Novel Role of Phosphorylation-Dependent Interaction between FtsZ and FipA in Mycobacterial Cell Division

The bacterial divisome is a multiprotein complex. Specific protein-protein interactions specify whether cell division occurs optimally, or whether division is arrested. Little is known about these protein-protein interactions and their regulation in mycobacteria. We have investigated the interrelationship between the products of the Mycobacterium tuberculosis gene cluster Rv0014c-Rv0019c, namely PknA (encoded by Rv0014c) and FtsZ-interacting protein A, FipA (encoded by Rv0019c) and the products of the division cell wall (dcw) cluster, namely FtsZ and FtsQ. M. smegmatis strains depleted in components of the two gene clusters have been complemented with orthologs of the respective genes of M. tuberculosis. Here we identify FipA as an interacting partner of FtsZ and FtsQ and establish that PknA-dependent phosphorylation of FipA on T77 and FtsZ on T343 is required for cell division under oxidative stress. A fipA knockout strain of M. smegmatis is less capable of withstanding oxidative stress than the wild type and showed elongation of cells due to a defect in septum formation. Localization of FtsQ, FtsZ and FipA at mid-cell was also compromised. Growth and survival defects under oxidative stress could be functionally complemented by fipA of M. tuberculosis but not its T77A mutant. Merodiploid strains of M. smegmatis expressing the FtsZ(T343A) showed inhibition of FtsZ-FipA interaction and Z ring formation under oxidative stress. Knockdown of FipA led to elongation of M. tuberculosis cells grown in macrophages and reduced intramacrophage growth. These data reveal a novel role of phosphorylation-dependent protein-protein interactions involving FipA, in the sustenance of mycobacterial cell division under oxidative stress

Anaerobic-aerobic treatment of swine wastewater in uasb and batch reactors in series

In this work it was evaluated the performance of two systems of swine wastewater treatment consisting of two-stage upflow anaerobic sludge blanket (UASB) reactors, with and without post-treatment in sequencing batch reactor (SBR), fed continuously, with aerobic phase. The UASB reactors in the first stage had 908 L in the sets I and II, and in the second stage 350 and 188 L, respectively. In the set II the post-treatment was performed in a SBR of 3,000 L. The hydraulic detention times in the anaerobic treatment systems were 100, 75 and 58 h in the set I; 87, 65 and 51 h in the set II; and 240 and 180 h in the SBR. The volumetric organic load applied in the first stage UASB reactors ranged from 6.9 to 12.6 g total COD (L d)-1 in the set I and 7.5 to 9.8 g total COD (L d)-1 in the set II. The average removal efficiencies of total COD, total phosphorus (Ptotal), and Kjeldahl and organic nitrogen (KN and Norg) in the anaerobic treatment systems were similar and reached maximum values of 97%, 64%, 68%, and 98%. In the SBR, the removal efficiencies of total COD and thermotolerant coliforms were up to 62 and 92% resulting, respectively, in effluent concentrations of 135 mg L-1 and 2x10(4)MPN (100 mL)-1. For Ptotal, total nitrogen (TN) and Norg, the average removal efficiencies in the SBR were up to 58, 25 and 73%, respectively.O desempenho de dois sistemas de tratamento de águas residuárias de suinocultura com reatores anaeróbios de fluxo ascendente com manta de lodo (UASB), em dois estágios, foi avaliado com e sem pós-tratamento em reator operado em batelada sequencial alimentada (RBS), com etapa aeróbia. Os reatores UASB do primeiro estágio possuíam 908 L nos conjuntos I e II, e no segundo estágio, 350 e 188 L, respectivamente. No conjunto II foi realizado o pós-tratamento em RBS de 3000 L. Os tempos de detenção hidráulica nos sistemas de tratamento foram de 100; 75 e 58 h no conjunto I; de 87; 65 e 51 h no conjunto II, e de 240 e 180 h no RBS. As cargas orgânicas volumétricas nos reatores UASB do primeiro estágio variaram de 6,9 a 12,6 g DQOtotal (L d)-1 no conjunto I, e de 7,5 a 9,8 g DQOtotal (L d)-1 no conjunto II. As eficiências médias de remoção de DQOtotal, fósforo total (Ptotal), nitrogênio Kjeldahl (NK) e nitrogênio orgânico (Norg.) nos sistemas de tratamento anaeróbio atingiram valores máximos de 97; 64; 68 e 98 %, respectivamente. No RBS, as eficiências de remoção de DQOtotal e coliformes termotolerantes foram de até 62 e 92%, reduzindo para 135 mg L-1 e 2 x 10(4) NMP (100 mL)-1, respectivamente, os valores médios no efluente. Para o Ptotal, nitrogênio total (NT) e Norg, as eficiências de remoção no RBS foram de até 58; 25 e 73%, respectivamente.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)UNESP Faculdade de Ciências Agrárias e Veterinárias Departamento de Engenharia RuralUNESP Faculdade de Ciências Agrárias e Veterinárias Departamento de Engenharia Rura

<i>Resonant Waves</i>: Immersed in Geometry

This article introduces Resonant Waves, a work of interactive new media art that incorporates cymatic patterns into an immersive installation. The authors describe their research and design process in creating Resonant Waves, and they discuss technical details about the installation, highlighting innovative aspects of the project and contextualizing the project in terms of previous cymatics research and related artistic explorations of complex phenomena. Finally, the authors discuss audience reaction to different installations of the project and identify directions for future research in immersive cymatics. </jats:p