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... Science Frontiers ONLINE No. 41: Sep-Oct 1985 Issue Contents Other pages Home Page Science Frontiers Online All Issues This Issue Sourcebook Project Sourcebook Subjects An Animal That Photosynthesizes At a recent meeting of the American Society for Photobiology, chemist Pill-Soon Song, of Texas Tech University, reported the discovery of a blue-green, trumpet-shaped protozoan that employs photosynthesis to sustain itself. Called Stentor coeruleus, this protozoan is only 0.2 mm long and swims backward by rotating its cilia. According to the article, this is the first instance of a photosynthesizing animal. (Anonymous; "Animal That Lives on Light," San Francisco Chronicle, June 28, 1985, p. 2. Cr. J. Covey) Comment. Nothing was said about whether the protozoan also ate food in the conventional manner. If verified, this is not a trivial discovery. Of course, some plants eat meat, but animals seem to have found sunlight too weak to utilize for mobility and other energy-rich processes and activities. From Science Frontiers #41, SEP-OCT 1985 . 1985-2000 William R. Corliss ...
Terms matched: 1 - Score: 34 - 15 May 2017 - URL: /sf041/sf041p06.htm
... new method for quantitative enumeration, we have found up to 2.5 x 108 virus particles per millilitre in natural waters. These concentrations indicate that virus infection may be an important factor in the ecological control of planktonic microorganisms, and that viruses might mediate genetic exchange among bacteria in natural aquatic environments." (Bergh, Oivind, et al; "High Abundance of Viruses Found in Aquatic Environments," Nature, 340:467, 1989.) A sip of water could therefore introduce a billion virus particles into your stomach! This level of virus density in natural water is about 10 million times that formerly estimated. Besides reducing your thirst, what are the implications of this discovery? First, it suggests that bacteria in natural waters are probably kept in check by viruses as well as protozoans. So far, this sounds good. Second, since viruses can ferry genetic material between organisms via transduction (i .e ., host DNA is carried to the next host). This means that genes for antibody resistance and increased bacterial virulence (as present in sewage) may be spread quickly and widely. Also, "engineered bacteria" proposed for use in agriculture, viz., the ice-minus bacterium created to protect strawberries, may die, but their new genes will soon be everywhere. (Weiss, R.; "Aquatic Viruses Unexpectedly Abundant," Science News, 136: 100, 1989.) From Science Frontiers #66, NOV-DEC 1989 . 1989-2000 William R. Corliss ...
Terms matched: 1 - Score: 13 - 15 May 2017 - URL: /sf066/sf066b10.htm
... beyond a few feet. Measured in millimeters, the marine snowflakes are much larger than the average interplanetary dust particles (but of course interplanetary dust itself is also a constituent of marine snow). The bigger marine snowflakes -- over 0.5 mm -- are a major food source for deep-sea denizens waiting below for this manna from the watery heaven. The reason for mentioning marine snow in Science Frontiers is that biologists like Alldredge are really pio-neering new territory, where new anomalies must surely dwell. "' We've essentially discovered a whole new class of particles in the ocean that no one knew was there," she exults. .. .. . "' They're islands, really, where the metabolic activities of algae, bacteria, and protozoans produce unique chemical environments,' says Alldredge." To illustrate, the carbon content of bacteria on marine snow is 10,000 times higher than that of bacteria found away from the snow. Why? (Cox, Vic; "It's No Snow Job," Sea Frontiers , 40:42, March/April 1994.) From Science Frontiers #93, MAY-JUN 1994 . 1994-2000 William R. Corliss ...
Terms matched: 1 - Score: 13 - 15 May 2017 - URL: /sf093/sf093b05.htm
... snorkeler, . it does herd microbes into clumps or microniches . which we cannot see either. These microbes. in effect, exist in a tangled. 3-D mesh that affects not only their movements but also those of their prey and predators. A few statistics confirm the amazing complexity of the seawater microcosm and its incredibly high microbe population density. The long strands in the oceanic gel are mostly crosslinked polysaccharides. If the polysaccharides in 1 milliliter of seawater could be placed end-to-end, they would stretch out to 5,600 kilometers! Coexisting proteins would span 310 kilometers ; DNA, 2 kilometers. This same milliliter may also contain up to a million bacteria and ten times as many virus particles. Also in this brew are, on the average, 1.000 protozoans and 100 phytoplankton. It's a microscopic metropolis, about the size of a sugar cube, and one in which you may never wish to swim again! The polysaccharides and proteins that comprise most of the thin goo are not alive, although the bacteria are. Just how this thin goo and its multitudinous inhabitants evolved has not been explained. Which came first, the goo or the bacteria? Being devoid of life's spark, the goo cannot evolve, or can it? (LaFee, Scott; "Meet Me at the Goo," New Scientist, p. 44, November 25, 2000.) Comment. Do similar microcosms thrive in freshwater lakes, in aquifer pores, the atmosphere? Don't shrug, even the atmosphere has its microstructure and is ...
Terms matched: 1 - Score: 13 - 15 May 2017 - URL: /sf134/sf134p09.htm
