N~+离子诱变高效降酚菌及其含酚废水模拟处理的研究

取降酚效果较好菌株E为诱变出发菌株,利用N+离子束诱变,获得若干突变菌株,计算诱变存活率和正突变率,利用正交实验对离子束诱变的优势菌KE2菌株进行了最适宜生长条件的优化,并进行实验室模拟实验.结果表明诱变注入的较适宜剂量为18.4×1014N+/cm2.诱变菌株中降酚效果最好的诱变菌KE2的降酚率较出发菌E高,且在传代时性状稳定.经初步鉴定,出发菌株E和诱变降酚菌KE2属于假单胞菌(Pseudo-monas.sp.).KE2降酚诱变菌的生长适宜参数为:葡萄糖浓度1 000 mg/L,pH值为7,温度30℃.实验室模拟实验显示,添加诱变菌株的一组降酚效果较好,在500 mg/L的酚浓度下,9 h降酚率可达到100%,1 000 mg/L的酚浓度下,加诱变菌组在12 h可完全降解,达到100%.     

常压室温等离子体诱变选育花脸香蘑新菌株

花脸香蘑作为一种营养丰富、菇型美观的珍稀食用菌,具有良好的开发利用价值。利用常压室温等离子体（ARTP）技术对野生花脸香蘑菌株610双核菌丝片段进行了诱变处理。利用拮抗试验进行了诱变菌株初筛。通过连续传代培养,自然淘汰劣势菌株并获得诱变效应稳定的48个菌株。综合平板培养和基于ISSR和SSR联合遗传多样性分析的结果,筛选出7个诱变菌株与出发菌株共同进行出菇比较试验。出菇试验及子实体蛋白和氨基酸营养分析的结果显示：诱变菌株Ls2和Ls3为筛选出的花脸香蘑优质高产新菌株。诱变菌株较出发菌株生物学效率分别提高10.27%和14.75%,总氨基酸含量、必需氨基酸含量以及氨基酸评分等指标也均显著高于出发菌株,品质提升效果极显著。     

等离子体-紫外复合诱变选育四羟基环孢菌素衍生物高产菌株

筛选可体内转化合成环孢菌素衍生物([γ-HyMeLeu4]CyA)的高产菌株。以稀有放线菌Nonomuraea dietziae为出发菌株,采用常温常压等离子体射流和紫外照射对其进行复合物理诱变。通过该诱变方法获得了具有稳定遗传性能的菌株,其转化效率比出发菌株提高了32%左右。结果表明,等离子体诱变可有效的用于该稀有放线菌,通过等离子体-紫外复合诱变筛选得到的突变菌株可用于工业生产。     

耐60℃高温乳酸菌的驯化及鉴定

目的对本实验室保存的ATCC 4356菌株进行温度梯度诱变,从而获得1株耐高温乳酸菌。方法采用温度梯度方法诱变菌株;通过革兰染色和原子力显微镜观察诱变前后菌株革兰染色特性和形态及表面结构的变化;通过生理生化特性鉴定,判断诱变前后菌株是否发生种属变化。结果在45~60℃诱变过程中,随温度升高传代次数递增,但最终均能成功驯化和稳定传代。驯化前后菌株在产酸能力、形态特征、革兰染色和生理生化特性方面无显著性变化,表明该诱导菌株未发生种属变化;原子力显微镜观察结果表明诱导前后菌株表面形态存在差异。结论温度梯度诱变技术能够成功驯化耐60℃高温乳酸菌,从而扩大其应用范围。     

复合诱变选育绿色产色链霉菌抑菌高活性菌株

以一株绿色产色链霉菌xzte06菌株为出发菌株,依次通过软X射线、低能离子束诱变、紫外线照射和微波诱变手段对菌株进行复合诱变,得到一株对产气荚膜梭状芽胞杆菌具有较强抑制活性的菌株W26菌株,且该菌株的遗传特性稳定。对菌株进行抑菌试验发现,该菌株液体深层发酵菌丝体的内酮提取物的抑菌活性与出发菌株相比提高了101.42%。     

雷帕霉素菌株的常压室温等离子体(ARTP)诱变选育

雷帕霉素由放线菌次级代谢产生,具有抗真菌、抗肿瘤以及免疫抑制等生理活性,是临床重要的器官移植、抗肿瘤原料药物。为了获得具有高发酵潜力的工业用菌株,对雷帕霉素菌株的摇瓶发酵工艺进行了优化。采用常压室温等离子体(ARTP)的方法对高产雷帕霉素菌株的单孢子悬液进行诱变处理,通过高压液相的方法对诱变菌株的发酵代谢产物进行检测,成功地从诱变菌株中筛选获得了发酵产量提高30%以上的诱变菌株,建立了ARTP诱变选育高产雷帕霉素菌株的方法,为后期进行该菌株的选育研究工作以及中试发酵工艺优化提供了方法和物质的基础。     

