Characterization of Streptomyces nymphaeiformis sp. nov., and its taxonomic relatedness to other polyhydroxybutyrate-degrading streptomycetes.

A polyhydroxybutyrate (PHB)-degrading actinomycete, strain SFB5AT, was identified as a species of Streptomyces based on its membrane fatty acid profile and the presence of ll-diaminopimelic acid in the cell wall. It formed sporulating mycelia on most agar media, but flat or wrinkled, moist colonies on trypticase soy agar. Spores were smooth, cylindrical, and borne on long, straight to flexuous chains. It produced a light brown diffusible pigment, but not melanin. Comparison of genomic digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values indicated that strain SFB5AT was related to Streptomyces litmocidini JCM 4394T, Streptomyces vietnamensis GIMV4.0001T, Streptomyces nashvillensis JCM 4498T and Streptomyces tanashiensis JCM 4086T, plus 11 other species. However, the dDDH and ANI values were well below the species differentiation thresholds of <70 and <95 %, respectively; also, multilocus sequence analysis distances exceeded the species threshold of 0.007. Moreover, strain SFB5AT differed from the other species in pigmentation and its ability to catabolize arabinose. Strain SFB5AT and 11 of its 15 closest relatives degraded PHB and have genes for extracellular, short-chain-length denatured polyhydroxyalkanoate depolymerases. These enzymes from strain SFB5AT and its closest relatives had a type 1 catalytic domain structure, while those from other relatives had a type 2 structure, which differs from type one in the position of a consensus histidine in the active site. Thus, phenotypic and genotypic differences suggest that strain SFB5AT represents a new species of Streptomyces, for which we propose the name Streptomyces nymphaeiformis sp. nov. The type strain is SFB5AT (=NRRL B-65520T=DSM 112030T).

Tracking and modeling the movement of Queensland fruit flies, Bactrocera tryoni, using harmonic radar in papaya fields.

Determining movement parameters for pest insects such as tephritid fruit flies is critical to developing models which can be used to increase the effectiveness of surveillance and control strategies. In this study, harmonic radar was used to track wild-caught male Queensland fruit flies (Qflies), Bactrocera tryoni, in papaya fields. Experiment 1 continuously tracked single flies which were prodded to induce movement. Qfly movements from this experiment showed greater mean squared displacement than predicted by both a simple random walk (RW) or a correlated random walk (CRW) model, suggesting that movement parameters derived from the entire data set do not adequately describe the movement of individual Qfly at all spatial scales or for all behavioral states. This conclusion is supported by both fractal and hidden Markov model (HMM) analysis. Lower fractal dimensions (straighter movement paths) were observed at larger spatial scales (> 2.5 m) suggesting that Qflies have qualitatively distinct movement at different scales. Further, a two-state HMM fit the observed movement data better than the CRW or RW models. Experiment 2 identified individual landing locations, twice a day, for groups of released Qflies, demonstrating that flies could be tracked over longer periods of time.