小单孢菌属的一个新种

从云南省丽江地区的高寒山区采集的土样中分离到两株小单孢菌Y81—917和Y81一558。它们不产生气生菌丝体。基内菌丝体蓝色。产生蓝色可扩散色素。孢子单个着生,表面皱褶。细胞壁化学组分II型。它们与所有已知的小单孢菌都不同,认为是小单孢菌属中的一个新种,定名为玉龙小单孢菌(Micromonospora yulongensis n. sp.),菌株Y81-917为模式株。     

小单孢菌及其在海洋药物开发中的前景

小单孢菌是除链霉菌外,生产抗生素的另一大家族。从分类地位、生态分布、分离方法以及产生物活性物质的状况等方面,介绍了小单孢菌研究的历史和现状。展望了小单孢菌在海洋药物开发中的前景。     

一株来源于海洋的抗肿瘤放线菌的分离鉴定

从福建东海海滩土样品中分离到一株海洋放线菌FIM02-523, 该菌株的发酵产物具有抗肿瘤活性。菌株FIM02-523在多数培养基上生长良好, 橙色-暗棕色, 无气生菌丝, 不产生可溶性色素。系统发育、化学分类特征、形态特征、生理生化特性等分析表明菌株FIM02-523是小单孢菌属(Micromonospora), 可能是模式菌种青铜小单孢菌(Micromonospora chalcea)的一个菌株。     

中国南海来源海洋链霉菌SCSIO 11863中Enterocins的分离鉴定(英文)

从南海底泥样品中分离到一株具有较强抗菌活性的放线菌株SCSIO 11863。表型和进化系统分析数据表明该菌属于链霉菌属并命名为Streptomyces sp.SCSIO 11863(KC904267)。16S rDNA序列分析表明它与白浅灰链霉菌Streptomyces albogriseolus strain ABRIINW EA1145(GQ925802)有99%的相似性。对该菌发酵液乙酸乙酯萃取物进行活性追踪分离得到了两个结构类似化合物,分别为Enterocin(1)和5-deoxyenterocin(2)。     

小单孢菌科放线菌的研究进展

小单孢菌科（Micromonosporaceae）菌株是一类具有气生菌丝和基内菌丝分化的经典放线菌,于二十世纪中期被发现,目前包含29属246种的成员。这类菌株不仅广泛分布于普通的陆地生态系统中,在淡水生态系统、海洋生态系统以及一些被认为对生命极具挑战的极端环境中也常能探测到这些微生物的踪迹。小单孢菌产生的抗生素和其他生物活性物质被广泛应用于医疗和农业的多个领域,一直以来受到研究人员的广泛关注。本文就小单孢菌科放线菌的分类学特征、生态分布、基因组特征及其在医药和农业领域的应用情况进行了综述,以期为推进小单孢菌科放线菌资源的高质量发掘奠定基础。     

小单孢菌40027菌株噬菌体的分离及其生物学特性的研究

以福堤霉素A产生菌──小单孢菌40027菌株为指示菌,从土壤中分离得到三株噬菌体:ΦHAU7、ΦHAU9和ΦHAU11。三株噬菌体的寄主专一性较强,在测试的15株放线菌菌株中,三株噬菌体能感染小单孢菌40027菌株和A-M-01菌株,ΦHAU9和ΦHAU11还能感染蔷薇小单孢菌(Micromonospora purprea)。三株噬菌体都是由多面体的头部和尾部组成;形成噬菌斑时培养基中适宜的Ca2 、Mg2 浓度分别为32mM和30mM;ΦHAU7在储存液中适宜的pH范围为6~12,而其它两株噬菌体的适宜的pH范围为6~10;在储存过程中三株噬菌体适宜的温度范围为28~37℃,经60℃保温30min后,除ΦHAU7仍有53%活力之外,其它两株噬菌体全部失活。限制性内切酶酶切结果表明:三株噬菌体基因组DNA均为双链DNA;基因组大小分别约为60kb、58kb和55kb。高压脉冲电泳结果揭示:三株噬菌体基因组DNA均具有粘性末端。     

南海链霉菌SCSIO 1635中抗霉素类化合物的分离鉴定(英文)

