The exoskeleton of mantis shrimp (MS) is rich in chitin, making it an essential source of this biopolymer with potential applications. This study represents the first application of deep eutectic solvents (DESs) system, composed of lactic acid and triethylbenzylammonium chloride, for the extraction of chitin from mantis shrimp shells, achieving a balance between high-purity and high molecular weight (Mw) while ensuring solvent recyclability. Under optimized conditions, the extracted chitin achieved a purity of 95.65%, with the Mw approximately 2.5 times higher than that obtained using conventional acid-base methods. Remarkably, the chitin purity remained at 94.84% after three cycles of DESs. This study provides a new perspective for a green route of DESs for highly efficient extract of chitin from MS shells and addresses critical challenges in marine waste valorization.

Chitin is the second most abundant biopolymer in the world after cellulose and commonly found in crustaceans. It is also the most abundant natural nitrogen-containing polysaccharide. The challenge in separation of chitin directly from snow crab (Chionoecetes opilio) shells is that the solvent used must be versatile in removing calcium carbonate and protein while also being efficient, environmentally friendly, and cost-effective. In this study, chitin was extracted from snow crab shells using a DES consisting of TEBAC and lactic acid. DES successfully removed minerals and proteins, with a deproteinization rate of 95.51

Optimizing the production process of high value-added chemicals derived from renewable biomass holds immense promise for clean energy utilization and environmental sustainability.

Chitin is the most productive nitrogen-containing polysaccharide in nature with immense potential for transforming into a range of chemicals. However, its dense crystal structure poses a challenge for depolymerization, limiting its applications. To overcome these challenges, a novel series of deep eutectic solvents (DESs) based on benzyltrimethylammonium chloride (TMBAC) as the hydrogen bond acceptor was developed. These TMBAC-based DESs, in combination with lactic acid, oxalic acid, and malic acid as the hydrogen bond donor demonstrated efficient chitin dissolution, achieving a solubility of up to 12% and an 88% recovery rate of regenerated chitin. The regenerated chitin was characterized using XRD, FT-IR, SEM, and 13C CP-MAS NMR, which indicated the preservation of chitin's chemical structure, a significant decrease in crystallinity, and a reduction in the molecular weight. Furthermore, the enzymatic hydrolysis efficiency of chitin was nearly doubled after treatment with TMBAC-based DESs, surpassing the effectiveness of untreated chitin. This approach holds promise for facilitating subsequent transformation and utilization of chitin.

Konjac glucomannan (KGM) is a natural polysaccharide derived from konjac, which has been widely used in various fields due to its numerous beneficial properties. However, the high viscosity and water absorption of KGM limit its application. Compared with KGM, Konjac glucomannan oligosaccharides (KGMOS) have higher water solubility and stronger application value. In this paper, a novel mannanase KgManA was cloned from Klebsiella grimontii to develop a new KGMOS-producing enzyme. Bioinformatic analysis shows that the structural similarity between KgManA and other enzymes was less than 18.33%. Phylogenetic analysis shows that KgManA shares different branches with the traditional mannanases containing the CMB35 domain, indicating that it is a novel mannanase. Then, the enzymatic properties were determined and substrate specificity was characterized. Surprisingly, KgManA is stable in a very wide pH range of 3.0 to 10.0; it has a special substrate specificity and seems to be active only for mannans without galactose in the side chain. Additionally, the three-dimensional structure of the enzyme was simulated and molecular docking of the mannotetraose substrate was performed. As far as we know, this is the first report to characterize the enzymatic properties and to simulate the structure of mannanase from K. grimontii. This work will contribute to the development and characterization of novel K. grimontii-derived mannanases. The above results indicate that KgManA is a promising tool for the production of KGMOS.

