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The toluene-degrading bacterium Acinetobacter sp. Tol 5 shows high adhesiveness mediated by the bacterionanofiber protein AtaA, which is a new member of the trimeric autotransporter adhesin (TAA) family. In contrast to other reported TAAs, AtaA mediates the adhesion of Tol 5 to various abiotic surfaces ranging from hydrophobic plastics to hydrophilic glass and stainless steel. The expression of ataA in industrially relevant bacteria improves their adhesiveness and enables immobilization directly onto support materials. This represents a new method that can be alternated with conventional immobilization via gel entrapment and chemical bonding. In this study, we demonstrate the feasibility of this immobilizing method by utilizing AtaA. As a model case for this method, the indigo producer Acinetobacter sp. ST-550 was transformed with ataA and immobilized on a polyurethane support. The immobilized ST-550 cells were transferred directly to a reaction solution containing indole as the substrate. The immobilized ST-550 cells showed a faster indigo production rate at high concentrations of indole compared with planktonic ST-550 not expressing the ataA gene, implying that immobilization enhanced the tolerance of ST-550 to the substrate indole. As a result, the immobilized ST-550 produced fivefold higher levels of indigo than planktonic ST-550. These results proved that AtaA is useful for bacterial immobilization.

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A new bifunctional receptor 1 for cooperative complexation of cations and anions is synthesized on the basis of benzo-15-crown-5, functionalized with a thiourea moiety as anion binding sites. When Na+ is bound to the crown moiety of 1, the association constants of I−, Br− and NO3− in CD3CN are significantly increased, as compared with free 1. Thermodynamic studies indicate that these large increases in complex stabilities can be ascribed primarily to the enthalpic effect.

An efficient strategy for the liquid-phase synthesis of cyclic metallopeptides, cyclo[Gly-l-Cys(terpyPt II )] n Cl n (n = 3, 4), has been developed, which could provide a powerful tool for arraying metal centers on cyclopeptide frameworks. † Experimental and spectral data for 1a,b, 2 and 3 are available from the RSC web site, see