我们从南海海底沉积环境分离了一株放线菌SCSIO1635,经16S rDNA的序列分析将该株菌鉴定为链霉菌属。我们从该菌的发酵液中分离得到了4个化合物,经质谱和核磁共振波谱解析,确定为抗霉素类化合物:异构体antimycin A1a和A1b(1)、deisovalerylblastmycin(2)、kitamycin A(3)和antimycin A9(4)。     

小单孢菌细胞壁中3－OHDAP的快速分析

本文介绍了用微结晶纤维素簿板层析对小单孢菌（Ｍｉｃｒｏｍｏｎｏｓｐｏｒａ）细胞壁中二氨基庚二酸（ＤＡＰ）异构体及其３－羟基衍生物（３－ＯＨＤＡＰ）进行快速分析的方法。在甲醇：水：冰乙酸：吡啶（１０：５：０．２５：１）的溶剂系统中测得Ｒ_{ＬＬ－ＤＡＰ}：ｍｅｓｏ－ＤＡＰ为０．８８,ＤＤ－ＤＡＰ为０．７８,３－ＯＨＤＡＰ为０．７２。     

小单孢菌细胞壁中3—OH DAP的快速分析

本文介绍了用微结晶纤维素薄板层析对小单孢菌细胞壁中二氨基庚二酸（ＤＡＰ）异构体及其３－羟基衍生物（３－ＯＨ ＤＡＰ）进行快速分析的方法。在甲醇：水：冰乙酸：吡啶（１０：５：０．２５：１）的溶剂系统中测得ＲＬＬ－ＤＡＰ：ｍｅｓｏ－ＤＡＰ为０．８８,ＤＤ－ＤＡＰ为０．７８,３－ＯＨ ＤＡＰ为０．７２。     

Isolation and characterization of plasmids from Micromonospora zionensis and Micromonospora rosaria

Three plasmids from Micromonospora species were isolated and characterized. Micromonospora zionensis NRRL5466 (a producer of sisomicin and G-52) carried a high-copy-number plasmid pMZ1 (9.9 kb). Micromonospora rosaria NRRL3718 (a producer of rosamicin) contained a large plasmid, pMR1 (53.5 kb), and a relatively small plasmid, pMR2 (11.0 kb).     

Effect of intercalating dyes on the production of antibiotics by Micromonospora rosaria and Micromonospora purpurea.

The effect of treatment with various intercalating dyes on the ability to produce antibiotics in Micromonospora rosaria and Micromonospora purpurea was studied. Treatment with acriflavine resulted in a high frequency loss of antibiotic productivity in both species. In M. rosaria, the loss of antibiotic-producing ability appeared to be strain-dependent. In M. purpurea, up to 90% of colonies were found to have lost gentamicin-producing ability when protoplasts were used in the test. These antibiotic-nonproducing strains were further studied. The following observations were made: (1) Unlike the producing ability, the resistance to the antibiotics is a very stable character in both species. (2) Protoplast fusion analysis indicates that rosamicin-nonproducing characteristics of MR 217-AF2 and MR 217-AF3 strains induced by the acriflavine treatment is due to chromosomal mutation or rearrangement but not to loss of a plasmid. (3) Gentamicin-nonproducing strains of M. purpurea responded differently to the supplementation of streptamine or DOS in the culture medium. When supplemented with streptamine or DOS, some of these strains regained the ability to produce antibiotic, showing that the biosynthesis of intermediate was affected in these strains.     

海洋链霉菌Streptomyces sp.SCSIO 1667中吲哚咔唑生物碱类成分的研究

运用大孔树脂柱及硅胶柱层析对南海海洋链霉菌Streptomyces sp.SCSIO 1667的代谢产物进行了研究,从SCSIO 1667菌株的发酵产物中分离得到两个indolocarbazole生物碱类化合物,经质谱,1D、2D NMR波谱数据分析鉴定为星形孢菌素(staurosporine,1)和K-252d(2)。     

Mutagenesis of Micromonospora rosaria by using protoplasts and mycelial fragments.

