春雷霉素高产菌株US95#的选育及大罐发酵工艺控制

紫外线与光修复交替处理春雷霉素产生菌得到了高产突变株,再结合自然分离选出了US95^#。该菌株不但产量高,还具有稳定的遗传性能,并在大罐良好发酵工艺控制和条件下,罐发酵水平在春雷霉素生产上有了重大突破,发酵水平比历史最高水平提高12．9％。     

应用原生质体技术选育天兰淡红链霉菌

本文报道柔红霉素产生菌——天兰淡红链霉菌原生质体的制备和再生方法,并从再生菌落中筛选得到摇瓶发酵单位提高５％的高产菌株３０＃。将再生高产株经铜蒸气激光辐照,得到在生产罐中发酵水平比对照出发菌株提高１２．９％的高产菌株８２＃。     

产黄青霉的杂交育种

选育高产菌株是工业微生物提高产量最有 效的方法。我们于1974-1977年,对产黄青霉 (Penicillium clirysogenusn)采用杂交育种和诱变 育种相结合的方法,选得了一株高产菌株杂 3-25-103,从1977年开始用于生产。该菌株在 20吨和58吨罐试验共229批,与同期对照菌 利“相比,青霉素发酵单位平均提高8%。青霉素 滤液产量比1976年同期提高6.45%。     

利用耐受自身代谢产物的方法提高庆大霉素的发酵单位

本实验根据抗生素产生菌解除自身产物反馈调节原理,对庆大霉素产生菌（降红小单孢）进行了摇瓶耐受高浓度庆大霉素实验,从耐受８,０００ｕ／ｍｌ庆大霉素的摇瓶中,筛得ｙ－３６１２０＃菌株。该株在某厂经摇瓶和罐上的生产能力考察,其摇瓶和罐上的生产能力,分别比出发菌株提高２２．８％和１５．４８％。实验表明,利用耐受自身产物的方法,选育抗生素的高产菌株,是提高抗生素发酵单位的一种简便、快速的途径。     

抗噬菌体谷氨酸高产菌株选育

从污染的谷氨酸发酵废液中分离纯化噬菌体,并以高滴定度侵染生产敏感菌,借助菌的自发突变筛选出抗噬突变株,再运用紫外线、亚硝基胍复合诱变手段经过初筛、复筛,最后选育出抗噬谷氨酸高产菌株。其过程简单、便利,可靠性高,是选育抗噬谷氨酸高产菌株的好方法,对发酵行业具有指导意义。曾选育到抗噬谷氨酸高产菌株,其摇瓶发酵产量比对照提高26.4%。     

南昌霉素高产菌株的链霉素抗性基因突变诱变筛选研究

通过对链霉素对南昌霉素（Nanchangmycin)产生菌NS－41－80菌株孢子的致死浓度测定基础上,采用诱变剂甲基磺酸乙酯（EMS）的不同诱发剂量对菌株孢子进行诱变处理,诱变处理的孢子涂布在含链霉素（10ug/mL)致死浓度的高氏平板上,获得了大量的链霉素抗性基因（str)突变株。然后从3,000株链霉素抗性基因（str)突变株中通过初筛获得比诱变出发菌株产素能力提高20％以上的菌株202株,再进一步通过摇瓶复筛,获得比出发菌株产素能力分别提高100％,200％,300％高产菌株为48株,7株和1株,分别为复筛菌和初筛菌株的23．76％和1．60％,3．46％和0．23％,0．5％和0．03％,将产素能力提高240％以上5个菌株连同出发菌株连续3批次进行摇瓶发酵结果,5个突变株的产素能力均比出发菌株的产素能力提高57％－96．4％,其中突变株80－5．3－165菌株摇瓶发酵单位达6,000ug/mL以上,3批次摇瓶平均发酵单位达5,855ug/mL,建立了南昌霉素高产菌株的链霉素抗性基因突变诱变快速高效的筛选方法。     

