pH值和初始淀粉质量浓度对发酵生产谷氨酰胺转胺酶的影响

研究了不同的 pH值对谷氨酰胺转胺酶 (MTG)发酵过程中菌体生长和产酶的影响 ,在此基础上探讨了不同初始淀粉质量浓度及中后期碳源流加对发酵过程的影响 .研究结果表明 :pH值对菌体的生长和产酶模式产生明显的影响 ,当发酵过程的 pH值控制在 6 .5时 ,最有利于菌体的生长和酶的合成 ,在此条件下可得到较高的菌体干重 (DCW )和酶活 ;初始淀粉质量浓度以 3g/dL较适宜 ,其DCW和MTG酶活最高 ,DCW为 2 5.1g/L ,酶活水平达 2 .94U /mL ;中后期采用流加碳源的策略使发酵时间比分批发酵最好水平缩短 12h左右 ,酶活提高到 3.0 5U/mL ,各项指标均比分批发酵最好水平有明显的提高 .     

高渗透压对细菌电转化率的影响

研究了革兰氏阴性细菌大肠杆菌JM109和革兰氏阳性细菌地衣芽孢杆菌0204在电转化过程中,高渗溶液如山梨醇、甘露醇、甘油、蔗糖和葡萄糖对其电转化率的影响.结果表明,高渗溶液能够有效保护细胞,提高转化率.在复苏培养基中,0.7mol/L甘露醇对地衣芽孢杆菌0204的保护效果最好,0.1mol/L蔗糖对大肠杆菌JM109的保护效果最好.由此得到质粒DNA对地衣芽孢杆菌0204的最高电转化率为9.8×102转化子/μg,质粒DNA对大肠杆菌JM109的最高电转化率为5.9×108转化子/μg.     

苏云金芽胞杆菌不同发酵阶段的补糖发酵

通过苏云金芽胞杆菌工程菌BMB005发酵不同阶段补加葡萄糖发酵试验,研究了补糖对苏云金芽胞杆菌发酵的影响.结果表明:对数生长期补加葡萄糖可以提高生物量,进而使发酵液中杀虫晶体蛋白的质量分数提高33 1%,而稳定期补加葡萄糖则是通过提高菌体合成晶体蛋白的能力而使发酵液中晶体蛋白的质量分数提高18 1%. 30 L发酵罐补糖实验结果表明:在起始碳源质量浓度为3 0 g/dL的情况下,对数生长期补加1 0 g/dL葡萄糖可以将发酵液中杀虫晶体蛋白的质量分数和生物效价分别提高37%和51%;稳定期补加 1 0 g/dL葡萄糖可以将发酵液中杀虫晶体蛋白的质量分数和生物效价分别提高33 7%和75 1%;而且稳定期补加比对数生长期补加葡萄糖更有利于增效因子的合成.     

半乳糖苷酶基因在大肠杆菌中过量表达及IPTG诱导条件

从嗜热脂肪芽孢杆菌 (IAM 110 0 1)中克隆出编码热稳定的半乳糖苷酶蛋白基因bgaB ,构建具T7强启动子的pET 2 0 (b) bgaB质粒 ,并在大肠杆菌BL2 1(DE3)中进行表达 .经IPTG诱导后 ,重组菌周质中乳糖酶酶活达到 0 .12U /mL ,胞内酶活为 1.35U /mL ,比酶活为 6 .6 6U/mg蛋白 ,比酶源菌产生的酶活提高 5 0倍 .通过对IPTG诱导时机、诱导浓度和诱导时间的优化研究 ,重组菌产生的比酶活进一步提高至酶源菌的 90倍 .     

谷氨酸脱羧酶发酵工艺的优化

用大肠杆菌AS1.505进行液态发酵生产谷氨酸脱羧酶并优化培养基,考察了碳源、氮源、复合营养物质、起始pH及发酵时间对酶活的影响,确定最佳产酶培养基组成为:葡萄糖1.0 g/dL,蛋白胨3.0 g/dL,氯化钠0.3 g/dL,磷酸氢二钾0.1 g/dL,硫酸镁0.02 g/dL,L-谷氨酸0.01g/dL,玉米浆1.5 g/dL,生物素30 t,g/L,麸皮4 g/dL;pH 6.5.在此基础上,设计发酵条件的优化实验.实验结果表明为:250 mL的三角瓶装液量25 mL,37℃,起始pH 6.5,培养18 h达到产酶高峰,产酶活力可达1 290 U/mL.     

