestinal innate mucosal immunity. This study demonstrated that L. reuteri administration could regulate chicken intestinal epithelium development to ensure the function of the intestinal mucosal barrier, which is beneficial for newborn animals.

Effects of lactic acid stress with lactic acid adaptation on the survival and expression of virulence‐related genes in Escherichia coli O157:H7

AbstractThis study was aimed to investigate the effects of lactic acid stress with acid adaptation on the survival and expression of virulence‐related genes in Escherichia coli O157:H7 (strains CICC21530, 89, 95, 112, 109, and J42). E. coli were subjected to acid adaption (pH 5.0) for 1–4 hr and then exposed to acid stress (pH 3.5) for 30–120 min. Results showed that exposure to pH 3.5 decreased the survival of E. coli strains, in which strains 109, 112, and J42 had stronger acid resistance. The expression of virulence‐related genes of most strains decreased after exposure to pH 3.5 compared with nonstressed cells. In addition, acid adaptation increased the acid resistance of most strains, except for CICC21530 and J42. And the virulence expression of most acid‐adapted cells decreased or showed no significant changes compared with nonadapted cells. There were no obvious relationships between the survival and expression of virulence‐related genes in E. coli O157:H7 strains. However, variable acid resistance of acid‐adapted strains was existed, and some acid adaptation increased the strain survival and expression of virulence‐related genes, which may still threaten food safety.Practical ApplicationsThis study evaluated the effects of lactic acid stress with acid adaptation on the survival and expression of virulence‐related genes in Escherichia coli O157:H7. Acid adaptation could enhance the survival and virulence expression of some strains, which will threaten the safety of acidic food during processing and storage. Furthermore, variable acid resistance of acid‐adapted strains should be noticed in surveillance and control of E. coli O157:H7 in environment and food, which is beneficial for its scientific and effective risk assessment and control.

Study on Corrosion Behaviour of Basalt Fibre Reinforced Concrete under NaOH Environment

Basalt fibre (BF) is an inorganic material with high temperature resistance, low temperature resistance, strong acid and alkali corrosion resistance and good compatibility. Addition of BF into the concrete can improve the multiple properties of concrete. The purpose of this paper is to study the durability of basalt fibre reinforced concrete (BFRC) under the alkaline environment and analyse its corrosion mechanism. To this end, in this paper, 20% sodium hydroxide (NaOH) solution was used to simulate the alkaline environment, and the control group of clear water was also set by immersing and corroding the test blocks for 90 days, 180 days and 270 days respectively. Then, the crack propagation, Na+ migration, water absorption, and compressive bearing capacity of the test blocks under different corrosion time were analysed and the failure mechanism was discussed. The results show that the addition of BF can effectively inhibit the generation and propagation of concrete cracks; in alkaline environment, the BF can effectively prevent the migration of Na+, but its effect decreases with the increase of corrosion time; compared with ordinary concrete, the BF addition in alkaline environment can improve the bearing capacity of concrete to certain degree, but insufficient or excessive addition will adversely affect the durability of concrete. Through the comprehensive analysis, when the BF content is 0.1%, the porosity, durability and compression bearing capacity of concrete are improved most obviously.

Fabrication of fluorine-free superhydrophobic coatings from montmorillonite with mechanical durability and chemical stability

In this study, durable superhydrophobic coatings were successfully prepared by modifying montmorillonite with stearic acid and organosiloxane, and this procedure was simple, efficient, and environmentally friendly. Different from the previously reported methods, the micro-/nanostructures of the superhydrophobic coatings were constructed by using the abundant natural montmorillonite as the building blocks. The surface topography of the coating was analyzed with a scanning electron microscope, while element compositions and functional groups were characterized by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, respectively. The as-prepared superhydrophobic coatings showed excellent wear resistance, and could maintain their superhydrophobicity after sandpaper abrasion for 180 cm in length. Apart from the superb wear resistance, the obtained superhydrophobic coatings also displayed strong acid resistance and anti-UV properties. In addition, the as-coated fabric not only possessed superhydrophobicity and the ability of oil–water separation, but also exhibited excellent fire resistance because of the thermal stability of MMT particles. Notably, the favorable comprehensive performance of the as-prepared coatings was indicative of their potential applications in oil/water separation and some harsh conditions, and as outdoor protective materials.

