Synthesis of vinyl arabinose ester catalyzed by protease from Streptomyces sp.

The transesterification of 0.5 M divinyladipate with 0.25 M arabinose in dimethylformamide for 7 days was catalyzed by Streptomyces sp. alkaline protease to give 5-O-vinyladipoyl-d-arabinofuranose at ca. 50% yield. Only enzymatic transesterification of primary hydroxyl group of arabinofuranose proceeded without esterification of arabinopyranose.     

Classification of novel soil streptomycetes as Streptomyces aureus sp. nov., Streptomyces laceyi sp. nov. and Streptomyces sanglieri sp. nov

The taxonomic positions of soil isolates known as Streptomyces groups A, B and C were clarified. Comparative 16S rDNA sequence studies indicated that representatives of all three taxa formed distinct phyletic lines within the Streptomyces tree though the group A strains were shown to be related to Streptomyces griseus and associated validly described species. The taxonomic integrity of all three groups was highlighted by DNA:DNA relatedness and ribotype data though the group A strains encompassed a higher degree of genetic variation than the group B and C strains. In light of these and earlier phenotypic data it is proposed that Streptomyces groups A, B and C be given species status as Streptomyces sanglieri sp. nov., Streptomyces aureus sp. nov. and Streptomyces laceyi sp. nov., respectively. This revised version was published online in June 2006 with corrections to the Cover Date.     

An Inhibitor of S-Hemolysin,SHI, Produced by Streptomyces sp. Strain No. 6288

Streptomyces sp. strain No. 6288 produces S-Hemolysin, which is a unique phospholipase C with a high substrate specificity for sphingomyelin. Moreover, the strain also produced two kinds of phospholipase inhibitors, designated as SHI and S-PLI, in different phases of cultivation. The purified SHI was shown to be a basic substance containing an amino group and glycoside moiety, and it was a more effective inhibitor of S-Hemolysin and sphingomyelinase from Streptomyces sp. with a higher substrate specificity for sphingomyelin than α-toxin from Clostridium perfringens.     

海洋放线菌Streptomyces sp.大片段DNA基因组文库的构建

目的:构建稀有海洋放线菌Streptomyces sp.基因组文库.方法:以稀有海洋放线菌Streptomyces sp.为实验材料,随机剪切提取的总DNA,5'-磷酸末端补平回收40kb左右的DNA片段,与pWEBTM载体连接,经包装蛋白包装成噬菌体后侵染宿主细胞E.coli EPI100,构建该菌株的基因组文库,并对该文库进行质量鉴定.结果:成功构建了稀有海洋放线菌Streptomyces sp.的基因组文库,效价达9.0×104CFU/mL,得到4000个阳性克隆子,远远大于按覆盖率为99%计算至少所需的837个阳性克降子数,且平均插入片段长度为36kb,重组率100%.阳性克隆子保存于96孔板中,-80℃保存.结论:所构建文库的各项指标均达到要求,为了进一步评估Streptomyces sp.所能合成的所有潜在天然产物,还需要进一步检测该文库中包含有生物合成基因簇的大肠杆菌的表达情况.     

Cloning and Nucleotide Sequence of the Mycodextranase Gene from Streptomyces sp. J-13-3

Mycodextranase (EC 3.2.1.61) is an α-glucanase that cleaves α-1,4-bonds of alternating α-1,3- and α-1,4-linked D-glucan (nigeran). The gene encoding mycodextranase from Streptomyces sp. J-13-3 was cloned by hybridization with a degenerate oligonucleotide probe from the amino-terminal amino acid sequence of the enzyme and its nucleotide structure was analyzed. The open reading frame consisted of 1,803 base pairs encoding a signal peptide of 60 amino acids and a mature protein of 540 amino acids with a calculated molecular weight of 56,078. The deduced amino acid sequence showed weak similality to a chitinase homolog from Streptomyces lividans and a chitinase from Xanthomonas sp.     

Streptomyces daliensis sp. nov. from soil

A novel actinomycete strain YIM 31724^T was isolated from a soil sample collected from Dali, Yunnan Province, People’s Republic of China. The strain is characterized by white to yellow white aerial mycelia, spiral spore chains and smooth spore surface. The cell wall of strain YIM 31724^T contained LL-diaminopimelic acid (A₂pm) and traces of meso-A₂pm. Whole-cell hydrolysates contained mainly glucose and small amounts of galactose and xylose. The menaquinones were MK-9(H₆) (31%) and MK-9(H₈) (69%). Phosphatidylethanolamine was the diagnostic phospholipid. The DNA G+C content of strain YIM 31724^T was 67.2 mol%. Phylogenetic analysis indicated that the strain belongs to the genus Streptomyces, with highest similarity to Streptomyces rimosus subsp. rimosus JCM 4667^T (rRNA gene sequence similarity value of 98.9%) and Streptomyces erumpens DSM 40941^T (rRNA gene sequence similarity value of 98.7%). Based on its phenotypic and genotypic characteristics, including low DNA–DNA hybridization results, strain is proposed as the type strain of a novel species, Streptomyces daliensis sp. nov.     

