核黄素产生菌的补料发酵

通过分析核黄素产生菌E .ashbyii在发酵过程中菌体量、糖质量浓度、pH值、核黄素质量浓度和粘度的变化及菌体形态与核黄素生物合成之间的联系 ,发现 pH值对菌体生长有显著的影响 ,菌体浓度过高会导致发酵液粘度过大 ,通风供氧困难 ,菌体活力下降 .采用先低浓度培养菌体 ,然后根据发酵液 pH值的变化进行多次适量补料 ,不仅可以控制菌体的过度增殖 ,缓解通风供氧不足造成的困难 ,而且还可以保持菌体活力 ,增加核黄素的产量 .     

在模型化基础上对青霉素补料分批发酵过程中经济效益的预测

在研究发酵动力学、生物过程反应计量学、代谢流分布和代谢流控制的基础上 ,结合专家知识、实验及生产数据 ,对生产规模的青霉素反复补料分批发酵 (即半连续发酵 )的全过程进行了数学模拟 ,建立了一套包含 2 5个过程变量和一系列经济学变量的改良机理模型 .根据这一模型 ,预测了一些工艺参数和经济学参数的改变对发酵过程经济效益的影响 ,发现在保持最大生物质浓度、稀释速率 ,及其它工艺条件不变的情况下 ,中间放料间隔时间、初始发酵液体积以及葡萄糖和电力的价格对经济效益产生较大的影响 .模拟运算结果表明 ,葡萄糖和电力的价格降低 5 % ,全年利润可分别提高 6 .35 %和 3.75 % ;中间放料间隔时间由 2 4h缩短为 12h和 1h(接近于连续发酵 ) ,全年利润可分别提高 7.2 2 %和 14 .11% ;初始发酵液装罐体积分数由 75 %提高到 85 % ,全年发酵利润可提高 5 .4 8% .     

葡萄糖对光滑球拟酵母发酵生产丙酮酸的影响

在30L发酵罐中研究了初始葡萄糖质量浓度和补料方式对光滑球拟酵母WSH-IP303发酵生产丙酮酸的影响．实验确定116.4g/L左右是较为适宜的初始葡萄糖质量浓度,发酵58h时丙酮酸质量浓度和产率分别为58.0g/L和0.516g/g．采用初始葡萄糖质量浓度为53.4g/L,发酵24h分批补料至葡萄糖总质量浓度为115g/L的培养方式,发酵64h时丙酮酸质量浓度和产率分别为60.2g/L和0.559g/g;采用初始葡萄糖质量浓度为62.6g/L,发酵24h开始连续补料至葡萄糖总质量浓度为115g/L的培养方式,发酵72h时丙酮酸质量浓度和产率分别为63.3g/L和0.586g/g,与葡萄糖总质量浓度相似(115g/L)的分批发酵相比,丙酮酸产量分别提高了3.8%和9.1%．实验结果表明适宜的初始葡萄糖质量浓度能促进光滑球拟酵母发酵生产丙酮酸;尽管葡萄糖补料培养可适度提高丙酮酸的产量及产率,但生产强度却有所下降．     

赖氨酸摇瓶发酵条件的优化

针对赖氨酸发酵的工业化要求,以黄色短杆菌（Ｂｒｅｖｉｂａｃｔｅｒｉｕｍｆｌａｖｕｍ）ＷＳＨＬ１为产生菌进行了摇瓶条件下的赖氨酸发酵条件研究．通过正交实验得到了较佳氮源配比;经在发酵过程中添加几种氮源的试验,发现发酵中后期添加适量有机氮源有利于发酵;考察不同初始硫酸铵和葡萄糖浓度对发酵的影响,确定了适合工业生产的浓度范围;采用分批补料培养方式,最终赖氨酸盐酸盐质量浓度为８５．５ｇ／Ｌ     

Brevibacterium sp.DGCDC-82发酵罐中生产胆固醇氧化酶

用Brevibacterium sp.DGCDC-82在7L发酵罐中分批培养.分别对添加剂吐温-80、培养温度、培养基的pH、通风量和搅拌速度在胆固醇氧化酶的生产中的影响进行了研究.结果显示以上条件均对产酶有影响.在不同的发酵阶段改变发酵操作条件,发酵20 h最高酶活可达1203U/L,生产强度可达60 U/(L·h).既有效地提高了胆固醇氧化酶的产量,又防止了发酵过程中的泡沫外溢.     

