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Simple Summary: The yak (Bos grunniens) is endemic to the Qinghai-Tibetan Plateau, and data on their nutritional requirements are lacking. Previous reports have shown that yaks have a higher nitrogen utilization efficiency than Bos taurus, so we hypothesize that yak diets should have a lower level of dietary crude protein than beef cattle. Two diets with different dietary protein content were designed to investigate the effect of dietary protein levels on yaks in the cold season. The results showed that during the cold season, high protein level could promote rumen microbial protein synthesis, elevate arginine and proline metabolism, purine and pyrimidine metabolism, taste transduction and glutathione metabolism pathways, enhance antioxidant and immune function, and promote growth performance of yak. However, a high-protein diet enhanced the renin secretion pathway, which might increase a yak's water intake. This experiment was aimed to compare the effects of two diets with different protein content on the growth performance, immune indexes, rumen fermentation characteristics and plasma metabolomics of growing yak in the cold season. A total of 24, 2-year-old healthy yaks with similar body weight (142.9 ± 3.56 kg) were randomly allocated to two isoenergetic diets with different protein content (10 vs 14%) according to a non-paired experimental design, and the protein of the diets was increased by increasing soybean meal, rapeseed meal and cottonseed meal. The growth performance experiment lasted 56 days. Four days before the end of the growth experiment, the digestion trial was conducted, and the rumen fluid and plasma was collected for measurement. The results showed that the average daily feed intake (p < 0.001) and average daily gain (p = 0.006) of yak fed a high-protein diet was significantly greater, while the feed conversion ratio was lower (p = 0.021) than that of yaks fed a low-protein diet. Plasma aspartate aminotransferase (p = 0.002), alanine aminotransferase (p < 0.001), malondialdehyde (p = 0.001), tumor necrosis factor-α (p = 0.032) and interferon-γ (p = 0.017) of the high-protein group were significantly lesser, whereas superoxide dismutase (p = 0.004) and interleukin-2 (p = 0.007) was significantly greater than that of the low-protein group. The rumen microbial crude protein (p < 0.047) and crude protein digestibility (p = 0.015) of yak fed a high-protein diet was significantly greater than that of the low-protein group. The metabolomics results showed that yaks fed a high-protein diet were elevated in protein digestion and absorption, arginine and proline metabolism, tryptophan metabolism, purine metabolism, butanoate metabolism, taste transduction, pyrimidine metabolism, pantothenate and CoA biosynthesis, glutathione metabolism and renin secretion pathways. It is concluded that a high-protein diet in the cold season can promote rumen microbial crude protein synthesis, enhance antioxidant and immune function and promote growth performance of yaks. [ABSTRACT FROM AUTHOR]

Rabbit hair is an excellent textile fiber owing to its softness and luster. However, the poor spinnability of rabbit hair restricts its application on textiles. In this article, ionic liquid (IL) solutions were used to treat rabbit hair at five different temperatures. The raw and treated rabbit hair was then characterized by microscope, scanning electron microscope (SEM), mechanical property, XRD, and properties related to spininability (crimp and friction property, moisture regain, and electrical performance). The results showed that the rabbit hair fiber's morphology was obviously curled, and mechanical properties and crystallinity were reduced after ILs treatment. Moreover, the friction performance was increased by 15% and the crimp rate was increased by 7.2 times. These results suggest that with proper temperatures of ILs treatment, the rabbit hair could show better potential for spinning. [ABSTRACT FROM AUTHOR]

Much attention has recently been devoted to the qualitative relationship between climate factors and drought; however, the influences of climate variability, land-use/cover changes (LUCC), and other human activities on drought have rarely been quantitatively assessed. Based on the Soil and Water Assessment Tool (SWAT) model and the Palmer drought severity index (PDSI), this study presents a framework to quantify drought changes in an attribution study, and quantifies the effects of climate factors, LUCC, and other human activities on drought in a typical basin (Yihe River) in eastern China from 1980 to 2019. (1) The SWAT–PDSI results revealed a slight decreasing trend from 1980 to 2019, indicating that the degree of drought increased—especially in the middle of the basin. (2) The precipitation in the basin exhibited a downward trend (−2.7 mm/10 a), while the temperature exhibited a significant increasing trend (0.13 °C/10 a, p < 0.05). Over the past 40 years, LUCC in the Yihe River Basin was mainly characterized by a reduction in the dryland area (149 km2) and an increase in the built-up area (135 km2), which changed by −1.77% and 18.96%, respectively. (3) Climate fluctuation was the main driving factor of drought change, with a contribution rate ranging from 68 to 84%, and the contribution to drought gradually increased. Among the various factors, the contribution of temperature exceeded that of precipitation from 2010 to 2019, suggesting that temperature has become the most important climate factor affecting drought. The contribution rates of LUCC to drought changes over the periods 1990–1999, 2000–2009, and 2010–2019 were 7.8%, 18%, and 12.6%, respectively. This indicates that the relative contributions of other human activities to drought changes gradually decreased. This study refines the drought attribution framework, which could provide scientific support for the quantitative attribution of drought and the formulation of disaster prevention and reduction strategies. [ABSTRACT FROM AUTHOR]

This study aimed to improve the thermostability of arylsulfatase from Pseudoalteromonas carrageenovora . A total of 10 single-site mutants were chosen using the PoPMuSiC program, and two mutants of K253N and P314T showed enhanced thermal stability. By saturation mutagenesis and thermostability analysis, K253H and P314T were the best mutants at the two sites. Combinational mutations of K253H, P314T and H260L were subsequently introduced, and the best mutant of K253H/H260L was selected. Thermal inactivation analysis showed the half-life ( t 1/2 ) value at 55 °C for K253H/H260L was 7.7-fold that of the wild-type enzyme (WT), meanwhile this mutant maintained the specific enzyme activity. Structure modeling demonstrated that the additional hydrogen bonds, optimization of surface charge–charge interactions, and increasing of hydrophobic interaction could account for the improved thermostability imparted by K253H/H260L. [ABSTRACT FROM AUTHOR]

A library of Pseudoalteromonas carrageenovora arylsulfatase mutants was constructed by introducing random mutagenesis using error-prone PCR. After screening, one mutant strain was obtained whose arylsulfatase had improved thermal stability. Protein sequence analysis revealed one amino acid substitution of H260L. The mutant arylsulfatase (named H260L) retained higher residual activity than wild-type enzyme (named WT) after incubation at 45, 50, 55 and 60 °C for 60 min. Thermal inactivation analysis showed that the half-life ( t 1/2 ) value at 55 °C for H260L was 40.6 min, while that of WT was 9.1 min. When p -nitrophenyl sulfate was used as a substrate, the optimal reaction temperature and pH for the mutant enzyme were 55 °C and pH 8.0, respectively. H260L was stable over the pH range of 6.0–9.0. Inhibition assay with EDTA indicated that metal ions play an important role during the catalytic process of the mutant enzyme. The desulfation ratio against agar of Gracilaria lemaneiformis was 82%. [ABSTRACT FROM AUTHOR]

An extracellular agarase from marine bacterium Stenotrophomonas sp. NTa was purified to homogeneity. By size exclusion chromatography and SDS-PAGE analysis, the enzyme was determined to be a homodimer with monomeric molecular mass of 89.0 kDa. The optimal temperature and pH of strain NTa agarase were 40 °C and 10.0, respectively. It exhibited striking stability across a wide pH range of 5.0–11.0. Agarase from Stenotrophomonas sp. NTa had a relatively good resistance against the detected inhibitors, detergents and urea denaturant. The K m and V max for agar were 11.3 mg/ml and 25.4 U/mg, respectively. Thin layer chromatography analysis, mass spectrometry, and enzyme assay using p -nitrophenyl-α/β- d -galactopyranoside revealed that strain NTa agarase was a β-agarase that degraded agarose into neoagarobiose, neoagarotetraose and neoagarohexaose as the predominant products, as well as a small amount of 3,6-anhydro-α- l -galactose. This is the first to present evidence of agarolytic activity in strain from genus Stenotrophomonas . [ABSTRACT FROM AUTHOR]

A novel alginate-degrading marine bacterium Microbulbifer sp. ALW1 was isolated from rotten brown alga. An extracellular alginate lyase was purified to electrophoretic homogeneity and had a molecular mass of about 26.0 kDa determined by SDS-PAGE and size exclusion chromatography. This enzyme showed activities towards both polyguluronate and polymannuronate indicating its bifunctionality while with preference for the former substrate. Using sodium alginate as a substrate, strain ALW1 alginate lyase was optimally active at 45 °C and pH 7.0. It was stable at 25 °C, 30 °C, 35 °C and 40 °C, but not stable at 50 °C. This alginate lyase showed good stability over a broad pH range (5.0–9.0). The enzyme activity was increased to 5.1 times by adding NaCl to a final concentration of 0.5 M. Strain ALW1 alginate lyase produced disaccharide (majority) and trisaccharide from alginate indicating that this enzyme could be a good tool for preparation of alginate oligosaccharides with low degree of polymerization (DP). The alginate oligosaccharides displayed the scavenging abilities towards radicals (DPPH, ABTS + and hydroxyl) and the reducing power. Therefore, the hydrolysates exhibited the antioxidant activity and had potential as a natural antioxidant. [ABSTRACT FROM AUTHOR]

