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41.
自养黄杆菌合成羟基丁酸和羟基戊酸共聚体的发酵研究   总被引:14,自引:2,他引:12  
采用本实验室从土壤中分离到的一株自养黄杆菌进行了羟基丁酸和羟基戊酸共聚体〔P(HB-co-HV)〕的发酵试验。实验结果表明,该菌株是自养黄杆菌葡萄糖运输突变株,可以葡萄糖、果糖、蔗糖、麦芽糖、乙酸盐、乳酸盐和苹果酸盐作为唯一碳源,尤以葡萄糖和果糖效果最佳。硫酸铵、氯化铵和蛋白胨等不同氮源不影响其生长,却影响细胞中P(HB-co-HV)的含量和P(HB-co-HV)中HV/HB的比例。应用两阶段控制方式,经42h的补料分批发酵,细胞浓度达34.9g·L~(-1),P(HB-co-HV)浓度达25.28g·L~(-1)。细胞和P(HB-co-HV)生产速率系数分别为0.83g·L~(-1)”·h~(-1)和0.61g·L~(-1)·h~(-1)。以基质为基准的细胞得率系数(Yx/s)、产物得率系数(Yp/s)和以干细胞为基准的产物得率系数(Yp/x)分别为0.283(g/g)、0.174(g/g)和0.73(g/g)。改变培养基中碳氮源组分可将P(HB-co-HV)中HB的含量调节在24%~78%之间。  相似文献   
42.
复方克痛宁临床应用镇痛效果   总被引:3,自引:0,他引:3  
曹宜生  程宝全 《蛇志》1995,7(1):51-53
应用复方克痛宁注射液,治疗各种痛证82例,显效50%,有效43.9%,总有效率93.9%。其中大多数病例都是经用其它药或疗法无效或效差而用本药获效的。对关节痛、神经血管性头痛等顽固性疼痛显著独特。用药次数最少1次,最多35例,仅极个别有轻微短暂口干、头晕副作用,各项常规化验检查均无异常,效果显著高于克痛宁或盐酸平痛新单用。临床应用的结果与动物试验观察到的协同增效结果一致。  相似文献   
43.
本文引用等效模型,对激光消融过程进行了推导与计算,和实验结果比较表明,所得公式与实验结果能较好相符,可用于描述紫外激光消融过程。  相似文献   
44.
The glp operons of Escherichia coli are negatively controlled by the glp repressor. Comparison of the repressor-binding affinities for consensus and altered consensus operators in vivo showed that all base substitutions at positions 3, 4, 5, and 8 from the center of the palindromic operator caused a striking decrease in repressor binding. Substitutions at other positions had a severe to no effect on repressor binding, depending on the base substitution. The results obtained indicate that the repressor binds with highest affinity to operators with the half-site WATKYTCGWW, where W is A or T, K is G or T, and Y is C or T. Strong cooperative binding of the repressor to tandem operators was demonstrated in vivo. Cooperativity was maximal when two 20-bp operators were directly repeated or when 2 bp separated the two operators. Cooperativity decreased with the deletion of 2 bp or the addition of 4 bp between the individual operators. Cooperativity was eliminated with a 6-bp insertion between the operators.  相似文献   
45.
46.
Protoplasts isolated from both 7-day-old light-grown and 4-day-old dark/dim light-grown cotyledons of four Brassica campestris varieties (Arlo, Sonja, Bunyip and Wonk Bok) were cultured in three liquid media: modified K8P, modified MS and modified Pelletier's B to compare the capacities for cell division and plant regeneration. Following cell wall regeneration the cultured protoplasts from dark/dim light-grown cotyledons of four varieties showed rapid division and high frequency of cell division compared with those isolated from light-grown cotyledons. The frequencies of cell division were significantly influenced by varieties and culture media but only in cultured protoplasts isolated from dark/dim light-grown cotyledons. The interaction between varieties and media was also significant. Cell colonies formed within 7–14 days in protoplast cultures from dark/dim light-grown cotyledons, and calli subsequently grown on a solid medium developed shoots when transferred onto a regeneration medium. Three of four tested varieties (Arlo, Sonja and Bunyip) showed shoot regeneration within 2–3 months after protoplast isolation, with a high degree of reproducibility in Arlo and Bunyip. Regenerated shoots, which were induced to root on half-strength MS medium with 0.1 mg.l–1 IBA, survived in soil and grew to produce siliques and set viable seeds in the greenhouse. The present report is the first to document the production of regenerated plants that set seeds in Brassica campestris from cotyledonary protoplasts.Abbreviations BAP benzylaminopurine - CPW Composition of Protoplast Washing-solution - 2,4-D 2,4-dichlorophenoxyacetic acid - EDTA ethylenediamine-tetraacetic acid - GA3 gibberellic acid - IBA indole-3-butyric acid - IAA indole-3-acetic acid - MS Murashige and Skoog medium - NAA -naphthaleneacetic acid - KT kinetin - FDA fluorescein diacetate - SDS sodium dodecyl sulfate  相似文献   
47.