海洋来源放线菌3275化学成分及抗肿瘤活性研究

从海洋来源的放线菌Streptomyces sp．3275中分到7个化合物,经IR,ESI-MS,NMR等光谱数据鉴定及与文献对照,确定其结构为环（脯-缬）（1）,环（脯-酪）（2）,环（脯-甘）（3）,环（脯-异亮）（4）,环（脯-亮）（5）,胆甾醇（6）及1-甲基-1,2,3,4．四氢咔啉-3-羧酸（7）;并采用SRB法对其抗肿瘤活性进行了测试,其中化合物2,3,5对温敏型小鼠乳腺癌细胞tsFT210显示弱的增殖抑制活性。     

链霉菌Strz-6木聚糖酶的纯化和固定化研究

链霉菌胞外木聚糖酶经过盐析、离子交换和分子筛层析纯化,粗酶液被纯化了32.5倍,比活力达498u/mg,活力回收46.6%。纯化后的酶固定在戊二醛交联的壳聚糖上,酶活回收率为42.8%。固定化酶的最适pH为6.0,最适温度为60℃,且固定化酶在65~75℃活力都较高。该酶的耐热性比较强,固定化酶热稳定性优于原酶;以木聚糖为底物,固定化酶的表观米氏常数为0.93×10-2g/L。     

链霉菌-ZLT产生的蓝色素性质研究

报道了一株链霉菌产生的蓝色素的性质。研究表明,该色素水溶性好,具有较高的热稳定性;低pH条件下,抗氧化还原能力较强。大多数所测试的金属离子基本不影响色素的性质。中性条件下色素耐日光,碱性条件下耐紫外光。     

Biodegradation and detoxification of nicotine in tobacco solid waste by a Pseudomonas sp.

A Pseudomonas sp. grew with nicotine optimally 3 g l^–1 and at 30 °C and pH 7. Nicotine was fully degraded within 10 h. The resting cells degraded nicotine in tobacco solid waste completely within 6 h in 0.02 m sodium phosphate buffer (pH 7) at maximally 56 mg nicotine h^–1 g dry cell^–1.     

微生物转谷氨酰胺酶的生产菌种诱变和发酵生产分析

对本研究室从土壤分离得到的使霉菌(Streptomyces sp.)WZFF．W-12菌株的斜面孢子预培养处于初萌发状态后,以亚硝基胍(NTG)进行诱变育种试验,并根据诱变处理后菌落的某些形态变化状况与产酶能力相结合的特征,初步判断产酶性能,挑选高酶活菌株,再经过初筛和复筛,获得一性能良好的产酶突变菌株WZFF.W-12.var MN-35,转谷氨酰酶活达0．53U／mL,比原始菌株提高了1．2倍。然后在摇瓶条件下,对其发酵过程中的主要培养基组成及各种培养条件对菌体生长和产酶的影响作用进行了研究,结果表明该菌株发酵生产转谷氨酰酶的适宜破源为可溶性淀粉 葡萄糖,氮源是多价胨外加少量的酵母膏,优化工艺条件为种龄时间24h、接种量10％、初始以值6．5、温度30℃和搅拌速度200r／min,产酶能力显著提高,用小型生化反应器可以稳定生产2.0U／mL以上的酶产品。     

链霉菌Strz-2胞外木聚糖酶的纯化和固定化研究

为探讨木聚糖酶被固定化后的酶活力变化 ,采用盐析、离子交换和分子筛层析方法对链霉菌胞外木聚糖酶进行了纯化 ,并采用DNS方法对固定化酶的性质进行了研究。结果如下 :粗酶液被纯化了 30 .5倍 ,比活力达 4 5 7.5 ,活力回收 4 2 .6 %。纯化后的酶固定在戊二醛交联的壳聚糖上 ,残活力为 4 1.8%。固定化酶的最适pH为 6 .0 ,最适温度为 5 5℃ ,且固定化酶在 6 5 -75℃活力都较高。该酶的耐热性比较强 ,固定化酶热稳定性优于原酶 ;以木聚糖为底物 ,固定化酶的表观米氏常数为 0 .83× 10 -2g/L。因此 ,固定化的木聚糖酶优于原酶     

海洋链霉菌S007次生代谢产物的分离鉴定(英文)

采用柱层析、制备薄层层析等方法从海洋链霉菌S007的发酵液提取物中分离得到了9个化合物,经波谱分析确定为嘧啶(1),吡咯-2-羧酸(2),卡拉霉素(3),3-吲哚丙酸(4),吲哚-3-羧酸(5),N-乙酰基酪胺(6),2’-胸腺嘧啶脱氧核苷(7),N-β-乙酰色胺酸(8)和三乙胺盐酸盐(9)。其中三乙胺盐酸盐是首次从链霉菌中得到;海虾致死实验结果显示:化合物3在40μg/mL浓度下对丰年虾的致死率为86.5%,表明卡拉霉素对丰年虾表现出很强的毒性作用。     

Production and characterization of thermostable xylanase and pectinase from Streptomyces sp. QG-11-3