生物转化法生产茶氨酸的重组大肠杆菌的构建

为构建生物转化法生产茶氨酸的基因工程菌，作者分析了影响大肠杆菌高效表达γ-谷氨酰基转肽酶的几个主要因素．将大肠杆菌JM109的ggt基因接入两种不同的质粒中后，转化大肠杆菌JM109，并在一定的条件下进行表达．通过对比E．coli JM109和转化子的γ-谷氨酰基转肽酶表达活性的不同，探讨了ggt基因的拷贝数、启动子的强弱等几个因素对γ-谷氨酰基转肽酶高效表达的影响．实验表明，将含有自身信号肽和启动子的E．coli JM109的ggt基因接入高拷贝的质粒pUC18中，仅提高ggt基因的拷贝数不能增加γ-谷氨酰基转肽酶的表达量．将含有自身信号肽但不含有自身启动子的E．coli JM109的ggt基因接入具有tac启动子的表达载体pEtac中，发现在强启动子tac的控制下，γ-谷氨酰基转肽酶的表达量提高至出发菌株的2．3倍．将构建的工程菌用于生物转化法生成茶氨酸，底物转化率相应地提高至出发菌株的1．7倍．     

黄孢原毛平革菌合成锰过氧化物酶的工艺

研究了多种营养条件及培养条件对黄孢原毛平革菌 (Phanerochaetechrysosporium )WX2 13合成锰过氧化物酶的影响 .当培养基中葡萄糖质量浓度为 10 g/L ,酒石酸铵质量浓度为0 .2 g/L,吐温 80质量浓度为 1g/L ,MnSO4 ·H2 O为 0 .14g/L ,采用苯二甲酸缓冲液 ,最终pH 4 .5 ,2 5 0mL的三角瓶装液量 90mL ,接种量为 1.2× 10 6mL- 1时所获酶活较高 .经条件优化后锰过氧化物酶的活力达到 5 5 9U/L ,比未优化前提高了 36% .加入染料培养 ,发现该酶对所选用的偶氮染料、三苯甲烷类染料、杂环类染料均有较好的脱色效果     

米曲霉ASP-m21产果胶酶及其酶学性质

以产果胶酶PG为主的米曲霉(Aspergillus oryzae)为出发菌株进行固态发酵研究.确定最适合发酵条件为:以30 g/dL麸皮,8 g/dL橘皮粉,添加2 g/dL的泡沫材料作为透气支撑载体,每千克原料添加8 g硫酸铵,10 g葡萄糖,接种体积分数为10%,经过42 h发酵,最终果胶酶酶活可达807 U/g(干曲计).果胶酶的最适反应温度为50 ℃,最适pH范围在3.0～3.6之间.试验结果表明:果胶酶在3.0～7.0的pH的范围内,适合产物生成速度最大的pH点在3.6左右,产物生成速度为0.3 mmol/(Lmin);50 ℃是酶促反应的最适温度,在30 min条件下生成的产物最高可达9 mmol/L.在桔子澄清实验中,向含有体积分数30%的橙汁中添加酶活为1 U/mL的果胶酶,分解果胶为半乳糖醛酸,并且随着半乳糖醛酸量的增加,橙子浆的黏度降低,透光率增加.反应7 h后,透光率可高达91.1%.     

管碟法测定Nisin效价

对管碟法测定Nisin效价的条件进行了研究,考察了几个参数的影响,得出了Nisin测定的最佳条件:90mm培养皿中培养基加量为15mL,Na2HPO4·12H2O质量浓度1g/dL,菌悬液浓度109CFU/mL,琼脂质量浓度1g/dL,培养基pH值7.0,牛津杯中样品加液量100μL.在此条件下,Nisin效价在5～100IU/mL,其对数值与抑菌圈直径有较好的线性关系.     