北冬虫夏草菌丝体片段诱变育种

目的：通过诱变育种提高北冬虫夏草菌种虫草多糖的含量。方法：对北冬虫夏草子实体进行组织分离,制备菌种,以此作为出发菌株,利用紫外线、微波及其二者结合分别对出发菌株进行诱变,并以其多糖含量为试验指标,探究北冬虫夏草菌丝体片段的诱变育种。结果：通过复合诱变（紫外40s、微波5s,生长正常）的菌株,经测定其多糖含量比对照菌株高17%。结论：通过对北冬虫夏草菌丝体片段进行诱变,找到多糖含量显著提高的菌株是可行的。     

酸奶生产菌株的诱变选育

通过诱变选育高产酸力菌株;首先采用紫外线和亚硝基胍对乳酸菌进行单因素诱变,确定紫外线照射剂量为150s,并得到一株产酸力为57.85°T的菌株,比原菌株产酸力提高了3.05%;NTG的诱变剂量是0.3mg/mL,处理时间为60min,得到产酸力为58.02°T的菌株,较出发菌株提高了6.52%。接着以紫外线和NTG对高产酸菌株进行了2轮复合诱变,最终得到产酸力达83.66°T的诱变株,较出发菌株产酸力提高了30.64%。     

梅岭霉素产生菌抗药性突变标志诱变筛选模型的初步研究

本文通过梅岭霉素 (Meilingmycin)产生菌南昌链霉菌NS 4 1 80菌株孢子对 6种抗生素敏感性测定 ,采用诱变剂EMS四种不同诱变剂量对菌株孢子进行诱变处理 ,诱变处理的孢子涂布在含致死浓度链霉素的高氏平板上。然后从抗药性突变标志菌株中进一步筛选梅岭霉素高产菌株。在 150 0多个抗药性突变株中通过初筛获得了比诱变出发菌株的产素能力提高 50 %以上菌株。通过诱变剂量分别与抗药性突变率和突变株产素产量的变势统计分析表明 ,菌株抗药性突变与产素突变密切相关 ,产素突变的EMS诱变剂量高于抗药性突变诱变剂量 ,在 0 .0 3mol/LEMS剂量作用下 ,菌株致死率为 99.4 3% ,抗药性突变率为 0 .0 4 4 0 % ,建立了梅岭霉素产生菌抗药性突变标志诱变推理性筛选模型。为南昌链霉菌高产菌种选育研究作了有益的尝试 ,并有助于其它链霉菌属的抗生素产生菌育种研究。     

菊粉酶产生菌的筛选及60Co诱变选育简

目的：从新疆石河子盐碱地菊芋生长根际土壤中分离筛选高产菊粉酶活力菌株。方法：通过稀释平板涂布法分离微生物;利用^60Co诱变选育,96孔板筛选突变菌株;采用3,5-二硝基水杨酸比色法测定菊粉酶酶活。结果：分离到12株具有菊粉酶活力的菌株,复筛得到1株高产菊粉酶活力菌株,将其命名为G-60;以此菌株为出发菌株进行^60Co诱变,利用96孔板对诱变菌株进行筛选,经摇瓶发酵酶活测定,得到1株高产菊粉酶酶活的突变株,酶活达46．62U/mL,是未诱变菌株酶活的2．72倍。结论：经诱变得到1株高产菊粉酶活力的突变菌株。     

Comparative studies of strains Ictero No. I and RGA as the type strain of Leptospira interrogans: agglutinin absorption test, protein and antigen profiles, and enzyme activities

Strain Ictero No. I, the first isolate of Leptospira, isolated by Inada and Ido in 1914, was found to be sufficiently qualified to be the type strain of Leptospira interrogans rather than strain RGA. In an agglutinin absorption test, anti-Ictero No. I serum was not absorbed completely with strain RGA, and 25% of the homologous titer remained unabsorbed, while anti-RGA serum was completely absorbed with strain Ictero No. I. Thus, strain Ictero No. I was not serologically identical with strain RGA, and the two strains were considered to be different serovars. A protein band with a molecular weight of approximately 33,000 daltons was detected in strain Ictero No. I but not in strain RGA by SDS-PAGE. By Western blotting, this protein band was detectable with anti-Ictero No. I serum but not with anti-RGA serum. The presence of the 33K protein in strain Ictero No. I, but not in strain RGA, was confirmed by radioimmunoprecipitation using [125I]-labeled antigens, indicating that the protein antigen was surface-exposed. Only 8 of the 89 enzymes activities were different between strains Ictero No. I and RGA (line Sapporo). From the above results, we propose that strain Ictero No. I should be designated as the type strain of L. interrogans instead of strain RGA.     