Actinidia arguta, commonly called hardy kiwifruit or kiwiberry, is a perennial vine of Actinidiaceae Actinidia genus. Understanding the main pathogens that cause the fruit rot of A. arguta during storage is of great significance for finding strategies to prevent fruit rot. In September 2020, the A. arguta (Sieb.et Zucc.) Planch. ex Miq. LD133 was harvested from a farm in Dandong City, Liaoning Province, China (40°31'N, 124°20'E). After being stored at room temperature for about a week, the fruit rotted (no mechanical damage or wound). Initial symptoms were localized irregular spots, which then became soft and the spots connected into large, flaky, light brown lesions. Later symptoms were dark brown lesions and rot that affect the entire fruit. The strain that shows the same morphology as observed in the four decaying tissues was isolated on PDA. The strain was white, edge irregular and surface wavy, and the reverse side was pale yellow (Fig. S1A). The black viscous acervuli appeared on the surface of the mycelium after 7 to 10 days at 25℃ with 12 hours photoperiod. Conidia were fusiform to ellipsoid, straight to slightly curved, 5.7×25.9 µm (width × length), n=30, with five versicolor cells (three brown median cells, two hyaline cells on apical and basal). The apical cell generally contains one to four appendages on conidia (Fig. S1B). For identify the selected strains, three genetic regions (ITS, TUB and TEF 1-α) were used for amplification and sequencing. These sequences of pathogen shared 98 to 100% homology with Neopestalotiopsis clavispora. Then, a phylogenetic tree was constructed by the Bayesian algorithm using PhyloSuite (v1.2.2) (Zhang et al. 2020). Based on the morphological and molecular characterization, the pathogen was identified as Neopestalotiopsis clavispora (Chamorro et al. 2016). Next, pathogenicity of the screened strains was determined by wound inoculation method. Ripe healthy fruits are immersed in 1% NaClO, rinsed twice with sterile water. A sterile needle was used to penetrate 1-2mm of peel, and then inoculate hyphae (about 5mm in length, 1mm in diameter), and 10 µL of sterile water as a control. The treated fruits are stored in an artificial climate chamber (22°C, 70% relative humidity with 12 hours photoperiod). The inoculated fruit began to show signs of rot on the second day, and after 6 days, lesions similar to those found during storage of the pathogenic isolated fruit appeared. Similarly, 10 µL (106 conidia/mL) conidial suspension exhibited decay symptoms. Compared with conidial suspension as inoculum, hyphae has shorter incubation period and stronger pathogenicity to fruit (Fig. S2). The pathogen was re-isolated from these infected fruits and identified as N. clavispora, thus fulfilling Koch's postulates. N. clavispora has been reported causing root and crown rot on strawberry in Spain, Argentina, Uruguay and Italy (Chamorro et al. 2016; Gilardi et al. 2019; Machin et al. 2019; Obregon et al. 2018), and as a pathogen on blueberry in Spain and Korea (Borrero et al. 2018; Lee et al. 2019), and causing leaf spot on macadamia in Brazil (Santos et al. 2019), and causing leaf spot on Syzygium cumini in India (Banerjee and Rana 2020). However, to our knowledge, this is the first report of Neopestalotiopsis clavispora causing postharvest fruit rot of A. argute in the worldwide. The identification of the pathogen is of great significance for conducting research on A. argute fruit preservation to prolong its shelf life and improve its merchantability.

Osteoarthritis impairs the functions of various joints, such as knees, hips, hands and spine, which causes pain, swelling, stiffness and reduced mobility in joints. Multiple factors, including age, joint injuries, obesity, and mechanical stress, could contribute to osteoarthritis development and progression. Evidence has demonstrated that genetics and epigenetics play a critical role in osteoarthritis initiation and progression. Noncoding RNAs (ncRNAs) have been revealed to participate in osteoarthritis development. In this review, we describe the pivotal functions and molecular mechanisms of numerous lncRNAs in osteoarthritis progression. We mention that long noncoding RNAs (lncRNAs) could be biomarkers for osteoarthritis diagnosis, prognosis and therapeutic targets. Moreover, we highlight the several compounds that alleviate osteoarthritis progression in part via targeting lncRNAs. Furthermore, we provide the future perspectives regarding the potential application of lncRNAs in diagnosis, treatment and prognosis of osteoarthritis.

