内质网应激预处理对人正常肝细胞缺氧再复氧损伤的保护作用

目的:研究内质网应激预处理对人肝细胞缺氧复氧损伤的保护作用。方法:将培养的人肝细胞分为4组:正常对照(C)组、细胞缺氧复氧损伤(H/R)组、内质网应激(ER)组、内质网应激预处理(ERP+H/R)组。收集各组细胞,以流式细胞仪检测细胞凋亡,Western-bloting及RT-PCR检测内质网应激特异蛋白GRP78表达水平,并通过透射电镜观察各组细胞超微结构改变。结果:ERP+H/R组细胞凋亡率明显低于H/R组(P<0.05),ER及ERP+H/R组GRP78蛋白表达明显高于H/R组(P<0.05)。结论:内质网应激预处理对肝细胞缺氧复氧损伤具有明显的保护作用,内质网应激特异性蛋白GRP78可能在肝细胞缺氧复氧损伤中作为一种关键性的保护蛋白出现。     

酶法产品推动原料药技术市场快进

近日,中化帝斯曼公司宣布,在华第3只酶法产品头孢克洛正式上市,这意味着酶法技术在国内推广应用再进一步,也凸显其对酶法产品在中国市场的潜力寄予厚望。依据中化帝斯曼提供的数据,酶法产品相对于化学合成在特殊化学原料、有机溶剂和COD排放等领域,以及原料产品本身的稳定性、纯度、色泽和气味等方面同样优势明显。中化帝斯曼有关负责人表示,酶法产品符合中国原料药产业升级和污染控制的需求,也符合中国     

溶剂稳定性蛋白酶产生菌Bacillus licheniformis YP1的发酵优化

溶剂稳定性蛋白酶产生菌Bacillus licheniformis YP1分离自油田土样。考察了碳源、氮源、金属离子等营养因素对YP1菌株发酵产溶剂稳定性蛋白酶的影响。YP1菌株发酵产胞外蛋白酶的最佳碳源为淀粉,果糖、甘露糖和乳糖显著抑制产酶;最佳氮源为酵母膏,干酪素、酵母粉和牛肉膏促进产酶,玉米浆和尿素显著抑制产酶。Mn^2＋可以显著促进酶活,Mg^2＋可以促进产酶,在初步优化的培养条件下,YP1菌株的胞外蛋白酶产量达980U。     

碱与微波联合处理蔗渣对里氏木霉发酵产纤维素酶的影响

以蔗渣为原料,采用碱和微波辐射联合处理后用于里氏木霉纤维素酶的液态发酵。采用单因素试验与正交试验确定了最佳的处理条件为:0.30 mol/L的NaOH溶液浸泡,微波功率160 W,处理5 min。在此条件下得到的单位能耗的酶活净增值最高。后续发酵结束后,酶活较未经处理的蔗渣发酵后所得酶活有显著提高。其中,β-葡萄糖苷酶活、滤纸酶(FPase)活、羧甲基纤维素酶(CMCase)活分别提高了81.3%,88.2%,154.5%。     

纤维质原料预处理技术

随着石油资源的大量消耗和逐步枯竭,寻找可再生性的替代能源,特别是新的液态燃料,已成为维持人类社会可持续发展的紧迫任务。在可再生性替代能源——生物能源领域发展力度最大的品种是燃料乙醇。但是越来越多的人们已经认识到,随着世界人口的增长,用淀粉和糖类生产燃料和化工产品的发展将受到很大的限制。只有粮食、食糖生产过剩的国家,才能将大量以粮食和食糖作为原料生产的乙醇用作汽车燃料。而植物光合作用产物的绝大部分为植物的枝、干、叶等木质纤维素类,是纤维素、半纤维素和木质素等聚合物的复合物,其中纤维素和半纤维素都可以被转化成乙醇,理论得率可以同粮食相仿（大于400L／t）。因而,即使像美国那样粮食和土地资源非常丰富的国家,目前也十分重视利用植物纤维原料生产乙醇技术的研究。 近年来,纤维素乙醇技术发展较快,突破了一些关键技术的瓶颈,取得了一些进展。为此,我们特别邀请由山东大学微生物技术国家重点实验室主任曲音波教授领衔的团队,围绕纤维素乙醇生产相关技术,分别就纤维质原料预处理技术、纤维素酶生产技术等进展进行连载,希望更多的读者增加对纤维素乙醇技术的了解。     

