Transposition of Tn5096 from a temperature-sensitive transducible plasmid in Streptomyces spp.

Transposon Tn5096 was inserted into a derivative of the temperature-sensitive plasmid pMT660 containing the bacteriophage FP43 pac site. The resulting plasmid, pRHB126, was transduced by FP43 into several Streptomyces species. Tn5096 transposed from pRHB126 into different sites in the genomes of Streptomyces ambofaciens, Streptomyces cinnamonensis, Streptomyces coelicolor A3(2), Streptomyces fradiae, Streptomyces griseofuscus, and Streptomyces thermotolerans.     

Oxidation and amidation of salicylate by Streptomyces species

Seven streptomycete strains were tested for biotransformation of salicylate. The products were identified by nuclear magnetic resonance spectroscopy and three types of conversion were found. Streptomyces cinnamonensis and Streptomyces spectabilis formed gentisate and salicylamide concurrently. Streptomyces rimosus transformed salicylate to salicylamide. Streptomyces lividans, Streptomyces coelicolor, Streptomyces griseus and Streptomyces avermitilis produced only gentisate. Time course studies of salicylate conversion by thin-layer chromatography and high pressure liquid chromatography showed that salicylamide was accumulated in the culture broth, whereas gentisate was further metabolized.Key words: salicylate, gentisate, salicylamide, biotransformation, Streptomyces spp.     

Ultrastructural studies of sporulation in Streptomyces.

This is the first study of sporogenesis in Streptomyces carried out on a relatively high number of species (seven) which allows us, using also previously published results, to establish a general picture of this process. In the sporogenesis of Streptomyces two basic stages can be considered: the sporulation septum synthesis and the arthrospore maturation. Our ultrastructural study of the sporulation septum formation suggests the existance within this genus of three basic types. Type I is distinguished because the septum is formed from the beginning by two separate cross walls. Within this type we include Streptomyces erythraeus, Streptomyces albus, and Streptomyces aureofaciens and also include Streptomyces venezuelae, Streptomyces griseus, and Streptomyces osteogriseus. Type II is distinguished because there is a deposit of material previous to the synthesis of the double annulus which completes the septum. This type can be divided into two subtypes. In the first the deposits are wedge-shaped and the double annulus is clearly visible, and to this group belong Streptomyces flaveolus, Streptomyces ambofaciens, and Streptomyces coelicolor. In the second the deposits, which have a different shape and are very well developed, constitute almost entirely the sporulation septum in which the double annulus is barely visible; Streptomyces antibioticus and also Streptomyces viridochromogenes belong to this group. Type III, represented by Streptomyces cinnamonensis, is distinguished because the septum is formed by a single cross wall.     

L-Phenylalanine and L-tyrosine catabolism by selected Streptomyces species.

L-Phenylalanine and L-tyrosine were completely catabolized through homogentisate by Streptomyces setonii 75Vi2 but only partially degraded by Streptomyces badius 252, Streptomyces sioyaensis P5, Streptomyces viridosporus T7A, and Streptomyces sp. strain V7. Intermediates of catabolism were confirmed by thin-layer, gas, and high-pressure liquid chromatography. Homogentisate 1,2-dioxygenase was present in all cell extracts.     

L-Phenylalanine and L-tyrosine catabolism by selected Streptomyces species

L-Phenylalanine and L-tyrosine were completely catabolized through homogentisate by Streptomyces setonii 75Vi2 but only partially degraded by Streptomyces badius 252, Streptomyces sioyaensis P5, Streptomyces viridosporus T7A, and Streptomyces sp. strain V7. Intermediates of catabolism were confirmed by thin-layer, gas, and high-pressure liquid chromatography. Homogentisate 1,2-dioxygenase was present in all cell extracts.     

Taxonomic status of Kitasatosporia, and proposed unification with Streptomyces on the basis of phenotypic and 16S rRNA analysis and emendation of Streptomyces Waksman and Henrici 1943, 339AL.

Species classified within the genus Kitasatosporia share many of the phenotypic characteristics typical of streptomycetes. By using a probabilistic identification scheme, they were identified with Streptomyces exfoliatus cluster 5, a species group within Streptomyces. The four species studied hybridized with a 16S rRNA genus probe for Streptomyces spp., indicating a close relationship between the two genera. The kitasatosporias were resistant to selected polyvalent streptomycete phages tested. Quantitative analysis showed that meso-diaminopimelic acid varied from 49 to 89% in Kitasatosporia species and from 1 to 16% in Streptomyces species depending on growth conditions. On the basis of 16S rRNA analysis, it is proposed to reduce Kitasatosporia to synonymy with Streptomyces. As a result, the new names proposed are Streptomyces mediocidicus comb. nov., Streptomyces phosalacineus comb. nov., Streptomyces setae comb. nov., and Streptomyces griseolosporeus comb. nov., nom. nov.     

