氮离子注入井冈霉素产生菌诱变高产菌株的研究

以井冈霉素生产菌株7105#为出发菌株,采用氮离子注入诱变处理,经摇瓶筛选,得到一株特性优良且A组分含量较高的9263#菌株。     

He-Ne激光与紫外线复合诱变选育西罗莫司高产菌株

以吸水链霉菌为出发菌株,采用He-Ne激光-紫外复合诱变对其单孢子悬液进行诱变筛选高单位突变株,经复筛选育出具有较好遗传稳定性的高产突变株11-1-6#,摇瓶效价达到401.9u/mL,比出发菌株提高了79%。     

纤维素分解菌的筛选及其紫外诱变

利用羧甲基纤维素钠为唯一碳源培养基从朽木、腐烂的竹叶与稻草中分离得到8株纤维素分解菌,测定了其产酶活性。对其中产酶活性较高的2#菌株进行紫外线诱变,进一步筛选得到突变株M10,其相对酶活较出发菌株提高了89.1%。     

棘白霉素B脱酰基酶产生菌转化条件的优化研究

为提高棘白霉素B脱酰基酶产生菌的转化率,通过紫外诱变复合Cu2+抗性处理筛选转化高产菌种,利用均匀设计方法优化菌种的转化工艺。结果表明,筛选得到的突变株132#的棘白霉素B转化率比出发菌株提高了22.6%,优化后的转化条件为:底物浓度2 400μg·mL-1,转化时间56h,转化温度30℃,发酵培养基pH值6.0。132#菌株在优化转化条件下的转化率较出发菌株在原始转化条件下提高了57.3%。优化的转化条件更有利于高产菌株的转化,转化率得到大幅提高,也为其工业化应用打下基础。     

优良菌株降解芘相互间影响作用研究

探讨了自行培养的2#、4#、9#菌在降解芘过程中的相互作用关系。分别对单一菌株、菌株间两两混合、三株菌混合三种情形对芘的降解作用进行研究。研究结果表明：三株菌中2#菌株的降解效果最好,5d内累积去除率为55.99%;菌株间两两混合时2#菌株的降解受到抑制,说明菌株间有相互抑制的作用;三株菌混合对芘降解时同样表现出相互抑制作用,抑制程度大于两两混合的情况,在降解过程中,pH值总体是下降的,并周期性地交替出现产酸和脱羧反应。     

替考拉宁高产菌株的选育

以替考拉宁产生菌1-16为出发菌株,经热诱变复合替考拉宁抗性筛选高产菌株,获得一株高产突变菌株TC3-25,其替考拉宁产量较出发菌株提高46%。传代试验表明该菌株的发酵水平较稳定。     

硫化物脱硫菌培养条件的选择和性能研究

通过细菌的初筛和复筛,得到了硫化钠脱硫效果较好的一株菌株命名为S1#。通过对菌株S1#培养条件的测定,得到菌株的最适培养条件:pH值,8;温度,45℃;摇床转速,200r/min;代谢负荷,(Na2S)3~5g/L,通过实验发现该菌株为兼氧菌株,能在氧气不足的环境下良好生长。在最适培养条件下对菌株S1#进行了生长曲线的测定,实验表明在S1#在12h进入对数生长期,菌株S1#的浊度值在30h的时候达到了最高峰。通过对菌株脱硫效果的测定,菌液中的硫化钠能很好地降低,将细菌对硫化钠脱硫效果测定时的溶液中沉淀烘干XRD衍射检测,发现有单质硫的存在,说明细菌能代谢硫化钠,并得到了单质硫。     

大观霉素高产菌的诱变选育和发酵条件研究

大观霉素产生菌Streptomyces spectabilisDG8#经紫外线诱变(30W、40cm、60s),氮离子注入(50keV,5×1014ion/cm2)后分离,在含有大观霉素的浓度梯度平板上筛选大观霉素抗性突变株,得到大观霉素抗性突变株SP0403,其发酵效价较出发菌株提高了69.4%,并且遗传特性稳定。对其进行了接种量、种龄、通气量和补料方面的探索。     

沼泽红假单胞菌在低温下对水中总氮的降解

本文采用亚硝酸盐诱变与温度驯化处理的复合诱变方法,对能够高效降解水中总氮的沼泽红假单胞菌出发菌株进行诱变处理,选育出能一株在低温条件下生长良好、性状稳定,且能够在低温条件下高效降解水中总氮的沼泽红假单胞菌驯化菌株。与出发菌株相比,驯化菌株在15℃时的生长以及总氮降解率均好于出发菌株,其对总氮降解率可达到69.08%,比出发菌株提高了43.49%。     

复合诱变法筛选FK506高产菌株

通过复合诱变的方法对出发菌株筑波链霉菌08-6—9进行处理,得到一株FK506高产菌株08-9-81,其摇瓶发酵水平较出发菌株提高73．6％,并顺利通过20L发酵罐放大,具有实际生产意义。     

卡泊芬净合成前体Pneumocandin Bo的发酵工艺研究

以Pneumocandin B0 PB5-31为出发菌株,从筛选高产菌株和提高产物中有效组分的比例两方面进行研究,以期提高Pneumocandin B0 的发酵水平.结果表明,紫外线诱变复合氯化锂后处理筛选出高产菌株,其发酵效价比出发菌株提高了72％;发酵培养基中添加0.3％的脯氨酸很好地提高了有效组分B0的比例.     