Ni-Sn alloys have been prepared by electrodeposition technique on nickel net substrates from pyrophosphoric acid solution system. The morphology, chemical compositions and catalytic properties for hydrogen evolution reaction (HER) of the Ni-Sn alloys are found to be sensitive to the electrodepositing potentials, while the crystalline phases of the electrodeposits are almost unchanged regardless of the potentials according to the X-ray diffraction (XRD) results. The Ni-Sn alloy deposited at −1.5 V exhibits the hydrogen overpotential of 161 mV when the polarization current density of 300 mA cm −2 at 25 °C, which is lower than that of 341 mV for the Raney-Ni electrode. In addition, the Ni-Sn alloy shows high durability in 30 wt% KOH solution for at least 3 months. The results imply that the deposited Ni-Sn alloys can be applied in practical as cathode in industrial water electrolyzer. [ABSTRACT FROM AUTHOR]

A gene (1,254 bp) encoding a lipase was identified from a deep-sea hydrothermal field thermophile Geobacillus sp. EPT9. The open reading frame of this gene encoded 417 amino acid residues. The gene was cloned, overexpressed in Escherichia coli, and the target protein was purified to homogeneity. The purified recombinant enzyme presented a molecular mass of 44.8 kDa. When p-nitrophenyl palmitate was used as a substrate, the recombinant lipase was optimally active at 55 °C and pH 8.5. The recombinant enzyme retained 44 % residual activity after incubation at 80 °C for 1 h, which indicated that Geobacillus sp. EPT9 lipase was thermostable. Homology modeling of strain EPT9 lipase was developed with the lipase from Bacillus sp. L2 as a template. The core structure exhibits an α/β-hydrolase fold and the typical catalytic triad might consist of Ser142, Asp346, and His387. The enzymatic activity of EPT9 lipase was inhibited by addition of phenylmethylsulfonyl fluoride, indicating that it contains serine residue, which plays an important role in the catalytic mechanism. [ABSTRACT FROM AUTHOR]

[Display omitted] • Super-hydrophilic PNF with hierarchically porous structure was fabricated. • Fe-Ni 3 S 2 /PNF was fabricated via mild and scalable electro-deposition strategies. • Fe-Ni 3 S 2 /PNF shows 10 mA cm−2 at 1.50 V cell voltage for overall water splitting. • Fe-Ni 3 S 2 /PNF shows excellent activity and durability under industrial conditions. Alkaline water electrolysis (AWE) offers a promising route for green hydrogen production. However, its industrial application is impeded by unsatisfactory energy conversion efficiency. Herein, a robust electrode composed of porous nickel foam (PNF) and Fe-doped Ni 3 S 2 (Fe-Ni 3 S 2) nanosheet arrays was fabricated and applied for industrial AWE. By conducting a scalable dynamic bubble-template method, PNF with high loading of active catalysts was prepared. The superhydrophilicity of PNF facilitates bubble detachment and promotes mass transfer, especially at high current densities. In addition, Fe-Ni 3 S 2 with optimized electronic structure is featured with enhanced electrical conductivity, sufficient exposure of active sites, and optimized adsorption of intermediates. Benefiting from the concerted advantages of PNF and Fe-Ni 3 S 2 , the obtained Fe-Ni 3 S 2 /PNF-5 electrode with an optimal Fe content of 5 mol% exhibits high catalytic activity for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Compared with the Pt/C/NF||IrO 2 /NF couple, the Fe-Ni 3 S 2 /PNF-5||Fe-Ni 3 S 2 /PNF-5 couple delivers a current density of 10 mA cm−2 at a low cell voltage of 1.50 V for AWE. Under industrial conditions, a competitive cell voltage of 1.75 V is needed for achieving a high current density of 400 mA cm−2. Besides, the couple can operate stably for 120 h, outperforming the commercial RN||RN couple. This work provides a novel strategy to elevate the loading amount of catalysts and improve the electrochemical performance of the electrode for practical AWE application. [ABSTRACT FROM AUTHOR]

A new gene encoding a superoxide dismutase (SOD) was identified from a thermophile Geobacillus sp. EPT3 isolated from a deep-sea hydrothermal field in east Pacific. The open reading frame of this gene encoded 437 amino acid residues. It was cloned, overexpressed in Escherichia coli (DE3), and the recombinant protein was purified to homogeneity. Geobacillus sp. EPT3 SOD was of the manganese-containing SOD type, as judged by the insensitivity of the recombinant enzyme to both KCN and HO, and the activity analysis of Fe or Mn reconstituted SODs by polyacrylamide gel electrophoresis. The recombinant SOD was determined to be a homodimer with monomeric molecular mass of 59.0 kDa. In comparison with other Mn-SODs, the manganese-binding sites are conserved in the sequence (His260, His308, Asp392, His396). The recombinant enzyme had high thermostability at 50 °C. It retained 57 % residual activity after incubation at 90 °C for 1 h, which indicated that this SOD was thermostable. The enzyme also showed striking stability over a wide range of pH 5.0-11.0. At tested conditions, the recombinant SOD from Geobacillus sp. EPT3 showed a relatively good tolerance to some inhibitors, detergents, and denaturants, such as β-mercaptoethanol, dithiothreitol, phenylmethylsulfonyl fluoride, Chaps, Triton X-100, urea, and guanidine hydrochloride. [ABSTRACT FROM AUTHOR]

Abstract: A new gene encoding an esterase (designated as EstEP16) was identified from a metagenomic library prepared from a sediment sample collected from a deep-sea hydrothermal field in east Pacific. The open reading frame of this gene encoded 249 amino acid residues. It was cloned, overexpressed in Escherichia coli, and the recombinant protein was purified to homogeneity. The monomeric EstEP16 presented a molecular mass of 51.7kDa. Enzyme assays using p-nitrophenyl esters with different acyl chain lengths as the substrates confirmed its esterase activity, yielding highest specific activity with p-nitrophenyl acetate. When p-nitrophenyl butyrate was used as a substrate, recombinant EstEP16 exhibited highest activity at pH 8.0 and 60°C. The recombinant enzyme retained about 80% residual activity after incubation at 90°C for 6h, which indicated that EstEP16 was thermostable. Homology modeling of EstEP16 was developed with the monoacylglycerol lipase from Bacillus sp. H-257 as a template. The structure showed an α/β-hydrolase fold and indicated the presence of a typical catalytic triad. The activity of EstEP16 was inhibited by addition of phenylmethylsulfonyl fluoride, indicating that it contains serine residue, which plays a key role in the catalytic mechanism. [Copyright &y& Elsevier]

CD4 and CD8 coreceptor double negative TCRαβ+ T (DNT) cells are increasingly being recognized for their critical and diverse roles in the immune system. However, their molecular and functional signatures remain poorly understood and controversial. Moreover, the majority of studies are descriptive because of the relative low frequency of cells and non-standardized definition of this lineage. In this study, we performed single-cell RNA sequencing on 28,835 single immune cells isolated from mixed splenocytes of male C57BL/6 mice using strict fluorescence-activated cell sorting. The data was replicated in a subsequent study. Our analysis revealed five transcriptionally distinct naïve DNT cell clusters, which expressed unique sets of genes and primarily performed T helper, cytotoxic and innate immune functions. Anti-CD3/CD28 activation enhanced their T helper and cytotoxic functions. Moreover, in comparison with CD4+, CD8+ T cells and NK cells, Ikzf2 was highly expressed by both naïve and activated cytotoxic DNT cells. In conclusion, we provide a map of the heterogeneity in naïve and active DNT cells, addresses the controversy about DNT cells, and provides potential transcription signatures of DNT cells. The landscape approach herein will eventually become more feasible through newer high throughput methods and will enable clustering data to be fed into a systems analysis approach. Thus the approach should become the "backdrop" of similar studies in the myriad murine models of autoimmunity, potentially highlighting the importance of DNT cells and other minor lineage of cells in immune homeostasis. The clear characterization of functional DNT subsets into helper DNT, cytotoxic DNT and innate DNT will help to better understand the intrinsic roles of different functional DNT subsets in the development and progression of autoimmune diseases and transplant rejection, and thereby may facilitate diagnosis and therapy. • We delineated the heterogeneity of naïve and activated DNT cells in mice. • nDNT subgroups primarily performed T helper, cytotoxic and innate immune functions. • Anti-CD3/CD28 activation enhanced DNT cell T helper and cytotoxic functions. • Ikzf2 is an important transcriptional factor for cytotoxic DNT cells. [ABSTRACT FROM AUTHOR]

