Variation. Brachionus calyciflorus Pallas (fig. 3) Bacterial species in soil and air is a species much subject to cyclomorphic variation, but none of the specimens in this collection showed of the Antarctic Continent such variation; they differed little from each other. R. E. CAMERON and F. A. MORELLI The only difference from temperate-water specimens Bioscience and Planetology Section is that the valley between the median and lateral Jet Propulsion Laboratory spines is greater and of slightly flattened form. California Institute of Technology Ecology of the Brachionids. In general, both of the R. M. JOHNSON foregoing species are found in temperate waters. This Department of Botany and Microbiology collection was taken from water temperatures of 2° Arizona State University and 3°C. But the same species are common in small During antarctic austral summers 1966-1972, ap- ponds in New Zealand where temperatures reach a proximately 425 soil samples have been collected minimum of 10°C. As far as Dr. Russell could de- from 160 separate sites (i.e., soil profiles), in 45 gen- termine, these were the first specimens of Brachionus eral areas (valleys, mountain ranges, islands, beaches, ever taken in polar waters. etc.). Aerial samples have been collected at or near the same sites, which included a variety of habitats. Other rotifiers. The author used alcohol to kill More than 400 isolants have been identified. A pre- and preserve the animals. This was a mistake. Dr. liminary list of identified microbial isolants has been Russell (communication) pointed out that neo- given previously (Cameron, 1971), including a brief synephrine is the only effective method of killing report on the occurrence and distribution of bac- bdelloidal rotifiers. Formalin should have been used teria in the Antarctic in comparison with those found as a preservative. As a result of maipreservation, in the Arctic and in deserts at lower latitudes (John- two specimens could not be identified. The evidence son and Holaday, 1970). shows that one of these was likely a sessile species Increased emphasis has been given to monitoring since it is associated with the remains of what appears aerial bacteria in the Antarctic, especially in regard to be a peduncle. The second specimen is believed, to field party activities (Morelli et al. 1972), an from the spurs and toes, to have been a species of aerobiological model (Cameron, in press), and the Habrotrocha. increased concern for conservation (Parker, 1972). As a Martian analogy, understanding of antarctic Other biota. Other animals found in the collec- microbial ecology is of continuing interest as it ap- tion were: plies to the Mars quarantine problem, selection of Amoeba terricola Greeff Martian landing sites for biological purposes, com- St ylonychi a sp. parison with a possible Martian microbial ecology, Macrobiotus sp. and as a test model for the biological exploration of Cyclopid copepods Mars (Horowitz, Cameron, and Hubbard, 1972). The collection contained copious populations of Based on standard methods for characterization of plants: bacteria (Breed et al., 1957), a detailed table (not chlorophyceae included here) was prepared showing the identity of chrysophyceae bacteria isolated from sites within a given geographi- cyanophyceae These were presented in detail by Thomas (1965). cal area, e.g., McKelvey Valley. A summary list of He concluded that the basic stock of biota in antarctic all the bacterial species identified to date is given in pools was transported by the Skua Cat haracta antarc- table 1, which also includes information on the com- tica (C. skua lonnbergi). Their preservation while mon habitat of each species (Breed et al., 1957). frozen into solid ice most of the year is explained by Table 2 summarizes the bacterial genera, showing experiments of Plateau (1872). frequency of identified isolants and their general geographical location. References This paper presents the results of one phase of research Thomas, C. W. 1965. On populations in Antarctic melt- carried out under National Aeronautics and Space Adminis- water pools, Pacific Science, 19(4) : 515-521. tration contract NAS 7-100. Logistic support and facilities Plateau, G. 1872. Résistance a lasphyxie par submersion, for the investigations in Antarctica and additional laboratory action du froid, action de la chaleur temperature maximum. support at the Jet Propulsion Laboratory were provided under Academie Royale Belgique. Bulletin, 34: 274-321. National Science Foundation contract NSF-0585 for the study Russell, C. R. 1959. Rotifera. B. A. N. Z. Antarctic Research of antarctic microbial ecology. D. R. Gensel performed the Expedition 1929-31. Reports, Series B, 8 (3): 83-87. isolation of most of the bacteria for test purposes. September-October 