自溶超声波耦合法提取啤酒废酵母中β-1,3-D-葡聚糖

采用自溶-超声波耦合法提取啤酒废酵母中β-1,3-D-葡聚糖。首先以自溶率为考察指标,将单因素和正交实验相结合,结果显示,pH=5.0条件下,质量分数5%NaCl和体积分数1.5%乙酸乙酯混合添加可以最大限度地促进酵母细胞的自溶,从而促进酵母细胞质壁分离。进而,采用超声波法从自溶后收集的细胞壁沉淀中提取β-1,3-D-葡聚糖,以质量分数2%NaOH作超声溶剂,利用Box-Behnken设计考察了超声功率、超声时间和超声次数对葡聚糖提取率的影响,确定最佳提取条件为:超声功率550 W,超声时间33 min,超声次数2次,在该条件下葡聚糖提取率达到50.5%,与纯超声波提取葡聚糖法相比提取率提高了2倍。     

红酵母细胞壁中主要多糖含量和类胡萝卜素产量的相关性研究

对红酵母菌株不同培养条件下类胡萝卜素产量和红酵母细胞壁中主要多糖β-1,3-D-葡聚糖、甘露聚糖含量进行了分析.结果表明:当葡萄糖作为碳源、(NH4)2SO4作为氮源且添加量为10 g·L-1、培养时间为72 h、pH值为5时,类胡萝卜素产量、β-1,3-D-葡聚糖含量和甘露聚糖含量均达到最大值,分别为(14.98±0.12)mg·L-1、(38.89±0.21)%和(6.12±0.13)%.同时发现红酵母细胞壁中β-1,3-D-葡聚糖、甘露聚糖的含量与类胡萝卜素产量间均存在正相关关系,这表明类胡萝卜素合成代谢途径和这两种多糖的合成代谢途径间存在一定的关系.     

自溶-超声波耦合法提取啤酒废酵母中β-(1,3)-D-葡聚糖研究

采用自溶-超声波耦合法提取啤酒废酵母中β-(1,3)-D-葡聚糖。首先以自溶率为考察指标,将单因素和正交试验相结合,结果显示pH5.0条件下,5% NaCl和1.5 %乙酸乙酯混合添加可以最大程度的促进酵母细胞的自溶,从而促进酵母细胞质壁分离。进而采用超声波法从自溶后收集的细胞壁沉淀中提取β-(1,3)-D-葡聚糖,以2% NaOH作超声溶剂,利用Box-Behnken设计考察了超声功率,超声时间和超声次数对葡聚糖提取率的影响,确定最佳提取条件为：超声功率550W,超声时间33min,超声次数2次,在此条件下葡聚糖提取率达到50.5%,与纯超声波提取葡聚糖法相比提取率提高了2倍。     

CMG-EGCG的合成及其抗氧化活性

采用1-(3-二甲基氨基丙基)-3-乙基碳二亚胺盐酸盐/4-二甲氨基吡啶化学偶联法将表没食子儿茶素没食子酸酯(EGCG)接枝到羧甲基酵母(1,3/1,6)-β-D-葡聚糖(CMG)的羧基上.通过FTIR、UV-Vis光谱和TGA对羧甲基酵母(1,3/1,6)-β-D-葡聚糖-EGCG(CMG-EGCG)的结构和热稳定性...     

新型抗真菌药阿尼芬净的研究进展

阿尼芬净是一种新型的棘白菌素类抗真菌药,能够抑制真菌细胞壁中1,3-β-D-葡聚糖的合成,对真菌有较高的特异性;对于念珠菌属以及曲霉菌属均有良好的抗菌作用,且安全性较高。介绍了阿尼芬净的作用机制、抗菌活性、药动学和临床评价。     

CMG-EGCG聚合物的合成及其抗氧化活性

采用1-(3-二甲基氨基丙基)碳二亚胺盐酸盐/4-二甲氨基吡啶化学偶联法将表没食子儿茶素没食子酸酯（EGCG）接枝到羧甲基酵母(1,3/1,6)-β-D-葡聚糖（CMG）的羧基上。通过FTIR、UV-Vis光谱和TGA对羧甲基酵母(1,3/1,6)-β-D-葡聚糖-EGCG（CMG-EGCG）的结构和热稳定性进行了表征，并分析了其抗氧化活性。Folin–Ciocalteu法测得CMG-EGCG中EGCG的含量为28.90 mg/g。结果表明，与CMG相比，CMG-EGCG具有更好的热稳定性和抗氧化活性，在质量浓度1.0×10-3 mg/L时，对DPPH自由基的清除率为78.85%，对ABTS自由基的清除率为93.00%，还原能力为1.15，可以应用于化妆品原料和食品工业。     

