重组毕赤酵母发酵生产α-葡聚糖酶的放大研究

研究了毕赤酵母高密度发酵组成型表达α-葡聚糖酶,从6.8 L发酵罐逐级放大至5000 L发酵罐的放大工艺。采用恒定p H和控制甘油残留浓度和溶解氧相结合的调控策略,进行了多批次的发酵试验。结果表明:三磷酸甘油醛脱氢酶启动子驱动的α-葡聚糖酶的生成具有生长偶联特征,集中在对数生长期和稳定期。6.8 L发酵罐中上清酶活达1253 U/m L,中试放大至50 L发酵罐中产酶最高达1300 U/m L,500 L发酵罐中酶活为740 U/m L。5000 L规模发酵罐中产酶达到589 U/m L。建立了以甘油作为碳源,发酵调控简单的工艺,避免了使用甲醇带来的安全问题,适合放大生产。     

烟曲霉酸的发酵培养基优化和反应器放大研究

烟曲霉酸是一种四环三萜类结构的化合物,具有良好的抗菌活性和抗癌效果。该研究在单因素试验的基础上,对来源于海洋的烟曲霉菌（Aspergillus fumigatus）CY018发酵生产烟曲霉酸的培养基进行了优化及放大培养。结果表明,优化后发酵培养基为甘露醇39.88 g/L,硝酸钠2.25 g/L,牛肉膏3.54 g/L,丁二酸钠8.4 g/L,硫酸镁0.3 g/L,硫酸亚铁0.01 g/L,磷酸二氢钾0.67 g/L。初始pH值调至4.2,摇瓶装液量50 mL/250 mL,转速160 r/min,28 ℃培养9 d。在此优化培养基及发酵条件下,烟曲霉酸的产量达到68.49 mg/L,为优化之前的4.1倍。并在此基础上进行了5 L反应器的放大研究,在发酵第7天得到了烟曲霉酸的最大产量为54.81 mg/L。该实验为HA生产的放大制备与应用推广打下了基础。     

某含钴氧化铜矿选矿试验研究

某含钴氧化型铜矿含铜3.22%、含钴0.045%, 采用先浮硫化矿后浮氧化矿原则流程, 进行了实验室验证试验及扩大连选试验研究。实验室验证试验获得了铜品位51.52%、钴品位0.138%的硫化铜精矿和铜品位19.53%、钴品位0.437%的氧化铜精矿; 扩大连选试验获得了铜品位45.11%、钴品位0.154%的硫化铜精矿和铜品位12.31%、钴品位0.261%的氧化铜精矿; 铜总回收率大于80%, 钴总回收率大于55%。研究成果可为该矿石工业应用工程设计提供依据。     

320m~3充气机械搅拌式浮选机研究

近年来,我国在浮选设备大型化的应用研究方面取得了巨大成功。本文介绍了大型浮选机的设计原则、放大方法、技术路线和手段。最新研制的世界上最大的320 m3充气机械搅拌式浮选机,搅拌力强,槽内矿粒分布均匀,单台浮选机的铜富集比可达20.62,硫富集比可达71.44,功率消耗比国外同类型浮选机节省5.88%以上。该机的成功研制标志着我国成为世界上少数几个完全掌握浮选设备大型化关键技术的国家之一。     

Large-scale immobilization of lipase fromPseudomonas fluorescens biotype I and an application for sardine oil hydrolysis

Large-scale production of thermostable lipase fromPseudomonas fluorescens biotype I was carried out in a fermenter with an antifoaming agent and physical deforming treatments. After cultivation, heat treatment was applied to kill the bacteria and to inactivate other enzmes. Large-scale immobilization of the lipase to a macroporous weak-anion exchange resin was performed with a lipase solution that had an ionic strength of less than 0.1 and an ethanol concentration of 50%. Almost all eicosapentaenoic acid and docosahexaenoic acid were liberated continuously from sardine oil by the immobilized lipase in a countercurrent fluidized-bed reactor. The cost of enzyme used in the reactor has been compared with a process in which soluble lipase fromCandida rugosa was used.     

基于介尺度PBM模型的生物反应器放大模拟及实验研究

对于通气搅拌式工业生物反应器的放大设计而言,精确预测气泡尺寸和体积传质系数非常重要,因此需要建立合适的气泡聚并和破碎模型,以保证反应器的高效操作。以5 L通气搅拌式生物反应器为对象,以气泡尺寸和体积传质系数的实验数据为基准,模拟并考察了两种聚并模型和四种破碎模型对生物反应器内流体流动行为以及传质能力的影响。结果表明,基于介尺度理论的修正聚并模型与考虑黏流剪切的破碎模型组合,所得模拟结果与实验数据吻合最好,这为大型生物反应器的桨型优化提供了模型基础。因为工业化生物发酵通常是在大型生物反应器中进行,搅拌桨型对生物反应器效能至关重要,故本研究在选定最优气泡聚并破碎模型的基础上,通过叶轮末端剪切力相等的放大原则将5 L通气搅拌式工业生物反应器放大到400 m³,同时考察了六斜叶圆盘搅拌桨、非对称式抛物线搅拌桨、布鲁马金式搅拌桨以及六直叶圆盘搅拌桨等桨型组合对气泡破碎能力和气体分散效果的影响,并通过综合对比气含率、体积传质系数等参数,得到400 m³通气搅拌式生物反应器的最优桨型组合。     

Scale-up Production of Milbemycin by Streptomyces hygroscopicus subsp. aureolacrimosus with Control of Internal Pressure,Temperature, Aeration and Agitation

The scale-up of Streptomyces hygroscopicus subsp. aureolacrimosus in submerged culture and the production of milbemycin, a 16-membered macrolide pesticidal antibiotic, are described. The primary scale-up of a dissolved oxygen (DO)-stat culture to 12000 dm³ failed for milbemycin production, when only agitation was used for DO control. Whenever production deteriorated in a plant-scale fermenter, several symptoms (such as morphological changes) were observed, termed SUDS (Scale-Up-Deteriorated production Syndrome). A series of experiments generating SUDS intentionally, replacing agitation-increasing with aeration-increasing operation, and examining internal pressure or temperature effects indicated alternative DO control procedures to prevent SUDS. Among these procedures investigated, a sole procedure resulted in successful scale-up to plant-scale (6000 and 12000 dm³). In the control procedure, these control variables were employed in the order of internal pressure, aeration, agitation and culture temperature. © 1997 SCI     

烟气脱硫三相流化床反应器的数学模拟与预测放大

研究了 0 .1m和 1m两种直径烟气脱硫三相流化床反应器冷态试验装置的性能 ,利用计算流体力学模型和数值计算方法模拟了反应器内气含率分布、液体轴向速度、压降、SO₂ 浓度轴向分布与反应器出口的SO₂ 浓度 ,获得了将反应器放大到 1m塔径的计算敏感参数C_w 的关联式 ,预测了反应器直径对塔内气含率分布和压降的影响