Enzyme activity, protein contents, and mRNA contents of group II phospholipase A2 (PLA2) in hepatocellular carcinoma (HCC) surgically obtained from 8 patients were compared with those in either its neighboring liver tissues or control liver tissues. The PLA2 specific activity towards the mixed micelles of 1-palmitoyl-2-oleoyl-phosphatidylglycerol and cholate was significantly greater in the tumor tissues (6.62 ± 1.46 nmol/min/mg) than those in the surrounding liver tissues (1.33 ± 0.22 nmol/min/mg) and controls (0.43 ± 0.04 nmol/min/mg). The results of immunoblot analysis using a specific anti-human group II PLA2 antibody and of Northern blot analysis using a human group II PLA2 cDNA as a probe demonstrated that group II PLA2 was responsible for the increased enzyme activity. The contents of immunoreactive group II PLA2 in the tumor tissues (8.81 ± 1.24 ng/mg) were significantly higher than those in the surrounding liver tissues (1.77 ± 0.27 ng/mg); those in the control tissues were below the analytical range of the method used. The group II PLA2 mRNA was also significantly increased in the tumor tissues, compared with that in the surrounding liver tissues, whereas it was not detectable in th controls. This indicates that group II PLA2 in HCC is induced at the pretranslational level.  相似文献   
48.
生态环境对川芎产、质量的影响   总被引:3,自引:0,他引:3  
生态环境对川芎产、质量的影响丁德蓉,陈兴福,卢进,黄文秀,刘岁荣(四川省中医药研究院药物种植研究所,南川648408)InfluenceofEcoenvironmentontheYieldandQualityofLigusticumchuanxion...  相似文献   
49.
Root, hypocotyl and cotyledon explants of Sesbania bispinosa, Sesbania cannabina, Sesbania formosa, and Sesbania sesban were cultured on Murashige and Skoog medium with benzyladenine (BA; 2.22, 4.44, 8.88 M) in combination with 2,4-dichlorophenoxyacetic acid (2,4-d; 2.26, 4.52, 9.05 M), indolebutyric acid (IBA; 0.25, 0.49, 4.92 M) or naphthaleneacetic acid (NAA; 2.69, 5.37, 10.74 M). Although all explant types developed some callus, callus occurred earliest and continued to grow fastest with hypocotyls. Media including 2.4-d or NAA gave the fastest growing callus. Callus was subcultured up to 10 times at 20-day intervals and retained a rapid growth rate. Shoots regenerated readily from both hypocotyls or cotyledons but not from roots. Shoot organogenesis was most frequent with IBA (0.25–4.92 M) in combination with BA (4.44–8.88 M) and did not occur with 2,4-d. With each species at least one medium induced shoot differentiation from more than 50 percent of the callus pieces. With one exception, media containing IBA that induced shoot organogenesis on explants also did so in callus, but media containing NAA, even when effective with explants, did not cause differentiation of callus. Shoots that differentiated were excised and cultured on MS medium without growth regulators or with IBA (2.46, 4.92, 9.84 M). Roots developed after 3–8 days on an appropriate rooting medium, often without IBA. Rooted plantlets were transplanted to pots in a greenhouse and developed into normal plants. Suitable media and protocols for initiating and subculturing callus and regenerating whole plants in vitro from callus and explants have thus been established for four species of Sesbania.  相似文献   
50.
黑龙江省北五味子一新变种   总被引:2,自引:0,他引:2  
本文发表了黑龙江省产北五味子一新变种:白果五味子  相似文献   
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