中华蚱蜢蛋白质的提取

对中华蚱蜢蛋白质进行了氨基酸组成分析、分类及提取工艺等方面的研究. 结果表明,中华蚱蜢蛋白质量分数56 84%,必需氨基酸质量分数 24 9%,具有很高的利用价值;各类型蛋白的提取率分别为水溶性蛋白43 4%,酸溶性蛋白 1 8%,碱溶性蛋白 1 9%,醇溶性蛋白 0 3%;提取水溶性蛋白较优的条件为固液比(g∶mL)1∶15,缓冲液 pH值 7 6,NaCl质量浓度 1 0 g/dL,提取时间4 h,提取率可为27 1%.     

杭州健康女性定量骨超声测定原发性骨质疏松

目的 评价杭州健康女性骨超声速度(SOS)值随增龄减少和骨质疏松患病率，建立杭州地区女性骨超声速度值参考数据库。方法 定量超声法测定1208例杭州地区健康女性桡骨远端(RAD)，第3指骨近节(PLX)，第V跖骨(MTR)和胫骨中段(TIB)的超声速度值。结果 RAD、PLX、MTR和TIBSOS峰值(Peak of SOS)均出现在40-45岁，TJB的SOS峰值出现在35—40岁，此后随年龄增长而下降。绝经后妇女在绝经后早期和晚期各有1个SOS快速减少期，前见于桡骨近端，平均年减少率为2．4％，后见于胫骨中段，平均年减少率为1．8％。各部位骨SOS累积减少率随年龄增长而增加，到85岁4部位累积减少为13％-18％。60岁以后骨质疏松性症(OP)检出率为45％-70％，OP检出率以桡骨远端最高，60-70岁平均为67％，第3指骨近端次之约50％，胫骨中段最低为36％；75岁以后分别为70％，65％和45％。结论 全身各部位骨超声速度值到达峰值的年龄不同，峰值也各有差异。绝经后妇女骨超声速度值随年龄增加减少较快，应予激素和补钙治疗，桡骨远端为本地区SOS检测和OP检出的敏感部位。     

Importance of echocardiography in prognosis of surgical outcomes in cholecystitis in elderly patients

The authors propose to use more often echocardiography (EchoCG) in examination of elderly (over 60 years) of age patients with cholecystitis that permits to increase surgical activity to 92.4%. Left ventricular ejection fraction is the most informative. When this fraction is lower than 45% surgery must be recommended on vital indications only. EchoCG was used in 155 patients with cholecystitis, 131 of them were operated. 2 (1.52%) patients died due to acute cardio-vascular insufficiency and pulmonary artery thromboembolism.     

脊髓胶质细胞在小鼠骨癌痛形成中的作用

Objective To evaluate the role of gliocyte in the spinal cord in the development of bone cancer pain (BCP) in mice. Methods Forty male C3H/He mice aged 8-10 weeks weighing 18-22 g were randomly divided into 4 groups ( n = 10 each) : group I sham operation (group S) , group II BCP, group Ⅲ PBS and group IV minocyline (group M) . In group BCP, PBS and M, bone cancer pain was produced by injection of NCTC2472 fibrosarcoma cell suspension (2 x 105 cells) 10 μl into medullary cavity of calcaneus bone, while in group S, PBS solution 10 μl was injected instead of cancer cell suspension. In group PBS and M, PBS 5 μl and minocyline 5 μl (dissolved to 0.2 mmol/L in PBS)_were given IT immediately before cancer cell inoculation once a day for 11 consecutive days respectively. Mechanical pain threshold was measured at 1 d before cancer cell inoculation, and at 0, 3, 5, 7, 9 and 11d after cancer cell inoculation. Cold pain threshold was measured at 3, 7, 9 and 11d after cancer cell inoculation. The animals were killed after measurement of pain threshold and L4-6, segment of spinal cord was removed for determination of GFAP and CD11b expression by Western blot. Results Compared with group S, mechanical pain threshold was significantly increased at 3-11 d after cancer cell inoculation in group BCP and PBS, and at 3 and S d after cancer cell inoculation in group M, and cold pain threshold was significantly increased at 7-11 d after cancer cell inoculation, and expression of CD11b and GFAP was up-regulated in group BCP, PBS and M ( P < 0.05) . Compared with group BCP, mechanical pain threshold was significantly decreased at 3-11 d after cancer cell inoculation, cold pain threshold was significantly decreased at 7-11 d after cancer cell inoculation, and expression of CD11b and GFAP was down-regulated in group M ( P <0.05) . ConclusionThe activiton of gliocyte in the spinal cord is involved in the development of bone cancer pian in mice.     

