土壤中选育产壳聚糖酶菌株的研究

采用酶法降解壳聚糖具有反应条件易于控制、产物安全性高和环境污染少等独特的优越性。因此,筛选出高活力产壳聚糖酶菌株有着重要意义。该研究以不同地区采集土样分离出的1株细菌为出发菌株S,采用紫外线诱变（30W,20cm,5min）,经初筛和复筛及控温培养处理,获得了一株产壳聚糖酶较好的突变菌株,结果表明：所产酶活力达到3．47U/ml,酶活力提高近2倍,并具有较好的遗传稳定性,明显优于出发菌株,为发酵产壳聚糖酶的进一步研究提供了高产菌株。     

Isolation and Characterization of a Novel Chitosan-Binding Protein from Non-Heading Chinese Cabbage Leaves

To know the mechanism of ammonia assimilation in non-heading Chinese cabbage (Brassica campestris L. ssp. chinensis (L.) Makino) leaves regulated by chitosan (CTS), a CTS-binding protein was isolated from non-heading Chinese cabbage leaves using the chitosan affinity chromatography approach and this CTS-binding protein was partially characterized. The profile of the 53.1 kDa purified protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis was compared with the native molecular weight of 106.5 kDa, which indicated that the purified protein was a dimer with identical subunits. After isoelectric focusing, a band was obtained at pH 8.25. The agglutination test and periodic acid-Schiff staining further revealed that the protein was a glycoprotein with lectin activity. Moreover, the purified protein contained 17.4% (w/w) neutral carbohydrate and 82.56% (w/w) protein. The comparison of this protein and the 67 kDa CTS-binding protein isolated previously from Rubus culture tissue exhibited some differences in characterization. According to results of peptide mass fingerprinting analysis, the protein purified in the present study does not show any similarity with any protein in the protein data bank. Thus, it was deduced that the protein purified in the present study is a novel CTS-binding protein.     

二氧化氯在葡萄保鲜中的应用研究

用壳聚糖作涂膜剂,ClO2作保鲜剂,研究了葡萄的保鲜效果。结果表明,能有效的控制葡萄的腐烂率和鲜重损失,保持感官品质,延长存放期。     

壳聚糖固定化谷胱甘肽硫转移酶的研究

目的：利用壳聚糖固定日本血吸虫谷胱甘肽硫转移酶,并对固定化酶性质及体外催化活性进行研究。方法：利用大肠杆菌BL21(DE3)表达日本血吸虫谷胱甘肽硫转移酶,并从中粗提谷胱甘肽硫转移酶,将其固定在用戊二醛交联的壳聚糖载体上,对游离酶和固定酶的最适pH、温度,游离酶和固定化酶对底物1-氯-2,4-二硝基苯(CDNB)和谷胱甘肽(GSH)的亲和力,温度的稳定性进行了研究。结果：固定化酶活回收率可达41．6％,最适pH6．5～7．0,最适温度37℃,对底物(CDNB和GSH)的亲和力略有下降,对温度稳定性大大提高。在体外固定化酶有很好的催化解毒作用。     

NUTRITIONAL VALUE OF THE FIELD CRICKET （GRYLLUS TESTACEUS WALKER）

The chemical composition and the nutritional quality of protein, fatty acids and chitin of adult field cricket Gryllus testaceus Walker were investigated. The adult insect contalned: crude protein 58.3 %; fat 10.3 %, chitin 8.7 % and ash 2.96 % on dry matter basis respectively. The essential amino acid profile compared well with FAO/WHO recommended pattern except for cysteine and methionine. The fatty acid analysis showed unsaturated acid of the field cricket to be present in high quantities, and the total percentage of oleic acid, linolic acid and linolenic acid was 77.51%. The chitin content of the insect was 8.7 % with a better quality than the commercial chitin that was prepared from shells of shrimp and crab. Therefore the chemical composition of the field cricket indicates the insect to be a good supplement to nutrition for food and feed, even a raw material for medicine.     

胶原／壳聚糖复合膜的制备及止血效果的研究

目的 以胶原和壳聚糖制备复合膜,检验其止血效果,并探讨其止血原因。材料与方法：以酸解法从牛腱中提取胶原,用甲壳素制得壳聚糖,以胶原和壳聚制成复合膜,通过动物实验测不同配比的复合膜对出血创面的止血时间,并与其它止血材料做对比。结果：各种配比的复合膜的止血效果均比明胶等一般止血材料好。结论：胶原/壳聚糖复合膜有良好的止血作用,可望在外科手术上得到广泛应用。     

成纤维细胞在壳聚糖/PHEA水凝胶膜上的粘附与生长行为

水凝胶是一类广泛溶涨于水 ,呈三维网状结构的聚合物具有很高的生物相容性 ,广泛地用于生物材料 ,如眼球的晶状体、人造脏器以及人造皮肤等。高含水量的水凝胶不利于细胞粘附 ,研究能使细胞粘附并生长的水凝胶是开发其在组织工程材料领域应用的关键 ,细胞易于粘附的水凝胶可用于细胞培养基材和组织工程移植支架材料。一般来说 ,由于细胞表面带有负电荷 ,带正电荷的基材表面 (如 ,多熔素 (Ｐｏｌｙｌ ｙｓｉｎｅ) )有利于细胞粘附 ,而带有酸性或中性基团的材料不利于细胞粘附[1 ] ,而且带高负电荷密度的基材会导致细胞新陈代谢的紊乱并抑制细…     

壳聚糖包衣对油菜种子萌发和幼苗生长以及几个生理生化指标的影响

不同酸溶剂与不同分子量壳聚糖包衣均促进油菜种子萌发和幼苗生长。其中壳聚糖无机酸溶剂包衣种子发芽率及幼苗生化等指标优于有机酸溶剂 ;小分子量壳聚糖包衣优于大、中分子量的。壳聚糖包衣处理有促进植物生长之功能     

天然多糖——几丁/壳聚糖在烟草工业上的应用——新型高效吸附剂的研究初探

二 将壳聚糖微粒化,用于香烟的过滤咀中,利用壳聚糖的吸附特性,测定其对烟气中的总粒相物及植物碱的吸附能力,比较其与醋酸纤维吸附能力的大小,得到令人欣喜。的结果。     

锰过氧化物酶的耦合固定化及其性质研究

分别采用海藻酸钠、明胶和壳聚糖为载体,并以戊二醛为交联剂,通过包埋-交联和吸附-交联两种耦合固定化方法制备固定化锰过氧化物酶。探讨了酶的不同固定化条件和固定化酶的部分性能。与游离酶相比,制备的3种固定化酶最适反应pH分别由7.0降低到5.0、5.0和3.0,最适反应温度分别由35℃升高到75℃、55℃和75℃。3种固定化酶的耐热性都显著提高,其中用壳聚糖制成的固定化酶在pH 2.2～11的宽范围内表现出很好的酸碱耐受性。30℃连续测定6～9次酶活力,重复使用的3种固定化酶显示出良好的稳定性。将固定化酶应用在偶氮染料的脱色中,用明胶制成的固定化酶在静置和摇床条件下,以及用海藻酸钠制成的固定化酶在摇床条件下,均表现出与游离酶相近的脱色能力,并且在重复进行的摇床实验中,脱色能力未降低,反应前后的酶活力均没有损失。