• Journal of Microbiology and Biotechnology
• /
• v.12 no.4
• /
• pp.706-709
• /
• 2002

Bacterial bioluminescence has been known to be a highly valuable reporter system for its potential application as an effective and simple environmental monitoring method for toxic compounds. In this short report, we constructed a streptomycetes-Escherichia coli shuttle vector-containing bioluminescence system and evaluated its potential application for toxic compounds monitoring. The luxAB biolurninescence genes from Vibrio harveyi were cloned into a streptornycetes-E. coli shuttle vector (named pESK004) and functionally expressed in Streptomyces lividans. The recombinant S. lividans containing pESK004 exhibited an optimal biolurninescence at the optical density ($OD_{600\;nm}$) of 0.4-0.5 and aldehyde concentration of 0.005%. When the recombinant bioluminescence streptomycetes was exposed to a toxic compound such as heavy metals, chlorinated phenols, or pesticides, the bioluminescence was decreased proportionally to the concentration of toxic compound in the assay mixture. The $EC_{50}$ (effective concentration to decrease 50% of the bioluminescence prior to exposure) values in the recombinant biolurninescence streptomycetes for mercury, 2,4-dichlorophenol, and malathion were measured at 2.2 ppm, 144.0 ppm, and 82.4 ppm, respectively. The degree of sensitivity and specificity pattern toward these toxic compounds characterized in this recombinant bioluminescence streptomycetes were unique when compared with previously reported bacterial bioluminescence systems, and this revealed that a recombinant bioluminescence streptomycetes might provide an alternative or complementary system for potential environmental monitoring.

• Journal of Microbiology
• /
• v.34 no.2
• /
• pp.184-191
• /
• 1996

The cellular fatty acids and quinones of streptomycetes isolated from volcanic soils were analysed. The strains contained fatty acids of 14 to 17 carbon chains, and 12-methyltetradecanoic acid and 14 methylpentadecanoic acid were dominant in most strains. The total profiles consisted of 74% branched fatty acid family, 16.8% linear family and 8.2% unsaturated family. The largest cluster of grey spore meases defined by numerical classification was separated from the remainders in the principal component analysis, but the other clusters were overlapped with one another. In the analysis of respiratory quinones, all of the strains contained either the menaquinone of 9 isoprene units with 6 hydrogenations of 8 hydrogenations as the major species. The distribution of menaquinones among the clusters could provide an important key in the chemotaxonomy of streptomycetes.

• Journal of Microbiology
• /
• v.33 no.4
• /
• pp.315-321
• /
• 1995

The relationship between morphological differentiation and production of trypsin-like protease (TLP_ in streptomycetes was studied. All the Streptomyces spp.In this study produced TLP just before the onset of aerial mycelium formation. Addition of TLP inhibitor, TLCK, to the top surface of colonies inhibited aerial mycelium formation as well as TLP inhibitor, TLCK, to the top surface of colonies inhibited aerial mycelium formation as well as TLP activity. Addition of 2% glucose to the Bennett agar medium repressed both the aerial mycelium formation and TLP production in S. abuvaviensis, S. coelicolor A3(2), S exfoliatus, S. microflavus, S. roseus, s. lavendulae, and S. rochei. However the addition of glucose did not affect S. limosus, S. felleus, S. griseus, S. phaechromogenes, and S. rimosus. The glucose repression on aerial mycelium formation and production of TLP was relieved by the addition of glucose anti-metabolite (methyl .alpha.-glucopyranoside). Therefore, it was concluded that TLP production is coordinately regulated with morphological differentiation and TLP activity is essential for morphological differentiation in streptomycetes. The proposed role of TLP is that TLP participates in the degradation of substrate mycelium protein for providing nutrient for aerial mycelial growth.

• Journal of Microbiology
• /
• v.40 no.1
• /
• pp.51-54
• /
• 2002

Heavy metal adsorptions of four streptomycetes were compared with each other, Among the test strains, Streptomyces viridochromogenes showed the most efficient metal binding activity, which was carried out by cell wall as well as freeze-dried mycelium. An order of adsorption potential (zinc > copper > lead > cadmium) was observed in single metal reactions, whereas this adsorption order was disturbed in mixed-metal reactions. The metal adsorption reactions were very fast, pH dependent and culture age-independen, suggestive of a physico-chemical reaction between cell wall components and heavy metal ions. The metal tolerant stains presented the weakest adsorbing activity, indicating that the metal biosorption was not the basis of the metal tolerance.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.6
• /
• pp.896-900
• /
• 2006

Cytokinin has been known to act as a plant hormone to promote cell division and function in diverse processes in plant growth and development. Besides being produced in plants, it is also produced by various bacteria and fungi; however, its ecological significance is still unclear. In this report, we present an interesting finding that transzeatin riboside (tZR), a naturally occurring cytokinin compound, increased antibiotic production in many different streptomycetes, including Streptomyces coelicolor Ml3O, S. pristinaespiralis ATCC 25486, S. violaceoruber Tu22, S. anfibioticus ATCC l1891, and S. griseus IFO 13350. In vitro plate assays showed that the addition of 100 $\mu$M tZR increased the growth inhibition of Pseudomonas syringae pv. syringae, a plant pathogen, by S. griseus, a streptomycin producer. We suggest that cytokinin could act as a signaling molecule for antibiotic production in streptomycetes, a group of rhizosphere bacteria.

• Proceedings of the Microbiological Society of Korea Conference
• /
• 2004.05a
• /
• pp.80-82
• /
• 2004

• Proceedings of the Korean Society for Applied Microbiology Conference
• /
• 2004.06a
• /
• pp.83-87
• /
• 2004

• Proceedings of the Zoological Society Korea Conference
• /
• 1997.10b
• /
• pp.103.1-103
• /
• 1997

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
• /
• 1999.10b
• /
• pp.227.1-227
• /
• 1999

No Abstract, See Full Text

• Journal of Microbiology and Biotechnology
• /
• v.16 no.1
• /
• pp.5-14
• /
• 2006

Streptomycetes are Gram-positive microorganisms producing secondary metabolites through unique physiological differentiation [4]. The microbes show unusual morphological differentiation to form substrate mycelia, aerial mycelia, and arthrospores on solid medium [19]. Substrate mycelium growth is sustaining with sufficient nutrients in the culture medium. The concentration of a specific individual substrate in the culture environment is the most important extracellular factor allowing vegetative mycelia growth, where extracellular hydrolytic enzymes participate in the utilization of waterinsoluble substrates. However, with starvation of nutrients in the culture medium, the vegetative mycelia differentiate to aerial mycelia and spores. It has been considered that shiftdown of essential nutrients for mycelia growth is the most important factor triggering morphological and physiological differentiation in Streptomyces spp. Since proteineous macromolecule compounds are the major cellular components, these are faced to endogenously metabolize following a severe depletion of nitrogen source in culture nutrients (Fig. 1). Various proteases were identified of which production was specifically related with the phase of mycelium growth and also morphological differentiation. The involvement of proteases and protease inhibitor is reviewed as a factor explaining the mycelium differentiation in Streptomyces spp.