在植物病原真菌防治策略中的克隆化几丁质酶

几丁质酶所水解的几丁质——β-1,4-联乙酰基-D-葡萄糖胺的同聚物,为大部份真菌(包括子囊菌、担子菌和不完全真菌)细胞壁的主要成份。人们已从真菌、细菌和植物中分离得几丁质酶,它通过使菌丝顶端的几丁质合成退化以抑制真菌的生长。细菌(如沙雷氏菌属)和真菌(如木霉菌属)合成和分泌几丁质酶,则根据周围生长介质中所存在的几丁质的诱导而产生。在健康植物中,几丁质酶的含量很低,它们的表达方法随着诸如抗微生物化合物、蛋白酶抑制剂、β-1,3-葡聚糖酶等其他组份及受到病原体侵袭时,由植物防卫系统的诱导而增加。体内细胞中诱导产生几丁质酶的积累,其既不在细胞内,亦不在细胞外。迄今为     

棘白菌素类抗真菌药米卡芬净研究进展

米卡芬净是一种新型的棘白菌素类抗真菌药物,具有很广的抗菌谱.它能够抑制真菌细胞壁的1,3-β-D葡聚糖的合成,对真菌细胞具有较高的特异性.介绍了米卡芬净的体外抗菌活性、药动学以及药物相互作用方面的研究进展.     

含有1,3-β葡聚糖和植物提取复配物的保湿研究

研究测试1,3-β葡聚糖和植物提取复配物在化妆品中的保湿作用以及运用,对比透明质酸的保湿功效.采用CM825型皮肤水分对测试仪,对两种添加有该原料的产品进行皮肤水份含量测试.两种产品都具有相对不错的保湿作用,只含有0.05％1,3-β葡聚糖粉末和2％MF-800的精华液对于皮肤角质层的保湿能力强于只含有0.1％透明质酸...     

β-葡聚糖在化妆品中的应用

介绍了β-葡聚糖的结构、分类和基本特性,以及β-葡聚糖的作用机理;阐述及分析了β-葡聚糖在化妆品中可具有抗衰老、祛皱、修复疤痕、抗敏消炎等多种功效及燕麦β-葡聚糖的经皮渗透作用,该产品市场应用前景广阔.     

Effects of Purified Saccharomyces cerevisiae (1→3)-β-Glucan on Venous Ulcer Healing

Water-insoluble glucan was isolated from the baker's yeast Saccharomyces cerevisiae. The yeast cells were treated with alkali and the residue then with acid. Chemical and NMR (1D and 2D) analyses showed that a linear (1→3)-β-glucan was purified that was not contaminated with other carbohydrates, proteins or phenolic compounds. The effects of the glucan on wound healing were assessed in human venous ulcers by histopathological analysis after 30 days of topical treatment. (1→3)-β-glucan enhanced ulcer healing and increased epithelial hyperplasia, as well as increased inflammatory cells, angiogenesis and fibroblast proliferation. In one patient who had an ulcer that would not heal for over 15 years, glucan treatment caused a 67.8% decrease in the area of the ulcer. This is the first study to investigate the effects of (1→3)-β-glucan on venous ulcer healing in humans; our findings suggest that this glucan is a potential natural biological response modifier in wound healing.     