Abstract: Homologous regions (hrs) of white spot syndrome virus (WSSV) might serve as origins of DNA replication or be involved in transcriptional regulation. To characterize the interaction between hrs of WSSV and the viral proteins, in this investigation, phage display technology was used. WSSV genomic DNA was sheared by sonication to generate fragments in lengths between 0.5 and 2.0kb. Then these fragments were blunt-ended with T4 DNA polymerase and cloned into the EcoRV site of rebuilt vector pCANTAB 5 EE to obtain WSSV genome phage display library. Using a 210bp DNA from the b minifragment of WSSV hr2 as the bait, biopanning of WSSV genome phage display library for five rounds resulted in the isolation of a recombinant phage clone containing an exogenous DNA fragment of 306bp. This DNA fragment was identified to be the 5′ terminus of the wsv021 open reading frame in WSSV genome. Temporal transcription analysis revealed that the wsv021 gene was transcribed at the early stage of WSSV infection. The gene was expressed as a fusion protein in Escherichia coli XL1-Blue. The electrophoretic mobility shift assay indicated that the recombinant WSV021 protein (rWSV021) could bind specifically to the 210bp DNA from the b minifragment of WSSV hr2. The wsv021 gene might be a functional gene involved in WSSV replication and transcriptional regulation. [Copyright &y& Elsevier]

Abstract: A novel protein from white spot syndrome virus (WSSV) was identified to match an open reading frame (wsv209) of WSSV genome by combining SDS-PAGE with mass spectrometry. This ORF contained 4818bp, encoding 1606 aa. The apparent molecular mass of the protein from WSSV virions on SDS-PAGE gel is 187kDa, so it was named VP187 and its gene was termed vp187. Temporal transcription analysis revealed that vp187 was a late gene. To characterize VP187, a segment of the vp187 gene (vp187p) was cloned into pET-GST vector and expressed as a fusion protein with glutathione S-transferase (GST) in Escherichia coli strain BL21 (DE3). Specific antibody was raised using the purified fusion protein (GST-VP187P). Western blot analysis showed that the mouse anti-GST-VP187P serum reacted specifically with VP187 present either in the WSSV virions or in the viral envelopes, and did not react with fractions of the viral nucleocapsids. VP187 was proved to locate in the WSSV virions as an envelope protein using immunoelectron microscopy. [Copyright &y& Elsevier]

Abstract: White spot syndrome virus (WSSV) is one of the most virulent pathogens in shrimp culture worldwide. Combining SDS-PAGE with mass spectrometry, a novel envelope protein from WSSV was identified to match an open reading frame (ORF) of WSSV genome. This ORF contained 3582nt, encoding 1194 aa, and was termed the vp124 gene. One part of the whole gene (named vp124p) was cloned into pET-GST vector and expressed as a fusion protein with glutathione S-transferase (GST) in Escherichia coli strain BL21 (DE3). Specific antibodies were raised using the purified fusion protein (GST-VP124P). Temporal transcription analysis revealed that the vp124 gene was a late gene. Western blot analysis showed that the mouse anti-GST-VP124P antibodies reacted specifically with VP124 present either in the WSSV virions or in the viral envelopes, and did not react with the proteins of the viral nucleocapsids. VP124 was located in the WSSV virions as an envelope protein using immunoelectron microscopy. [Copyright &y& Elsevier]

AbstractAstaxanthin, a ketone carotenoid known for its high antioxidant activity, holds significant potential for application in nutraceuticals, aquaculture, and cosmetics. The increasing market demand necessitates a higher production of astaxanthin using Phaffia rhodozyma. Despite extensive research efforts focused on optimizing fermentation conditions, employing mutagenesis treatments, and utilizing genetic engineering technologies to enhance astaxanthin yield in P. rhodozyma, progress in this area remains limited. This review provides a comprehensive summary of the current understanding of rough metabolic pathways, regulatory mechanisms, and preliminary strategies for enhancing astaxanthin yield. However, further investigation is required to fully comprehend the intricate and essential metabolic regulation mechanism underlying astaxanthin synthesis. Specifically, the specific functions of key genes, such as crtYB, crtS, and crtI, need to be explored in detail. Additionally, a thorough understanding of the action mechanism of bifunctional enzymes and alternative splicing products is imperative. Lastly, the regulation of metabolic flux must be thoroughly investigated to reveal the complete pathway of astaxanthin synthesis. To obtain an in-depth mechanism and improve the yield of astaxanthin, this review proposes some frontier methods, including: omics, genome editing, protein structure-activity analysis, and synthetic biology. Moreover, it further elucidates the feasibility of new strategies using these advanced methods in various effectively combined ways to resolve these problems mentioned above. This review provides theory and method for studying the metabolic pathway of astaxanthin in P. rhodozyma and the industrial improvement of astaxanthin, and provides new insights into the flexible combined use of multiple modern advanced biotechnologies. [ABSTRACT FROM AUTHOR]

The work function is the key surface property that determines the energy required to extract an electron from the surface of a material. This property is crucial for thermionic energy conversion, band alignment in heterostructures, and electron emission devices. This work presents a high‐throughput workflow using density functional theory (DFT) to calculate the work function and cleavage energy of 33,631 slabs (58,332 work functions) that are created from 3,716 bulk materials. The number of calculated surface properties surpasses the previously largest database by a factor of ≈27. Several surfaces with an ultra‐low (<2 eV) and ultra‐high (>7 eV) work function are identified. Specifically, the (100)‐Ba‐O surface of BaMoO3 and the (001)‐F surface of Ag2F have record‐low (1.25 eV) and record‐high (9.06 eV) steady‐state work functions. Based on this database a physics‐based approach to featurize surfaces is utilized to predict the work function. The random forest model achieves a test mean absolute error (MAE) of 0.09 eV, comparable to the accuracy of DFT. This surrogate model enables rapid predictions of the work function (≈ 105 faster than DFT) across a vast chemical space and facilitates the discovery of material surfaces with extreme work functions for energy conversion and electronic device applications. [ABSTRACT FROM AUTHOR]

• Mutant arylsulfatase K253Q was obtained by error-prone PCR based directed evolution. • K253Q increased the desulfation activity against the sulfate groups in agar. • K253Q has a great potential for application in improvement of the agar quality. Enzymatic desulfation using arylsulfatase provides an attractive approach to improve agar quality. We have previously characterized a functional arylsulfatase from Pseudoalteromonas carrageenovora. To further improve its enzymatic performance, we isolated a mutant arylsulfatase of K253Q with improved enzyme activity from a random mutant library. Compared to wild-type arylsulfatase (WT), K253Q showed 33% increase in enzyme activity, with optimal temperature and pH of 55 °C and 8.0, respectively. K253Q demonstrated better substrate binding ability with lower K m value. Structure analysis indicated that a combination of the additional hydrogen bond and the enhanced substrate binding affinity could account for the improved enzyme activity of K253Q. K253Q exhibited about 54% sulfate removal against agar, resulting in additional 8% increase in 3,6-AG content and 20% increase in gel strength compared to WT. Scanning electron microscopy showed that K253Q treatment led to a stronger crosslinking structure of agar. [ABSTRACT FROM AUTHOR]

The industrial applications of the κ-carrageenases have been restricted by their poor thermostability. In this study, based on the folding free energy change (ΔΔG) and the flexibility analysis using molecular dynamics (MD) simulation for the alkaline κ-carrageenase KCgCD from Pseudoalteromonas porphyrae (WT), the mutant S190R was identified with improved thermostability. After incubation at 50 °C for 30 min, the residual activity of S190R was 63.7%, 25.7% higher than that of WT. The Tm values determined by differential scanning calorimetry were 66.2 °C and 64.4 °C for S190R and WT, respectively. The optimal temperature of S190R was 10 °C higher than that of WT. The κ-carrageenan hydrolysates produced by S190R showed higher xanthine oxidase inhibitory activity compared with the untreated κ-carrageenan. MD simulation analysis of S190R showed that the residues (V186–M194 and P196–G197) in F5 and the key residue R150 in F3 displayed the decreased flexibility, and residues of T169–N173 near the catalytic center displayed the increased flexibility. These changed flexibilities might be the reasons for the improved thermostability of mutant S190R. This study provides a useful rational design strategy of combination of ΔΔG calculation and MD simulation to improve the κ-carrageenase's thermostability for its better industrial applications. Key points: Mutant κ-carrageenase S190R is identified by rational design based on ΔΔG and MD simulation. Mutant κ-carrageenase S190R increases the thermostability. Mutant enzyme-treated κ-carrageenan exhibits high xanthine oxidase inhibitory activity. [ABSTRACT FROM AUTHOR]

