中华鳖白底板病和红底板病细菌的分离鉴定及致病性

从患白底板病和红底板病的病鳖中分离出７株细菌,应用一般细菌分离鉴定的方法和美国生物－梅里埃（Ｂｉｏ Ｍｅｒｉｅｕｘ ＵＳＡ）公司ＶＩＴＥＫ全自动微生物鉴定系统进行鉴定,结果显示有３株嗜水气单胞菌（Ａｅｒｏｍｏｎａｓ ｈｙｄｒｏｐｈｉｌａ）、１株温和气单胞菌（Ａｅｒｏｍｏｎａｓ ｓｏｂｒｉａ<.I>）、１株金黄色葡萄球菌（Ｓｔａｐｈｙｌｏｃｏｃｃｕｓａｕｒｅｕｓ）、１株肺炎克雷伯氏菌（Ｋｌｅｂｓｉｅｌｌａ ｐｎｅｕｍｏｎｉａｅ）和 １株美人鱼弧菌（Ｖｉｂ     

L-山梨糖脱氢酶的纯化及性质的研究

从５Ｌ罐发酵Ｌ－山梨糖的Ｇｌｕｃｏｎｏｂａｃｔｅｒ　ＳＣＢ３２９和Ｂａｃｉｌｌｕｓ　ｔｈｕｒｉｎｇｉｅｎｓｉｓ　ＳＣＢ９３３混合菌株中差速离心收集ＳＣＢ３２９菌体,破碎,离心获得无细胞抽提液,硫酸铵分级沉淀蛋白后依次经ＤＥＡＥＣｅｌｌｕｌｏｓｅ ５２和Ｑ Ｓｅｐｈａｒｏｓｅ ＦＦ柱层析分离得到了Ｌ－山梨糖脱氢酶（ＳＤＨ）,它能将Ｌ－山梨糖脱氢氧化为Ｌ－山梨酮,ＳＤＳ－ＰＡＧＥ电泳测得分子量约为６０ＫＤ。动力学性研究表明它为一个典型的Ｍｉｃｈａｅｌｉｓ－Ｍｅｎｔｅｎ氏酶,对Ｌ－山     

脱卤脱亚硫酸菌脱氯呼吸链的遗传分析*

以携有结合转座子Ｔｎ９１６的Ｅｎｔｅｒｏｃｏｃｃｕｓ　ｆａｅｃａｌｉｓ　ＪＨ２－２为供体,脱卤脱亚硫酸菌ＨＳＳ１（Ｄｅｓｕｌｆｉｔｏｂａｃｔｅｒｉｕｍ　ｄｅｈａｌｏｇｅｎａｎｓ,Ｓｍ抗性突变株）为受体,在厌氧条件下,通过滤膜杂交、结合转移,将Ｔｈ９１６转移并插入到受体菌的染色体上,其转移频率为：１．１×１０^－７～３×１０^－８。　在丙酮酸／乳酸－３－氯－４－羟基苯氧乙酸、Ｔｃ、Ｓｍ培养基上,筛选脱氯呼吸的缺陷型突变株,并用反向ＰＣＲ（Ｉ     

二种重组α-乙酰乳酸脱羧酶在啤酒生产中降低双乙酰的作用

利用已构建的含有短芽孢杆菌（Ｂａｃｉｌｌｕｓ ｂｒｅｖｉｓ）和产气肠杆菌（Ｅｎｔｅｒｏｂａｃｔｅｒ　ａｅｒｏｇｅｎｅｓ）α－乙酰乳酸脱羧酶（α－ａｃｅｔｏｌａｃｔａｔｅ ｄｅｃａｒｂｏｘｙｌａｓｅ, α-ＡＬＤＣ）基因的工程菌株,并使它们分别在大肠杆菌中高效表达,获得重组α－ＡＬＤＣ。在实验室,用 ２Ｌ体积的麦芽汁进行啤酒生产试验,添加 ２种重组α－ＡＬＤＣ后,使啤酒中的双乙酰含量快速下降到或始终保持在０.１ｍｇ／Ｌ以下。证明得到的重组ａ－ＡＬＤＣ能有效地降低啤酒中双乙酰含量。     