Super-Stable, Highly Efficient, and Recyclable Fibrous Metal-Organic Framework Membranes for Precious Metal Recovery from Strong Acidic Solutions.

Precious metals such as palladium (Pd) and platinum (Pt) are marvelous materials in the fields of electronic and catalysis, but they are tapering day by day. Zr(IV)-based metal-organic frameworks (MOFs) are competent for their recovery, notably in harsh environments, while the general powder form limits their practical application. Porous MOF-based membranes with ultraefficient metal ion permeation, strong stability, and high selectivity are, therefore, strikingly preferred. Herein, a set of polymeric fibrous membranes incorporated with the UiO-66 series are fabricated; their adsorption/desorption capabilities toward Pd(II) and Pt(IV) are evaluated from strongly acidic solutions; and the MOF-polymer compatibilities are investigated. Polyurethane (PU)/UiO-66-NH2 showed strong acid resistance and high chemical stability, which are attributable to strong π-π interactions between PU and MOF nanoparticles with a high configuration of energy. The as-fabricated MOF membranes show extremely good adsorption/desorption performances without ruptures/coalitions of nanofibers or leak of MOF nanoparticles, and successfully display the efficacy in a gravity-driven or even continuous-flow system with good recycle performance and selectivity. The as-fabricated MOF membranes set an example of potential MOF-polymer compatibility for practical applications.

Compromise between mechanical and chemical protection mechanisms in the Mytilus edulis shell.

The shell of Mytilus edulis is a multilayered system for protecting this bivalve. In contrast to well-developed research on the nacre materials, the protective function of the complete M. edulis shell has not been widely studied. In particular, the question of why nacre is situated on the inner side of the shell rather than on the outer side remains unclear. Herein, the acid resistance of different shell layers was compared using etching tests and the mechanical protection performance of the shell was tested using three-point bending. Two bending loads, including static and dynamic, were applied on the shell samples from outside in (i.e. out-in bending) and from inside out (i.e. in-out bending), respectively. Our etching results show that the external prismatic calcite endows M. edulis with stronger acid resistance than if nacre was on the outside. In contrast, the static out-in and in-out bending tests reveal that a better mechanical protection of the shell against slow mechanical attacks is achieved if the nacre is on the outside. However, the shell has the same mechanical properties against dynamic mechanical attacks regardless of nacre location. Briefly, the nacre should be on the outside of the shell for better mechanical protection while the outside location of the prismatic layer offers a stronger resistance against etching. The inside natural location of nacre is a compromise between mechanical and chemical protection mechanisms against a complex survival environment. This strongly contributes to our understanding of biological design principles and further development of shell-inspired protective materials.

Stable Covalent Organic Frameworks as Efficient Adsorbents for High and Selective Removal of an Aryl-Organophosphorus Flame Retardant from Water.

A critical challenge in environmental remediation is the design of adsorbents with proper pore size for the removal of organic pollutants. Three covalent organic frameworks (COFs) with different pore sizes were successfully prepared by a room-temperature solution-suspension method and used to remove a typical aryl-organophosphorus flame retardant [triphenyl phosphate (TPhP)] from aqueous solution. The prepared COFs showed strong acid resistance and thermal stability. The 1,3,5-triformylphloroglucinol (TFP) reacted with benzidine (BD) (COF2) and exhibited the highest sorption capacity for TPhP, followed by the reaction of TFP and 4,4″-diamino- p-terphenyl (DT) (COF3), and the reaction of TFP and p-phenylenediamine (COF1). Their adsorption equilibriums were achieved within 12 h, and COFs with a larger pore size have higher initial sorption rate but longer time to reach sorption equilibrium. According to the Langmuir fitting, the maximum sorption capacities of three COFs for TPhP were 86.1, 387.2, and 371.2 mg/g, respectively. The density functional theory calculation verified that COF1 with a small pore size prevents TPhP molecules from entering the pores, resulting in extremely low sorption capacity, whereas a relatively too large pore size (COF3) will decrease the sorption energy, which is also not conducive to the adsorption of TPhP. Moreover, the prepared COFs can selectively adsorb TPhP in the presence of coexisting compounds and had high removal of TPhP from actual municipal wastewater, showing a promising application potential for selective removal of micropollutants from water by precisely controlling the COF structure.