Fungal infection has become a major threat to crop loss and affects food safety. The waste water from agar processing industries extraction has a number of active substances, which could be further transformed by microorganisms to synthesize antifungal active substances. In this study, Bacillus subtilis was used to ferment the waste water from agar processing industries extraction to analyze the antifungal activity of the fermentation broth on Alternaria alternata and Alternaria spp. Results showed that 25% of the fermentation broth was the most effective in inhibited A. alternata and Alternaria spp., with fungal inhibition rates of 99.9% and 96.1%, respectively, and a minimum inhibitory concentration (MIC) was 0.156 μg/mL. Metabolomic analysis showed that flavonoid polyphenols such as coniferyl aldehyde, glycycoumarin, glycitin, and procyanidin A1 may enhance the inhibitory activity against the two pathogenic fungal strains. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that polyphenols involved in the biosynthesis pathways of isoflavonoid and phenylpropanoid were upregulated after fermentation. The laser confocal microscopy analyses and cell conductivity showed that the cytoplasm of fungi treated with fermentation broth was destroyed. This study provides a research basis for the development of new natural antifungal agents and rational use of seaweed agar waste. Key points: • Bacillus subtilis fermented waste water has antifungal activity • Bacillus subtilis could transform active substances in waste water • Waste water is a potential raw material for producing antifungal agents [ABSTRACT FROM AUTHOR]

Fungal infection has become a major threat to crop loss and affects food safety. The waste water from agar processing industries extraction has a number of active substances, which could be further transformed by microorganisms to synthesize antifungal active substances. In this study, Bacillus subtilis was used to ferment the waste water from agar processing industries extraction to analyze the antifungal activity of the fermentation broth on Alternaria alternata and Alternaria spp. Results showed that 25% of the fermentation broth was the most effective in inhibited A. alternata and Alternaria spp., with fungal inhibition rates of 99.9% and 96.1%, respectively, and a minimum inhibitory concentration (MIC) was 0.156 μg/mL. Metabolomic analysis showed that flavonoid polyphenols such as coniferyl aldehyde, glycycoumarin, glycitin, and procyanidin A1 may enhance the inhibitory activity against the two pathogenic fungal strains. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that polyphenols involved in the biosynthesis pathways of isoflavonoid and phenylpropanoid were upregulated after fermentation. The laser confocal microscopy analyses and cell conductivity showed that the cytoplasm of fungi treated with fermentation broth was destroyed. This study provides a research basis for the development of new natural antifungal agents and rational use of seaweed agar waste. Key points: • Bacillus subtilis fermented waste water has antifungal activity • Bacillus subtilis could transform active substances in waste water • Waste water is a potential raw material for producing antifungal agents [ABSTRACT FROM AUTHOR]

Anaerobic fermentation of carrageenan residues for the production of antifungal active compounds and their use to inhibit the growth of phytopathogenic bacteria is a novel approach to the utilization of carrageenan residues. In the present study, the treatment of carrageenan residue by anaerobic biofermentation technique showed strong growth inhibitory activity against Fusarium graminearum and Magnaporthe oryzae , which are the typical phytopathogens that reduce the crop yield, with MIC values of 0.0016% (v/v) and 0.00032% (v/v), respectively. The total concentration of polyphenols and flavonoids increased significantly to 20.41 μg/mL and 29.97 μg/mL after anaerobic fermentation. Amino acid metabolic pathway analysis showed that the substances and energy used by colonies to produce antifungal drugs are derived from amino acid metabolism, especially alanine and γ-aminobutyric acid (GABA). The results of redundancy analysis (RDA) indicated that anaerobic fermentation of carrageenan gum residues increased the abundance of specific bacterial groups included Bacillus, Komona, Caproiciproducens, Lactobacillus, Bovibacillus, and SN8, and that the increase in the number of these species favored the production of polyphenols and flavonoids with antifungal activity. This study provides a viable avenue for resource utilization of carrageenan residues. [Display omitted] • Anaerobic fermentation of carrageenan residues has antifungal activity. • Fermentation significantly increased total polyphenols and flavonoid contents. • Anaerobic fermentation of carrageenan residues increased the abundance of bacteria. • Increase of the species favored polyphenols and flavonoids with antifungal activity. • Carrageenan residues are potential materials for producing antifungal ingredients. [ABSTRACT FROM AUTHOR]

The industrial applications of the κ-carrageenases have been restricted by their poor thermostability. In this study, based on the structural information of alkaline κ-carrageenase from Pseudoalteromonas tetraodonis (WT) and with the aid of Disulfide by Design2 computational tool, two disulfide bond mutants of K44C-A119C and T120C-Q250C were identified with improved thermostability and enzymatic activity. K44C-A119C and T120C-Q250C increased the enzyme activity by 19.0% and 7.3%, respectively. After treatment at 50 °C for 30 min, the residual activities of K44C-A119C, T120C-Q250C, and WT were 80.1%, 78.6%, and 45.4%, respectively. The T m values of K44C-A119C, T120C-Q250C, and WT determined by differential scanning calorimetry were 56.0 °C, 54.8 °C, and 51.2 °C, respectively. The increasement of disulfide bond and its adjacent non-covalent interactions would account for the increased thermostability of the mutants. Molecular dynamics simulation analysis revealed that the improved thermostability and catalytic activities of K44C-A119C and T120C-Q250C could be attributed to the increased flexibility of finger F6 and the less structural deviation in some loops and β-sheets. In addition, the κ-carrageenan hydrolysates by K44C-A119C exhibited higher tyrosinase inhibitory activity than the untreated κ-carrageenan. These findings provide a useful strategy to improve κ-carrageenases' thermostability and enzyme activity for their better industrial applications. [Display omitted] • Mutant κ-carrageenases K44C-A119C and T120C-Q250C are identified by rational design of disulfide bonds. • K44C-A119C and T120C-Q250C increase the thermostability and enzymatic activity simultaneously. • Mutant enzyme-treated κ-carrageenan exhibits high tyrosinase inhibitory activity. [ABSTRACT FROM AUTHOR]

To assess the availability and affordability of oral anti-diabetic medicines in Shaanxi Province, Western China. In 2015, the prices and availability of 8 anti-diabetic medicines covering 31 different dosage forms and strengths were collected in six cities of Shaanxi Province. A total of 72 public hospitals and 72 private pharmacies were sampled, using a modified methodology developed by the World Health Organization (WHO) and Health Action International (HAI). Medicine prices were compared with international reference prices to obtain a median price ratio. For urban residents, affordability was assessed as the lowest-paid unskilled government workers to purchase cost of standard treatment in days' wages; for rural residents, days' net income was used. The mean availabilities of originator brands (OBs) and generics were 34.3% and 28.7% in public hospitals, and 44.1% and 64.4% in the private pharmacies. OBs and the lowest priced generics (LPGs) were procured at 12.38 and 4.52 times the international reference price in public hospitals, and 10.26 and 2.81 times the international reference prices in private pharmacies. Treatments with OBs were unaffordable even for urban residents. The affordability of the LPGs was good, except for acarbose, repaglinide and pioglitazone. Most anti-diabetic medicines cannot met the WHO's availability target (80% availability) in Shaanxi Province. The high prices of OBs had severely influenced the affordability of medicines, especially for the rural residents. Effective policies should be initiated to ensure the Chinese people a better access to more affordable anti-diabetic medicines. [ABSTRACT FROM AUTHOR]

The purpose of the study is to explore the underlying mechanisms of xenon (Xe) which protects against spinal cord ischemia/reperfusion injury (SCIRI). A SCIRI rat model was induced by abdominal artery occlusion for 85 min and reperfusion. Xe postconditioning (50% Xe) was administered 1 h after 1 h of reperfusion. At reperfusion time points (2, 4, 6, and 24 h), rats were treated with spinal cord scans by MRI to assess the time of peak spinal cord injury after SCIRI. Subsequently, endoplasmic reticulum (ER) stress inhibitor sodium 4-phenylbutyrate (4-PBA) was administered by daily intraperitoneal injection (50 mg/kg) for 5 days before SCIRI. At 4 h after reperfusion, motor function, immunofluorescence staining, hematoxylin and eosin (HE) staining, Nissl staining, TUNEL staining, real-time reverse transcription polymerase chain (RT-PCR) reaction, and western blot analyses were performed to investigate the protective effects of Xe against SCIRI. In the rat I/R model, spinal cord edema peaked at reperfusion 4 h. SCIRI activated ER stress, which was located in neurons. Xe postconditioning remarkably alleviated hind limb motor function, reduced neuronal apoptosis rate, increased the number of normal neurons, and inhibited the expression of ER stress–related protein in spinal cord. Furthermore, the administration of the ER stress inhibitor 4-PBA strongly decreased ER stress–induced apoptosis following SCIRI. Xe postconditioning inhibits ER stress activation, which contributes to alleviate SCIRI by suppressing neuronal apoptosis. [ABSTRACT FROM AUTHOR]

