| a new depsipeptide antibiotic, variapeptin. | a culture similar to streptomyces variabilis was found to produce a novel cyclic hexadepsipeptide antibiotic named variapeptin. variapeptin is structurally related to azinothricin, a83586c, and citropeptin. the antibiotic was active against gram-positive bacteria and showed cytotoxic activity against mammalian cells. | 1990 | 1368536 |
| [parallel variability of the producers of the antibiotic heliomycin, actinomyces olivocinereus and actinomyces variabilis]. | | 1974 | 4449495 |
| ammosamide d, an oxidatively ring opened ammosamide analog from a marine-derived streptomyces variabilis. | ammosamide d (1), an oxidized analog of the ammosamide family, was isolated from a marine-derived streptomyces variabilis. pyrroloquinoline containing alkaloids are a growing class of natural products, with 1 being the first example of an oxidized analog resulting in a 5,6-dioxo-5,6-dihydroquinoline ring system. attempts at chemical conversion of ammosamide b to ammosamide d revealed that a strong chemical oxidant is required. ammosamide d has modest cytotoxicity to the mia paca-2 pancreatic can ... | 2012 | 22515470 |
| precursor-directed generation of amidine containing ammosamide analogs: ammosamides e-p. | ammosamides e-f (1-2), are amidine analogs of the ammosamide family of alkaloids isolated from a marine-derived streptomyces variabilis. further studies with s. variabilis revealed a variety of aryl and alkyl amines added into the fermentation media could be efficiently incorporated into the ammosamide framework to generate a library of precursor-directed amidine analogs, ammosamides g-p (9 - 18). we demonstrate that the amines are introduced via non-enzymatic addition to the iminium ion of ammo ... | 2013 | 23209870 |
| streptomyces wuyuanensis sp. nov., an actinomycete from soil. | a novel actinomycete, strain fx61(t), was isolated from a saline sample collected from the inner mongolian autonomous region in china and subjected to a taxonomic study using a polyphasic approach. the predominant menaquinones were mk-9(h6), mk-9(h8) and mk-9(h4). the major fatty acids were iso-c16 : 0, anteiso-c15 : 0, iso-c15 : 0, iso-c16 : 1 h, c16 : 0, iso-c14 : 0 and anteiso-c17 : 0. the phospholipid profile contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, p ... | 2013 | 23355697 |
| hybrubins: bipyrrole tetramic acids obtained by crosstalk between a truncated undecylprodigiosin pathway and heterologous tetramic acid biosynthetic genes. | heterologous expression of bacterial artificial chromosome (bac) clones from the genomic library of streptomyces variabilis snt24 in streptomyces lividans sbt5 which carried a truncated undecylprodigiosin biosynthetic gene cluster led to the identification of hybrubins a-c. the hybrubins represent a new carbon skeleton in which a tetramic acid moiety is fused to a 2,2'-dipyrrole building block. gene knockout experiments confirmed that hybrubins are derived from two convergent biosynthetic pathwa ... | 2016 | 26800378 |
| effect of aeration and agitation on extractive fermentation of clavulanic acid by using aqueous two-phase system. | in this work, the effects of agitation and aeration rates on aqueous two-phase system (atps)-based extractive fermentation of clavulanic acid (ca) by streptomyces variabilis daufpe 3060 were investigated through a 2(2) full factorial design, where oxygen transfer rate (otr) and oxygen uptake rate (our) were selected as the responses. aeration rates significantly influenced cell growth, our, and ca yield, while otr was practically the same in all the runs. under the intermediate agitation (950 rp ... | 2016 | 27451982 |
| streptomyces euryhalinus sp. nov., a new actinomycete isolated from a mangrove forest. | a gram-positive, aerobic, non-motile actinomycete (strain ms 3/20(t)) was isolated from the sediment of the sundarbans mangrove forest in india. on international streptomyces project (isp) medium 2, the isolate produced yellowish brown to red aerial hyphae that carried spiny-surfaced spores in a retinaculum-apertum arrangement. whole-cell hydrolysate of the strain contained ll-diaminopimelic acid and galactose. predominant menaquinones were mk-9(h8) and mk-9(h6). diagnostic polar lipids were gly ... | 2017 | 28174421 |
| isolation, screening, and identification of novel isolates of actinomycetes from india for antimicrobial applications. | the search for novel bioactive compounds from the natural environment has rapidly been gaining momentum with the increase in multi-drug resistant (mdr) pathogens. in the present study, the antimicrobial potential of novel actinomycetes has been evaluated by initial screening of six soil samples. primary and secondary screening was performed against bacillus subtilis, staphylococcus aureus, escherichia coli, candida albicans, candida tropicalis, trichophyton rubrum, and other mdr bacterial and fu ... | 2016 | 27999566 |
| characterization of cytotoxic compound from marine sediment derived actinomycete streptomyces avidinii strain su4. | to investigate the cytotoxic activity of actinomycete isolated from marine sediment. | 2012 | 23569845 |
| streptomyces tunisiensis sp. nov., a novel streptomyces species with antibacterial activity. | a novel actinomycete strain designated cn-207(t) was isolated from northern tunisian soil. this strain exhibited potent broad spectrum antibacterial activity against clinical isolates of methicillin-resistant staphylococcus species and several other gram-positive and gram-negative bacteria. strain cn-207(t) developed greyish aerial mycelium and pale grey substrate mycelium on yeast extract/malt agar. the isolate produced branching vegetative mycelia with sporangiophores bearing sporangia develop ... | 2014 | 24306769 |
| [variability in the production of heliomycin by actinomyces variabilis during cultivation under laboratory conditions]. | | 1974 | 4611507 |
| [localization of the antibiotic heliomycin in colonies and mycelium of actinomyces variabilis and actinomyces olivocinereus]. | | 1974 | 4600717 |
| structural studies on new depsipeptide antibiotics, variapeptin and citropeptin. | variapeptin and citropeptin were found as novel hexadepsipeptide antibiotics produced by streptomyces variabilis and streptomyces flavidovirens, respectively. their structures were elucidated by nmr spectral analysis including a variety of 2d techniques. variapeptin and citropeptin are structurally realted to azinothricin and a83586c, respectively. | 1990 | 2358400 |
| screening of wild type streptomyces isolates able to overproduce clavulanic acid. | the selection of new microorganisms able to produce antimicrobial compounds is hoped for to reduce their production costs and the side effects caused by synthetic drugs. clavulanic acid is a β-lactam antibiotic produced by submerged culture, which is widely used in medicine as a powerful inhibitor of β-lactamases, enzymes produced by bacteria resistant to antibiotics such penicillin and cephalosporin. the purpose of this work was to select the best clavulanic acid producer among strains of strep ... | 2014 | 25477926 |