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Agromyces albus sp. nov. is proposed for an aerobic, oxidase-and catalase-positive actinomycete that was isolated from the above-ground part of a plant (Androsace sp., in the family Primulaceae). The strain is characterized by white colonies, fragmenting hyphae that penetrate into agar media and chemotaxonomic properties that are typical of the genus Agromyces. Analysis of 16S rDNA sequences confirmed that the strain belongs to the genus Agromyces and revealed its close phylogenetic relationship with Agromyces ramosus. DNA-DNA pairing studies showed that the strain belongs to a separate genomic species; this is consistent with its distinction from other Agromyces species at the phenotypic level. The G+C content of the DNA was 69?0 mol%. The type strain is VKM Ac-1800The genus Agromyces was established by Gledhill & Casida (1969) for microaerophilic to aerobic, filamentous, branching, fragmenting, catalase-negative actinomycetes that showed a negative oxidase reaction and inhabited soil; it originally contained a single species, Agromyces ramosus. Later, strictly aerobic, catalase-and oxidase-positive and non-filamentous agromycetes were described (Zgurskaya et al., 1992;Suzuki et al., 1996;Takeuchi et al., 2001;Li et al., 2003). Members of the genus are characterized by B2c-type peptidoglycan [based on L-DAB (2,4-diaminobutyric acid) (Schleifer & Kandler, 1972)], the major isoprenoid quinone MK-12 and the predominant cellular fatty acids anteiso-C 15 : 0 , anteiso-C 17 : 0 and iso-C 16 : 0 (Gledhill & Casida, 1969;Zgurskaya et al., 1992;Suzuki et al., 1996;Sasaki et al., 1998;Takeuchi et al., 2001;Li et al., 2003). Currently, the genus harbours eight species and four subspecies with validly published names, which are presented in Table 1; they were all isolated from soil or the mangrove rhizosphere. In this work, we report the characterization of Agromyces albus sp. nov., which was isolated from the above-ground part of a plant (Androsace sp., in the family Primulaceae) collected at the seed-formation stage in the Central-Chernozem Biosphere Park, Belgorod region, Russia.For isolation of micro-organisms, the surface-unsterilized part of the plant (stem top with several leaves and inflorescence) was cut into pieces, added to 1 ml 0?85 % NaCl (w/v) and ground with a pestle. One drop of this suspension was plated onto modified corynebacterium agar that contained 5 g glucose, 3 g yeast extract, 5 g casein peptone, 2 g Casamino acids, 3 g beef extract, 5 g NaCl, 15 g agar, 100 ml skimmed milk and 900 ml distilled water (pH 7?2-7?4) and incubated for 3 weeks at room temperature (18-24 u C). Morphology and life cycle were studied in cultures grown on corynebacterium (CB) agar (Zgurskaya et al., 1992) by phase-contrast microscopy. Gram-reaction was tested by the rapid test with KOH (Ryu, 1938). Physiological and chemotaxonomic features were examined as described previously (Evtushenko et al., 2000). For chemotaxonomic study, shaken cultures had been grown in liquid CB medium and harvested at the exponential-growth phase...

Supplementation of culture medium with MgSO4 or Na2SO4 in millimolar concentrations caused an enhanced measles virus (MV) yield from cultured quail embryo cells. MgSO4 at 25-50 mM concentrations exhibited the most pronounced and consistent stimulatory effect. MV infectivity increases ranged from 2- to 200-fold; the effect was highly reproducible for stationary monolayer, roller or microcarrier-grown cell culture types. MgSO4 also improved MV plaque development and caused MV plaque size enlargement on Vero cell monolayers. At mM concentrations MgSO4 was not operative as a MV thermostabilizing agent; rather, salt-induced enhancement of MV yields appeared to be due to intracellular events, e.g., augmented viral protein synthesis.

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