Overactive microglia and severe neuroinflammation play crucial roles in the development of major depressive disorder. Preconditioning with lipopolysaccharide (LPS) provides protection against severe neuroinflammation. However, administering high doses of LPS to mice triggers depressive symptoms. Therefore, the optimal dose of LPS preconditioning needs to be determined by further experiments. LPS preconditioning is an effective agent in anti-inflammation and neuroprotection, but the mechanism by which LPS preconditioning acts in depression remain unclear. This study finds that the anti-inflammation mechanism of low-dose LPS preconditioning is mainly dependent on G-protein-coupled receptor 84 (GPR84). We use low-dose LPS for preconditioning and re-challenged mice or BV2 microglia with high-dose LPS. In addition, RNA-seq is used to explore underlying changes with LPS preconditioning. Low-dose LPS preconditioning reduces the expression of pro-inflammatory mediators and inhibits microglial activation, as well as suppresses the depressive-like behavior when the mice are re-challenged with high-dose LPS. Further investigation reveals that the tolerance-like response in microglia is dependent on the GPR84. Here, we show that low-dose LPS preconditioning can exert anti-inflammation effects and alleviates inflammation-induced depressive-like behavior in mice. As a potential therapeutic target for depression, LPS preconditioning needs to be given further attention regarding its effectiveness and safety. [ABSTRACT FROM AUTHOR]

Abstract: Sensory evaluation, GC–MS and omission test were used to characterize aromas of noninstant Oolong tea (NIOT), original instant Oolong tea (OIOT) and its counterparts treated by two enzyme extracts from Aspergillus niger. The results showed that OIOT had stronger sweet, fruity, and roasted notes, but weaker grass and floral notes than NIOT. After treated by the crude enzymes extracted from the fermented broth from tea waste (TW) medium, the treated‐OIOT had an improved aroma similar to that of NIOT, due to the increases of 2‐pentyl‐furan and 3‐cis‐hexen‐1‐ol. In comparison, after the treatment of crude enzymes from wheat bran and orange peel (WBOP) medium, the treated‐OIOT showed significantly aroma difference from NIOT and OIOT, which was attributed to the increases of 3‐cis‐hexen‐1‐ol, γ‐terpinene, and β‐trans‐farnesene. These results revealed that the original aroma of OIOT could be effectively modified and improved by the enzyme extracts, particularly by that from the TW medium. Practical applications: Tea is one of the most popular beverages all over the world. Instant tea is an important tea product that is processed from teas by extraction, concentration and drying. Instant tea is more convenient than teas for industrially producing tea foods such as tea beverage, tea break, and tea ice cream. However, the aroma profile of instant tea is always inferior to those of the original unprocessed noninstant teas, because the characteristic aroma of the original unprocessed tea could undergo significant changes during the preparation of instant tea. The present manuscript shows two enzyme extracts from Aspergillus niger could improve the aroma of instant Oolong tea, providing interesting information to promote the aroma of instant tea via enzymatic treatments, which may help to develop effective approaches to enhancing the quality of instant teas. [ABSTRACT FROM AUTHOR]

Introduction: The debate on efficacy of fusion added to decompression for lumbar spinal stenosis (LSS) is ongoing. No meta-analysis has compared the effectiveness of decompression versus decompression plus fusion in treating patients with LSS.Methods: A literature search was performed in the Web of Science, PubMed, Embase, and Springer databases from 1970 to 2016. Relevant references were selected and the included studies were manually reviewed. We included trials evaluating decompression surgery compared to decompression plus fusion surgery in treating patients with LSS. The primary outcomes analyzed were back pain, leg pain, Oswestry Disability Index scores (ODI), the quality-of-life EuroQol-5 Dimensions (EQ-5D), duration of operation, intraoperative blood loss, length of hospital stay, major complications, walking ability, number of reoperation, and finally clinically excellent and good rates. Data analysis was conducted using the Review Manager 5.2 software.Results: Fifteen studies involving 17,785 patients with LSS were included. The overall effect mean difference (MD) (95% CI) in the differences between pre- and post-operative back pain, leg pain, operative time, intraoperative blood loss, and length of stay were 0.04 (-0.36, 0.44), 0.69 (-0.38, 1.76), -2.04 (-3.12, -0.96), -3.96 (-6.64, -1.27) and -4.21 (-10.03, 1.62) (z = 0.18, 1.26, 3.71, 2.89 and 1.41, respectively; P = 0.86, 0.55, 0.0002, 0.004 and 0.16, respectively) in random effects models. The overall effect MD (95% CI) in ODI, EQ-5D, and walking ability were 0.43 (-1.15, 2.00), 0.01 (-0.01, 0.03) and 0.04 (-0.49, 0.57) (z = 0.52, 1.16 and 0.15, respectively; P = 0.59, 0.24 and 0.88, respectively) in fixed effects models. The overall effect odds ratio (OR) (95% CI) of major complications, number of reoperations, and clinically excellent and good rates between the two groups were 0.70 (0.60, 0.81), 1.04 (0.90, 1.19) and 0.31 (0.06, 1.59) (z = 4.63, 0.53 and 1.40, respectively; P < 0.00001, 0.60 and 0.16, respectively). Our study reveals no difference in the effectiveness between the two surgical techniques.Conclusions: The additional fusion in the management of LSS yielded no clinical improvements over decompression alone within a 2-year follow-up period. But fusion resulted in a longer duration of operation, more blood loss, and a higher risk of complications. Therefore, the appropriate surgical protocol for LSS should be discussed further. [ABSTRACT FROM AUTHOR]

Ultrasound pretreatment is a potent step to disintegrate primary sludge (PS). The supernatant of sonicated PS is recycled as an alternative carbon source for biological phosphorus removal. In this study, we investigated the role of temperature on PS disintegration during sonication. We found that a temperature of 60 °C yielded a dissolution rate of about 2% soluble chemical oxygen demand (SCOD) as compared to 7% SCOD using sonication at the specific energy (SE) of 7359 kJ/kg TS. Using the SE of 6000 kJ/kg TS with heat insulation during sonication, the SCOD dissolution rate of PS was similar to the result at the SE of 7051 kJ/kg TS without heat insulation. Upon treatment with sonication, the PS released low concentrations of Cu and Zn into the supernatant. The phosphorus-accumulating organisms (PAOs) used the supernatant of sonicated PS as the carbon source. Supplementation with the diluted sonicated PS supernatant (SCOD ≈ 1000 mg/L) in anaerobic phase resulted in the release of phosphorus (36 mg/L) and the production of polyhydroxyalkanoates (PHAs) (0.36 g PHA/g SS). Compared with sodium acetate, higher polyhydroxyvalerate (PHV) faction in the polyhydroxyalkanoates (PHAs) was observed in the biomass when incubated with sonicated PS as the carbon source. This work provides a simple pathway to conserve energy and to enhance efficiencies of ultrasonic pretreatment and the recovery of carbon source from the sludge for improving the phosphorus removal in the ENR system. [ABSTRACT FROM AUTHOR]

Polysaccharide extracted from red seaweed Bangia fusco-purpurea (BFP) is a novel sulfated galactan, differed from agarans and carrageenans in fine structure. In this study, in vitro fermentation characteristics of BFP by human gut microbiota and its protective effect on lipopolysaccharide (LPS)-induced injury in Caco-2 cells were investigated. Our results showed that BFP was mainly degraded at transverse colon for 18 h fermentation by gut microbiota with reduced molecular weight. Meanwhile, BFP fermentation was associated with increased short-chain fatty acids (SCFAs) as compared to control group, especially acetic acid was increased to 129.53 ± 0.24 from 82.14 ± 0.23 mmol/L, and butyric acid was up to 1.56 ± 0.004 from 0.62 ± 0.01 mmol/L. Furthermore, BFP promoted abundances of Bacteroidetes and Firmicutes , while decreased numbers of Proteobacteria. The up-regrated beneficial differential metabolites were SCFAs, L-proline, arginine, folic acid, pyridoxamine, thiamine, etc. (p < 0.05), and their related metabolic pathways mainly included mTOR, arginine biosynthesis, and vitamin metabolism. Notably, BFP fermentation products at transverse colon significantly restored cell viability of LPS-treated Caco-2 cells from 73.79 ± 0.48 % to 93.79–99.64 %, which might be caused by increased beneficial differential metabolites (e.g. , SCFAs). Our findings suggest that BFP has prebiotic potential and can enhance gut health. • In vitro gut fermentation of Bangia fusco-purpurea polysaccharide (BFP) was explored. • BFP was mainly degraded at transverse colon by gut microbiota. • BFP significantly altered the composition and diversity of gut microbiota. • BFP significantly enhanced the production of SCFAs and beneficial metabolites. • Fermented products of BFP attenuated LPS-induced injury in Caco-2 cells. [ABSTRACT FROM AUTHOR]

We report the polarization-dependent Raman spectra of exfoliated MoI3, a van der Waals material with a "true one-dimensional" crystal structure that can be exfoliated to individual atomic chains. The temperature evolution of several Raman features reveals an anomalous behavior suggesting a phase transition of magnetic origin. Theoretical considerations indicate that MoI3 is an easy-plane antiferromagnet with alternating spins along the dimerized chains and with inter-chain helical spin ordering. The calculated frequencies of phonons and magnons are consistent with the interpretation of the experimental Raman data. The obtained results shed light on the specifics of the phononic and magnonic states in MoI3 and provide a strong motivation for further study of this unique material with potential for future spintronic applications. [ABSTRACT FROM AUTHOR]