Comparative virulence characterization of the Shiga toxin phage-cured Escherichia coli O104:H4 and enteroaggregative Escherichia coli

Escherichia coli O104:H4 (E. coli O104:H4), which caused in 2011 a massive foodborne outbreak in Germany, is characterized by an unusual combination of virulence traits. E. coli O104:H4 contains a prophage-encoded Shiga toxin (Stx) gene, which is the cardinal virulence factor of enterohemorrhagic E. coli (EHEC). However, the outbreak strain shares highest DNA sequence similarity with enteroaggregative E. coli (EAEC) and displays the EAEC-characteristic tight adherence to epithelial cells. The virulence potential of the underlying EAEC background has not been investigated and it is therefore not clear whether E. coli O104:H4 displays distinct virulence characteristics in comparison to prototypical EAEC. In this study, we performed a detailed comparative phenotypic characterization of the Stx phage-cured E. coli O104:H4 strain C227-11φcu, the closely related EAEC strain 55989 and two other well-characterized EAEC strains 042 and 17-2 with focus on virulence traits. C227-11φcu displayed superior aggregative adherence phenotype to cultured HCT-8 epithelial cells, adhering with 3–6 times more bacteria per epithelial cells than the tested EAEC strains. Otherwise, C227-11φcu showed similar virulence characteristics to its closest relative 55989, i.e. strong acid resistance, good biofilm formation and cytotoxic culture supernatants. Furthermore, C227-11φcu was characterized by significantly weaker motility and pro-inflammatory properties than 55989 and 042, nevertheless stronger than 17-2. Taken together, C227-11φcu displayed mostly robust, but not outstanding virulence characteristics in comparison to the tested EAEC. Therefore, it appears likely that the combination of Stx production and EAEC characteristics in general, rather than an exceptionally potent EAEC background resulted in the unusual virulence of the E. coli O104:H4. Thus, the emergence of such hypervirulent strains in the future might be more likely than previously anticipated.

Well-defined heteroatom-rich porous carbon electrocatalyst derived from biowaste for high-performance counter electrode in dye-sensitized solar cells

A low-cost and widely available natural resource of pomelo peel (PP) was used as a precursor to fabricate multiple active components synergistically driven heteroatom-doped porous carbon in counter electrode of dye-sensitized solar cells. The electrocatalyst was prepared via a ZnCl2 activation combined with a post-carbonization process under an N2 atmosphere (noted as PPA). The resulting PPA counter electrode with well-defined porosity and abundant heteroatoms possesses a very similar high power conversion efficiency of 8.29% compared with Pt counterpart (8.24%) based on the liquid I3−/I− electrolyte. Furthermore, PPA has a strong acid resistance, after PPA was treated with 2 M HCl (noted as PPE), only resulting in a slightly decreased PCE (8.13%), the little change of photovoltaic performance is mainly ascribed to the stable structure and powerful interaction between metals and support that display excellent electrocatalytic activities. The superior electrochemical performance is attributable to the synergistic effect of chemical activation and heteroatom-doping of PP-derived porous carbon coupled with well-defined pores and uniformly distributed elemental composition. Given these excellent electrocatalytic properties, structural stability, facile to large-scale preparation, the porous heteroatom doping carbon has a potential application for an alternative electrocatalyst of triiodide reduction reaction (IRR) in practical high-performance DSC devices.

