Proposal of Lysinibacillus boronitolerans gen. nov. sp. nov., and transfer of Bacillus fusiformis to Lysinibacillus fusiformis comb. nov. and Bacillus sphaericus to Lysinibacillus sphaericus comb. nov. SORST, JST, Chiyoda-ku, Tokyo, JapanThree strains of a spore-forming, Gram-positive, motile, rod-shaped and boron-tolerant bacterium were isolated from soil. The strains, designated 10a T , 11c and 12B, can tolerate 5 % (w/v) NaCl and up to 150 mM boron, but optimal growth was observed without addition of boron or NaCl in Luria-Bertani agar medium. The optimum temperature for growth was 37 6C (range 16-45 6C) and the optimum pH was 7.0-8.0 (range pH 5.5-9.5). A comparative analysis of the 16S rRNA gene sequence demonstrated that the isolated strains were closely related to Bacillus fusiformis DSM 2898 T (97.2 % similarity) and Bacillus sphaericus DSM 28 T (96.9 %). DNA-DNA relatedness was greater than 97 % among the isolated strains and 61.1 % with B. fusiformis DSM 2898 T and 43.2 % with B. sphaericus IAM 13420 T . The phylogenetic and phenotypic analyses and DNA-DNA relatedness indicated that the three strains belong to the same species, that was characterized by a DNA G+C content of 36.5-37.9 mol%, MK-7 as the predominant menaquinone system and iso-C 15 : 0 (32 % of the total) as a major cellular fatty acid. In contrast to the type species of the genus Bacillus, the strains contained peptidoglycan with lysine, aspartic acid, alanine and glutamic acid. Based on the distinctive peptidoglycan composition, phylogenetic analyses and physiology, the strains are assigned to a novel species within a new genus, for which the name Lysinibacillus boronitolerans gen. nov., sp. nov. is proposed. The type strain of Lysinibacillus boronitolerans is strain 10aIt is also proposed that Bacillus fusiformis and Bacillus sphaericus be transferred to this genus as Lysinibacillus fusiformis comb. nov. and Lysinibacillus sphaericus comb. nov., respectively.

We examined the abundance of viruses on microorganisms in activated sludge and the dynamics of their community structure. Direct counting with epifluorescence microscopy and pulsed-field gel electrophoresis (PFGE) were applied to 20 samples from 14 full-scale wastewater treatment plants (wwtps) treating municipal, industrial, or animal wastewater. Furthermore, to observe the dynamics of viral community structure over time, a laboratory-scale sequencing batch reactor was operated for 58 days. The concentrations of virus particles in the wwtps, as quantified by epifluorescence microscopy, ranged from 4.2 x 10(7) to 3.0 x 10(9) mL-1. PFGE, improved by the introduction of a higher concentration of Tris-EDTA buffer in the DNA extraction step, was successfully used to profile DNA viruses in the activated sludge. Most of the samples from different wwtps commonly had bands in the 40-70 kb range. In the monitoring of viral DNA size distribution in the laboratory-scale reactor, some bands were observed stably throughout the experimental period, some emerged during the operation, and others disappeared. Rapid emergence and disappearance of two intense bands within 6 days was observed. Our data suggest that viruses--especially those associated with microorganisms--are abundant and show dynamic behavior in activated sludge.

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Terfestatin A (TrfA), terphenyl-β-glucoside, was isolated from Streptomyces sp. F40 in a forward screen for compounds that inhibit the expression of auxin-inducible genes in Arabidopsis (Arabidopsis thaliana). TrfA specifically and competitively inhibited the expression of primary auxin-inducible genes in Arabidopsis roots, but did not affect the expression of genes regulated by other plant hormones such as abscisic acid and cytokinin. TrfA also blocked the auxin-enhanced degradation of auxin/indole-3-acetic acid (Aux/IAA) repressor proteins without affecting the auxin-stimulated interaction between Aux/IAAs and the F-box protein TIR1. TrfA treatment antagonized auxin responses in roots, including primary root inhibition, lateral root initiation, root hair promotion, and root gravitropism, but had only limited effects on shoot auxin responses. Taken together, these results indicate that TrfA acts as a modulator of Aux/IAA stability and thus provides a new tool for dissecting auxin signaling.

The conjugative transfer ranges of three different plasmids of the incompatibility groups IncP-1 (pBP136), IncP-7 (pCAR1), and IncP-9 (NAH7) were investigated in soil bacterial communities by culture-dependent and culture-independent methods. Pseudomonas putida, a donor of each plasmid, was mated with soil bacteria, and green fluorescent protein (GFP), encoded on the plasmid, was used as a reporter protein for successful transfer. GFP-expressing transconjugants were detected and separated at the single-cell level by flow cytometry. Each cell was then analyzed by PCR and sequencing of its 16S rRNA gene following either whole-genome amplification or cultivation. A large number of bacteria within the phylum Proteobacteria was identified as transconjugants for pBP136 by both culture-dependent and culture-independent methods. Transconjugants belonging to the phyla Actinobacteria, Bacteroidetes, and Firmicutes were detected only by the culture-independent method. Members of the genus Pseudomonas (class Gammaproteobacteria) were identified as major transconjugants of pCAR1 and NAH7 by both methods, whereas Delftia species (class Betaproteobacteria) were detected only by the culture-independent method. The transconjugants represented a minority of the soil bacteria. Although pCAR1-containing Delftia strains could not be cultivated after a one-to-one filter mating assay between the donor and cultivable Delftia strains as recipients, fluorescence in situ hybridization detected pCAR1-containing Delftia cells, suggesting that Delftia was a "transient" host of pCAR1. P lasmids are circular or linear extrachromosomal replicons, which are often transmissible by conjugation (1, 2). Plasmids can spread among bacteria effectively and act as key "vehicles" of pathogenicity and environmentally relevant traits (1). Therefore, the conjugative transfer of plasmids is one of the most important mechanisms to promote the rapid evolution and adaptation of bacteria. Knowledge about the host range of a plasmid is essential to the understanding of how the plasmid is transferred in different environments. A plasmid host is generally recognized in two ways: (i) cells can obtain the plasmid by conjugative transfer and (ii) cells can replicate and maintain the plasmid after cell division. Although some plasmids are known to make junctions to cross the kingdom barrier (3), to date, plasmid host ranges have been determined by using culture-dependent methods by detecting colonies of transconjugants on selective media. This method is unable to detect uncultivated or noncultivable hosts and is limited by both the transfer system and its replication and maintenance systems. Recently, several studies have shown that noncultivable bacteria carry plasmids (4, 5), suggesting that other uncultivated or noncultivable bacteria could also have plasmids. Because the majority of environmental bacteria are difficult to cultivate, determining an accurate host range for the plasmid transfer function (i.e., a transfer range of plasmids) has not yet been accomplishe...