甲壳素可转化为多种高附加值产品和系列化学品.该文综述了以甲壳素及其降解产物N-乙酰氨基葡萄糖转化制备平台化合物3-乙酰氨基-5-乙酰基呋喃和其他含氮化合物等化学品的研究进展.对以3-乙酰氨基-5-乙酰基呋喃作为平台化合物进一步转化为其他化合物进行了概述,并对这些领域的研究方向进行了展望,以期促进甲壳素转化含氮化学品领域的发展.

Endo-polygalacturonase II B (PgaB) from Aspergillus luchuensis was orthologous to endo-polygalacturonase from Aspergillus niger with mutant sites Thr42Ser and Glu52Ala. Mature pgaB gene was cloned from the genomic DNA of A. luchuensis and secreted expressed with over 90% purity in Pichia Pastoris and reached 1.0 g/L after 144 hr culture. The recombinant PgaB was further purified by Ni-NTA chromatography. Using polygalacturonic acid (PGA) as substrate, the optimal condition for PgaB activity was 40°C and pH 4.5, respectively. Km and Vmax of PgaB were 0.19 mmol/l and 103.58 μmol min-1  mg-1 , respectively. The relative activity of PgaB remained more than 60% and 40% of maximum activity at 50 and 60°C for 7 hr. PgaB increased the light transmittance by 85% and showed high efficiency in juice clarification. The main product was galacturonic acid oligosaccharides with degrees of polymers (DP) 1-3. The PgaB is a potential pectinolytic enzyme in food industries. PRACTICAL APPLICATIONS: Endo-polygalacturonase II B (PgaB) was identified from Aspergillus luchuensis, a filamentous fungus widely used in food and beverage fermentation in East Asia. PgaB still kept its most activity at 60°C for 7 hr. Polygalacturonic acid (PGA) can be digested effectively by the PgaB and the main products are galacturonic acid oligosaccharides with degrees of polymers (DP) 1-3. PgaB shows high efficiency in juice clarification. The PgaB is a potential pectinolytic enzyme for the applications in food industries.

Konjac glucomannan is safely and widely used in the functional food industry. Compared with glucomannan, glucomannan oligosaccharides have higher water solubility making them easier to absorb and utilize. These oligosaccharides are also associated with many biological activities. A novel glucomannan hydrolase PpGluA with high activity and substrate specificity which releases a series of konjac glucomannan oligosaccharides having DP 2–9 is described here. Selenium is one of the essential trace elements for humans. The selenium-modified glucomannan oligosaccharides were prepared by the sodium selenite-nitric acid method for the first time. Antitumor activity studies demonstrated that selenium-modified glucomannan oligosaccharides had better activity than inorganic sodium selenite and glucomannan oligosaccharides and inhibited tumor by inducing apoptosis through the mitochondrial pathway. This study suggests that selenium-modified glucomannan oligosaccharides may be have potential as a new functional food for inhibition of tumors.

2,5-Furandicarboxylic acid (FDCA) is a promising bio-based building block as a green alternative to petroleum-based terephthalate in polymer production. Most of FDCA is produced by the oxidation of 5-hydroxymethylfurfural (HMF), which is derived from hexose. Although the chemical conversion is widely applied, the biocatalytic conversion is expected due to the relatively mild condition and fewer toxic chemicals consumption. However, it's difficult to catalyze the conversion of HMF to FDCA by a single enzyme. Here, a newly enzymatic cascade reaction process was introduced with a yield of 94.0% by the combination of 5-hydroxymethylfurfural oxidase (HMFO) and lipase. Briefly, a flavine adenosine dinucleotide independent (FAD-independent) HMFO of Methylovorus sp. MP688 was used to convert HMF to 2,5-diformylfuran (DFF) and 5-formylfuroic acid (FFA), which consecutively transformed to FDCA by a lipase Novozym 435. To facilitate the purification, a coupled alkali precipitation was developed to recover FDCA from organic solvent with an improved purity from 84.4 to 99.0% and recovery of 78.1%. This work will help to construct the green biorefinery route for the bulk FDCA from biomass by enzymes.

