Submitted to: International Journal of Systematic and Evolutionary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 25, 1996
Publication Date: N/A
Interpretive Summary: Spiroplasmas have been proposed for use as biological control agents, either by direct pathogenicity to insects, or as carriers of toxin genes. However, before this could be achieved, adequate classifications must be developed for their identification. The organism descibed in this paper, although isolated from syrphid flies (Diptera:Syrphidae), frequently occurs in horse flies and deer flies. Identification of this organism and related organisms, will promote an understanding of natural processes that can be exploited for biocontrol. The understanding of the taxonomy of insect-associated organisms, which this study promotes, will lead to more rational development of biological control organisms. These results will be of interest to microbial taxonomists, insect pathologists, and workers in biological control and integrated pest management.
Spiroplasma strain EA-1 (subgroup VIII-1) from the syrphid fly Eristalis arbustorum was serologically distinct from other spiroplasma species, groups, and subgroups. Cells of these strains, as envisioned by light microscopy, were short, helical, and motile. Electron microscopic examination showed wall-less cells delimited by a single membrane. The unusually short cells passed through 220 nm filter pores without reduction in titer. The organisms grew well in SM-1, M1D, and SP-4 liquid media. Growth also occurred in conventional horse serum medium and 1% serum fraction medium. Strain EA-1 grew over a temperature range from 10 to 41 degrees C, with an optimum at 32 degrees C. The doubling time at the optimal temperature was 1.0 h. The strain catabolized glucose and hydrolyzed arginine but did not hydrolyze urea. The guanine + cytosine (G + C) content of the deoxyribonucleic acid was about 30 +/- 1 mol%. The genome size was about 1230 kb pairs. Strain EA-1, representing subroup VIII- 1, is herein designated the type strain (ATCC 33826) of a new species, Spiroplasma syrphicola.