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Mutants of Escherichia coli K-12 were constructed such that each possessed one single major system for phosphate transport. A comparison of these strains showed that one of the systems (PIT) was fully constitutive, required no binding protein, and operated in spheroplasts. It permitted the complete exchange of intracellular phosphate with extracellular phosphate (or arsenate) and was completely inhibited by uncouplers. The other system, PST, was repressible by phosphate concentrations above 1 mM, required the phosphate-binding protein for full activity, and did not operate in spheroplasts. It catalyzed very little exchange between internal and external phosphate and was resistant to uncouplers. The maximal velocities attained by the two systems were approximately the same, but the affinity for phosphate in the PST system was greater by two orders of magnitude. In strains in which both systems were fully operative, the initial rates of uptake were nearly additive, and the systems appeared to interact with a common intracellular phosphate pool.

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Metal phthalocyanines can be very efficient as catalysts and photocatalysts in oxidation reactions using molecular oxygen as oxidant. Different types of soluble low molecular weight or oligomeric and insoluble heterogeneous catalysts and photocatalysts were developed. The heterogeneous metal phthalocyanines exist either impregnated on SiO 2, Al 2 O 3, charcoal and TiO 2 or covalently and coordinatively bound on SiO 2 and organic polymers or ionically bound on an organic ion exchanger. The catalytic oxidations of toxic sulfide and thiol derivative are studied. In addition, toxic phenols were employed as substrates for the photooxidation. Heterogeneous catalysts can exhibit higher activities then low molecular weight phthalocyanines. These systems exhibit a good stability for re-use. Photooxidations are more efficient than oxidations. A Si(IV) phthalocyanine derivative on a polymer ion exchanger is most active and stable. Also some examples for photooxidations in the direction of photochemical synthesis are given.