高丁醇比丙酮丁醇梭菌的选育与应用

设计了专一性分离方法,从土样中分离了多株能产生溶剂的梭苗,经多次单细胞分离、纯化,再经亚硝基胍和甲基磺酸乙酯诱变和抗性筛选,获得几株高丁醇的丙酮丁醇梭菌。对高产菌株的性状稳定性、发酵过程、混合原料应用、温度的影响进行了研究。结果证明菌株性状稳定,丁醇产量为总溶剂的７０％;过程为典型的丙酮丁醇发酵,对温度可耐受到３９－４０℃;能利用玉米和薯干,玉米和高梁进行正常发酵。菌株已在百吨生产罐,连续应用一年     

对甜菜夜蛾高毒苏云金芽孢杆菌菌株的选育*

采用物理诱变——虫体传代模式,选育获得一株对甜菜夜蛾高毒菌株BtCZE 99985。通过摇瓶和40t发酵罐3年10批发酵试验,表明该菌株具有良好的发酵性能。摇瓶试验表明,与出发菌株93005、对照菌株HD-1-580、GC-91相比较,该菌株对甜菜夜蛾的毒效分别提高429％、655％、114％。40t发酵罐发酵试验表明,该菌株对甜菜夜蛾测定的LC50平均值为0．076μL/mL,比GC-91菌株(平均0．213μL/mL)的毒效提高180％。     

阿霉素高产株选育及其发酵工艺优化

目的:筛选阿霉素高产菌株,并优化发酵工艺,提高发酵水平。方法:采用微波与氯化锂复合诱变,用正交设计法优化发酵培养基配方,通过摇瓶试验,控制接种量为10%,发酵培养温度29℃,搅拌转速300 r/min,罐压0.04 MPa,空气流量1∶1vvm,保证溶氧浓度40%以上情况下。结果:获得一株阿霉素发酵单位比出发菌株提高83%的高产株;优化后的发酵培养基组成为:淀粉8%,黄豆饼粉3%,Fe SO4·7H2O 0.006%,Ca CO30.3%,其阿霉素发酵效价比原工艺提高2.3倍。结论:采用该方法选育与工艺优化,提高阿霉素发酵单位,有效、快速,结果令人满意,具有工业应用价值。     

天兰淡红链霉菌（S.coeruleorubidus）激光高产株的选育

本文首次报导铜蒸气激光选育天兰淡红链霉菌（S．coeruleorubidus）的研究结果，曾得到生产罐中抗生素发酵单位比其对照株提高14．7％的高产株，最高发酵单位曾达国内最好水平，已在国内应用。     

奈替米星发酵放大工艺研究

考察了奈替米星摇瓶发酵代谢特征,研究了磷酸盐和甲硫氨酸对菌丝生长和发酵单位的促进与提高作用。进而,以相同单位体积搅拌功率为基准放大,使１５ｔ发酵罐奈替木星发酵过程接近摇瓶水平。     

Production of Chlorflavonin, an Antifungal Metabolite of Aspergillus candidus

Production of chlorflavonin, a new antifungal antibiotic, by strains of Aspergillus candidus is described. Two wild strains of the fungus had distinctly different chlorflavonin-producing capabilities. One strain produced 25 mug of chlorflavonin per ml per 4 to 5 days in a pilot scale fermentor with stirring, using a medium containing corn steep liquor and glucose. Production of antibiotic was favored by high rates of agitation-aeration. Crude chlorflavonin was extracted from the whole brew with a hydrocarbon solvent and then purified by recrystallization from benzene and petroleum ether. The overall yield from fermentation brew to pure product was 50%.     