Strong acid resistance from electrochemical deposition of WO3 on super‐hydrophobic CuO‐coated copper surface

In marine and industrial environments, salts and aggressive contaminants in water may cause corrosion and degradation, including acid corrosion and erosion. Super‐hydrophobic (SH) metal oxide films can keep surfaces dry by expelling water droplets. This inhibits corrosion. However, acid rain can dissolve the metal oxide films. Thus, it is necessary to protect SH films against acid erosion. In this work, a WO3 film was added on top of CuO‐coated SH copper surface using electrochemical deposition. The composite SH CuO‐WO3 film exhibited a strong acid resistance. After 48 h immersion in 0.2 N sulfuric acid, the film retained its nearly perfect micro‐nano structure with a static water contact angle of 160 ± 2°. After acid erosion, the corrosion rate in a 3.5% (w/w) NaCl solution was tested using potentiodynamic polarization curves. Its corrosion current density was found to be four orders of magnitude lower compared with CuO‐coated copper. This kind of acid resistant SH surfaces with much enhanced ability against atmospheric oxygen corrosion in the presence of salty water have potential applications in marine and other industrial environments.

Acid and Base Resistant Zirconium Polyphenolate-Metalloporphyrin Scaffolds for Efficient CO2 Photoreduction.

A series of zirconium polyphenolate-decorated-(metallo)porphyrin metal-organic frameworks (MOFs), ZrPP-n (n = 1, 2), featuring infinite ZrIV -oxo chains linked via polyphenolate groups on four peripheries of eclipse-arranged porphyrin macrocycles, are successfully constructed through a top-down process from simulation to synthesis. These are the unusual examples of Zr-MOFs (or MOFs in general) based on phenolic porphyrins, instead of commonly known carboxylate-based types. Representative ZrPP-1 not only exhibits strong acid resistance (pH = 1, HCl) but also remains intact even when immersed in saturated NaOH solution (≈20 m), an exceptionally large range of pH resistance among MOFs. The metallation at the porphyrin core gives rise to materials with enhanced sorption and catalytic properties. In particular, ZrPP-1-Co, with precise and uniform distribution of active centers, exhibits not only high CO2 trapping capability (≈90 cm3 g-1 at 1 atm, 273 K, among the highest in Zr-MOFs) but also high photocatalytic activity for reduction of CO2 into CO (≈14 mmol g-1 h-1 ) and high selectivity over CH4 (>96.4%) without any cocatalyst under visible-light irradiation (λ > 420 nm). Given the strong chemical resistance under extreme alkali conditions, these catalysts can be recycled without appreciable loss of activity. The possible mechanism for photocatalytic reduction of CO2 -to-CO over ZrPP-1-Co is also proposed.

Amino acid decarboxylase-dependent acid tolerance, selected phenotypic, and virulence gene expression responses of Salmonella enterica serovar Heidelberg

Salmonella enterica serovar Heidelberg (S. Heidelberg) is one of the pathogens most frequently detected in recent years in food products from animals; here, we examine the acid tolerance of this strain. Mild acid (pH5.5–5.0) induced a strong acid resistance in S. Heidelberg; the induced acid resistance improved within 0.5–6h and resulted in >95% cell survival following challenge in pH3.0 medium. Addition of lysine or arginine to pH2.5 acid challenge medium significantly improved the survival of S. Heidelberg; lysine induced the largest increase in survival. The lysine and arginine decarboxylase-related genes (i.e., cadA, cadB, adiA, and adiY) are acid induced genes, and they play an important role in S. Heidelberg acid resistance. RT-PCR showed that the genes expression levels increased as acid adaptation pH decreased. The increased expression was maintained for at least 4h during adaptation. Moreover, acid adaptation may have increased the production of cellulose and swimming in S. Heidelberg; pH5.5 acid-adapted cells showed a red, dry, and rough morphotype on Congo red plates. The transcriptional levels of Enterotoxin gene (stn) increased three times following acid adaptation; however, the expression of Salmonella pathogenicity island 1 virulence genes significantly decreased.