脊髓胶质细胞在小鼠骨癌痛形成中的作用

Objective To evaluate the role of gliocyte in the spinal cord in the development of bone cancer pain (BCP) in mice. Methods Forty male C3H/He mice aged 8-10 weeks weighing 18-22 g were randomly divided into 4 groups ( n = 10 each) : group I sham operation (group S) , group II BCP, group Ⅲ PBS and group IV minocyline (group M) . In group BCP, PBS and M, bone cancer pain was produced by injection of NCTC2472 fibrosarcoma cell suspension (2 x 105 cells) 10 μl into medullary cavity of calcaneus bone, while in group S, PBS solution 10 μl was injected instead of cancer cell suspension. In group PBS and M, PBS 5 μl and minocyline 5 μl (dissolved to 0.2 mmol/L in PBS)_were given IT immediately before cancer cell inoculation once a day for 11 consecutive days respectively. Mechanical pain threshold was measured at 1 d before cancer cell inoculation, and at 0, 3, 5, 7, 9 and 11d after cancer cell inoculation. Cold pain threshold was measured at 3, 7, 9 and 11d after cancer cell inoculation. The animals were killed after measurement of pain threshold and L4-6, segment of spinal cord was removed for determination of GFAP and CD11b expression by Western blot. Results Compared with group S, mechanical pain threshold was significantly increased at 3-11 d after cancer cell inoculation in group BCP and PBS, and at 3 and S d after cancer cell inoculation in group M, and cold pain threshold was significantly increased at 7-11 d after cancer cell inoculation, and expression of CD11b and GFAP was up-regulated in group BCP, PBS and M ( P < 0.05) . Compared with group BCP, mechanical pain threshold was significantly decreased at 3-11 d after cancer cell inoculation, cold pain threshold was significantly decreased at 7-11 d after cancer cell inoculation, and expression of CD11b and GFAP was down-regulated in group M ( P <0.05) . ConclusionThe activiton of gliocyte in the spinal cord is involved in the development of bone cancer pian in mice.     

脊髓胶质细胞在小鼠骨癌痛形成中的作用

Objective To evaluate the role of gliocyte in the spinal cord in the development of bone cancer pain (BCP) in mice. Methods Forty male C3H/He mice aged 8-10 weeks weighing 18-22 g were randomly divided into 4 groups ( n = 10 each) : group I sham operation (group S) , group II BCP, group Ⅲ PBS and group IV minocyline (group M) . In group BCP, PBS and M, bone cancer pain was produced by injection of NCTC2472 fibrosarcoma cell suspension (2 x 105 cells) 10 μl into medullary cavity of calcaneus bone, while in group S, PBS solution 10 μl was injected instead of cancer cell suspension. In group PBS and M, PBS 5 μl and minocyline 5 μl (dissolved to 0.2 mmol/L in PBS)_were given IT immediately before cancer cell inoculation once a day for 11 consecutive days respectively. Mechanical pain threshold was measured at 1 d before cancer cell inoculation, and at 0, 3, 5, 7, 9 and 11d after cancer cell inoculation. Cold pain threshold was measured at 3, 7, 9 and 11d after cancer cell inoculation. The animals were killed after measurement of pain threshold and L4-6, segment of spinal cord was removed for determination of GFAP and CD11b expression by Western blot. Results Compared with group S, mechanical pain threshold was significantly increased at 3-11 d after cancer cell inoculation in group BCP and PBS, and at 3 and S d after cancer cell inoculation in group M, and cold pain threshold was significantly increased at 7-11 d after cancer cell inoculation, and expression of CD11b and GFAP was up-regulated in group BCP, PBS and M ( P < 0.05) . Compared with group BCP, mechanical pain threshold was significantly decreased at 3-11 d after cancer cell inoculation, cold pain threshold was significantly decreased at 7-11 d after cancer cell inoculation, and expression of CD11b and GFAP was down-regulated in group M ( P <0.05) . ConclusionThe activiton of gliocyte in the spinal cord is involved in the development of bone cancer pian in mice.     