Both mycelial fragments and protoplasts were successfully employed for mutagenesis of Micromonospora rosaria NRRL 3718, and the results were compared. The optimal conditions and effective procedures for mutagenesis of M. rosaria by a chemical mutagen, N-methyl-N'-nitro-N-nitrosoguanidine, have been determined. Mutation was efficiently induced when mycelial fragments were treated with N-methyl-N'-nitro-N-nitrosoguanidine at a concentration of 0.3 to 0.5 mg/ml in the reaction buffer of pH 7.0. Optimal treatment time was 20 to 40 min. Ampicillin treatment was very effective for enrichment of auxotrophs. Protoplasts showed much higher sensitivity to the lethal effect of N-methyl-N'-nitro-N-nitrosoguanidine. Although protoplasts have some advantage of single cell characteristics, the frequency of auxotrophs obtained was somewhat lower. Up to 4% of the colonies were shown to be auxotrophs under the well-defined conditions. This mutagenesis method with protoplasts or fragmented mycelia (or both) should be applicable to other actinomycetes that have limited or no sporulation.     

Chemistry of Antibiotics from Micromonospora: III. Isolation and Characterization of Everninomicin D and Everninomicin B

The isolation of everninomicin D and everninomicin B, two closely related antibiotics produced by Micromonospora carbonacea, is described. The structures of everninomicin D and B are shown to parallel closely that of curamycin, a polysaccharidic antibiotic with a low molecular weight and a dichloroisoeverninic acid end group.     

Isolation and Structural Elucidation of DDMP-Conjugated Soyasaponins as Genuine Saponins from Soybean Seeds

The composition and the structures of native “group B saponin” in soybean seeds were reinvestigated. Five kinds of saponins named soyasaponins αg, βg, βa, γg, and γa, according to elution order from HPLC, were isolated and the structures were characterized as 2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) attaching through an acetal linkage to the C-22 hydroxyl of the aglycones of soyasaponins V, I, II, III, and IV, respectively, by UV, IR, MS, and NMR. DDMP-conjugated saponins were detected as major saponin constituents by extraction under mild conditions, and soyasaponins I–V were not detected. Therefore it was strongly suggested that these DDMP-conjugated saponins were genuine saponins in the intact soybeans.     

开口箭甾体皂甙元的分离鉴定及其抗荔枝霜疫霉菌活性

在以荔枝霜疫霉菌为指示菌的生物活性测定导向跟踪下,运用TLC、硅胶柱层析、反相硅胶柱层析和凝胶柱层析等分离纯化方法,从开口箭(Tupistra chinensis)甲醇提取物的乙酸乙酯分部萃取物中分离纯化得到2个抗菌化合物。经现代光谱(MS、IR、1D NMR和2D NMR)分析,确定化合物1为1β,2β,3β,4β,5β,7α-六羟基螺甾-25(27)-烯-6-酮,化合物2为螺甾-25(27)-烯-1β,2β,3β,4β,5β,6β,7α-七醇。离体抗菌活性测定化合物1和化合物2抑制荔枝霜疫霉菌(Peronophythora litchii)孢子囊萌发的EC50分别为100.28 mg.mL-1和124.37 mg.mL-1。用质量浓度为500 mg.mL-1的两个化合物分别处理后接种霜疫霉菌,供试荔枝果实的发病率分别为16.7%和18.9%。     

Isolation and regeneration of Micromonospora olivoasterospora protoplasts

The conditions for preparation and regeneration of the protoplasts of M. olivoasterospora were developed. It was found that effective formation of the protoplasts required preliminary cultivation of M. olivoasterospora in the medium containing glycine in a concentration inhibiting its growth at least by 60-80 per cent. The strains studied markedly differed in their sensitivity to glycine and were highly sensitive to it. The efficacy of the protoplast formation depended on the culture age and increased with the use of the lytic enzyme 3 of Cytophaga dissolvens. The possibility and advisability of the use of prolonged lysis of the Micromonospora cell walls were shown. A rich organic medium was used for regeneration of the protoplasts.     

Induction of ermAMR from a Clinical Strain of Enterococcus faecalis by 16-Membered-Ring Macrolide Antibiotics

We cloned the MLS_B resistance determinant by PCR from a clinical isolate of Enterococcus faecalis 373, which is induced more strongly by a 16-membered-ring macrolide, tylosin, than by erythromycin. To elucidate the molecular basis of resistance of E. faecalis 373, we analyzed the cloned gene, designated ermAMR, by site-directed mutagenesis and reporter gene assay. Our results showed that an arginine-to-cysteine change in the seventh codon of the putative leader peptide endowed tylosin with resistance inducibility and that TAAA duplication enabled the control region to express the downstream methylase gene at a drastically increased level.