Life Cycles in Arthrobacter Pascens and Arthrobacter Terregens

Abstract

Two soil organisins, ilrll~robacler pascelzs and Arllzrobecler lerregetzs, the first producing a growth-promoting substance, the "terregens factor", and thc second requiring it, pass through a complex morpl~ological life cycle. T I I~ kinds of aged cclls are found of which, on transfer to fresh medium, onc for~ns a cystite \vhich 'gcrminates' and looses free cells from a ruptured tube, the other follows thc ~~s u a l course of 'normal' cell cli~.ision. The similarity in for111 to that of the type species Artlrrobacter g1obifor1,ze is quite distinct.

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.…”

Cystite formation of Arthrobacter ureafaciens NRIC 0157.

“…Sguros (1955) regarded the cystites of Arthrobacter oxydans biotype xanthum (ϭATCC 14358 T ) and A. oxydans biotype album (ϭATCC 14359) as resting cells (arthrospores). Chaplin (1957) observed the cystite formation of Arthrobacter pascens and Arthrobacter terregens at the lag phase and agreed with the gonidia concept reported by Jensen (1934). Starr and Kuhn (1962) found the swollen cells of Arthrobacter atrocyaneus ATCC 13752…”

“…The fragmentation of cystites of A. ureafaciens NRIC 0157 T , however, was not found in a fresh YPM medium, and projections from cystites divided into vegetative cells as the normal cell division occurred. Chaplin (1957) described that the cells of A. pascens swelled and produced germ tubes at the lag phase when cells were transferred to a fresh medium after long cultivation and that the swollen cells (1 to 2 mm in the cell size) released small cells (0.5 to 1 mm in the cell size). In this study, A. ureafaciens NRIC 0157…”

“…Thus swollen cells described by Chaplin (1957) might be cells formed during the normal life cycle and not cystites. In consideration of these results in this study, the characteristics of cystites were different from those of 176 TANAKA, UCHIMURA, and KOMAGATA Vol.…”

Characterization of a Propionic Acid Producing Actinomycete, Actinomyces propionicus, Sp.nov.

“…propionicus may be identical with those of P. arabinosum (Skerman, 1959), although the cells of A . propionicus continue to enlarge under certain conditions of substrate and age to form huge spheres not unlike the cystites of Arthrobacter specks (Chaplin, 1957;Skerman, 1959). Although there have been no direct experiment; to determine the nature of these morphological changes, the impression gained €rom general observation strongly suggests that these coccoidal or swollen forms are a result of abnormal cell-wall formation and do not Actinomyces propionicus 317 constitute a normal phase of the organism's growth.…”