Transductional construction of a threonine-producing strain of Serratia marcescens.

A threonine-producing strain of Serratia marcescens Sr41 was constructed according to the following process. Thr- strain E-60 was derived from strain HNr59 having constitutive levels of threonine-sensitive aspartokinase and homoserine dehydrogenase. Thr+ transductant T-570 was constructed from strain E-60 and phage grown on strain HNr21 having feedback-resistant threonine-sensitive aspartokinase and homoserine dehydrogenase. This transductant lacked both feedback inhibition and repression for the two enzymes. Thr- strain N-11 was derived from strain AECr174 lacking feedback inhibition and repression of lysine-sensitive aspartokinase. Subsequently, the threonine region of strain T-570 was transduced into strain N-11. One of the THR+ transductants, strain T-693, produced markedly high levels of the two aspartokinases and homoserine dehydrogenase, which were insensitive to feedback inhibition. This strain produced about 25 mg of threonine per ml in the medium containing sucrose and urea.     

Transductional construction of a threonine-producing strain of Serratia marcescens.

A threonine-producing strain of Serratia marcescens Sr41 was constructed according to the following process. Thr- strain E-60 was derived from strain HNr59 having constitutive levels of threonine-sensitive aspartokinase and homoserine dehydrogenase. Thr+ transductant T-570 was constructed from strain E-60 and phage grown on strain HNr21 having feedback-resistant threonine-sensitive aspartokinase and homoserine dehydrogenase. This transductant lacked both feedback inhibition and repression for the two enzymes. Thr- strain N-11 was derived from strain AECr174 lacking feedback inhibition and repression of lysine-sensitive aspartokinase. Subsequently, the threonine region of strain T-570 was transduced into strain N-11. One of the THR+ transductants, strain T-693, produced markedly high levels of the two aspartokinases and homoserine dehydrogenase, which were insensitive to feedback inhibition. This strain produced about 25 mg of threonine per ml in the medium containing sucrose and urea.     

灰黄霉素菌的诱变效应

以灰黄霉素产生菌D－756为出发菌株,经过三代紫外线＋氯化锂诱变处理,获得耐氯变株F－1012,该变株在形态特征及产量、耐氯性等方面均发生变化,当发酵培养基中的氯化物浓度由1.5%提高到2.0%,F－1012的大米孢子效价提高了34.5%;当固体平板培养基中氯化物浓度提高到11％时,F－1012的孢子存活率比出发菌株提高了25.5％。     

Alternation of the Dissimilation Pathway for Glycerol and Amplification of Glycerol Dehydrogenase in Mutant Strains of Cellulomonas sp. NT3060

Mutant strain ME544, which is able to grow on glycerol slowly, was derived from glycerol-negative mutant strain G011, which is a derivative strain of Cellulomonas sp. NT3060 and is defective in both the enzyme activities of glycerol kinase and glycerol 3-phosphate dehydrogenase. The mutant strain still lacked both the enzyme activities involved in the dissimilation of glycerol and had the same level of glycerol dehydrogenase activity as the parent strain. Dihydroxyacetone kinase activity in mutant strain ME544 was inducibly formed, reaching 4-fold the level in mutant strain G011 in glycerol medium. Thus, the mutant strain seemed to dissimilate glycerol by means of glycerol dehydrogenase followed by an increase in dihydroxyacetone kinase. Subsequently, a mutant strain, GP1807, which was resistant to the inhibition of growth on glycerol by 1,2-propanediol, was derived from mutant strain ME544. Glycerol dehydrogenase activity of the mutant strain was amplified about 6-fold compared to that of the wild type strain.     