Acetoin (3-hydroxy-2-butanone) is an important four-carbon compound widely used in the food industry and other industrial applications. This study aimed to identify a novel butanediol dehydrogenase that can efficiently catalyze the formation of acetoin. A novel butanediol dehydrogenase, BtBDH, was identified from Bacillus thuringiensis subsp. Kurstaki ACCC 10066, and its enzymatic properties were characterized. The optimum pH and temperature for the oxidation activity of BtBDH were 10.0 and 50 °C, respectively, and those for the reduction activities were 7.5 and 35 °C, respectively. In addition, it exhibits stability over a wide pH range (6–10) and temperatures up to 70 °C. BtBDH showed good stability after storage for 3 months at 4 °C. Moreover, ethylenediaminetetracetic acid (EDTA) inhibits the enzymatic activity of BtBDH, indicating that the enzyme is metal-dependent. This study characterized a novel (2R,3R) −2,3-butanediol dehydrogenase. Its excellent oxidation activity and stability ensure its great industrial application potential in the production of acetoin.

Carbohydrates are major biomass source in fuel-targeted biorefinery. Arthrospira platensis is the largest commercialized microalgae with good environmental tolerance and high biomass production. However, the traditional target of A. platensis cultivation is the protein, which is the downstream product of carbohydrates. Aiming to provide the alternative non-food carbohydrates source, the feasible manipulation technology on the cultivation is needed, as well as new separation methodology to achieve maximum utilization of overall biomass. The present study aimed to demonstrate the feasibility of industrially producing carbohydrate-enriched A. platensis and characterize the structure of the polysaccharide involved. Cultivated in industrial-scale outdoor open raceway ponds under nitrogen limitation, A. platensis accumulated maximally 64.3%DW of carbohydrate. The maximum biomass and carbohydrate productivity reached 27.5 g m−2 day−1 and 26.2 g m−2 day−1, respectively. The efficient extraction and purification of the polysaccharides include a high-pressure homogenization-assisted hot water extraction followed by flocculation with a non-toxic flocculant ZTC1 + 1, with the polysaccharide purity and total recovery reaching 81% and 75%, respectively. The purified polysaccharide was mainly composed of (1→3)(1→4)- or (1→3)(1→2)-α-glucan with a molecular weight of 300–700 kDa, which differed from the commonly acknowledged glycogen. By the way of controlled nitrogen limitation, the high carbohydrate production of A. platensis in the industrial scale was achieved. The α-glucan from A. platensis could be a potential glucose source for industrial applications. A non-toxic separation method of carbohydrate was applied to maintain the possibility of utilization of residue in high-value field.

固定化酶作为一种绿色高效的生物催化剂,其性能远超游离酶.目前酶的固定化技术适用范围仍然较小,酶的研究范围多停留在模型酶阶段,扩大固定化酶的研究范围具有十分重要的意义.金属有机骨架材料(MOFs)作为酶固定化的载体在近些年得到了广泛的探索,但是具有生物功能的酶-MOFs复合材料的许多特性仍有待挖掘.采用仿生矿化的合成方法将5-羟甲基糠醛氧化酶(HMFO)固定到以沸石咪唑酯(ZIF-8)为代表的MOFs材料中,制备得到一种新的生物催化剂HMFO@ZIF-8,扫描电子显微镜表征其形态区别于经典的菱形十二面体.采用考马斯亮蓝法测定蛋白质浓度,计算得到酶的固定化效率达到89.0％.HMFO@ZIF-8催化5-羟甲基糠醛的转化率达到84.3％,收率和选择性均高于游离酶.拓展了MOFs固定化酶的研究范围,为研究其他生物大分子复合材料的生物催化剂提供一定的借鉴意义.

