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Here, a novel double‐crosslinked hydrogel dressing with enhanced antibacterial and anti‐inflammatory activities is reported. Carboxymethyl chitosan is crosslinked with silane and Ca2+ to form a double‐crosslinked hydrogel, and silver nanoparticles are loaded to introduce antibacterial properties to the hydrogel. The covalent crosslinking preserves the integrity of the hydrogel matrix, while the ionic crosslinking dissipates the energy under deformation. It combines high stretchability, toughness, tissue adhesion, and antimicrobial function. This hydrogel exhibits excellent cytocompatibility and hemocompatibility. Moreover, in vitro and in vivo investigations demonstrate its efficacy in accelerating bacterial‐infected wound healing. Given its excellent cytocompatibility and mechanical properties, this hydrogel is anticipated to be widely used in bacteria‐associated wound management. [ABSTRACT FROM AUTHOR]

Here, a multifunctional film (MFF) as an alternative tissue adhesive in the form of an interpenetrating network consisting of self‐crosslinked aldehyde‐functionalized chitosan (AC) and crosslinked poly(acrylic acid) (PAA) further coordinated with Ag+ is reported. The MFF combines enhanced toughness and stretchability, which is attributed to the synergistic effects of the double‐network design. Covalent crosslinking maintains the overall integrity of the MFF matrix, while noncovalent crosslinking dissipates energy under deformation. Upon contact, the MFF quickly dries the tissue surface followed by instant physical crosslinking to the tissue. Subsequent covalent crosslinking between the aldehyde groups of the MFF and the primary amine groups on the surface of the tissue further stabilizes the adhesion. Meanwhile, Ag+ provides strong antibacterial properties to the MFF. Notably, in vivo studies demonstrate that the MFF allows facile and tough attachment to the wet and dynamic surface of rabbit liver and presents superior hemostasis and sealing properties. Furthermore, the MFF can be safely degraded without causing abnormal defects in vivo. The outstanding physicochemical properties of the MFF can potentially be a good alternative to existing sutures or staples and has potential for use in clinical practice. [ABSTRACT FROM AUTHOR]

Of note, isotope-labeled PtdGlc was observed in the brain of SP 13 sp C6-PtdGlc treated mice, which demonstrated that PtdGlc could reach to brain (Figure S4). Dear Editor, Alzheimer's disease (AD) is a commonly progressive disorder of neurodegenerative disease.1 Until now, no approach to treat the pathological progression of AD has been proven to be effective.1 Our data favored that the treatment of phosphatidylglucoside (PtdGlc), a novel glucosylated lipid enriched in the brain, protects against A and tau pathology, cognition deficits in APP/PS1 mice, and alleviates neuroinflammation through activation of PPAR and restoration of the neurotrophin signaling. Activated microglia cells and astrocytes can trigger inflammatory processes and regulate neuroinflammation in the brain.8 ASC and Caspase 1 levels were reduced by PtdGlc treatment in APP/PS1 mice, while NLRP3 expression was unchanged. To examine whether the PtdGlc reached to brain, the mice was injected with stable isotope-labeled PtdGlc ( SP 13 sp C6-D-PtdGlc) via the tail vein. [Extracted from the article]

Marine‐polysaccharide degrading enzymes have recently been studied extensively. They are particularly interesting as they catalyze the cleavage of glycosidic bonds in polysaccharide macromolecules and produce oligosaccharides with low degrees of polymerization. Numerous findings have demonstrated that marine polysaccharides and their biotransformed products possess beneficial properties including antitumor, antiviral, anticoagulant, and anti‐inflammatory activities, and they have great value in healthcare, cosmetics, the food industry, and agriculture. Exploitation of enzymes that can degrade marine polysaccharides is in the ascendant, and is important for high‐value use of marine biomass resources. In this review, we describe research and prospects regarding the classification, biochemical properties, and catalytic mechanisms of the main types of marine‐polysaccharide degrading enzymes, focusing on chitinase, chitosanase, alginate lyase, agarase, and carrageenase, and their product oligosaccharides. The state‐of‐the‐art discussion of marine‐polysaccharide degrading enzymes and their properties offers information that might enable more efficient production of marine oligosaccharides. We also highlight current problems in the field of marine‐polysaccharide degrading enzymes and trends in their development. Understanding the properties, catalytic mechanisms, and modification of known enzymes will aid the identification of novel enzymes to degrade marine polysaccharides and facilitation of their use in various biotechnological processes. [ABSTRACT FROM AUTHOR]