Solid-state cultivation of Chaetomium cellulolyticum on alkali-pretreated sawdust

Solid-state fermentations (78% initial moisture content) of alkali-pretreated Eastern Hard Maple sawdust were conducted in tray and tumble fermentors using chaetomium cellulolyticum. Crude protein content of the solids rose from 0.9 to 11% in the tray fermentor and 8% in the tumble fermentor in 20 days. These levels were almost equal to those achieved in corresponding slurry-state fermentations (1–5% (w/v)) of the same substrate. Specific growth rates were two to four times lower in the solid-state fermentors but this was offset by their greater solids-handling capacity: the rate of protein production per unit volume of fermentation mixture was comparable to that of the 5% (w/v) slurry and two to three times higher than that of the 1% (w/v) slurry.     

Media and Fermentation Processes for the Rapid Production of High Concentrations of Stable Blastospores of the Bioinsecticidal Fungus Paecilomyces fumosoroseus

In shake flask and fermentor studies, various media components and culture inocula were tested to improve P. fumosoroseus spore production rates, yield and stability. To evaluate inoculum potential and inoculum scale-up for fermentor studies, conidia and liquid culture-produced spores of various strains of P. fumosoroseus were compared as inoculum. Inoculation of liquid cultures with blastospores at concentrations of at least 1×10⁶ spores mL^-1 resulted in the rapid production of high concentrations of blastospores (∼1×10⁹ spores mL^-1, 48 h fermentation time) for all strains tested. The rapid germination rate of blastospores (90% after 6 h incubation) compared to conidia (>90% after 16 h incubation) and the use of higher inoculum rates reduced the fermentation time from 96 to 48 h for maximal spore yields. A comparison of various complex nitrogen sources showed that liquid media supplemented with acid hydrolyzed casein or yeast extract supported the production of high concentrations of blastospores that were significantly more desiccation-tolerant (79-82% survival after drying) when compared to blastospores produced in media supplemented with other nitrogen sources (12-50% survival after drying). For rapid spore production, requirements for trace metals and vitamin supplementation were dependent on the type of hydrolyzed casein used in the medium. Fermentor studies with two strains of P. fumosoroseus showed that high concentrations (1.3-1.8×10⁹ spores mL^-1) of desiccation-tolerant blastospores could be produced in 48-h fermentations. These studies have demonstrated that the infective spores of various strains of the fungal bioinsecticide Paecilomyces fumosoroseus can be rapidly produced using deep-tank, liquid culture fermentation techniques.     

Influence of Dissolved Oxygen Levels on Production of l-Asparaginase and Prodigiosin by Serratia marcescens

The effect of dissolved oxygen concentrations on the behavior of Serratia marcescens and on yields of asparaginase and prodigiosin produced in shaken cultures and in a 55-liter stainless-steel fermentor was studied. A range of oxygen transfer rates was obtained in 500-ml Erlenmeyer flasks by using internal, stainless-steel baffles and by varying the volume of medium per flask, and in the fermentor by high speed agitation (375 rev/min) or low rates of aeration (1.5 volumes of air per volume of broth per min), or both. Dissolved oxygen levels in the fermentation medium were measured with a membrane-type electrode. Peak yields of asparaginase were obtained in unbaffled flasks (3.0 to 3.8 IU/ml) and in the fermentor (2.7 IU/ml) when the level of dissolved oxygen in the culture medium reached zero. A low rate of oxygen transfer was accomplished by limited aeration. Production of prodigiosin required a supply of dissolved oxygen that was obtainable in baffled flasks with a high rate of oxygen transfer and in the fermentor with a combination of high-speed agitation and low-rate aeration. The fermentation proceeded at a more rapid rate and changes in pH and cell populations were accelerated by maintaining high levels of dissolved oxygen in the growth medium.     