Overexpression of ESBP6 improves lactic acid resistance and production in Saccharomyces cerevisiae

Polylactic acid plastics are receiving increasing attention for the control of atmospheric CO2 emissions. Lactic acid, the building block for polylactic acid, is produced by fermentation technology from renewable carbon sources. The yeast Saccharomyces cerevisiae, harboring the lactate dehydrogenases gene (LDH), produces lactic acid at a large scale due to its strong acid resistance, to its simple nutritional requirements and to its ease of genetic engineering. Since improvement of lactic acid resistance is correlated with an increase of lactic acid production under non-neutralizing condition, we isolated a novel gene that enhances lactic acid resistance using a multi-copy yeast genomic DNA library. In this study, we identified the ESBP6 gene, which increases lactic acid resistance when overexpressed and which encodes a protein with similarity to monocarboxylate permeases. Although ESBP6 was not induced in response to lactic acid stress, it caused weak but reproducible sensitivity to lactic acid when disrupted. Furthermore, intracellular pH in the ESBP6 overexpressing strain was higher than that in the wild-type strain under lactic acid stressed condition, suggesting that Esbp6 plays some roles in lactic acid adaptation response. The ESBP6 overexpressing strain carrying the LDH gene induced 20% increase in lactic acid production compared with the wild-type strain carrying the LDH gene under non-neutralizing conditions. These results indicate that overexpression of ESBP6 provides a novel and useful tool to improve lactic acid resistance and lactic acid production in yeast.

Controllable synthesis of magnetic carbon composites with high porosity and strong acid resistance from hydrochar for efficient removal of organic pollutants: An overlooked influence

Facile fabrication of magnetic carbon composites (MCs) via pyrolysis of hydrochar in the presence of ZnCl2 and an iron salt has been attracting enormous interest to simultaneously realize high-surface area and magnetization. During this synthesis, the interactions between the carbon matrix and iron salts have remained unknown. In this work, a closer look was taken on iron salt interactions and their respective effect on MC characteristics. These newly fabricated MCs can provide guidance for further design of efficient MCs. It was discovered that ferric chloride (FeCl3) promoted the enhancement of MC porosity, largely due to the strong reduction reaction between amorphous carbon and iron oxide (γ-Fe2O3 and Fe3O4). Various other iron salts (including ferrous oxalate (FeC2O4), ferric citrate (FeC6H5O7), and ferric sulfate (Fe2(SO4)3) were also evaluated. These compounds inhibited pore structure development, resulting from decreased carbonization seen in the composite. This phenomenon was observed from complexation reactions between Zn2+ and the corresponding anions of these salts. Also, high Fe content and low γ-Fe2O3:Fe3O4 ratios led to decreased acid resistance of the MC. Finally, higher porosity in resultant MCs resulted in larger adsorption capacity for organic pollutants (roxarsone). This study will aid in further optimization of MCs to ultimately maximum performance.

Two highly stable and selective solid phase microextraction fibers coated with crown ether functionalized ionic liquids by different sol–gel reaction approaches