核黄素产生菌T30的补料发酵

对核黄素产生菌Ｔ３０补料发酵进行了研究。结果表明，发酵液呈非牛顿特性，充足的溶氧是核黄素高产的关键。补料发酵可以提高核黄素的产量，补料以补糖为主，补单糖或双糖均可。补糖时间与发酵液的ｐＨ值和菌体生长情况密切相关。发酵４８ｈ以后，控制发酵液的ｐＨ值在５．４～６．２之间，多次少量补糖，核黄素的产量可提高２０％～３０％．经补糖发酵后，Ｔ３０的核黄素产量可达８ｇ／Ｌ以上。     

发酵过程中基于动态解耦的仿人智能协调控制

以青霉素发酵过程为对象,建立了能够反映发酵过程中比生长速率和pH值变化的动态数学模型,并将仿人智能协调控制和仿人智能模糊控制融入到发酵过程的优化控制中进行仿真,对发酵补料系统进行动态解耦控制,实现发酵过程控制的智能化处理,达到优化发酵生产的目的.     

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.     

生物过程模型化与控制中空气湿度的测量

在好氧发酵等生物过程中通入的空气 ,其水分含量即湿度对氧的传递速率、微生物细胞的呼吸和生长、发酵液体积以及补料稀释率都将产生很大的影响 ,并进而影响发酵过程产率 .对发酵过程进行模拟和对不可测变量进行间接计算 (即所谓软测量 )时 ,如果忽视空气的湿度 ,计算和模拟结果将产生很大的偏差 .因此 ,对好氧发酵过程来说 ,必须高度重视空气湿度的测量和控制 .     

粪产碱杆菌在不同底物限制性条件下连续培养

为了提高菌体阶段菌体的生长密度、对分批发酵有一些优化指导作用,对菌体本身特性进行了研究.以葡萄糖、氯化铵分别为限制性底物,对粪产碱杆菌进行了连续培养,模拟了粪产碱杆菌在不同的营养条件下的发酵情况,并对连续培养特性和动力学性质进行了分析.结果表明:在葡萄糖限制条件下粪产碱杆菌的比生长速率与限制性底物浓度的关系符合Monod方程,建立了相应的模型方程;同时还建立了两种限制条件下的葡萄糖的消耗动力学模型;并对两种限制条件下的维持系数、菌体产率进行了比较.比较表明:葡萄糖限制对菌体产率的影响比氯化铵限制时大,在氯化铵限制条件下菌体产率最大为0.4 g/(h·L),而葡萄糖限制条件下菌体产率最大只为0.3 g/(h·L)左右;氯化铵限制条件下的维持系数是葡萄糖限制条件下的2倍,说明发酵过程中主要的维持消耗是在产胶期热凝胶的合成过程中.     

pH值对聚唾液酸分批发酵的影响及补料发酵

研究了不同pH值对聚唾液酸发酵过程中菌体生长和产聚唾液酸的影响.发酵初期pH自然下降时有利于菌体生长,菌体生长对数期较长,最大菌体干重可达6.9g/L;发酵中后期pH控制在6.4时有利于聚唾液酸的延续合成,合成对数期比其它pH条件下的合成对数期延长了11h.动力学特性表现为部分相关模式,而在其它pH条件下,动力学特性表现为相关模式.对聚唾液酸的流加补料发酵进行了初步研究,最终使菌体干重达到11.16g/L,聚唾液酸产量达到2.606g/L.     