Arctic charr strain crosses: effects on growth and sexual maturity

Three Arctic charr strains and their crosses were evaluated with respect to growth and sexual maturation frequency. No significant heterosis was observed for growth. One out of five crosses was heavier, but not significantly so, than the best performing parental strain at ages 1 + and 2. The five other crosses did not perform better than the best performing parental strain at any age. Cross-breeding was not recommended as an effective method to improve growth performance in Arctic charr. Growth performance of reciprocal crosses differed significantly in all strain combinations: crosses resembled more the male parent strain than the female parent strain. ANOVA for male maturation frequency showed a highly significant effect of the male parent strain and a weakly significant effect of female parent strain. In the Ottsjö strain mature males were significantly larger than immature fish and females. Such size difference was also observed in the offspring when sires of the Ottsjö strain were crossed with dams of the faster growing Honavan strain or with dams of the Rensjö strain. When Ottsjö dams were crossed to sires of the other strains no significant size difference between mature males and other fish was found.     

Comparisons of Characteristics of Mercury-Tolerant Bacterium Pseudomonas oleovorans G-1 and Its Mercury-Sensitive Mutant Strain

An Hg²⁺-sensitive mutant strain was isolated from an Hg²⁺-tolerant bacterium Pseudomonas oleovorans G-1 strain by mutagenesis with N-methyl-N′-nitro-N-nitrosoguanidine. The Hg²⁺-sensitive mutant strain was about 10-times as sensitive to Hg²⁺ as the parent strain. Moreover, the mutant strain was considerably more sensitive to Cr⁶⁺ than the parent strain, but it did not show an appreciable change in sensitivity to Cd²⁺ and Cu²⁺. The mutant strain was considerably more sensitive to antibiotics achromycin, chloramphenicol and streptomycin than the parent strain. A more rigid structure was observed in the cell envelope of the mutant strain than the parent strain under transmission electron microscope. Higher amounts of DNA but less protein and RNA were found in the mutant strain compared to the parent strain. Disc electrophoretic patterns showed some differences in protein bands between the parent and mutant strain.     

Compressive axial strain distributions in cancellous bone specimens

The compressive axial strain distribution in cylindrical trabecular bone specimens was studied using digitized images of the specimen surface. Specimens were tested with strain rate 0.00015 s-1. Images were taken at 0, 1, 2, 3, 4, 6, 8 and 10% strain. Using an optical illusion of movement by rapidly changing succeeding images, failures were classified as transverse (33%) or oblique collapses (67%). The location of failure was not determined by the specimen density gradient. Local axial strain in the distal, intermediate and proximal third was measured throughout the compression in the transversely failing specimens, whereas local strain in the obliquely failing specimens was measured in the pre-failure phase only. Axial strain inhomogeneity was observed in the pre-failure as well as in the post-failure phase. In the pre-failure phase the intermediate third was strained significantly less than the thirds near the ends. In the post-failure phase specimen strain occurred solely in the collapsed part. Ultimate strain of the transversely failing specimens was 2.5% and ultimate strain of the failing third was 3.7%. At failure less than 1% strain was observed in the intermediate third and at 10% specimen strain 1.5% local strain was found in the intermediate third. The results indicate unreliability of conventional stiffness and strain measurements in trabecular bone specimens probably due to lack of trabecular constraint at the end surfaces. Conventional measurements tend to underestimate stiffness and, by giving an average value of strain in spite of considerable strain inhomogeneity, to underestimate failure strain.     

Cloning and Characterization of the Genomic RNA Sequence of the Mumps Virus Strain Associated with a High Incidence of Aseptic Meningitis

cDNA clones of the mumps virus wild-type strain, associated with a high incidence of aseptic meningitis (ODATE-1 strain), were isolated and analyzed from genomic nucleotide position 22 to 8520 containing the NP, P, M., F, SH and HN protein coding region. The ODATE-1 strain exhibited a RFLP profile identical to that of the Urabe vaccine strain in spite of the fact that the virus was isolated from non-vaccinated cases. However, a comparison of nucleotide and amino acid sequences among the ODATE-1 strain, Urabe strain and Miyahara strain revealed that the ODATE-1 strain was not related to the Urabe strain.     

phbC基因敲除对土壤杆菌产可得然胶的影响

本文构建了phbC基因无痕敲除菌株ΔphbC,分析了ΔphbC菌株生长代谢情况和产生的可得然胶在产量、凝胶性质和红外结构的变化。结果显示,ΔphbC菌株在发酵过程中氨基氮消耗情况与野生型菌株一致,在蔗糖消耗方面,ΔphbC菌株与野生型菌株在18 h之后出现显著差异,蔗糖消耗比野生型菌株明显降低。ΔphbC菌株可得然胶产量约24 g/L,相对于野生型菌株降低了45%;胶凝胶强度为812.521 g/cm^2,相对于野生型菌株降低了21%;红外结构与野生型菌株一致,无明显差异。phbC基因不影响菌体生长,不影响可得然胶结构,但是影响可得然胶的合成。