In this work, two novel crown ether functionalized ionic liquid (FIL)-based solid phase microextraction (SPME) fibers were prepared by sol–gel technology using the synthesized 1-(trimethoxysily)propyl 3-(6′-oxo-benzo-15-crown-5 hexyl) imidazolium bis(trifluoromethanesulphonyl)imide ([TMSP(Benzo15C5)HIM][N(SO2CF3)2]) and 1-allyl-3-(6′-oxo-benzo-15-crown-5 hexyl) imidazolium bis(trifluoromethanesulphonyl)imide ([A(Benzo15C5)HIM][N(SO2CF3)2]) as selective stationary phases. Owing to the introduction of trimethoxysilypropyl to the imidazole cation, the [TMSP(Benzo15C5)HIM][N(SO2CF3)2] could be chemically bonded to the formed sol–gel silica substrate through the hydrolysis and polycondensation reaction. Similarly, the [A(Benzo15C5)HIM][N(SO2CF3)2] was able to participate in the formation of the organic–inorganic copolymer coatings through the free radical crosslinking reaction. These two fibers were determined to have “bubble-like” surface characteristics analogous to a previously prepared [A(Benzo15C5)HIM][PF6]-based fiber. Their thermal stabilities were much higher than that of the [A(Benzo15C5)HIM][PF6]-based coating. They were capable of withstanding temperatures as high as 400°C without evident loss of the crown ether FILs. They also had strong solvent, acid and alkali resistance, good coating preparation reproducibility and high selectivity for medium polar to polar compounds. The high selectivity of these two fibers could be attributed to the strong ion-dipole, hydrogen bonding and π–π interactions provided by the synergetic effect of ILs and benzo-15-crown-5 functionalities. Moreover, the selectivity of these two fibers was rather different although the structures of these two crown ether FILs were very similar. This is maybe because the relative contents of the crown ether FILs chemically bonded to the organic–inorganic copolymer coatings were quite different when prepared by different sol–gel reaction approaches.

Purification and characterization of a novel extracellular inulinase from a new yeast species Candida kutaonensis sp. nov. KRF1T

A novel extracellular exoinulinase was purified and characterized from a new yeast strain KRF1(T), and the gene encoding the enzyme was successfully cloned. The enzyme was stable at low pH between 3.0 and 6.5. The K (m) and V (max) values of the purified enzyme for inulin were 2.3 mg/mL and 4.8 mg/min, respectively. The optimum temperature of the inulinase was 50 °C, and the enzyme remained 78 % of activity at 60 °C for 2 h. The inulinase showed an amino acid sequence identity of 58 % to its closest homolog in Meyerozyma (Pichia) guilliermondii. In the secondary structure, the domain G (VMEVH) of the enzyme contained three unique residues (V, M, and H). Compared with previously reported inulinases, the enzyme from strain KRF1(T) displayed strong acid resistance, notable thermostability, and high affinity for the substrate of inulin. Based on sequence analysis of the 26S rDNA D1/D2 domain and phenotypic characterization, the yeast strain KRF1(T) was found to represent a novel anamorphic, ascomycetous yeast species. A complete description of the species is given and the name Candida kutaonensis sp. nov (type strain = KRF1(T) = AS 2.4027(T) = CBS 11388(T)) is proposed.

Complete Genome Sequencing of Lactobacillus acidophilus 30SC, Isolated from Swine Intestine

Lactobacillus acidophilus 30SC has been isolated from swine intestines and considered a probiotic strain for dairy products because of its ability to assimilate cholesterol and produce bacteriocins. Here, we report the complete genome sequence of Lactobacillus acidophilus 30SC (2,078,001 bp) exhibiting strong acid resistance and enhanced bile tolerance.

Functional defect-patching of a zeolite membrane for the dehydration of acetic acid by pervaporation

Pervaporation (PV) using zeolite membrane is one of the emerging technologies undergoing a rapid growth in recent years, regarded as an alternative method to distillation for its energy-efficient. However, grain boundary defects, especially for hydrophilic zeolite membranes, inevitably formed due to their polycrystalline structures and strong negative surface charges of Al-containing zeolites during hydrothermal synthesis, degrade their selectivity by providing nonselective transport pathway for permeating species. We show that functional defect-patching (FDP) can improve the PV performances of thin columnar membrane of a certain zeolite (mordenite) by eliminating grain boundary defects, by grafting functional polymer groups onto grain boundaries. This methodology enables the preparation of mordenite zeolite membrane (MZM) with high PV performances for the dehydration of acetic acid (AcOH) and holds promise for realizing high-throughput and scalable production of the membrane with improved energy efficiency. Furthermore, durable tests for acid stability showed that the FDP-treated membrane displayed a reasonably strong acid resistance. Finally, the products fabricated were characterized by a variety of techniques such as scanning electron microscopy (SEM), X-ray diffraction (XRD), diffuse reflectance FT-IR spectroscopy (DRIFTS) and thermogravimetric analysis (TGA).