一个具两型子囊的齿裂菌属新种

生于蒙古栎（Ｑｕｅｒｃｕｓ　ｍｏｎｇｏｌｉｃａ）和波罗栎（Ｑ．Ｄｅｎｔａｔａ）上的齿裂菌属一新种,即异襄齿裂菌（Ｃｏｃｃｏｍｙｃｅｓｄｉｍｏｒｐｈｕｓ）。该种因子囊同时以两种状态存在而明显区别于齿裂菌属其它成员。主、副模式标本保藏于安徽农业大学森林保护教研室（ＡＡＵＦＰ）。     

拮抗菌BS—98分泌抗菌蛋白的条件及其发酵液特性

由本室分离得到一株强烈抑制芦笋茎枯病等植物病原真菌的拮抗菌ＢＳ—９８菌株（Ｂａｃｉｌｌｕｓｓｕｂｔｉｌｉｓ）。用环柱法检测该菌株的抗菌活性表明,该菌株除抑制芦笋茎枯病菌ＰｈｏｍａａｓｐａｒａｇｉＳａｃｃ外,对小麦赤霉病菌（Ｆｕｓａｒｉｕｍｇｒａｍｉｎｅａｒｕｍ）,棉花枯萎病菌（Ｆｕｓａｒｉｕｍｏｘｙｓｐｏｒｕｍｆｓｐ．Ｖａｓｉｎｆｅｃｔｕｍ）、棉花黄萎病菌（Ｖｅｒｔｉｃｉｌｌｕｍａｌｂｏ—ａｔｒｕｍ）、黄瓜灰霉病菌（Ｂｏｔｒｙｔｉ     

变孢毛霉的一个新变种及对Mucor luteus Linnemann和M.variosporus Schipper的合格化

根据国际植物命名法规,对两个不合格发表的毛霉种名：Ｍｕｃｏｒ　ｌｕｔｅｕｓ　Ｌｉｎｎｅｍａｎｎ和ＭｕｃｏｒｖａｒｉｏｓｐｏｒｕｓＳｃｈｉｐｐｅｒ进行了合格化。对变孢毛霉（Ｍｉｃｏｒｖａｒｉｏｓｐｏｒｕｓ）的一个新变种进行了描述。     

高活性反硝化颗粒污泥的研究

以上流式厌氧污泥床（ＵＡＳＢ）反应器中的反硝化颗粒污泥为样品,研究了颗粒污泥的基本特性。测定出颗粒污泥中的优势无机元素为Ｃａ、Ｐ．颗粒表面以球菌和短杆菌为主。反硝化菌是颗拉中的优势菌群,数量可达６．５ｘ１０^８－１．５ｘ１０^１０个／ｍｌ颗粒污泥。初步鉴定了两株脱氮菌Ｍｉｃｒｏｃｏｃｃｕｓｓｐ．ｓｔｒａｉｎＮ_１和ＰｓｅｕｄｏｍｏｎａｓａｅｒｕｇｉｎｏｓａｓｔｒａｉｎＮ_２．     

黑木耳电泳核型分析

采用等高锁状均质电场（ＣＨＥＦ）凝胶电泳技术,对黑木耳（Ａｕｒｉｃｕｌａｒｉａ　ａｕｒｉｃｕｌａ）电泳核型进行分析,以酿酒酵母（Ｓａｃｃｈａｒｏｍｙｃｅｓ　ｃｅｒｉｖｉｓｉａｅ）菌株ＹＰＨ７５５和祭酒裂殖酵母（Ｓｃｈｉｚｏｓａｃｃｈａｒｏｍｙｃｅｓ　ｐｏｍｂｅ）菌株ＡＳ２．２１４的染色体ＤＮＡ大小作为分子量标记,估计黑木耳基因组中至少包含９条ＤＮＡ分子量在８５０ｋｂ至５８００ｋｂ之间的染色体,多数染色体ＤＮＡ分子量在１０００ｋｂ至３４００ｋｂ之间,基因组大小在２２Ｍｂ以上。     

