Morphology of the Genus Actinomyces. I

Abstract

II CHARLES DRECHSLER BOTANICAL GAZETTE [JANUARY has occurred in the family, with A ctinomyces at the head of a transition series developing increasingly well marked fungoid characteristics, or else that A ctinomyces is the probable progenitor of the groups Corynebacterium and Mycobacterium by degenerative reduction. The view that the ray fungus represents an organism with hyphomycetous affinities was advanced early by HARZ (7) and DEBARY (2). These authors regarded as conidia the clavate elements of the actinomycotic lesion, which BOSTROEM'S studies later properly degraded to the rank of degenerative structures. SAUVA-GEAU and RADAIS (20), DOMEC (3), THAXTER (22), GASPERINI (4), and others placed a number of congeneric forms among the Hyphomycetes on account of their production of aerial spores. It may be mentioned in this connection that an examination of a considerable number of species has convinced the writer that this disposition is the only one which is in harmony with the morphological conditions represented in the genus. The material used in these studies, with the exception of authentic cultures of the species described by WAKSMAN and CURTIS (23), and of a number of organisms isolated by H. J. CONN from soil collected near Geneva, New York, was largely obtained from soil collected in Cambridge, Massachusetts. By the use of the dilution method more than iooo plants belonging to the genus were isolated from this source; and of these about 3oo, representing probably more than ioo species, were selected for morphological examination. Approximately 400 additional individuals were derived from soil collected in Porto Rico,

Studies upon an Oral Aerobic Actinomycete

“…1, notably A the very close similarity between Arthrobacter and Nocardia. Attention is also drawn to the similarity between the reported 'gonidia' formation in Arthrobacter (Chaplin, 1957) and the frequent reports of apparently similar processes in Nocardia (Bergey's Manual, 1957, p. 715), Leptotrichia (Bulleid, 1924), and Streptomyces (Dreschler, 1919); such forms were not common in the present organism, but in P1. 2, fig.…”

Geomicrobiology and Geomicrobiological Attack on Sedimented Organic Matter

“…In recent years the Actinomycetes, with affinities placing them between Fungi and Bacteria, have received considerable attention. There seems to be some indecision regarding the systematic position of these organisms, q. v. DRECHSLER [68], HENRICI [69], WAKSMAN [55], and BERGEY [70], but their morphological characteristics are well defined. Thus, according to W AKSMAN, the Actinomycetes form elongated, usually filamentous, cells; the filaments are usually 1 J..l or less (and do not exceed 1.5 J..l) in diameter.…”

III. On a form ofBotrytis cinerea, with colourless sclerotia

“…1-90) were prepared. Of these, 24 tubes contained both black and colourless sclerotia in the proportion of 528 of the former to 39 of the latter, and the remaining 66 tubes contained only black sclerotia. In the G tubes (IV.…”

“…On September 10, however, when tubes (E. [1][2][3][4][5][6] were again examined and the aberrant sclerotium in (E. 6), now quite mature, was found to be still lacking any sign of pigmentation, it was decided to isolate this sclerotium and breed from it. In tube (E. 6) there were iu addition to the colourless sclerotium 24 normal black sclerotia and a black sclerotial crust around the bottom of the tube, where the medium had contracted away from the glass.…”

“…MUNN ( 56), who has most recently investigated this fungus, writes : "It was observed that in many cases the appressoria are incipient stages of the sclerotia (Plate 3, figs. 23,24)." Now if MuNN's figs.…”