卡泊芬净合成前体Pneumocandin B0的发酵工艺研究

以Pneumocandin B0 PB5—31为出发菌株,从筛选高产菌株和提高产物中有效组分的比例两方面进行研究,以期提高Pneumocandin B0的发酵水平。结果表明,紫外线诱变复合氯化锂后处理筛选出高产菌株,其发酵效价比出发菌株提高了72％;发酵培养基中添加0．3％的脯氨酸很好地提高了有效组分B0的比例。     

Biosynthetic pathway of diepoxy bicyclic FA from linoleic acid by Clavibacter sp. ALA2

The biosynthetic pathway of two bicyclic FA, 12∶17, 13∶17-diepoxy-9(Z)-octadecenoic acid (DEOA) and 7-hydroxy-12∶17, 13∶17-diepoxy-9(Z)-octadecenoic acid (hDEOA), by Clavibacter sp. ALA2 was investigated. When cultivated with linoleic acid as a substrate, the strain produced 12,13,17-trihydroxy-9(Z)-octadecenoic acid (THOA), DEOA, and hDEOA as well as other FA. To clarify the synthetic route to these bicyclic FA, the strain was cultivated with purified THOA as a starting substrate. THOA was consumed almost completely by the strain with sequential generation of DEOA and hDEOA. Moreover, the strain produced hDEOA when cultivated with purified DEOA. Therefore, it was confirmed that THOA was a precursor of these bicyclic FA and that hDEOA was generated from DEOA. Based on our previously reported result that linoleic acid is first converted to 12,13-dihydroxy-9(Z)-octadecenoic acid (DHOA) and the present results, the overall biosynthetic pathway for the diepoxy bicyclic FA from linoleic acid was postulated as: linoleic acid→DHOA→THOA→DEOA→hDEOA.     

Temperature factor in tailoring the morphology of Y-α-SiAlON microcrystals fabricated by combustion synthesis

Silicon was used as the only combustible agent, and single-phase Y-α-SiAlON powders were fabricated from a proper starting composition, but the grain morphology of the products was represented by equiaxed microcrystals. For the same starting materials, as a modified method of combustion synthesis was applied, single-phase Y-α-SiAlON powders were also obtained and the grain morphology of the products changed to rod-like microcrystals. It is of great importance to control the reaction temperature to tailor the grain morphology of Y-α-SiAlON microcrystals. The article is published in the original.     

润滑油生物降解菌的筛选

以被石油基润滑油污染的土壤为出发菌源,通过增加环境选择压力的方法,驯化、筛选分离出对石油基润滑油具有一定降解能力的菌株RHY-1,该菌株的100 mL菌悬液48 h对5 mL润滑油的降解率为82.4％,可生长的pH值范围为3.0～11.0,可耐受的NaC1浓度为27 g·L-1;在30℃、pH值为8.0、NaCl浓度为...     

磷细菌突变株生理特性的研究

本文对经过筛选培育出的一株解磷能力较强的磷细菌突变株Ｄ０１７Ｐ的生理特性进行了研究。其中,最佳氮源为麦麸汁,与出发菌株所用马铃薯汁相比,生物量增加９．８倍,解磷能力提高７１．４％,最佳碳源为蔗糖,与出发菌株所用碳源葡萄糖比较,解磷能力提高２８．８％,金属离子,培养温度,ｐＨ,气／液比等也对突变株的生长有一定影响,其结果可作为选定工业化条件的参考。     

Permuteins of interleukin 1{beta}--a simplified approach for the construction of permutated proteins having new termini

A technique for the rapid and simple generation of permutatedversions of the interleukin-1ß (IL-1ß) geneis described. In this method, the human IL-1ß cDNAis twice amplified by the polymerase chain reaction (PCR) andthe resulting DNA fragments are ligated in tandem. Between thetwo genes, the DNA sequence encodes a short four amino acidloop to link the native N- and C-terminal ends of the IL-1ßprotein. By using PCR amplification from this starting template,a new version of the IL-1ß cDNA was obtained thatencodes a permutated form of the IL-1ß protein wherethe new N- and C-terminal amino acids correspond to residues65 and 64 of the native IL-1ß sequence, respectively.The name ‘permutein’ is proposed to describe proteinsgenerated by this technology. The molecular profile (IL-1 receptorbinding, biologic activity and solution properties) of the IL-1permutein produced by this technology, permutein 65/64, is shownto be identical to that of native IL-1ß The approachshould be useful to define further the structural features ofthis protein that are important for its function.     

Analytical prediction of deformation of polycaproamide cloth

A method of combined approximation of isothermal “families” of creep and relaxation curves is proposed for obtaining more precise numerical values of the viscoelastic characteristics of cloth. The applicability of the equation of nonlinear-hereditary elasticity designed for analytical prediction of the stress—strain state of the fabric and in particular, stress—strain diagrams and more complex strain regimes was demonstrated. St. Petersburg State University of Technology and Design. Translated fromKhimicheskie Volokna, No. 1, pp. 40–43, January–February, 1999.     

紫外诱变柠檬酸生产菌黑曲霉的选育

初步研究了柠檬酸生产菌黑曲霉产柠檬酸的影响因素和培养条件,通过紫外诱变考察了出发菌株的受诱变性,统计了紫外诱变黑曲霉引起的生物学效应,在紫外诱变过程中筛选到一株稳定高产菌株10min-3,产酸增加了5.33%,可作为进一步诱变筛选的出发菌株.