羧甲基酵母葡聚糖在护肤品中的应用研究

以一氯乙酸钠为醚化剂羧甲基化修饰酵母β葡聚糖,通过测定红外光谱和取代度鉴定制备的羧甲基葡聚糖样品。比较改性前后酵母葡聚糖的吸湿、保湿性能,初步研究羧甲基葡聚糖的人体皮肤刺激性和改善皮肤纹理深度的作用。结果显示制得的羧甲基葡聚糖取代度为0.60,羧甲基化修饰后葡聚糖保湿吸湿能力增强,能减轻由果酸引起的皮肤红斑和刺痛感,并具有抗皱功能,是一种有效的功能性皮肤护理成分。     

Spent Brewer’s Yeast as a Source of Insoluble β-Glucans

In the brewing process, the consumption of resources and the amount of waste generated are high and due to a lot of organic compounds in waste-water, the capacity of natural regeneration of the environment is exceeded. Residual yeast, the second by-product of brewing is considered to have an important chemical composition. An approach with nutritional potential refers to the extraction of bioactive compounds from the yeast cell wall, such as β-glucans. Concerning the potential food applications with better textural characteristics, spent brewer’s yeast glucan has high emulsion stability and water-holding capacity fitting best as a fat replacer in different food matrices. Few studies demonstrate the importance and nutritional role of β-glucans from brewer’s yeast, and even less for spent brewer’s yeast, due to additional steps in the extraction process. This review focuses on describing the process of obtaining insoluble β-glucans (particulate) from spent brewer’s yeast and provides an insight into how a by-product from brewing can be converted to potential food applications.     

Comparison of bioethanol production of simultaneous saccharification & fermentation and separation hydrolysis & fermentation from cellulose-rich barley straw

Cellulose rich barley straw, which has a glucan content of 62.5%, followed by dilute acid pretreatment, was converted to bioethanol by simultaneous saccharification and fermentation (SSF). The optimum fractionation conditions for barley straw were an acid concentration of 1% (w/v), a reaction temperature of 158 °C and a reaction time of 15 min. The maximum saccharification of glucan in the fractionated barley straw was 70.8% in 72 h at 60 FPU/gglucan, while the maximum digestibility of the untreated straw was only 18.9%. With 6% content WIS (water insoluble solid) for the fractionated barley straw, 70.5 and 83.2% of the saccharification yield were in SHF and SSF (representing with glucose equivalent), respectively, and a final ethanol concentration of 18.46 g/L was obtained under the optimized SSF conditions: 34 °C with 15 FPU/g-glucan enzyme loading and 1 g dry yeast cells/L. The results demonstrate that the SSF process is more effective than SHF for bioethanol production by around 18%.     

Chitinous polymers: extraction from fungal sources,characterization and processing towards value-added applications

Chitin, chitosan and their complexes with β-glucan (chitin–glucan complex, CGC, and chitosan–glucan complex, ChGC) are value-added polysaccharides extracted from the cell-walls of many fungi. Commercial chitin and its deacetylated form, chitosan, are currently obtained from marine waste material, mostly animal sources (crustaceans and marine invertebrates), through harsh chemical procedures that have low reproducibility due to the variability of the composition of the sources and their seasonal character. These disadvantages are overcome by using fungi as sources of chitinous polymers. The extraction of chitin/chitosan from fungi cell-walls has the great advantage of yielding products with stable composition and properties, using simpler procedures, with the added benefit of also generating CGC and ChGC, two copolymers that combine the proven properties of chitin/chitosan with those of β-glucans. Over the last decades, fungal chitinous polymers have been the focus of extensive research that included optimization of the cultivation conditions of a wide range of species and the development of optimized extraction, purification and characterization techniques, as well as the demonstration of the biopolymers' biological properties, which include immunomodulatory, anticancer, antioxidant and antimicrobial activity. Given these properties, several attempts were made to develop applications for them in areas ranging from biomedicine and pharmaceuticals to food and agriculture. Despite their wide range of proven functional properties that include the ability to form different polymeric structures, as well as biological activity, fungal chitinous biopolymers are still underexplored. Nevertheless, these biopolymers hold great potential for development into valuable products or applications that are surely worth further investigation. © 2019 Society of Chemical Industry     

磷酸酯化法制备可溶性酵母(1→3)-β-D-葡聚糖磷酸酯

研究了磷酸酯化法制备可溶性酵母(1→3)-β-D-葡聚糖磷酸酯的工艺,采用红外光谱和13C核磁共振光谱比较了酯化前后酵母(1→3)-β-D-葡聚糖的分子结构的变化,并通过E.coli诱导小鼠腹膜炎实验,考察酵母(1→3)-β-D-葡聚糖磷酸酯的的免疫活性。实验研究了尿素添加量、反应时间、反应温度和酯化剂配比对磷酸酯化反应的影响,得出制备可溶性酵母葡聚糖磷酸酯较适宜的反应条件:尿素15 g,反应时间5 h,温度100℃,酯化剂配比(体积比)11∶4,该条件下其得率达到80%,取代度0.055,溶解度122.8 mg/mL。红外光谱和13C核磁共振光谱表明:磷酸基团成功地链接在葡聚糖分子中的C2,C4和C6位,其中少量的磷酸基团取代在C4位。活性实验结果表明:磷酸化葡聚糖能有效提高E.coli诱导的患腹膜炎小鼠的免疫能力。     