流化床生物膜反应器用于酵母菌体培养

研究了流化床生物膜反应器用于酵母菌体培养的结果，发现在气升式反应器中加入载体，形成流化床生物膜反应器，可以进一步提高反应器的传氧速率、间歇培养的菌体浓度和连续培养的生产强度。     

酒精浓缩废水对SCP菌体培养的影响

研究了浓缩废水对菌体培养的影响，发现用间歇培养的方法难以较清楚的表明废水的浓缩与菌体培养之间的关系；用连续培养方法发现，在一定的稀释率的条件下，废水浓缩一倍，菌体浓度增加一倍，反应器生产能力也增加一倍。     

The relationship between pH and concentrations of antioxidants and vasoconstrictors in local anesthetic solutions.

pH affects the efficacy of local anesthetics by determining the percentage of the lipid-soluble base form of the anesthetic available for diffusion and penetration of the nerve sheath. The purpose of this study was to determine the relationship between pH and the concentrations of antioxidant and vasoconstrictor in dental local anesthetic solutions over real-time and after accelerated aging. Several batches of lidocaine and mepivacaine with vasoconstrictors were tested. Results showed that, immediately upon receipt from the manufacturers, three batches were below the USP pH limit (pH 3.3), and two batches contained less than the minimum limit of vasoconstrictors (90%). Real-time tests on batches that were within normal limits revealed that solutions were stable past 4 yr. Accelerated aging tests revealed a strong correlation between a decrease in pH and loss of antioxidants and vasoconstrictors. In conclusion, a quality batch of local anesthetic should remain efficacious long past the manufacturer's stated shelf life; a batch that is less than optimal, or one that is exposed to environmental stresses, will degrade rapidly, and efficacy may be affected by decreases in pH and loss of vasoconstrictor. pH may be an inexpensive, readily available screening test for efficacy of local anesthetics.     

溶氧控制和pH控制在赖氨酸分批发酵过程中的应用

研究了溶氧和ｐＨ值对赖氨酸产生菌ＦＢ４２发酵的影响，结合发酵过程的动力学分析，得出了分批发酵操作的溶氧和ｐＨ控制模式。结果表明两种控制都使发酵水平得到提高，但以溶氧控制更有效，在溶氧控制模式下，发酵的转化率从３３．６％提高到３８．１％。     

杂交瘤细胞代谢流分析模型及其在批式培养中的应用

通过物料衡算和线性规划方法建立了进行代谢流分析的数学模型，并首次应用于批式培养过程.分析结果表明，细胞对葡萄糖等底物的代谢效率很低，细胞对谷氨酰胺等氨基酸浓度的变化响应迟缓，在底物充裕的迟滞期及谷氨酰胺限制条件下的代谢效率高于对数生长期.另外限制谷氨酰胺等氨基酸进入能量代谢，既可减少氨的积累，也会减少乳酸的生成.     

人胃黏膜成纤维细胞原代培养条件的优化

目的 通过优化人胃黏膜成纤维细胞的原代培养条件,提高培养成功率,为进一步研究胃癌相关成纤维细胞奠定基础.方法 原代培养采用植块法,利用免疫组织化学、细胞形态学和电镜等方法进行细胞鉴定;分析不同培养表面、培养基和培养液pH值对原代细胞培养游出情况的影响,筛选适合的培养条件.结果 Logistic逐步回归分析提示RPMI 1640培养基的Waldχ2值=32.4533,P<0.01,标准化回归系数=0.7852,说明使用RPMI 1640培养基更利于原代成纤维细胞游出;pH=7.4的培养液的Waldχ2值=49.4756,P<0.01,标准化回归系数=0.4867,说明培养液pH值为7.4更利于原代成纤维细胞游出;不同水平的培养表面条件对成纤维细胞游出率的影响差异无统计学意义(P>0.05),而且各培养条件之间无交互作用.结论 通过优化培养表面、培养基种类和pH值等培养条件,可以提高人胃黏膜成纤维细胞原代培养的成功率.     