脊髓胶质细胞在小鼠骨癌痛形成中的作用

Objective To evaluate the role of gliocyte in the spinal cord in the development of bone cancer pain (BCP) in mice. Methods Forty male C3H/He mice aged 8-10 weeks weighing 18-22 g were randomly divided into 4 groups ( n = 10 each) : group I sham operation (group S) , group II BCP, group Ⅲ PBS and group IV minocyline (group M) . In group BCP, PBS and M, bone cancer pain was produced by injection of NCTC2472 fibrosarcoma cell suspension (2 x 105 cells) 10 μl into medullary cavity of calcaneus bone, while in group S, PBS solution 10 μl was injected instead of cancer cell suspension. In group PBS and M, PBS 5 μl and minocyline 5 μl (dissolved to 0.2 mmol/L in PBS)_were given IT immediately before cancer cell inoculation once a day for 11 consecutive days respectively. Mechanical pain threshold was measured at 1 d before cancer cell inoculation, and at 0, 3, 5, 7, 9 and 11d after cancer cell inoculation. Cold pain threshold was measured at 3, 7, 9 and 11d after cancer cell inoculation. The animals were killed after measurement of pain threshold and L4-6, segment of spinal cord was removed for determination of GFAP and CD11b expression by Western blot. Results Compared with group S, mechanical pain threshold was significantly increased at 3-11 d after cancer cell inoculation in group BCP and PBS, and at 3 and S d after cancer cell inoculation in group M, and cold pain threshold was significantly increased at 7-11 d after cancer cell inoculation, and expression of CD11b and GFAP was up-regulated in group BCP, PBS and M ( P < 0.05) . Compared with group BCP, mechanical pain threshold was significantly decreased at 3-11 d after cancer cell inoculation, cold pain threshold was significantly decreased at 7-11 d after cancer cell inoculation, and expression of CD11b and GFAP was down-regulated in group M ( P <0.05) . ConclusionThe activiton of gliocyte in the spinal cord is involved in the development of bone cancer pian in mice.     

脊髓胶质细胞在小鼠骨癌痛形成中的作用

目的 评价脊髓胶质细胞在小鼠骨癌痛形成中的作用.方法 健康雄性C3H/He小鼠40只,周龄8～10周,体重18～22 g,随机分为4组(n=10):假手术组(S组)、骨癌痛组(B组)、PBS组(P组)和米诺环素组(M组).S组跟骨骨髓腔内注射PBS 10 μl;余3组跟骨骨髓腔内注射含2×105个骨纤维肉瘤细胞的PBS 10 μl制备骨癌痛模型,于造模前即刻开始PBS组鞘内注射PBS 5μl,M组鞘内注射米诺环素(用PBS溶解为0.2 mmol/L)5μl,1次/d,连续11 d.于造模前1 d、造模后即刻、3、5、7、9、11 d时测定机械痛阈;于造模后3、7、9、11 d机械痛阈测定结束后测定冷痛阈.痛阈测定结束后处死小鼠,取脊髓组织,测定神经胶质纤维酸性蛋白(GFAP)和CD11b的表达水平.结果 与S组比较,B组和P组造模后3-11 d时、M组造模后3、5 d时机械痛阈升高,B组、P组和M组造模后7～11 d时冷痛阈升高,脊髓CD11b和GFAP表达上调(P<0.05).与B组比较,M组造模后3-11 d时机械痛阈降低,造模后7-11 d时冷痛阈降低,脊髓CD11b和GFAP表达下调(P<0.05).结论 脊髓胶质细胞(星形胶质细胞和小胶质细胞)的激活参与了小鼠骨癌痛的形成.     

