"Rubber Whales" Drink Oil from Tankers to Prevent Spills
reactor retention time by speeding pH elevation. Grace agitated the reactor liquor at 1000 p.p.m. to speed C 0 2 removal and precipitate formation. Under these conditions up to 98% of phosphates present were precipitated, mostly as magnesium ammonium phosphate. The process also reduces nitrogen, BOD, and COD (chemical oxygen demand) levels.
PHOTOSYNTHESIS:
A Richer Soybean A more efficient crop plant, a once distant goal of photosynthesis research, may finally have been reached. Dr. Robert W. Keck told scientists at the International Conference on the Photosynthetic Unit at Gatlinburg, Tenn., last week that a mutant soybean plant carries out photosynthetic reactions at rates faster than does normal soybean. Although field tests haven't yet been conducted, Dr. Keck expects the mutant to require less sunlight, water, and fertilizer than does the normal variety. More of the mutant's protein seems to be found in its seeds, which are the source of oil and protein for use as food. The mutant was first observed more than 20 years ago as a pale green soybean variety that had grown normally in an open field in spite of its sickly appearance. A study about 10 years ago showed that although the mutant has about half the amount of chlorophyll per leaf compared to the normal soybean plant, the mutant still manages to fix carbon dioxide at a rate at least as fast as the normal plant. Beyond that point, however, the mutant was studied only as a classroom exercise in plant genetics, Dr. Keck says. Working with Dr. Richard A. Dilley
The Coast Guard has successfully tested "rubber whales," a new system for preventing oil spills developed by Ocean Science and Engineering, Inc., Washington, D.C. The "whales" are re-usable 140-foot rubber-nylon blad-
ders, made by Uniroyal, which are parachuted with attached pumps and hoses near stricken tankers. Some 500 tons of oil are pumped from the ship into a bag, and each bag is towed ashore.
and Dr. Bacon Ke at Charles F. Kettering Research Laboratory, Yellow Springs, Ohio, Dr. Keck finds that leaves and isolated chloroplasts from the mutant fix carbon dioxide faster than leaves and chloroplasts from normal soybeans at all light intensities. Dr. Keck and his colleagues have analyzed the components of a mutant chloroplast and find that there is also less P700, a special form of chlorophyll that is oxidized by light energy absorbed by the other chlorophylls. The ratio of chlorophyll molecules per P700 molecule remains the same in both mutant and normal plants, Dr. Keck observes. The electron removed from P700 in this photooxidation provides the reducing power to convert carbon dioxide to carbohydrates. Chloroplasts also oxidize water to
produce oxygen, and electrons from water ultimately travel through an electron transport chain to reduce the photooxidized form of P700. This chain includes cytochromes and plastoquinone. Dr. Keck finds that the amount of cytochromes and plastoquinone is unchanged in the mutant. As a result, the mutant has twice as much of these electron transport components per chlorophyll molecule. Other scientists have suggested that the overall rate of photosynthesis is limited by the amount of plastoquinone, and Dr. Keck observes that electron transport through plastoquinone in the mutant is indeed twice as fast as in the normal plant. Formation of the molecule adenosine triphosphate, which may be associated with electron transport, is also faster in the mutant. Since the mutant uses light energy more efficiently, it should be possible to plant mutant soybean plants closer together, Dr. Keck says. The amount of water required per acre doesn't depend on the number of plants, he says, so less water would be used per plant. Dr. Keck also has preliminary evidence that mutant plants have a greater proportion of their protein in their seeds. The total amount of protein is the same as in normal plants, however, so a greater percentage of the nutrients that feed each plant goes into seed protein. Consequently, the mutant may require less fertilizer to make the same amount of seed protein, he says. Other scientists have recently found a pea mutant that may also have a decreased amount of chlorophyll and a greater rate of photosynthesis, Dr. Keck says. Similar mutants in other plants may be found by looking for poorly colored plants that seem to grow normally, he suggests.
Worker checks regular soybeans Photosynthetic efficiency
MAY 25, 1970 C&EN 15