Here, a novel macroporous hydrogel dressing is presented that can accelerate wound healing and guard against bacteria‐associated wound infection. Carboxymethyl agarose (CMA) is successfully prepared from agarose. The CMA molecular chains are cross‐linked by hydrogen bonding to form a supramolecular hydrogel, and the hydroxy groups in the CMA molecules complex with Ag+ to promote hydrogel formation. This hydrogel composite exhibits pH‐responsiveness and temperature‐responsiveness and releases Ag+, an antibacterial agent, over a prolonged period of time. Moreover, this hydrogel exhibits outstanding cytocompatibility and hemocompatibility. In vitro and in vivo investigations demonstrate that the hydrogel has enhanced antibacterial and anti‐inflammatory capabilities and can significantly accelerate skin tissue regeneration and wound closure. Astonishingly, the hydrogel can cause the inflammation process to occur earlier and for a shorter amount of time than in a normal process. Given its excellent antibacterial, anti‐inflammatory, and physicochemical properties, the broad application of this hydrogel in bacteria‐associated wound management is anticipated. [ABSTRACT FROM AUTHOR]

In spite of the fact that several flavors and fragrances are obtained either by chemical synthesis or by extraction from plants, the application of biocatalysis for the sake of a safe and productive pathway by more sustainable chemical processes is the main alternative. The current study focuses on the synthesis of three flavor esters, namely cis‐3‐hexen‐1‐yl acetate, 2‐phenylethyl acetate, and methyl phenylacetate, via transesterification and esterification of the natural corresponding alcohols or acids. The impact of optimizing variables that influence this lipase‐catalyzed synthesis, such as enzyme formulations, solvent‐free media, and acetylating agents, is crucial to achieving higher conversions. The enzymatic transesterification using Novozym 435 afforded cis‐3‐hexen‐1‐yl, and 2‐phenylethyl acetates with high yields (>90%) in green solvents. Similar results were obtained in solvent‐free system, which is more economic for the scaling up of this synthesis. In the case of esterification reactions, the removal of water, formed as a by‐product, with the use of Aquasorb enhanced the conversions as in the case of methyl phenylacetate attained with a conversion of 89% in the presence of Novozym 435. However, this effect was not observed in the larger scale reaction (with 0.85 mol of cis‐3‐hexen‐1‐ol). Instead, the efficient strategy of gradual addition of acetic acid has proven to significantly improve the yield of cis‐3‐hexen‐1‐yl acetate (from 2% up to about 80% in the case of the preparative reaction with 100 mL substrate). Box‐Behnken analysis was also performed to identify the lowest amount of acetylating agent and the shorter time to obtain the highest conversion ratio. This analysis showed that a triacetin/alcohol molar ratio of 1 and 1.75 can be sufficient to obtain a conversion >90% and up to 95%, for cis‐3‐hexen‐1‐yl acetate and 2‐phenylethyl acetate, respectively, similarly to what is obtained with higher triacetin/alcohol molar ratios and comparable reaction time. [ABSTRACT FROM AUTHOR]

Summary: A highly efficient, rapid, green and safe procedure for the preparation of free all‐trans‐astaxanthin from Haematococcus pluvialis algal extract, by a crude extracellular enzyme extract, was reported. The free all‐trans‐astaxanthin obtained by the biocatalysed method had fewer side products compared to the saponification procedure. Through single‐factor experiments and a Box–Behnken design, it was possible to find the optimal biocatalytic conditions for the hydrolysis of 2 mg of H. pluvialis oil with 14.7 mg (protein content) of lyophilised crude extracellular enzyme extract obtained from Pseudomonas aeruginosa. The reaction was carried out in 30 min at pH 9.16 and 36 °C, in 5.5 mL total reaction volume, under nitrogen atmosphere and dark conditions. The hydrolysis ratio of the astaxanthin esters was 98.72%, and the production of free all‐trans‐astaxanthin was 82.83 μg per mg of H. pluvialis oil. The method herein reported was simpler than other enzymatic methods previously described and allowed saving of time and costs. Preparation of free all‐trans‐astaxanthin by a rapid biocatalytic method based on crude extracellular enzyme extract. [ABSTRACT FROM AUTHOR]