Marine bacterium Microbulbifer sp. ALW1 was revealed to be able to effectively degrade Laminaria japonica thallus fragments into fine particles. Polysaccharide substrate specificity analysis indicated that ALW1 could produce extracellular alginate lyase, laminarinase, fucoidanase and cellulase. Based on alignment of the 16 S rRNA sequence with other reference relatives, ALW1 showed the closest relationship with Microbulbifer aggregans CCB-MM1T. The cell morphology and some basic physiological and biochemical parameters of ALW1 cells were characterised. ALW1 is a Gram-negative, rod- or oval-shaped, non-spore-forming and non-motile bacterium. The DNA–DNA relatedness values of ALW1 with type strains of M. gwangyangensis (JCM 17,800), M. aggregans (JCM 31,875), M. maritimus (JCM 12,187), M. okinawensis (JCM 16,147) and M. rhizosphaerae (DSM 28,920) were 28.9%, 43.3%, 41.2%, 35.4% and 45.6%, respectively. The major cell wall sugars of ALW1 were determined to be ribose and galactose, which differed from other closely related species. These characteristics indicated that ALW1 could be assigned to a separate species of the genus Microbulbifer. The complete genome of ALW1 contained one circular chromosome with 4,682,287 bp and a GC content of 56.86%. The putative encoded proteins were categorised based on their functional annotations. Phenotypic, physiological, biochemical and genomic characterisation will provide insights into the many potential industrial applications of Microbulbifer sp. ALW1. Key points. Key points: Microbulbifer sp. ALW1 has Laminaria japonica degradation capability. Genomic information of strain ALW1 is useful for analysing the polysaccharides degradation process. Microbulbifer sp. ALW1 could be potentially applied in producing functional materials. [ABSTRACT FROM AUTHOR]

Drought-induced risk has attracted the attention of many scholars, but the risk of combined events caused by drought and high-temperature heat waves still needs further study. Based on MODIS products and meteorological data, the spatiotemporal variation characteristics of summer drought and high-temperature heat waves in the North China Plain from 2000 to 2018 were analyzed by the standardized precipitation evapotranspiration index (SPEI), crop water stress index (CWSI) and high-temperature threshold, and their combined-events risk was evaluated. The results showed that (1) from 2000 to 2018, summer drought in the North China Plain became more severe. Especially in Henan, Anhui and Jiangsu Provinces, drought increased significantly. (2) From 2000 to 2018, the frequency and intensity of high-temperature heat wave events in the North China Plain gradually increased at rates of 0.28 times/10 year and 1.6 °C/10 year, respectively. (3) The slightly high risk and high risk caused by summer drought were mainly distributed in Hebei Province and Tianjin Municipality in the north, and the risk change was characterized by a decrease in the north and an increase in the south. (4) The combined-events risk of summer drought and high-temperature heat waves did not increase significantly, with an increase rate of approximately 0.01/10 year. Among them, the increase rate of combined-events risk in Henan Province was the largest (0.14/10 year), followed by the obvious increase in northern Anhui, Jiangsu and southern Shandong, while the risk in Beijing showed a decreasing trend. The research results have scientific guiding significance for formulating disaster prevention and reduction strategies. [ABSTRACT FROM AUTHOR]

Keywords: ab initio; band alignment; electron emission; high throughput; machine learning; thermionic energy conversion; work functionMachine LearningIn article number 2401764, Peter Schindler and co‐workers establish the largest work function database using high‐throughput ab initio calculations and train an accurate machine learning model to enable rapid predictions of this crucial surface property. This work led to the discovery of several stable surfaces with extreme work functions..By Peter Schindler; Evan R. Antoniuk; Gowoon Cheon; Yanbing Zhu and Evan J. ReedReported by Author; Author; Author; Author; Author [Extracted from the article]

Chondroitinase plays an important role in structural and functional studies of chondroitin sulfate (CS). In this study, a new member of chondroitinase B of PL6 family, namely ChSase B6, was cloned from marine bacterium Microbulbifer sp. ALW1 and subjected to enzymatic and structural characterization. The recombinant ChSase B6 showed optimum activity at 40 °C and pH 8.0, with enzyme kinetic parameters of Km and Vmax against chondroitin sulfate B (CSB) to be 7.85 µg/mL and 1.21 U/mg, respectively. ChSase B6 demonstrated thermostability under 60 °C for 2 h with about 50% residual activity and good pH stability under 4.0–10.0 for 1 h with above 60% residual activity. In addition, ChSase B6 displayed excellent stability against the surfactants including Tween-20, Tween-80, Trion X-100, and CTAB. The degradation products of ChSase B6-treated CSB exhibited improved antioxidant ability as a hydroxyl radical scavenger. Structural analysis and site-directed mutagenesis suggested that the conserved residues Lys248 and Arg269 were important for the activity of ChSase B6. Characterization, structure, and molecular dynamics simulation of ChSase B6 provided a guide for further tailoring for its industrial application for chondroitin sulfate bioresource development. [ABSTRACT FROM AUTHOR]

• P. haitanensis polysaccharides (PHP) were extracted by ultra-high pressure (UHP). • UHP increased total sugar, uronic acid, and 3,6-anhydro-ʟ-galactose contents of PHP. • UHP resulted in a more rough and porous structure for PHP. • UHP especially 500–600 MPa increased antioxidant and hypolipidemic abilities of PHP. Porphyra haitanensis polysaccharides (PHPs) have potential antioxidant and hypolipidemic activities, but still need improvement. Therefore, ultra-high pressure (UHP) assisted extraction was applied to modify the structure, antioxidant, and hypolipidemic activities of PHPs. UHP assisted extraction increased the total sugar, uronic acid, and 3,6-anhydro-ʟ-galactose contents of PHP, which increased by 15.85 %–16.12 %, 18.95 %–24.32 %, 20.54 %–23.66 % with 500–600 MPa UHP, respectively. Meanwhile, UHP modified PHP became more rough and porous than native PHP. Besides, UHP assisted extracted PHP showed better in vitro antioxidant and hypolipidemic abilities. Especially, 500–600 MPa UHP increased 72.43 %–86.42 % 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacities, 12.32 %–12.82 % pancreatic lipase inhibitory ability, and 14.93 %–15.23 % glycocholate binding abilities of PHP (p < 0.05). Moreover, UHP assisted extracted PHP greatly decreased the lipid droplet and triglyceride contents of 3T3-L1 adipocytes (p < 0.05). Our findings can provide the theoretical basis for the high value utilization of Porphyra haitanensis and its polysaccharides with UHP modification. [ABSTRACT FROM AUTHOR]

In this study, the antimicrobial activity on Escherichia coli (E. coli) of a polysaccharide (BFP) prepared from Bangia fusco-purpurea with the underlying mechanism was investigated. The results showed that BFP could against the growth of E. coli in a concentration-dependent manner. The inhibitory effect of BFP on E. coli might be through disrupting the morphology, increasing the intracellular reactive oxygen species levels, and decreasing the Ca2+-Mg2+-ATPase activity in E. coli. Furthermore, BFP significantly reduced the biofilm formation in E. coli by down-regulating the critical biofilm-related genes, including flhD , flhC , fliM , csgA , and csgD , especially fliM , and weakened the bacteria's infection and pathogenic potentials. Notably, the metabolomic analysis demonstrated that BFP performed antimicrobial activity mainly by up-regulating the sphingosine and phospholipids metabolites, down-regulating the amino acid metabolites, and the two-component system in E. coli. The findings advance the understanding on the underlying mechanisms of red seaweed polysaccharide BFP against E. coli , and further provide the scientific basis for developing BFP as a natural antimicrobial agent applied in food additives or pharmaceutical ingredients. • B. fusco-purpurea polysaccharide (BFP) showed antimicrobial activity on E. coli. • BFP reduced biofilm formation in E. coli and weakened their infection potential. • BFP achieved antimicrobial activity by regulating the metabolites in E. coli cells. • BFP reduced biofilm formation in E. coli by down-regulating two-component system. • BFP can be used as a natural antibacterial agent in food or pharmaceuticals. [ABSTRACT FROM AUTHOR]

