SummaryBacterial cell division involves the dynamic assembly of a diverse set of proteins that coordinate the invagination of the cell membrane and synthesis of cell wall material to create the new cell poles of the separated daughter cells. Penicillin‐binding protein PBP 2B is a key cell division protein in Bacillus subtilis proposed to have a specific catalytic role in septal wall synthesis. Unexpectedly, we find that a catalytically inactive mutant of PBP 2B supports cell division, but in this background the normally dispensable PBP 3 becomes essential. Phenotypic analysis of pbpC mutants (encoding PBP 3) shows that PBP 2B has a crucial structural role in assembly of the division complex, independent of catalysis, and that its biochemical activity in septum formation can be provided by PBP 3. Bioinformatic analysis revealed a close sequence relationship between PBP 3 and Staphylococcus aureus PBP 2A, which is responsible for methicillin resistance. These findings suggest that mechanisms for rescuing cell division when the biochemical activity of PBP 2B is perturbed evolved prior to the clinical use of β‐lactams.

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A highly sensitive sensor for the determination of H(2)O(2) is presented in this paper. The constant-current electrochemical deposition (ECD) was used to synthesize ZnO nanorod arrays on indium-tin oxide (ITO) substrate. It was found that high temperature sintering could improve the intensity and stability of the photocurrent of ZnO nanorod arrays modified electrode. Meanwhile, it was found that H(2)O(2) could greatly enhance the photocurrent of ZnO nanorod arrays modified electrode, based on which a highly sensitive sensor could be developed for the detection of H(2)O(2) with a detection limit of 2.0 x 10(-13) mol L(-1). The ZnO nanorod electrode was characterized by XRD, SEM and XPS. The XPS results showed that H(2)O(2) removed the lattice oxygen from ZnO surface and then resulted in the increase of photocurrent. It is believed that more highly sensitive sensors can be developed to detect the bioactive compounds which can produce H(2)O(2) through an enzymatic reaction.

In this work, the chemiluminescence analysis method was used to detect the free radical during sonodynamic process. MCLA, which can specifically react with singlet oxygen ((1)O(2)) or superoxide anion to emit photon, was used to detect free radical formation in the sonosensitization of metallophthalocyanine in real time. The ultrasound-induced chemiluminescence of MCLA enhanced by sulfonated phthalocyanines Nickel did not show the expected structure-activity relationship which was well known as type II mechanism for the photodynamic therapy related to singlet oxygen production. The results showed that free radical are involved in the sonosensitization, and the catalytic performance of NiPcS(4) was the main reason for the increase of SCL.