Chito/chitin oligosaccharides has positive effects on triggering the resistance mechanism of plants. In 1980, it was first reported that chito/chitin oligosaccharide could induce plant immunity. Since then, chito/chitin oligosaccharide has been considered as a potent elicitor of plant immunity that is used in many crops, such as rice, wheat, cucumber, pepper, oilseed rape, tomato, bean, tobacco, flower crops, fruit crops and so on. This part summarized the study about the effect of the chito/chitin oligosaccharide application in lab/field experiments, In the studies, researchers found that chito/chitin oligosaccharide stimulates a variety of plant responses, which are mainly about the effects of chito/chitin oligosaccharide on inducing plant disease resistance, promoting plant growth and preventing plant from abiotic stress, such as cold stress. These effects demonstrate the ability of chito/chitin oligosaccharide to control plant fungi and virus diseases, enhance plant growth and yield, as well as prolong the shelf life of flowers and fruits. Meanwhile, the applications of chito/chitin oligosaccharide derivatives chemical constitution and the effect of used as plant disease vaccine are also reviewed, and the complexity mechanism of chito/chitin oligosaccharide activated plant immunity is discussed. Plant induced disease resistance and the mechanism has been studied for a long time, but its application in agricultural production has not fully developed. Considering the excellent physical properties - high solubility, nontoxicity, bio-compatibility and the cost advantage - rich in production, low cost, the excellent effects on plants, chito/chitin oligosaccharide showed huge economic benefits and will have a good application prospect.

为获得高硒含量的葡甘寡糖,以天然魔芋葡甘聚糖经酶解制备的魔芋葡甘寡糖为原料,合成硒化魔芋葡甘寡糖,采用傅里叶变换红外光谱和核磁共振波谱对其结构进行表征,采用电感耦合等离子体质谱法检测其硒含量;利用体外抗氧化实验研究其抗氧化活性.结果表明:合成的硒化魔芋葡甘寡糖为葡甘寡糖亚硒酸酯,硒含量达5.9 g/kg,远高于富硒土壤种植魔芋提取的天然多糖;硒化魔芋葡甘寡糖对羟自由基具有很好的清除作用,可作为理想的抗氧化有机硒食品原料.

Colon cancer (CC) is the third common neoplasm worldwide, and it is still a big challenge for exploring new effective medicine for treating CC. Natural product promoting human health has become a hot topic and attracted many researchers recently. Pectin, a complex polysaccharide in plant cell wall, mainly consists of four major types of polysaccharides: homogalacturonan, xylogalacturonan, rhamnogalacturonan I and II, all of which can be degraded into various pectin oligosaccharides (POS) and may provide abundant resource for exploring potential anticancer drugs. POS have been regarded as a novel class of potential functional food with multiple health-promoting properties. POS have antibacterial activities against some aggressive and recurrent bacterial infection and exert beneficial immunomodulation for controlling CC risk. However, the molecular functional role of POS in the prevention of CC risk and progression remains doubtful. The review focuses on antioxidant and anti-inflammatory roles of POS for promoting human health by regulating some potential oxidative and inflammation-activated pathways, such as ATP-activated protein kinase (AMPK), nuclear factor erythroid-2-related factor-2 (Nrf2), and nuclear factor-κB (NF-κB) pathways. The activation of these signaling pathways increases the antioxidant and antiinflammatory activities, which will result in the apoptosis of CC cells or in the prevention of CC risk and progression. Thus, POS may inhibit CC development by affecting antioxidant and antiinflammatory signaling pathways AMPK, Nrf2, and NF-κB. However, POS also can activate signal transduction and transcriptional activator 1 and 3 signaling pathway, which will reduce antioxidant and anti-inflammatory properties and promote CC progression. Specific structural and structurally modified POS may be associated with their functions and should be deeply explored in the future. The present review paper lacks the important information for the linkage between the specific structure of POS and its function. To further explore the effects of prebiotic potential of POS and their derivatives on human immunomodulation in the prevention of CC, the specific POS with a certain degree of polymerization or purified polymers are highly demanded to be performed in clinical practice.