苏云金杆菌超氧化物歧化酶的纯化和性质研究*

苏云金杆菌（Ｂａｃｉｌｌｕｓ　ｔｈｕｒｉｎｇｉｅｎｓｉｓ）９１６５超氧化物歧化酶（ＳＯＤ）,经硫酸铵分级沉淀、ＳｅｐｈａｄｅｘＦ－１００凝胶过滤及非变性凝胶电泳（ＰＡＧＥ）三步纯化,纯酶比活力为４３８８ｕ／ｍｇ,属Ｍｎ－ＳＯＤ,分子量为４７．９ｋｕ,由二个亚基组成,含１９种氨基酸。     

Production of nattokinase by high cell density fed-batch culture of Bacillus subtilis

Bacillus subtilis was cultivated to high cell density for nattokinase production by pH-stat fed-batch culture. A concentrated mixture solution of glucose and peptone was automatically added by acid-supplying pump when culture pH rose above high limit. Effect of the ratio of glucose to peptone in feeding solution was investigated on cell growth and nattokinase production by changing the ratio from 0.2 to 5 g glucose/g peptone. The highest cell concentration was 77 g/L when the ratio was 0.2 g glucose/g peptone. Cell concentration decreased with increasing the ratio of glucose to peptone in feeding solution, while the optimum condition existed for nattokinase production. The highest nattokinase activity was 14,500 unit/mL at a ratio of 0.33 g glucose/g peptone, which was 4.3 times higher than that in batch culture.     

氮源对重组大肠杆菌发酵产L-精氨酸的影响

考察有机氮源种类、蛋白胨用量以及(NH4)2SO4用量对重组E.coli发酵产L-精氨酸的影响.结果表明:以蛋白胨作为有机氮源且用量在10 g/L,( NH4 )2SO4用量在15 g/L时,摇瓶发酵产L-精氨酸产量最高,达到9.4g/L.在5L发酵罐进行补料分批培养,通过补加(NH4)2 SO4,L-精氨酸产量可以达到18.8 g/L,比未补加提高了108.9％.     

维生素在丙酮酸过量合成中的重要作用

研究了烟酸、硫胺素、吡哆醇、生物素和核黄素对一株光滑球拟酵母(\%Torulopsis glabrata\%) WSH\|IP303以葡萄糖为碳源、以氯化铵为唯一氮源生产丙酮酸的影响。利用正交试验方法,确证了硫胺素是影响WSH\|IP303生产丙酮酸的最重要因素。在硫胺素浓度一定(0.01～0.015mg/L)的前提下,提高烟酸浓度有助于加快耗糖速度。当烟酸、硫胺素、吡哆醇、生物素和核黄素的浓度分别为8、0.015、0.4、0.04和01mg/L时,摇瓶发酵48h,丙酮酸产量和产率可分别达到52.4g/L和0525g/g。采用优化的维生素组合方式,进行2.5L罐分批发酵,在初糖浓度120g/L的条件下发酵57.5h,丙酮酸产量和产率分别达到69.4g/L和0593g/g,分别比摇瓶培养的最好结果提高了32.%和13%。     

营养条件和流加发酵对放射型根瘤菌(Rhizobium radiobacter)产辅酶Q10的影响

利用放射型根瘤菌WSH2 6 0 1(RhizobiumradiobacterWSH2 6 0 1)重点考察了葡萄糖、蔗糖、玉米浆和蛋白胨、添加物以及流加发酵对细胞生长和产辅酶Q1 0 的影响 ,结果表明 ,葡萄糖和蔗糖适合于生产辅酶Q1 0 的最佳浓度分别为 30g L和 40g L ;辅酶Q1 0 发酵时玉米浆和蛋白胨的最适浓度分别为 11g L和 16g L ;添加蕃茄汁、玉米浆能提高发酵液的生物量 ,玉米浆、异戊醇、L 甲硫氨基酸等能促进辅酶Q1 0 的积累 ;与分批发酵相比 ,在 7L罐上流加蔗糖其细胞生物量 (DCW)和辅酶Q1 0 积累量增加 ,若在流加蔗糖的同时流加适当浓度的玉米浆能显著提高辅酶Q1 0 的产量 ,最大产量达到 5 2 .4mg L ;最大生物量 (DCW)和胞内辅酶Q1 0 含量 (C B值 )分别达到 2 6 .4g L和 2 .38mg g DCW ,比不流加的分批发酵分别提高 5 3 %和 33% ,比只流加蔗糖分别提高 2 4%和 2 6 %。     

