Survival of Microorganisms in Nature.
Final rept. 10 Dec 78-28 Feb 82,
PENNSYLVANIA STATE UNIV UNIVERSITY PARK
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A new, non-obligate system of bacterial predation on bacteria in soil was discovered. The predators comprising this system were a genetically unstable strain of Streptomyces venezuelae a new kind of budding bacterium now designated as Ensifer adhaerens, gen. n., sp. n. and a myxobacterium. The natural population of these organisms in soil is attracted to and rapidly destroys lyses added Micrococcus luteus cells. There is also attack of predator on predator in this system. The transitory myceloid stage that occurs in the pleomorphic growth cycle of various Arthrobacter species was expanded by manganese removal so that it became the main form of growth. This stage was found to be more sensitive to bacteriophage attack than were the other growth stages. A new procedure for isolating Arthrobacter sp. bacteriophage from soil was developed for these studies. It was found that the encystment of Azotobacter vinelandii does not require prior intracellular production of poly-Beta-hydroxybutyrate, and that it is triggered by hypoxanthine. The human pathogen, Pseudomonas aeruginosa, was found to survive well in soil. It did not utilize pyocyanin production for this but, instead, went into a cell dormancy state with some of the characteristics of a cyst. Author