庆大霉素产生菌原生质体融合高产株与发酵罐试产的研究

对庆大霉素产生菌绛红色小单孢菌（Micromonospora purpurea）原生质体分别用硫酸二乙酯（DES）和紫外线（uv）进行诱变、融合,用庆大霉素进行抗性筛选、再生后得到高产菌株;经摇瓶连续10批次发酵考查,平均发酵单位在2200±U/ml;又经5L发酵罐连续发酵考查7批次,产量平均1900±U/ml。产品质量符合药典。     

Rapid ethanol fermentations using vacuum and cell recycle

Cell recycle and vacuum fermentation systems were developed for continuous ethanol production. Cell recycle was employed in both atmospheric pressure and vacuum fermentations to achieve high cell densities and rapid ethanol fermentation rates. Studies were conducted with Saccharomyces cerevisiae (ATCC No. 4126) at a fermentation temperature of 35°C. Employing a 10% glucose feed, a cell density of 50 g dry wt/liter was obtained in atmospheric-cell recycle fermentations which produced a fermentor ethanol productivity of 29.0 g/liter-hr. The vacuum fermentor eliminated ethanol inhibition by boiling away ethanol from the fermenting beer as it was formed. This permitted the rapid and complete fermentation of concentrated sugar solutions. At a total pressure of 50 mmHg and using a 33.4% glucose feed, ethanol productivities of 82 and 40 g/liter-hr were achieved with the vacuum system with and without cell recycle, respectively. Fermentor ethanol productivities were thus increased as much as twelvefold over conventional continuous fermentations. In order to maintain a viable yeast culture in the vacuum fermentor, a bleed of fermented broth had to be continuously withdrawn to remove nonvolatile compounds. It was also necessary to sparge the vacuum fermentor with pure oxygen to satisfy the trace oxygen requirement of the fermenting yeast.     

Conversion of d-psicose to allitol by Enterobacter agglomerans strain 221e

Enterobacter agglomerans strain 221e transformed d-psicose to allitol at a faster rate in the presence of d-glucose in the reaction mixture when the entrance of oxygen was restricted. Cells grown on glycerol were found to be suitable for the transformation reaction. The transformation rates were about 97.0, 95.0 and 62.5%, respectively, when 0.5, 1.0 and 2.0% substrates were used. No consumption of substrate or product was observed in any case. In flask and jar fermentor reactions, the cells of strain 221e showed similar transformation activities. Cells stored at −20°C for 10 d showed almost same transformation activity as intact cells.     

重组人生长激素在大肠杆菌BL21（DE3）中高效表达研究

对重组人生长激素基因工程菌ｐＥＴ－１１ｂ／ｒｈＧＨ／ＢＬ２１的培养条件进行了优化,在ＮＢＳ ＭＰＰ－４０发酵罐中实现了高密度培养和高效表达,三批实验结果表明,在较短的发酵时间（１２ｈ）内细菌干重达８５ｇ／Ｌ,重组人生长激素占总蛋白量的２５％左右。     

Dialysis Continuous Process for Ammonium-Lactate Fermentation of Whey: Experimental Tests

Laboratory experiments were conducted to validate theoretical predictions describing a dialysis continuous process for the fermentation of whey lactose to ammonium lactate, in which the fermentor contents are poised at a constant pH by adding ammonia solution and dialyzed through a membrane against water. Dried sweet-cheese whey was rehydrated to contain 230 mg of lactose per ml, supplemented with 8 mg of yeast extract per ml, charged into a 5-liter fermentor without sterilization, adjusted in pH (5.3) and temperature (44°C), and inoculated with Lactobacillus bulgaricus. The fermentor and dialysate circuits were connected, and steady-state conditions were established. A series of such conditions was managed nonaseptically for 94 days to study the process and to demonstrate efficiency and productivity. As time progressed, the fermentation remained homofermentative and increased in conversion efficiency, although membrane fouling necessitated dialyzer cleaning about every 4 weeks. With a retention time of 19 h, 97% of the substrate was converted into products. Relative to nondialysis continuous or batch processes for the fermentation, the dialysis continuous process enabled the use of more concentrated substrate, was more efficient in the rate of substrate conversion, and additionally produced a second effluent of less concentrated but purer ammonium lactate.