Streptomyces sp. QG-11-3, which produces a cellulase-free thermostable xylanase (96 IU ml⁻¹) and a pectinase (46 IU ml⁻¹), was isolated on Horikoshi medium supplemented with 1% w/v wheat bran. Carbon sources that favored xylanase production were rice bran (82 IU ml⁻¹) and birch-wood xylan (81 IU ml⁻¹); pectinase production was also stimulated by pectin and cotton seed cake (34 IU ml⁻¹ each). The partially purified xylanase and pectinase were optimally active at 60°C. Both enzymes were 100% stable at 50°C for more than 24 h. The half-lives of xylanase and pectinase at 70, 75 and 80°C were 90, 75 and 9 min, and 90, 53 and 7 min, respectively. The optimum pH values for xylanase and pectinase were 8.6 and 3.0, respectively, at 60°C. Xylanase and pectinase were stable over a broad pH range between 5.4 and 9.4 and 2.0 to 9.0, respectively, retaining more than 85% of their activity. Ca²⁺ stimulated the activity of both enzymes up to 7%, whereas Cd²⁺, Co²⁺, Cr³⁺, iodoacetic acid and iodoacetamide inhibited xylanase up to 35% and pectinase up to 63%; at 1 mM, Hg²⁺ inhibited both enzymes completely. Journal of Industrial Microbiology & Biotechnology (2000) 24, 396–402. Received 29 September 1999/ Accepted in revised form 02 February 2000     

链霉菌发酵麦草产木聚糖酶的试验研究

通过正交设计试验 ,找出利用链霉菌和麦草基质发酵生产木聚糖酶的试验条件。培养基 (g/L) :麦草粉 ,4 5 ;(NH4 ) 2 SO4 ,7.5 ;酵母膏 ,8;K2 HPO4 ·3H2 O ,1;MgSO4 ·7H2 O ,0 .5 ;NaCl,0 .3。接种量为 5 .0× 10 8个孢子 / 5 0mL培养基 ,振荡培养 (12 0r/min) 5d     

Isolation and Structure Elucidation of a New Antifungal and Antibacterial Antibiotic Produced by Streptomyces sp. 201

An antibacterial and antifungal antibiotic was isolated from the culture filtrate of Streptomyces sp. 201, and its structure was determined as 2-methyl-heptyl isonicotinate by extensive use of NMR spectroscopy. The compound exhibited marked antimicrobial activity against Bacillus subtilis, Shigella sp., Klebsiella sp., E. coli, Proteus mirabilis, and the pathogenic fungi, Fusarium moniliforme, F. semitectum, F. oxysporum, F. solani and Rhizoctonia solani.     

Streptomyces yatensis sp. nov., a novel bioactive streptomycete isolated from a New-Caledonian ultramafic soil

The taxonomic position of an actinomycete isolated from an ultramafic soil in New Caledonia was examined using a polyphasic approach. The organism, which was designated SFOCin 76, was found to have chemical and morphological properties typical of streptomycetes and formed a distinct phyletic line in the Streptomyces violaceusniger clade of the 16S rDNA tree. It also showed a unique pattern of phenotypic properties that distinguished it from representatives of all of the validly described species classified in this clade. It is, therefore, proposed that strain SFOCin 76 be classified in the genus Streptomyces as Streptomyces yatensis sp. nov. This revised version was published online in June 2006 with corrections to the Cover Date.     

Characterization of Two Isozymes of Coniferyl Alcohol Dehydrogenase from Streptomyces sp. NL15-2K

We purified two isozymes of coniferyl alcohol dehydrogenase (CADH I and II) to homogeneity from cell-free extracts of Streptomyces sp. NL15-2K. The apparent molecular masses of CADH I and II were determined to be 143 kDa and 151 kDa respectively by gel filtration, whereas their subunit molecular masses were determined to be 35,782.2 Da and 37,597.7 Da respectively by matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Thus, it is probable that both isozymes are tetramers. The optimum pH and temperature for coniferyl alcohol dehydrogenase activity were pH 9.5 and 45 °C for CADH I and pH 8.5 and 40 °C for CADH II. CADH I oxidized various aromatic alcohols and allyl alcohol, and was most efficient on cinnamyl alcohol, whereas CADH II exhibited high substrate specificity for coniferyl alcohol, and showed no activity as to the other alcohols, except for cinnamyl alcohol and 3-(4-hydroxy-3-methoxyphenyl)-1-propanol. In the presence of NADH, CADH I and II reduced cinnamaldehyde and coniferyl aldehyde respectively to the corresponding alcohols.     

Isolation and Characterization of a Spore Germination Inhibitor from Streptomyces sp. CB-1-1, a Phytopathogen Causing Root Tumor of Melon

The germination rate and activation conditions of spores were examined for four strains of Streptomyces sp., a phytopathogen causing root tumor of melon. An inhibitor was isolated from the agar-cultured material of strain CB-1-1 and then characterized. The inhibitor selectively acted on spore germination and did not affect hyphal growth, and inhibition was abolished by washing the spores in water. The inhibitor was produced by an agar culture, and most of the inhibitor existed in the spores. The IC₅₀ value for the inhibitor was approximately 0.25 μg/ml.