聚乙烯醇-硼酸固定化方法的改进

在固定化细胞技术中,常采用聚乙烯醇作为包埋介质,但聚乙烯醇固定化颗粒水溶膨胀性较大、易碎.笔者采用延时包埋法与加入化学药剂法对其进行了改进.结果表明,用这两种方法制得的聚乙烯醇固定化颗粒的水溶膨胀性大大减少、不易破碎;电镜观察发现,改进后的聚乙烯醇凝胶网状结构明显优于未经过改进的聚乙烯醇凝胶的网状结构.      

Contents Volume 3

Mitigation and Adaptation Strategies for Global Change -     

Isolierung von Pyridin-3-methyl-carbinol-glucuronid,einem Metaboliten des 3-Acetylpyridins

The Science of Nature -     

聚己内酯与聚羟基丁酸戊酸酯的脱氮性能对比

以可生物降解聚合物聚己内酯(PCL)和聚羟基丁酸戊酸酯(PHBV)作为反硝化缓释碳源和微生物载体,利用清水释碳和批式反硝化试验选出适用于再生水反硝化深度脱氮生物滤池的可生物降解碳源滤料,通过比较与分析碳源滤料的表面形态及物质特性和附着微生物的群落特征揭示其性能优越的原因.结果表明,PHBV反硝化启动时间短,反硝化速率高,剩余有机物浓度低,相比PCL具有更稳定持续的反硝化效果.原因是其表面粗糙,且含有大量C—O和CO等亲水性基团,易于微生物附着和降解利用;其表面附着的微生物种类多样,其中发硫菌属(Thiothrix)、假单胞属(Pseudomonas)、菌胶团属(Zoogloea)、黄杆菌属(Flavobacterium)和脱氯菌属(Dechloromonas)等优势菌属均具有异养反硝化功能.因此,PHBV更适合作为再生水反硝化深度脱氮生物滤池的碳源滤料.     

Molecular prenatal diagnosis of 3-hydroxy−3-methylglutaryl coa lyase deficiency

We report the first molecular prenatal diagnosis of 3-hydroxy-3-methylglutaryl CoA lyase (HL) deficiency. The proband had a classic but severe presentation with hypoketotic hypoglycaemia and acidosis, secondary mental retardation, and epilepsy, and HL deficiency was documented in cultured fibroblasts. We found him to be homozygous for the frameshift mutation N46fs (+1), which yields a distinct pattern on single-strand conformation polymorphism (SSCP) analysis. In two subsequent pregnancies, molecular prenatal diagnosis was performed using SSCP. In the first, chorionic villus biopsy was normal. In the second pregnancy, amniocentesis revealed an affected fetus. In both pregnancies, the diagnosis was confirmed enzymatically. HL activity was less than 7 per cent of control values in amniocytes and fetal liver of the affected pregnancy. In the second pregnancy, amniotic fluid metabolite measurements by stable isotope dilution-selected ion monitoring mass spectrometry showed greater than 100-fold increases of 3-hydroxy-3-methylglutaric acid and of 3-methylglutaconic acid levels compared with controls.     

3-甲基喹啉的微生物降解

从处理油制气废水的活性污泥中分离得到一株菌种Q10，经16SrDNA序列分析鉴定为睾丸酮丛毛单胞菌，该菌可以利用3-甲基喹啉作为唯一碳源和能源生长。着重研究了该菌在好氧条件下利用3-甲基喹啉作为唯一碳源和能源的降解特性．并初步分析了3-甲基喹啉的降解中间产物。实验结果表明：菌种Q10对3-甲基喹啉具有较高的降解性能．3-甲基喹啉降解的主要途径是首先生成单羟基化合物、多羟基化合物，然后主要在苯环上发生开环反应进一步降解。     

喹啉的O3及O3/UV降解规律

研究了O3单独作用及O3/UV联合作用时喹啉的降解规律,并对结果进行了比较.研究表明,空气吹脱和UV本身对喹啉的去除贡献率都不大.O3单独作用时,提高体系的初始pH值有利于喹啉的降解.O3/UV联合作用时,在某个临界pH值上,无论是提高还是降低体系的初始pH值都有可能提高喹啉的去除速率.初始pH值较低时,O3单独作用时喹啉的去除速率明显低于O3/UV联合作用时喹啉的去除速率,但在初始pH值较高的情况下,UV的介入可能会降低喹啉的降解速率.无论是O3单独作用还是O3/UV联合作用,喹啉的降解基本上满足伪一级反应动力学规律,如果体系的pH值基本保持恒定,这种规律就更为明显.