A Murine Monoclonal Antibody to Glycogen: Characterization of Epitope‐Fine Specificity by Saturation Transfer Difference (STD) NMR Spectroscopy and Its Use in Mycobacterial Capsular α‐Glucan Research

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), is a major pathogen responsible for 1.5 million deaths annually. This bacterium is characterized by a highly unusual and impermeable cell envelope, which plays a key role in mycobacterial survival and virulence. Although many studies have focused on the composition and functioning of the mycobacterial cell envelope, the capsular α‐glucan has received relatively minor attention. Here we show that a murine monoclonal antibody (Mab) directed against glycogen cross‐reacts with mycobacterial α‐glucans, polymers of α(1–4)‐linked glucose residues with α(1–6)‐branch points. We identified the Mab epitope specificity by saturation transfer difference NMR and show that the α(1–4)‐linked glucose residues are important in glucan–Mab interaction. The minimal epitope is formed by (linear) maltotriose. Notably, a Mycobacterium mutant lacking the branching enzyme GlgB does not react with the Mab; this suggests that the α(1–6)‐branches form part of the epitope. These seemingly conflicting data can be explained by the fact that in the mutant the linear form of the α‐glucan (amylose) is insoluble. This Mab was subsequently used to develop several techniques helpful in capsular α‐glucan research. By using a capsular glucan‐screening methodology based on this Mab we were able to identify several unknown genes involved in capsular α‐glucan biogenesis. Additionally, we developed two methods for the detection of capsular α‐glucan levels. This study therefore opens new ways to study capsular α‐glucan and to identify possible targets for further research.     

Mild enzymatic isolation of mannan and glucan from yeast Saccharomyces cerevisiae

An enzymatic procedure to isolate polysaccharides from the yeast saccharomyces cerevisiae was developed which would both be environmentally friendly and preserve the native structure of the polymers. Two proteases and three enzyme cocktails were employed. To isolate the cell wall polysaccharides, the cell walls were first separated from the internal components by mechanical cell disruption. The quality of cell disruption was investigated for four types of glass beads with diameters from 0.25 – 1.5 mm and monitored via the inner cellular proteins released. With large glass beads (Ø = 0.75 – 1.5 mm) both brewer's and baker's yeast cells exhibited more than 90% cell disruption after as little as 12 min, whereas disruption was still incomplete with smaller beads. The isolated cell wall material was purified on microporous membranes, freeze-dried and then incubated with enzymes. Proteases caused protein lysis in the outer cell wall and released soluble mannan. The insoluble glucan was separated by centrifugation and the mannan was purified by dialysis or chromatography. In the digestion with proteases, complete conversion was achieved at concentrations higher than 240 mg g^–1 of cell wall material within 26 h. Cell walls from baker's yeast had to undergo a preliminary extraction with petroleum ether. Complete conversion was only possible with one of the enzyme cocktails investigated, and this was achieved after as little as 6 h for cell walls from both baker's and brewer's yeast. The activity of the two other enzyme cocktails investigated was weaker, with brewer's yeast cell walls generally reacting more readily than those of baker's yeast.     

生物柴油研究与应用现状及展望

简要介绍生物柴油的主要特性，评述其生产方法，重点介绍了国内外生物柴油研究应用情况及发展趋势，并指出低成本制备技术的开发是生物柴油领域研究的热点，最后对我国生物柴油的发展进行了展望。     

化妆品用主要动物性特殊添加成分

概述了化妆品中常用的特殊动物性成分的分类 ,详细介绍了几种主要特殊动物性成分如胶朊水解物、动物脏器提取物、蚕丝水解物、蜂产品、水貂油、蚯蚓提取物等的提取方法、应用范围及在化妆品中的作用 ,并对这些特殊动物性添加成分的功效作了评价