Abstract: Phospholipase D (PLD) can react with phospholipids as substrates, generally phosphatidylcholine (PtdCho), and the PLD‐substrate intermediate can be cleaved by another alcohol, resulting in transphosphatidylation of the substrate, which can be used in the production of special lipids. In this study, the reaction conditions affecting the transphosphatidylation of PtdCho with serine were optimized and the reaction specificity of a novel PLD prepared from Acinetobacter radioresistens a2 was evaluated for transphosphatidylation with a variety of phospholipid substrates and head group donors. Based on the yield of phosphatidylserine, experimental kinetic data, maximum transphosphatidylation rate, and kinetic constant, the specificity of PLD in transphosphatidylation was found to be affected by unsaturated fatty‐acid phospholipid substrates. The catalytic efficiency of PLD prepared from A. radioresistens a2 on the synthesis of natural phospholipids is on the order of l‐serine > ethanolamine and glycerol ≫ inositol. Moreover, it was found that the transphosphatidylation of PtdCho with saccharides was related to the length of the carbon chain and the number of saccharide units. [ABSTRACT FROM AUTHOR]

Natural astaxanthin (Ax) is an additive that is widely used because of its beneficial biochemical functions. However, the methods used to produce free Ax have drawbacks. Chemical saponification methods produce several by-products, and lipase-catalyzed hydrolysis methods are not cost effective. In this study, a bacterial strain of Stenotrophomonas sp. was selected to enzymatically catalyze the saponification of Ax esters to produce free all-trans-Ax. Through single-factor experiments and a Box-Behnken design, the optimal fermentation conditions were determined as follows: a seed culture age of 37.79 h, an inoculum concentration of 5.92%, and an initial broth pH of 6.80. Under these conditions, a fermentation curve was drawn, and the optimal fermentation time was shown to be 60 h. At 60 h, the degradation rate of the Ax esters was 98.08%, and the yield of free all-trans-Ax was 50.130 μg/mL. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:649-656, 2016 [ABSTRACT FROM AUTHOR]

A new α-neoagarobiose hydrolase (NABH) called AgaWH117 was cloned from Agarivorans gilvus WH0801. The gene encoding this hydrolase consists of 1,086 bp and encodes a protein containing 361 amino acids. This new NABH showed 74% amino acid sequence identity with other known NABHs. The molecular mass of the recombinant AgaWH117 was estimated to be 41 kDa. Purified AgaWH117 showed endolytic activity during neoagarobiose degradation, yielding 3,6-anhydro- l-galactose ( l-AHG) and d-galactose as products. It showed a maximum activity at a temperature of 30 °C and a pH of 6.0 and was stable at temperatures below 30 °C. Its Km and Vmax values were 2.094 mg/mL and 6.982 U/mg, respectively. The cloning strategy used and AgaWH117 isolated in this study will provide information on the saccharification process of marine biomass. This study provides a method to produce l-AHG from agarose by using AgaWH117 without an acid and describes its one-step purification by using Bio-Gel P2 chromatography. [ABSTRACT FROM AUTHOR]

This study obtained an anchovy flavourful fish sauce by a bioprocess of aerobic fermentation with Aspergillus oryzae OAY1 in a period of time as short as 3 days. Amino nitrogen of the fish sauce increased to 7.35 mg mL-1 by optimisation with response surface methodology (RSM). Results of chemical analysis showed that amino nitrogen, hydrolysis degree, reducing sugar and total amino acids all increased, along with the enhanced antioxidant activity. With regard to biogenic amines, most of the tested biogenic amines decreased after fermentation. Electronic nose test revealed that the odour of the fish sauce became more balanced and favourable after fermentation. In addition, volatile odorant analysis and sensory evaluation showed that no particularly unpleasant flavour ingredient was found in the anchovy fish sauce, and the taste was overall satisfactory. Meanwhile, consumer acceptance test showed that the anchovy fish sauce produced in this study using A. orzyae OAY1 had a high consumer acceptance similar to the commercial anchovy fish sauce. This aerobic fast-fermentation process provided an efficient method for high-quality fish sauce production. [ABSTRACT FROM AUTHOR]

Macroporous Hydrogel Dressing: A Macroporous Hydrogel Dressing with Enhanced Antibacterial and Anti-Inflammatory Capabilities for Accelerated Wound Healing (Adv. Funct. Keywords: agarose; antibacterial; biopolymers; hydrogels; wound healing EN agarose antibacterial biopolymers hydrogels wound healing 1 1 1 05/23/20 20200520 NES 200520 In article number 2000644, Changhu Xue, Xiangzhao Mao, and co-workers develop a macroporous hydrogel dressing with antibacterial and anti-inflammatory properties for accelerated wound healing. Agarose, antibacterial, biopolymers, hydrogels, wound healing. [Extracted from the article]