A large amount of carrageenan residue containing perlite is produced in carrageenan process. Management of carrageenan residue is an environmental issue in carrageenan green and clean production. Repeated recovery of perlite from carrageenan residue could reduce resource waste and environmental pollution. However, research on methods, reuse characteristics, and mechanisms of repeatedly recovered perlite remains lacking. In this study, a green recovery scheme was obtained to recover perlite by combining food-grade hydrochloric acid and hydrogen peroxide, and influence of elemental structure changes on gel structure during repeated recovery was investigated. The permeability of recovered perlite (2.61/Darcy) reached reuse standard, showing good economic value. The C–O–C bond of polysaccharide and inner ether galactose ring in carrageenan residue were degraded by hydrogen peroxide and hydrochloric acid. More importantly, gel strength and transparency of carrageenan increased by 42.86% and 16.46% with recycling times, probably due to repeated adsorption and release of K+ from recovered perlite. The C–K bond effectively shielded electrostatic repulsion between carrageenan segments and promotes formation of gel network. The characteristics of carrageenan and recycling times were consistent with gaussian model, y = y 0 + A w π / 2 e − 2 (x − x c) 2 w 2 , with a maximum number of cycles of 4.21. It provides a technical research basis for green and clean carrageenan extraction. [Display omitted] • Perlite was repeatedly recovered from carrageenan residue by combining extraction with low concentration of food-grade hydrogen peroxide and hydrochloric acid treatment method and reused for extraction of carrageenan. • The industrial production profit of recovered perlite could reach ¥ 1065.3/ton. • Management of carrageenan residue could improve the utilization rate of waste and reduce the waste of resources. • Recovered perlite was used to extract carrageenan, gel strength and transparency of carrageenan increased by 42.86% and 16.46%. • The characteristics of carrageenan and recycling times were consistent with gaussian model, y = y 0 + A w π / 2 e − 2 (x − x c) 2 w 2 , with a maximum number of cycles of 4.21. [ABSTRACT FROM AUTHOR]

The presence of sulfate groups in agar compromises the agar quality by affecting the crosslinking during gelling process. Some arylsulfatases can catalyze the hydrolysis of sulfate bonds in agar to improve the agar quality. Immobilized arylsulfatases prove beneficial advantages for their industrial applications. Here, a previously characterized mutant arylsulfatase K253H/H260L was immobilized on the synthesized magnetic Fe3O4 nanoparticles after functionalization by tannic acid (MNPs@TA). The surface properties and molecular structures of the immobilized arylsulfatase (MNPs@TA@ARS) were examined by scanning electron microscopy and Fourier transform infrared spectroscopy. Enzymatic characterization showed that MNPs@TA@ARS exhibited shifted optimal temperature and pH with deviated apparent Km and Vmax compared to its free counterpart. The immobilized arylsulfatase demonstrated improved thermal and pH stability and enhanced storage stability with modest reusability. In addition, MNPs@TA@ARS displayed enhanced tolerance to various inhibitors and detergents. The utilization of the immobilized arylsulfatase for agar desulfation brought the treated agar with improved quality. [ABSTRACT FROM AUTHOR]

Laminarin and its derived oligosaccharides have diverse bioactivities. The β‐1,3‐glucanase in marine bacteria can be employed as a tool to digest laminarin in the cell wall of brown algae. Here, we cloned, expressed and characterised a β‐1,3‐glucanase (laminarinase), MaLamNA, from the previously characterised marine bacterium Microbulbifer sp. ALW1, phylogenetically distinct from the glycoside hydrolase families of characterised laminarinases. The recombinant laminarinase was heterologously expressed and purified from Pichia pastoris GS115 cells with a molecular mass of 57.3 kDa. MaLamNA exerted its hydrolytic activity specifically against laminarin, with the highest activity at 45 °C and pH 4.5–5.5, respectively, and demonstrated high stability against extreme acidic and alkaline pH exposure. The addition of reducing agent dithiothreitol could significantly enhance the activity of MaLamNA. The hydrolytic products of laminarin by MaLamNA exhibited more effective antioxidant activities than the undigested laminarin. These characteristics of MaLamNA provide clues to its industrial application for laminarin bioresource development. [ABSTRACT FROM AUTHOR]

In this study, we evaluated the structural characteristics and novel biological activity of polysaccharide purified from red seaweed Bangia fusco-purpurea (BFP). Methylation, GC/MS, and NMR analyses suggested that the proposal repeating structure of BFP was →3)-β- D -Gal p -(1→, →3)-β- D -Gal p 6S-(1 → 4)-α- D -Gal p -(1→, →4)-α- D -Gal p -(1 → 4)-α- L -AnGal p -(1 → 3)-β- D -Gal p -(1→, and →4)-α- D -Gal p -(1 → at a molar ratio of 13: 1: 1: 1. Interestingly, BFP exhibited significant cell migration- and tube formation-promoting activities toward human umbilical vein endothelial cells (HUVECs) in a concentration-dependent manner via increasing the N-cadherin expression and decreasing the E-cadherin expression. Furthermore, ERK and p38 mitogen-activated protein kinase (MAPK) specific inhibitors exhibited potent inhibitory effects on BFP-induced cell migration but not JNK MAPK inhibitor, suggesting ERK and p38 MAPK signaling pathways were mainly involved in BFP-induced cell migration. Moreover, vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitor significantly inhibited BFP-induced cell migration and tube formation in HUVECs, suggesting VEGF receptors of HUVECs were involved in the pro-angiogenesis activity of BFP. This is the first report that a sulfated polysaccharide possessing a pro-angiogenic effect was obtained from red seaweed. Our findings are expected to promote the practical use of red seaweed B. fusco-purpurea and its polysaccharide in the development of the in vitro and ex vivo vascular endothelial cell-based cell therapy products. • A polysaccharide named BFP is purified from red seaweed Bangia fusco-purpurea. • The primary repeating backbone structure of BFP is established. • BFP potently enhances cell migration and tube formation activities in HUVECs. • BFP promotes cell migration via upregulating N-cadherin expression in HUVECs. • ERK/p38 MAPK and VEGFR signaling pathways are involved in BFP induced angiogenesis. [ABSTRACT FROM AUTHOR]

The bacterium Microbulbifer sp. ALW1 was previously characterized with the capability to break down the cell wall of brown algae into fine pieces. The biological functions of strain ALW1 were yet to be elucidated. In this study, a gene, namely MaCel5A, was isolated from the ALW1 strain genome, encoding an endo-β-1,4-glucanase. MaCel5A was phylogenetically categorized under the glycoside hydrolase family GH5, with the highest identity to a putative cellulase of Microbulbifer thermotolerans. The recombinant MaCel5A protein purified from heterologous expression in E. coli exhibited maximum activity at 50 °C and pH 6.0, respectively, and functioned selectively toward carboxymethyl cellulose and barley β-glucan. Recombinant MaCel5A demonstrated considerable tolerance to the exposure to high temperature up to 80 °C for 30 min retaining 49% residual activity. In addition, MaCel5A showed moderate stability against pH 5.0–11.0 and strong stability in the presence of nonionic surfactant. MaCel5A exhibited strong halo-stability and halotolerance. The activity of the enzyme increased about tenfold at 0.5 M NaCl, and about fivefold even at 4.0 M NaCl compared to the enzyme activity without the addition of salt. The two conserved glutamic acid residues in MaCel5A featured the typical catalytic acid/base and nucleophile machinery of glycoside hydrolases. These characteristics highlight the industrial application potential of MaCel5A. [ABSTRACT FROM AUTHOR]

The present study aims to evaluate the deodorization of Bangiafusco‐purpurea using microorganism fermentation with commercial starter cultures of Saccharomyces cerevisiae, Acetobacter pasteurianus, and Lactobacillus plantarum. The results showed the fermentation with S. cerevisiae, A. pasteurianus, and L. plantarum resulted in significantly decreases (p <.05) of the fishy malodor in B. fusco‐purpurea. Among the three strains, S. cerevisiae was the best for reducing the fishy malodor. The optimal inoculum size and fermentation time were 0.2% and 4 hr, respectively. After the fermentation with the S. cerevisiae, the content of 1‐octen‐3‐ol, (E)‐2‐octen‐1‐ol, hexanal, non‐(2E)‐enal, (E,E)‐2,4‐decadienal, 3,5‐octadien‐2‐one, and 2‐pentyl‐furan were hard to be detected in the seaweed, whereas increases were observed in the concentrations of 2‐butyl‐1‐octanol, cedrol, diisobutyl phthalate, and 2,4‐di‐t‐butylphenol. The odor active value analysis indicated the removal of fishy odor was related to the reduction, dehydrogenation, and deformylating oxygenation of hexanal, nonanal, non‐(2E)‐enal, and (E,E)‐2,4‐decadienal and esterification of 1‐octen‐3‐ol and (E)‐2‐octen‐1‐ol. Our findings provide a technical and scientific basis for the removal of fishy odor from B. fusco‐purpurea. Practical applications: Bangia fusco‐purpurea is a seaweed that can reduce the risks of cardiovascular and chronic metabolic diseases in human body. However, the seaweed has a strong fishy malodor, which largely declines consumer's acceptance. In this study, the commercial starters of Saccharomyces cerevisiae, Acetobacter pasteurianus, and Lactobacillus plantarum were shown to reduce the fishy malodor in B. fusco‐purpurea via fermentation. After the fermentation with the microorganisms especially with the S. cerevisiae, the fishy malodor significantly reduced, and the overall aroma acceptance of B. fusco‐purpurea products greatly improved. Therefore, this study provides a technical basis for the removal of fishy odor from B. fusco‐purpurea and processing value‐added products from it and facilitating its health benefits for human. [ABSTRACT FROM AUTHOR]