1972 187 As indicated in our results, Corynebacterium spp. bacter tumescens and A. simplex. These isolants were most frequently isolated from soil of the coastal were first reported as cultured from Australian soils, region of McMurdo Sound. C. sepedonicurn repre- (Breed et al., 1957). Additional microbial studies on sented approximately 85 percent of the isolants of borders of nearby continents could gain further evi- the genus. An increasing variety of isolants has been dence for Gondwanaland. found in active personnel areas or heavily organically The results here, while not complete, indicate the contaminated areas, such as McMurdo Station , Cape Royds, and Romanes Beach. In the dry valleys the Table 1. Bacterial species isolated from soil and air of coryneforrns also were the most abundant. C. bovis the Antarctic Continent and their habitat in nonantarctic represented almost 40 percent of the isolants, and - environments. C. sepedonicum represented only 25 percent of the Antarctic species Nonantarctic habitats isolants. Air samples were collected primarily in the 1971-1972 austral summer from Taylor, Wright, and Achromobacterium parvulus soil Achromobacterium stenohalis sea water Victoria Valleys. Bacillus spp. were most frequently Art hrobacter citreus soil—chicken feces isolated: B. coagulans, 30 percent; B. subtilis, 25 Arthrobacter globiformis soil—widely distributed percent; and B. cereus, 20 percent. These percent- Arthrobacter oxydans soil ages contrast significantly with the frequency of soil Arthrobacter pascens soil isolants (table 2). Soil and air samples from the Art hrobacter simplex Australian soil Arthrobacter tumescens Australian soil interior were taken between 560 and 250 km from Arthrobacter urea faciens soil the South Pole. The most abundantly recovered soil Bacillus alvei widely distributed; in soil and microorganisms were Arthrobacter spp., but air sam- beehives ple isolants were primarily Bacillus spp. For Decep- Bacillus cereus soil, dust, and milk Bacillus coagulans spoiled food, cream, cheese, tion Island, Arthrobacter spp. were the most fre- and silage quently isolated soil and air forms. Bacillus brevis soil, dust, milk, air, cheese; Of the most prevalent antarctic soil bacteria as widely distributed shown by our studies, only the Arthrobacter genus Bacillus lentus soil contains predominantly soil forms. Micrococcus and Bacillus firnzis soil and decomposed materials Bacillus spp. were as frequently isolated as Brevi- Bacillus pumilis soil, dust and cheese bacterium spp. Of the Bacillus spp., a significant Bacillus sphaericus widely distributed in nature number were recovered from the air, showing that Bacillus subtilis soil—air they are a prominent bacterial component of the Bacillus megaterium soil, water, dust and aerial plankton and that they do survive, at least for decomposing materials Brevibacterium ammogenes putrefying materials a time, in antarctic air. Significantly, many of the Brevibacterium fulvum water Bacillus spp. had optimum growth temperatures of Brevibacterium imperiale unknown habitat 37 0 to 45 0 C., and, as indicated in table 2, a number Brevibacteriurn incertum unknown habitat of them could originate from contaminating sources. Brevibacteriurn sulfureum air Brevibacterium tegument Cola unknown habitat A similar statement could be made about Micro- Corynebacterium bovis dairy products—fresh drawn coccus spp., which are from such sources as skin sur- milk faces, milk, and dairy utensils. The presence of cer- Corynebacterium equi infections of horses, swine, tain aerial micrococci would indicate the presence cattle and buffaloes of personnel; more studies are needed to show the Corynebacterium hoagii unknown habitat Corynebacterium isolated from witches broom correlations of numbers and activities of personnel hypertrophicans with numbers and kinds of bacterial isolants. Diph- Corynebacterium normal throat flora theroids may not be named from the soil habitat, but pseudodiphtheriticum Corynebacterium rathayl pathogenic on Dactylis they can include contaminants, such as Art hro bacter glomeratus cit reus, isolated from chicken feces. Corynebac- Corynebacterium sepedonicum rot-ring of potatoe tubers— terium bovis and C. sepedonicum also can probably Germany represent contaminating species in the Antarctic. Corynebacterium striatum mucus membranes, skin Bacteria originating from pollution foci are undoubt- glands of mammals including man edly borne to other locations by personnel, their ve- Corynebacterium xerosis skin and body parts hicles, equipment and supplies, wind currents, me- cytophaga hutchinsonii soil teoric precipitation, and bird carriers. Flavobacterium arborescens water A possibility of microbial support for Gondwana- Flavobacterium fucatum