β‐poly(l‐malic acid) production by fed‐batch culture of Aureobasidium pullulans ipe‐1 with mixed sugars

β‐poly(l ‐malic acid) (PMLA) is a biopolyester, which has attracted growing attention due to its potential applications in medicine and other industries. In this study, the biosynthetic pathway of PMLA and the fermentation strategies with mixed sugars were both investigated to enhance PMLA production by Aureobasidium pullulans ipe‐1. Metabolic intermediates and inhibitors were used to study the biosynthetic pathway of PMLA. It showed that exogenous addition of l ‐malic acid, succinic acid, TFA, and avidin had negligible effect on PMLA production, while pyruvic acid and biotin were the inhibitors, indicating that PMLA biosynthesis was probably related to phosphoenolpyruvate via oxaloacetate catalyzed by phosphoenolpyruvate carboxylase. Sucrose was suitable for achieving the highest PMLA concentration, while fructose generated a higher yield of PMLA (PMLA produced per biomass). Furthermore, the fed‐batch culture using fed solution with different sugar mixture for PMLA production was implemented. During the fed‐batch culture with mixed solution, fructose could increase PMLA production. Compared with the batch culture, the feeding with mixed sugar (sucrose and glucose) increased PMLA concentration by 23.9%, up to 63.2 g/L, and the final volume of the broth was increased by 25%. These results provide a good reference for process development and optimization of PMLA production.     

Effect of nitrogen source and nitrogen concentration on the production of pyruvate by Torulopsis glabrata

The effect of nitrogen sources including yeast extract, peptone, soybean hydrolyzate and some inorganic nitrogen sources, as well as the nitrogen concentration on the fermentative production of pyruvate by Torulopsis glabrata WSH-IP12 was investigated. The addition of yeast extract greatly inhibited pyruvate accumulation, while peptone was shown to be the most favorable nitrogen source. In flask culture, 15 g l(-1) peptone was needed to consume 80 g l(-1) glucose with 23.4 g l(-1)of pyruvate accumulated. Pyruvate production was markedly dependent on the ratio of carbon to nitrogen (C:N), its production was improved by increasing the concentration of glucose and peptone proportionally and reduced by exclusively increasing the glucose concentration. In a glucose fed-batch culture, cell growth and pyruvate production slowed after 28 h. However, cell growth and pyruvate production recovered after further nitrogen, in the form of peptone and ammonium sulfate, was added to the culture. A final concentration of pyruvate of 54.5 g l(-1) was achieved at 64 h (yield to glucose consumed of 0.471 g g(-l)). By using aqueous ammonia instead of potassium hydroxide for pH control, 57.3 g l(-1) pyruvate with a yield of 0.498 g g(-1) was produced by 55 h. This result further indicates that nitrogen level plays an important role in the production of pyruvate.     

Efficient conversion of lactic acid to butanol with pH-stat continuous lactic acid and glucose feeding method by Clostridium saccharoperbutylacetonicum

In order to achieve high butanol production by Clostridium saccharoperbutylacetonicum N1-4, the effect of lactic acid on acetone–butanol–ethanol fermentation and several fed-batch cultures in which lactic acid is fed have been investigated. When a medium containing 20 g/l glucose was supplemented with 5 g/l of closely racemic lactic acid, both the concentration and yield of butanol increased; however, supplementation with more than 10 g/l lactic acid did not increase the butanol concentration. It was found that when fed a mixture of lactic acid and glucose, the final concentration of butanol produced by a fed-batch culture was greater than that produced by a batch culture. In addition, a pH-controlled fed-batch culture resulted in not only acceleration of lactic acid consumption but also a further increase in butanol production. Finally, we obtained 15.5 g/l butanol at a production rate of 1.76 g/l/h using a fed-batch culture with a pH-stat continuous lactic acid and glucose feeding method. To confirm whether lactic acid was converted to butanol by the N1-4 strain, we performed gas chromatography–mass spectroscopy (GC-MS) analysis of butanol produced by a batch culture during fermentation in a medium containing [1,2,3-¹³C₃] lactic acid as the initial substrate. The results of the GC-MS analysis confirmed the bioconversion of lactic acid to butanol.     