κ-Carrageenase can degrade κ-carrageenan to produce bioactive κ-carrageenan oligosaccharides (KCOs) that have potential applications in pharmaceutical, food, agricultural, and cosmetics industries. Immobilized enzymes gain their popularity due to their good reusability, enhanced stability, and tunability. In this study, the previously characterized catalytic domain of Pseudoalteromonas purpurea κ-carrageenase was covalently immobilized on the synthesized amine-modified zeolitic imidazolate framework-8 nanoparticles with the formation of cross-linked enzyme aggregates, and the immobilized κ-carrageenase was further characterized. The immobilized κ-carrageenase demonstrated excellent pH stability and good reusability, and exhibited higher optimal reaction temperature, better thermostability, and extended storage stability compared with the free enzyme. The KCOs produced by the immobilized κ-carrageenase could significantly decrease the TC, TG, and LDL-C levels in HepG2 cells, increase the HDL-C level in HepG2 cells, and reduce the free fatty acids level in Caco-2 cells. Biochemical assays showed that the KCOs could activate AMPK activity, increase the ratios of p-AMPK/AMPK and p-ACC/ACC, and downregulate the expression of the lipid metabolism related proteins including SREBP1 and HMGCR in the hyperlipidemic HepG2 cells. This study provides a novel and effective method for immobilization of κ-carrageenase, and the KCOs produced by the immobilized enzyme could be a potential therapeutic agent to prevent hyperlipidemia. • κ-Carrageenase-CLEA is immobilized on amine-modified ZIF-8. • Stability and reusability of immobilized κ-carrageenase are enhanced. • Immobilized κ-carrageenase efficiently produces κ-carrageenan oligosaccharides. • κ-Carrageenan oligosaccharides show hypolipidemic activity in HepG2 cells. • κ-Carrageenan oligosaccharides can regulate lipid metabolism by activating AMPK pathway. [ABSTRACT FROM AUTHOR]

It is difficult to improve pH stability of enzymes. In the present study, a semi-rational strategy was validated to improve the alkaline stability of an α- L -rhamnosidase. The strategy combined the prediction of folding free energy and binding free energy. Through alanine scanning and virtual saturation mutation, 9 mutations were selected as mutant candidates. The mutant R307Y was confirmed with higher pH stability than the WT. In addition, the mutant also showed an increase of enzyme activity. The structure simulation and molecular dynamics analysis indicated that the interactions, especially hydrogen bonds, hydrophobic interactions and the local structural stability were enhanced by introducing aromatic residues, which play an important role in increasing the rigidity and maintaining the alkaline pH stability. The study not only provides a α- L -rhamnosidase mutant with better pH stability and enzyme activity, but also provides an effective strategy for improving enzyme pH stability. [Display omitted] • Folding and binding free energy are proposed to semi-rationally design the pH stability of enzymes. • The increased rigidity plays a significant role in maintaining the alkaline pH stability. • The increased rigidity is attributed to the introduction of aromatic residues. • The aromatic residues enhanced hydrogen bonds, hydrophobic interactions and stability. • It is the first semi-rational design for improve pH stability of α- L -rhamnosidase. [ABSTRACT FROM AUTHOR]

In this study, a low-molecular-weight saccharide fragment (LMWAs-L) was prepared from alginate lyase (EC 4.2.2.3) hydrolyzed ascophyllan by ultra-filtration separation method. LMWAs-L was a homogeneous saccharide fraction with an average molecular weight of 6.96 kDa. Enzymolysis process optimization experiments revealed that the optimum process parameters for preparing LMWAs-L were the enzyme concentration 0.02 U/mL, initial pH 6.8, and enzymolysis temperature 43 °C. After optimization, the yield of LMWAs-L was increased to 9.74% higher than that without optimization. Interestingly, LMWAs-L exhibited stronger enhancing activities on the proliferation and migration of human skin fibroblasts cells in vitro and better antibacterial activities as compared to native ascophyllan at the same mass concentration. Our study establishes a simple way to prepare low-molecular-weight saccharide with beneficial bioactivities from ascophyllan efficiently. This is the first report to reveal that ascophyllan and its low-molecular-weight saccharide have the potentials to be developed as natural biological dressing and antibacterial agents. • Alginate lyase degrades ascophyllan to produce low-molecular-weight hydrolysates. • A low-molecular-weight saccharide fraction (LMWAs-L) is purified from hydrolysates. • A simple and efficient preparation method for LMWAs-L is established. • LMWAs-L exhibits stronger migration enhancing effect on HSF cells than ascophyllan. • LMWAs-L shows better antibacterial activities as compared to native ascophyllan. [ABSTRACT FROM AUTHOR]

In this study, a sulfated polysaccharide (BFP) was isolated from the edible red alga Bangia fusco-purpurea. Gel-filtration and thin layer chromatographically analyses suggested that BFP was a homogenous polysaccharide. The chemical structural analysis revealed that BFP mainly consisted of galactose together with a small amount of uronic acid, mannose, and glucose. Its molecular mass was estimated to be 133.18 kDa by high-performance liquid chromatography (HPLC) analysis. BFP inhibited α-amylase and α-glucosidase in a concentration-dependent manner. The IC50 values of BFP against α-amylase and α-glucosidase were estimated to be 1.26 ± 0.11 mg/mL and 1.34 ± 0.07 mg/mL, respectively. Kinetic analyses suggested that BFP showed competitive and non-competitive inhibition against α-amylase and α-glucosidase, respectively. Circular dichroism spectral and fluorescence spectral analyses suggested that BFP affects the conformational structures of these enzymes, which may lead to the inhibition of the enzymatic activities. Abbreviations: Ara: D-arabinose; AnGal: anhydro-L-galactose residues; CD spectroscopy: Circular Dichroism spectroscopy; DNS: dinitrosalicylic acid; FT-IR: fourier transform infrared spectra; Fuc: L-fucose; Gal: D-galactose; Glc: D-glucose; GlcA: D-Glucuronic acid; HPLC: high performance liquid chromatography; Man: D-mannose; pNPG: p-nitrophenyl-α-D-glucoside; TFA: trifluoroacetic acid; TLC: thin-layer chromatography; PMP: 1-phenyl-3-methyl-5-pyrazolone; Xyl: D-xylose Inhibitory effects of a sulfated polysaccharide isolated from edible red alga Bangia fusco-purpurea on α-amylase and α-glucosidase [ABSTRACT FROM AUTHOR]

A new alginate lyase gene of algl17 was cloned from an alginate-degrading marine bacterium Microbulbifer sp. ALW1. The gene contained 2220 bp and encoded a 739-amino acid protein classified into the PL-17 family. The recombinant alginate lyase AlgL17 was overexpressed and purified from Escherichia coli BL21 (DE3) with a molecular mass of 84.9 kDa. This enzyme showed activities towards sodium alginate, polyM and alginate oligosaccharide, but very low activity towards polyG. These results indicate that AlgL17 is a polyM-specific oligoalginate lyase. When sodium alginate was used as a substrate, the optimum reaction temperature and pH for the enzyme were 35 °C and pH 8.0, respectively. Recombinant AlgL17 was stable at 25 °C, but not stable at 30 °C and 35 °C. It showed good stability over a pH range of 5.0–8.0. The enzyme activity was increased to 1.7 times by adding NaCl to a final concentration of 0.7 M. The ability of the recombinant AlgL17 producing 4-deoxy-L- erythro -5-hexoseulose uronic acid (DEH) from sodium alginate and polyM block indicates that AlgL17 is an exo-type alginate lyase. • A new alginate lyase from a marine bacterium Microbulbifer sp. ALW1 was overexpressed in Escherichia coli BL21 (DE3). • The recombinant enzyme was identified to be an exo -oligoalginate lyase. • We identified the enzymatic hydrolysates and their antioxidant activities. [ABSTRACT FROM AUTHOR]

Highlights • β-Agarase was immobilized on tannic acid modified-Fe 3 O 4 magnetic nanoparticles. • The immobilized β-agarase showed excellent pH, thermal stability and reusability. • Neoagaro-oligosaccharide were successfully prepared by immobilized β-agarase. • Neoagaro-oligosaccharide obtained revealed varying activity in antioxidant. Abstract β-Agarase was immobilized by using tannic acid modified-Fe 3 O 4 magnetic nanoparticles (TA-MNPs) as a support material. The MNPs were synthesized by improved chemical coprecipitation method and modified with TA for agarase immobilization. TA-MNPs and immobilized β-agarase were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and thermal gravimetric analysis (TGA), all of which indicated the successful surface modification of MNPs with TA and the immobilization of β-agarase. The optimal immobilization conditions for 25 mg TA-MNPs included 100 r/min oscillation speed, immobilization time of 2 h, immobilization temperature of 15 °C, and initial β-agarase concentration of 3 mL (480 U). Immobilized β-agarase showed better pH and thermal stability and excellent reusability than the free enzyme. Results revealed the promising application of β-agarase-TA-MNPs for the preparation of neoagaro-oligosaccharides with different average polymerization degrees and varying activities in the antioxidant. [ABSTRACT FROM AUTHOR]