脊髓胶质细胞在小鼠骨癌痛形成中的作用

Objective To evaluate the role of gliocyte in the spinal cord in the development of bone cancer pain (BCP) in mice. Methods Forty male C3H/He mice aged 8-10 weeks weighing 18-22 g were randomly divided into 4 groups ( n = 10 each) : group I sham operation (group S) , group II BCP, group Ⅲ PBS and group IV minocyline (group M) . In group BCP, PBS and M, bone cancer pain was produced by injection of NCTC2472 fibrosarcoma cell suspension (2 x 105 cells) 10 μl into medullary cavity of calcaneus bone, while in group S, PBS solution 10 μl was injected instead of cancer cell suspension. In group PBS and M, PBS 5 μl and minocyline 5 μl (dissolved to 0.2 mmol/L in PBS)_were given IT immediately before cancer cell inoculation once a day for 11 consecutive days respectively. Mechanical pain threshold was measured at 1 d before cancer cell inoculation, and at 0, 3, 5, 7, 9 and 11d after cancer cell inoculation. Cold pain threshold was measured at 3, 7, 9 and 11d after cancer cell inoculation. The animals were killed after measurement of pain threshold and L4-6, segment of spinal cord was removed for determination of GFAP and CD11b expression by Western blot. Results Compared with group S, mechanical pain threshold was significantly increased at 3-11 d after cancer cell inoculation in group BCP and PBS, and at 3 and S d after cancer cell inoculation in group M, and cold pain threshold was significantly increased at 7-11 d after cancer cell inoculation, and expression of CD11b and GFAP was up-regulated in group BCP, PBS and M ( P < 0.05) . Compared with group BCP, mechanical pain threshold was significantly decreased at 3-11 d after cancer cell inoculation, cold pain threshold was significantly decreased at 7-11 d after cancer cell inoculation, and expression of CD11b and GFAP was down-regulated in group M ( P <0.05) . ConclusionThe activiton of gliocyte in the spinal cord is involved in the development of bone cancer pian in mice.     

脊髓胶质细胞在小鼠骨癌痛形成中的作用

Objective To evaluate the role of gliocyte in the spinal cord in the development of bone cancer pain (BCP) in mice. Methods Forty male C3H/He mice aged 8-10 weeks weighing 18-22 g were randomly divided into 4 groups ( n = 10 each) : group I sham operation (group S) , group II BCP, group Ⅲ PBS and group IV minocyline (group M) . In group BCP, PBS and M, bone cancer pain was produced by injection of NCTC2472 fibrosarcoma cell suspension (2 x 105 cells) 10 μl into medullary cavity of calcaneus bone, while in group S, PBS solution 10 μl was injected instead of cancer cell suspension. In group PBS and M, PBS 5 μl and minocyline 5 μl (dissolved to 0.2 mmol/L in PBS)_were given IT immediately before cancer cell inoculation once a day for 11 consecutive days respectively. Mechanical pain threshold was measured at 1 d before cancer cell inoculation, and at 0, 3, 5, 7, 9 and 11d after cancer cell inoculation. Cold pain threshold was measured at 3, 7, 9 and 11d after cancer cell inoculation. The animals were killed after measurement of pain threshold and L4-6, segment of spinal cord was removed for determination of GFAP and CD11b expression by Western blot. Results Compared with group S, mechanical pain threshold was significantly increased at 3-11 d after cancer cell inoculation in group BCP and PBS, and at 3 and S d after cancer cell inoculation in group M, and cold pain threshold was significantly increased at 7-11 d after cancer cell inoculation, and expression of CD11b and GFAP was up-regulated in group BCP, PBS and M ( P < 0.05) . Compared with group BCP, mechanical pain threshold was significantly decreased at 3-11 d after cancer cell inoculation, cold pain threshold was significantly decreased at 7-11 d after cancer cell inoculation, and expression of CD11b and GFAP was down-regulated in group M ( P <0.05) . ConclusionThe activiton of gliocyte in the spinal cord is involved in the development of bone cancer pian in mice.