Heterotrophic production of Chlorella sp. TISTR 8990—biomass growth and composition under various production conditions

The green microalga Chlorella sp. TISTR 8990 was grown heterotrophically in the dark using various concentrations of a basal glucose medium with a carbon‐to‐nitrogen mass ratio of 29:1. The final biomass concentration and the rate of growth were highest in the fivefold concentrated basal glucose medium (25 g L^?1 glucose, 2.5 g L^?1 KNO₃) in batch operations. Improving oxygen transfer in the culture by increasing the agitation rate and decreasing the culture volume in 500‐mL shake flasks improved growth and glucose utilization. A maximum biomass concentration of nearly 12 g L^?1 was obtained within 4 days at 300 rpm, 30°C, with a glucose utilization of nearly 76% in batch culture. The total fatty acid (TFA) content of the biomass and the TFA productivity were 102 mg g^?1 and 305 mg L^?1 day^?1, respectively. A repeated fed‐batch culture with four cycles of feeding with the fivefold concentrated medium in a 3‐L bioreactor was evaluated for biomass production. The total culture period was 11 days. A maximum biomass concentration of nearly 26 g L^?1 was obtained with a TFA productivity of 223 mg L^?1 day^?1. The final biomass contained (w/w) 13.5% lipids, 20.8% protein and 17.2% starch. Of the fatty acids produced, 52% (w/w) were saturated, 41% were monounsaturated and 7% were polyunsaturated (PUFA). A low content of PUFA in TFA feedstock is required for producing high quality biodiesel. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1589–1600, 2017     

可溶性TRAIL蛋白的高密度培养及补料策略研究

采用分批补料的方法高密度培养重组大肠杆菌C600/PbvTRAIL制备人可溶性TRAIL蛋白,优化发酵工艺,探索简单高效的分离纯化方法并测定蛋白生物活性。通过比较几种不同的补料策略：间歇流加、Dostat、pHstat,摸索了一种流加策略,即DOstatpHstat组合流加,有效的避免了发酵过程中,尤其是诱导表达阶段乙酸积累的增加,使TRAIL蛋白在高密度培养条件下,得到高效表达。菌体密度最终达到300g/L（WCW）以上,可溶性TRAIL蛋白占菌体总蛋白的4.2%,含量为1.1g/L。在整个发酵过程中,乙酸浓度接近于0,且未使用任何特殊手段,如纯氧、加压等,简化了发酵工艺,降低了发酵成本,为TRAIL的工业化生产创造了条件。     

Improved algal oil production from Botryococcus braunii by feeding nitrate and phosphate in an airlift bioreactor

To improve biomass and microalgal oil production of Botryococcus braunii, fed‐batch culture was investigated in an airlift photobioreactor. The optimal feeding time of the fed‐batch culture was after 15 days of cultivation, where 1.82 g/L of the microalgal biomass was obtained in the batch culture. Nitrate nutrient was the restrictive factor for the fed‐batch cultivation while phosphate nutrient with high concentration did not affect the microalgal growth. The optimal mole ratio of nitrate to phosphate was 34.7:1, where nitrate concentration reached the initial level and phosphate concentration was one quarter of its initial level. With one feeding, the biomass of B. braunii reached 2.56 g/L after 18 days. Two feedings in 2‐day interval enhanced the biomass production up to 2.87 g/L after 19 days of cultivation. The hydrocarbon content in dry biomass of B. braunii kept at high level of 64.3% w/w. Compared with the batch culture, biomass production and hydrocarbon productivity of B. braunii were greatly improved by the strategic fed‐batch cultivation.