一种产生纤溶酶的链霉菌C-3662的鉴定及发酵研究

对一株从土壤中分离的纤溶酶产生菌链霉菌C-3662的形态、培养、生理生化和化学分类特征进行了研究,发现其与泛温链霉菌(Streptomyces eurythermus Corbaz et al. 1968)的特征很相符。通过对链霉菌C-3662的16S rDNA序列进行测定与比对,发现它与泛温链霉菌的16S rDNA序列也有高达98.19%的同源性。根据多相分类原则,认为链霉菌C-3662属于泛温链霉菌。对链霉菌C-3662的发酵培养基组成等的研究表明,合适的发酵培养基中应含有氮源黄豆饼粉2.0%、碳源淀粉1.0%和葡萄糖2.5%以及少量的无机盐类如硫酸镁。链霉菌C3662的发酵过程研究表明,纤溶酶是在菌丝体生长停止之后才大量产生。     

链霉菌属菌株AS4.693和AS4.702的分类学研究

链霉菌属“Setae”种群原为北里孢菌属Kitasatosporia (Omura,1982)。1992年,Wellington根据16S rRNA序列分析结果将其并入链霉菌属,并建立“Setae”种群。通过对保藏的链霉菌AS 4.693、AS 4.702进行的形态学、细胞化学、分子遗传分类研究结果表明,它们与链霉菌属“Setae”种群中的典型种——西唐链霉菌Streptomyces setae(JCM3304’)具有相似性。它们的rDNA相似性高达100％,证明它们应归属于同一种群。AS.4.693定名为西唐链霉菌不规则新亚种Streptomyces setae subsp.irregularis nov.,AS 4.702定名为西唐链霉菌波曲弗氏新亚种Streptomyces setae subsp.flexuofradiae nov.。     

Characterization of phi HAU3, a broad-host-range temperate streptomyces phage, and development of phasmids.

phi HAU3 is a temperate Streptomyces phage with cohesive ends and a broad host range that includes Streptomyces hygroscopicus 10-22, a producer of antifungal compounds, but it fails to grow on Streptomyces lividans 66. Two phasmid derivatives were constructed that function as lambda cosmid vectors in Escherichia coli and as phages in Streptomyces spp.     

Molecular analysis of beta-lactamases from four species of Streptomyces: comparison of amino acid sequences with those of other beta-lactamases

Genes encoding extracellular beta-lactamases of Streptomyces badius, Streptomyces cacaoi, Streptomyces fradiae and Streptomyces lavendulae were cloned and mapped in Streptomyces lividans. DNA sequence analysis of the beta-lactamase genes revealed a high overall G + C content, ranging from 71 to 75 mol%, with a G + C content of 95 mol% at the third position of the codons for all four genes. The primary structure of the beta-lactamases including their signal peptides was deduced. The four beta-lactamases exhibited homology to each other and to class A beta-lactamases from other bacterial genera. We suggest that Streptomyces beta-lactamases are representatives of a superfamily of genes, from which class A beta-lactamases of Gram-negative bacteria may have evolved.     

Use of mutagens in the improvement of production strains of microorganisms

Physical and chemical agents were employed in our laboratories to induce mutation in a variety of microorganisms used for production of antibioties or enzymes. Improved production strains ofPenicillium chrysogenum (penicillin-producer),Streptomyces griseus (streptomycin-producer),Streptomyces nodosus. (amphotericin B-producer),Streptomyces noursei (nystatin-producer),Streptomyces umbrinus (diumycin-producer),Streptomyces prasinus (prasinomycin-producer),Streptomyces roseochromogenes (steroid-16α-hydroxylase-producer), andArthrobacter simplex (steroid-1-dehydrogenase-producer) were developed by use of mutation selection techniques. The methods found to be most successful with each species are described. The genealogical relationships within species of a number of strains ofPenicillium chrysogenum, Streptomyces prasinus, andStreptomyces roseochromogenes are presented.     