Colon cancer (CC) is the third common neoplasm worldwide, and it is still a big challenge for exploring new effective medicine for treating CC. Natural product promoting human health has become a hot topic and attracted many researchers recently. Pectin, a complex polysaccharide in plant cell wall, mainly consists of four major types of polysaccharides: homogalacturonan, xylogalacturonan, rhamnogalacturonan I and II, all of which can be degraded into various pectin oligosaccharides (POS) and may provide abundant resource for exploring potential anticancer drugs. POS have been regarded as a novel class of potential functional food with multiple health-promoting properties. POS have antibacterial activities against some aggressive and recurrent bacterial infection and exert beneficial immunomodulation for controlling CC risk. However, the molecular functional role of POS in the prevention of CC risk and progression remains doubtful. The review focuses on antioxidant and anti-inflammatory roles of POS for promoting human health by regulating some potential oxidative and inflammation-activated pathways, such as ATP-activated protein kinase (AMPK), nuclear factor erythroid-2-related factor-2 (Nrf2), and nuclear factor-kappa B (NF-kappa B) pathways. The activation of these signaling pathways increases the antioxidant and antiinflammatory activities, which will result in the apoptosis of CC cells or in the prevention of CC risk and progression. Thus, POS may inhibit CC development by affecting antioxidant and antiinflammatory signaling pathways AMPK, Nrf2, and NF-kappa B. However, POS also can activate signal transduction and transcriptional activator 1 and 3 signaling pathway, which will reduce antioxidant and anti-inflammatory properties and promote CC progression. Specific structural and structurally modified POS may be associated with their functions and should be deeply explored in the future. The present review paper lacks the important information for the linkage between the specific structure of POS and its function. To further explore the effects of prebiotic potential of POS and their derivatives on human immunomodulation in the prevention of CC, the specific POS with a certain degree of polymerization or purified polymers are highly demanded to be performed in clinical practice.

Green alga Chlorella is rich in nutrients and oil,attracting the wide attention of researchers. However,algal residues cannot be used fully after the extraction of the active substance because of lack of high-efficient technology.In this paper,three enzymes,cellulase,pectinase and neutral protease,were screened for extracting polysaccharides from the algal residues of Chlorella.The orthogonal experiments were carried out to optimize the reaction conditions of the three enzymes.Two double-enzymatic cascade processes for extracting polysaccharides from Chlorella were established via optimal reaction conditions. The extraction rate of polysaccharide was found to be up to 20.80% and 20.19%,respectively,which was much higher than that of the single enzyme alone,also significantly higher than the sum of extraction rates of two separate enzymes alone,and the extraction rates were doubled.The finding provides a technic basis for making full use of Chlorella residues,promoting the development of Chlorella industry.

Chitooligosaccharide (COS) has been shown to regulate many biological functions, such as antimicrobial effect and antitumor activity. In the present study, highly N-acetylated chitooligosaccharide (NACOS) was prepared by N-acetylation of COS, and the anti-inflammatory activity of NACOS in macrophages were evaluated. The results indicated NACOS significantly suppressed the LPS-induced pro-inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) expression. Furthermore, the increased levels of reactive oxygen species (ROS) and nitric oxide (NO) were repressed by NACOS in a dose dependent manner. However, NACOS itself had no significant effect on the cell viability and cellular morphology. Signal transduction studies demonstrated that NACOS remarkably inhibited LPS-enhanced phosphorylation of phosphatidylinositol 3-kinase (PI3K) and Akt. These findings provide a possible molecular mechanism by which NACOS inhibit LPS-induced inflammatory response in macrophages, and a basis for utilizing NACOS in pharmaceutical therapy against inflammation.