优化细胞表面组分与结构以提高P.Putida 5-x细胞的重金属吸附能力

研究了生物吸附剂Pseudomonas putida 5-X细胞的最佳制备条件,以提高其对重金属的吸附能力。并用Pseudomonas putida 5-X细胞为生物吸附剂处理含铜离子城市污水。实验结果表明,在优化的条件下,Pseudomonas putida 5-x细胞对铜离子的吸附容量可达87．3mg／g,经生物吸附过程处理后,废水中Cu^2 的含量降低至微量级,而且该吸附剂可有效循环使用5次。     

超声提取和超声水解法从野葛根中提取纯化葛根素和大豆苷元

采用超声法从野葛根中提取葛根异黄酮,再将提取物在盐酸水溶液中超声水解结合有机溶剂萃取法从野葛根中分离纯化葛根素和大豆苷元。葛根素收得率为1．2％,纯度为97．8％;大豆苷元收得率为0．5％,纯度为98．2％。超声法从野葛根中提取分离葛根异黄酮活性成分葛根素和大豆苷元具有省时、节能、提取率和产品纯度高的优点。     

Effects of Temperature Acclimation Pretreatment on the Ultrastructure of Mesophyll Cells in Young Grape Plants （Vitis vinifera L. cv. Jingxiu） Under Cross-Temperature Stresses

Leaves from annual young grape plants （Vitis vinifera L. cv. Jingxiu） were used as experimental materials. The ultrastructural characteristics of mesophyll cells in chilling-treated plants after heat acclimation （HA） and in heat-treated plants after cold acclimation （CA） were observed and compared using transmission electron microscopy. The results showed that slight injury appeared in the ultrastructure of mesophyll cells after either HA （38℃ for 10 h） or CA （8℃ for 2.5 d）, but the tolerance to subsequent extreme temperature stress was remarkably improved by HA or CA pretreatment. The increases in membrane permeability and malondialdehyde concentration under chilling （0℃） or heat （45℃） stress were markedly inhibited by HA or CA pretreatment. The mesophyll cells of plants not pretreated with HA were markedly damaged following chilling stress. The chloroplasts appeared irregular in shape, the arrangement of the stroma lamellae was disordered, and no starch granules were present. The cristae of the mitochondria were disrupted and became empty. The nucleus became irregular in shape and the nuclear membrane was digested. In contrast, the mesophyll cells of HA-pretreated plants maintained an intact ultrastructure under chilling stress. The mesophyll cells of control plants were also severely damaged under heat stress. The chloroplast became round in shape, the stroma lamellae became swollen, and the contents of vacuoles formed clumps. In the case of mitochondria of control plants subjected to heat stress, the outer envelope was digested and the cristae were disrupted and became many small vesicles. Compared with cellular organelles in control plants, those in CA plant cells always maintained an integrated state during whole heat stress, except for the chloroplasts, which became round in shape after 10 h heat stress. From these data, we suggest that the stability of mesophyll cells under chilling stress can be increased by HA pretreatment. Similarly, CA pretreatment can protect chloroplasts, mitochondria, and the nucleus against subsequent heat stress; thus, the thermoresistance of grape seedlings was improved. The results obtained in the present study are the first, to our knowledge, to offered cytological evidence of cross-adaptation to temperature stresses in grape plants.     

黄花杓兰种子无菌萌发的培养条件研究

授粉１５周后的黄花杓兰（Cypripedium flavum P.F.Hunt et Summerh.)种子经０．５％ＮaClO溶液处理后,无菌下播于培养基因表面,２０周后种子最高萌发率达到９０％。ＫＴ和ＢＡ促进兰花种子萌发的机理是作为一种萌发诱导物质直接起作用。而不仅仅是拮抗ＡＢＡ的抑制作用而促进种子的萌发,培养基,激素和种子预处理萌发率高低的关键,种皮是阻碍黄花杓兰种子萌发的主要原因之一。