Characterization of a new ScbR-like γ-butyrolactone binding regulator (SlbR) in Streptomyces coelicolor

γ-Butyrolactones in Streptomyces are well recognized as bacterial hormones, and they affect secondary metabolism of Streptomyces. γ-Butyrolactone receptors are considered important regulatory proteins, and various γ-butyrolactone synthases and receptors have been reported in Streptomyces. Here, we characterized a new regulator, SCO0608, that interacted with SCB1 (γ-butyrolactone of Streptomyces coelicolor) and bound to the scbR/A and adpA promoters. The SCO0608 protein sequences are not similar to those of any known γ-butyrolactone binding proteins in Streptomyces such as ScbR from S. coelicolor or ArpA from Streptomyces griseus. Interestingly, SCO0608 functions as a repressor of antibiotic biosynthesis and spore formation in R5 complex media. We showed the existence of another type of γ-butyrolactone receptor in Streptomyces, and this SCO0608 was named ScbR-like γ-butyrolactone binding regulator (SlbR) in S. coelicolor.     

三种不同菌落形态的林肯链霉菌发酵特性的研究

考察三种不同形态的林肯链霉菌在种子培养、发酵过程中的一些发酵特性,在馒头状,草帽状和梅花状三种茵落形态中,梅花状茵落的发酵单位最高,其发酵单位比草帽状的高11％,比馒头状的高出8．3％。     

链霉菌细胞色素P450研究进展

链霉菌中存在大量的细胞色素P450,它们在链霉菌次生代谢产物的生物合成和外来化学物质代谢过程中发挥了重要作用.本文综述了链霉菌中发现的细胞色素P450及其功能的研究进展,分析了存在的问题和研究应用前景.     

Enhancement of Lignin Degradation in Streptomyces spp. by Protoplast Fusion

Protoplast fusion was investigated as a technique for genetically manipulating two lignin-degrading Streptomyces strains, Streptomyces viridosporus T7A and Streptomyces setonii 75Vi2. Four of 19 recombinants tested showed enhanced production of acid-precipitable polymeric lignin (APPL), producing 155 to 264% more APPL from corn stover lignocellulose than was produced by the wild-type S. viridosporus T7A. APPLs are lignin degradation intermediates known to be potentially valuable chemical products produced by bioconversion of lignin with Streptomyces spp. The prospects of utilizing protoplast fusion to construct APPL-overproducing Streptomyces strains was considered especially promising.     

链霉菌调控蛋白DasRABC的研究进展

越来越多的研究证明DasR及其相邻的DasABC转运蛋白超家族在链霉菌代谢和形态分化中发挥重要调控作用。就DasR的结构、调控序列特点及其与DasABC的关系、DasRABC调控链霉菌发育及次生代谢、DasRABC与链霉菌营养利用等几方面讨论调控蛋白DasRABC的研究进展。     

Heterogeneity of ribosomal proteins among Streptomyces species and its application to identification

The ribosomal proteins from 11 Streptomyces strains representing various numerical taxonomic clusters were compared by two-dimensional PAGE. The protein patterns were specific for each species and were unaffected by acridine dye treatment, suggesting genetic stability of ribosomal proteins. An attempt was made to identify one strain of Streptomyces by both traditional taxonomic methods and analysis of the ribosomal protein patterns. Both methods identified the strain as Streptomyces lavendulae, and protein pattern analysis also showed that Streptomyces avidinii was closely related to this species. The practical application of ribosomal protein patterns in Streptomyces taxonomy was therefore demonstrated.     

Mycolic acid-containing bacteria induce natural-product biosynthesis in Streptomyces species

Natural products produced by microorganisms are important starting compounds for drug discovery. Secondary metabolites, including antibiotics, have been isolated from different Streptomyces species. The production of these metabolites depends on the culture conditions. Therefore, the development of a new culture method can facilitate the discovery of new natural products. Here, we show that mycolic acid-containing bacteria can influence the biosynthesis of cryptic natural products in Streptomyces species. The production of red pigment by Streptomyces lividans TK23 was induced by coculture with Tsukamurella pulmonis TP-B0596, which is a mycolic acid-containing bacterium. Only living cells induced this pigment production, which was not mediated by any substances. T. pulmonis could induce natural-product synthesis in other Streptomyces strains too: it altered natural-product biosynthesis in 88.4% of the Streptomyces strains isolated from soil. The other mycolic acid-containing bacteria, Rhodococcus erythropolis and Corynebacterium glutamicum, altered biosynthesis in 87.5 and 90.2% of the Streptomyces strains, respectively. The coculture broth of T. pulmonis and Streptomyces endus S-522 contained a novel antibiotic, which we named alchivemycin A. We concluded that the mycolic acid localized in the outer cell layer of the inducer bacterium influences secondary metabolism in Streptomyces, and this activity is a result of the direct interaction between the mycolic acid-containing bacteria and Streptomyces. We used these results to develop a new coculture method, called the combined-culture method, which facilitates the screening of natural products.