The response of the biosensors was compared with the mutagenic response of the traditional Salmonella mutagenicity assay. For the chemicals tested (acridine, B[a]A, B[a]P, chrysene, mitomycin C and sodium azide), E. coli DPD1718 was consistently more sensitive than E. coli K12C600. The biosensors were of comparable sensitivity to the Salmonella assay but were more rapid, reproducible and easier to measure. These data validate the adoption of optimised assays making use of microbial biosensors for routine
screening of test chemicals. “
“ArsH is widely distributed in bacteria, and its function remains to be characterized. In this study, we investigated the function of ArsH from Synechocystis sp. PCC 6803. The inactivation of arsH by insertion of a kanamycin-resistance gene in Synechocystis sp. PCC 6803 resulted in the decrease of arsenic and chromium accumulation compared with the wild type. AZD1208 ic50 ArsH expression in Escherichia coli strain Rosetta increased its resistance to chromate by reducing chromate
in the medium and cells to chromium (III). In addition, ArsH in Rosetta conferred resistance to arsenic. The purified Synechocystis ArsH was able to reduce chromate and ferric iron at the expense of NADPH. Nonlinear regression values of K0.5 for chromate and ferric iron were 71.9 ± 17.8 μM and 59.3 ± 13.8 μM, respectively. The expression level of arsH was induced by arsenite and arsenate, but not chromate or ferric iron. Our results suggest www.selleckchem.com/products/Fulvestrant.html that Synechocystis ArsH had no substrate specificities and shared some biochemical properties that other enzymes possessed. ArsH may be involved in coordinating oxidative stress response generated by arsenic. “
“The pyruvate–acetaldehyde–acetate (PAA) pathway has diverse roles in eukaryotes. Our previous study on acetyl-coenzyme A synthetase 1 (ACS1) in Gibberella zeae suggested that the PAA pathway is important for lipid production, which is required for perithecia maturation. In this study, we deleted all three pyruvate decarboxylase (PDC) genes, which encode enzymes that function upstream of ACS1
in the PAA pathway. Results suggest PDC1 is required for lipid accumulation in the aerial mycelia, and deletion of PDC1 resulted in highly wettable mycelia. However, the total amount of lipids in the PDC1 deletion mutants was similar to that of the wild-type strain, likely due to compensatory MycoClean Mycoplasma Removal Kit lipid production processes in the embedded mycelia. PDC1 was expressed both in the aerial and embedded mycelia, whereas ACS1 was observed only in the aerial mycelia in a PDC1-dependent manner. PDC1 is also involved in vegetative growth of embedded mycelia in G. zeae, possibly through initiating the ethanol fermentation pathway. Thus, PDC1 may function as a key metabolic enzyme crucial for lipid production in the aerial mycelia, but play a different role in the embedded mycelia, where it might be involved in energy generation by ethanol fermentation.