Effect of intraperitoneal administration of two different batches of albumin solutions on peritoneal solute transport in CAPD patients

The effects of intraperitoneal administration of two different batches of human albumin (batch A and batch B) on peritoneal solute transport and dialysate white cell count were studied in 16 CAPD patients. The studies were done on two separate days during a 4-h dwell, one day without and one day with the intraperitoneal administration of 10 g/l human albumin. Marked differences were found between the two batches. The transport of all measured solutes increased during administration of batch A compared to the control experiments: urea 78% +/- 62%, lactate 51% +/- 38%, creatinine 96% +/- 54%, glucose 67% +/- 55%, inulin 27% +/- 33% IgG 126% +/- 80%, mean +/- SD; P less than 0.02). In the experiments with batch A the white cell count of the test bag was greater than that of the effluent ('night bag') before the test (13 +/- 5 vs 194 +/- 61 mm3/l; P less than 0.02). These effects were also observed when the dialysate was buffered to pH = 7.4 before inflow. Albumin batch B showed no effect on solute transport and white cell count. The effects of solute transport and white cell count are probably caused by the greater concentration of prekallikrein activator in batch A when compared to batch B (30.1 vs 0 U/l). Caution is warranted when human albumin is used for simultaneous measurement of peritoneal fluid and solute kinetics.     

肛瘘切开或挂线术后应用参肤皮汤治疗效果观察

目的探讨参肤皮汤对肛瘘患者术后疼痛、创面pH值及肛周细菌的影响.方法：将120例肛瘘术后患者按单双日住院分成2组,对照组予高锰酸钾溶液坐浴,治疗组予参肤皮汤口服加熏洗,分别于术后3、7、14 d评价疼痛程度和创面pH值,术后7 d进行创面细菌培养.结果：术后7 d和14 d,治疗组疼痛程度及创面pH值低于对照组（P〈 0.05）;术后7 d治疗组创面细菌培养阴性率高于对照组（P〈 0.05）.结论：参肤皮汤口服熏洗并用,能够改善肛瘘术后患者疼痛程度,降低创面pH值,提高创面细菌培养阴性率.     

Influences of buffer systems on chondrocyte growth during long-term culture in alginate

OBJECTIVE: Chondrocyte behavior is very sensitive to culture environment such as physical and biochemical conditions. As extracellular pH (pHo) and the existence of bicarbonate could affect the chondrocyte fate, hence, the purpose of this study is to investigate the buffer system effect on chondrocyte fate during relatively long-term culture. METHODS: In order to examine whether effects seen were due to bicarbonate or to pHo, we had to devise a system which could differentiate between the two effects. Culture media buffered by N-2-hydroxyethyl piperazine-N'-2-ethanesulfonic acid (HEPES) only and the combination of HEPES and bicarbonate were used. Bovine articular chondrocytes were cultured in alginate beads for up to 12 days. pHo was kept constant by culture of 3 beads in 2 ml culture medium. Cell density, intracellular pH (pHi) and glycosaminoglycan (GAG) were measured at day 5 and day 12. Cell morphology, distribution and viability in alginate beads were monitored over 12 days of culture. RESULTS: Compared to culture in the absence of bicarbonate, a higher proliferation rate of chondrocytes was observed in the presence of bicarbonate. pHi was more alkaline, about 0.2 pH unit, in the presence of bicarbonate than that in the absence of bicarbonate. About 50% more GAG was deposited in alginate beads when chondrocytes were cultured in the combination of HEPES and bicarbonate, compared to chondrocytes cultured in the absence of NaHCO3 at the end of 12 days of culture. CONCLUSION: The presence of bicarbonate results in more alkaline in the pHi of bovine chondrocytes after long-term culture. The combination of bicarbonate and HEPES in culture medium improves cell growth, matrix production in three-dimensional alginate beads.