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Full-Text Articles in Life Sciences
A New Class Of Homoserine Lactone Quorum-Sensing Signals, Amy Schaefer, E Greenberg, Colin Oliver, Yasuhiro Oda, Jean Huang, Gili Bittan-Banin, Caroline Peres, Silke Schmidt, Katarina Juhaszova, Janice Sufrin, Caroline Harwood
A New Class Of Homoserine Lactone Quorum-Sensing Signals, Amy Schaefer, E Greenberg, Colin Oliver, Yasuhiro Oda, Jean Huang, Gili Bittan-Banin, Caroline Peres, Silke Schmidt, Katarina Juhaszova, Janice Sufrin, Caroline Harwood
Jean J. Huang
Quorum sensing is a term used to describe cell-to-cell communication that allows cell-density-dependent gene expression. Many bacteria use acyl-homoserine lactone (acyl-HSL) synthases to generate fatty acyl-HSL quorum-sensing signals, which function with signal receptors to control expression of specific genes. The fatty acyl group is derived from fatty acid biosynthesis and provides signal specificity, but the variety of signals is limited. Here we show that the photosynthetic bacterium Rhodopseudomonas palustris uses an acyl-HSL synthase to produce p-coumaroyl-HSL by using environmental p-coumaric acid rather than fatty acids from cellular pools. The bacterium has a signal receptor with homology to fatty acyl-HSL receptors …
Acyl‐Hsl Signal Decay: Intrinsic To Bacterial Cell–Cell Communications, Ya-Juan Wang, Jean Huang, Jared Leadbetter
Acyl‐Hsl Signal Decay: Intrinsic To Bacterial Cell–Cell Communications, Ya-Juan Wang, Jean Huang, Jared Leadbetter
Jean J. Huang
No abstract available.
The Acid Stress Response Of The Cyanobacterium Synechocystis Sp. Strain Pcc 6308, Jean Huang, Nancy Kolodny, Jennifer Redfearn, Mary Allen
The Acid Stress Response Of The Cyanobacterium Synechocystis Sp. Strain Pcc 6308, Jean Huang, Nancy Kolodny, Jennifer Redfearn, Mary Allen
Jean J. Huang
The cyanobacterium Synechocystis sp. strain PCC 6308 has been shown to exhibit predictable physiological responses to acid stress. Originally isolated from a Wisconsin lake, this cyanobacterium grows optimally under alkaline conditions in the laboratory. After acid stress at a pH of between 4.4 and 7.7, cells return to exponential growth following a lag phase. The organism's response to this tolerable acid stress involves cell concentration-dependent neutralization of the external medium to pH 6 or above within 5 min, maintenance of a transmembrane pH gradient, and maintenance of photosystem II efficiency. Lethal acid stress, at a pH below 4.4, results in …
Identification Of Quip, The Product Of Gene Pa1032, As The Second Acyl-Homoserine Lactone Acylase Of Pseudomonas Aeruginosa Pao1, Jean Huang, Ashley Petersen, Marvin Whiteley, Jared Leadbetter
Identification Of Quip, The Product Of Gene Pa1032, As The Second Acyl-Homoserine Lactone Acylase Of Pseudomonas Aeruginosa Pao1, Jean Huang, Ashley Petersen, Marvin Whiteley, Jared Leadbetter
Jean J. Huang
The relevance of the acyl homoserine lactone (acyl-HSL) quorum signals N-3-oxododecanoyl-homoserine lactone (3OC12HSL) and N-butanoyl-homoserine lactone to the biology and virulence of Pseudomonas aeruginosa is well investigated. Previously, P. aeruginosa was shown to degrade long-chain, but not short-chain, acyl-HSLs as sole carbon and energy sources (J. J. Huang, J.-I. Han, L.-H. Zhang, and J. R. Leadbetter, Appl. Environ. Microbiol. 69:5941-5949, 2003). A gene encoding an enzyme with acyl-HSL acylase activity, pvdQ (PA2385), was identified, but it was not required for acyl-HSL utilization. This indicated that P. aeruginosa encodes another acyl-HSL acylase, which we identify here. A comparison …
Utilization Of Acyl-Homoserine Lactone Quorum Signals For Growth By A Soil Pseudomonad And Pseudomonas Aeruginosa Pao1, Jean Huang, Jong-In Han, Lian-Hui Zhang, Jared Leadbetter
Utilization Of Acyl-Homoserine Lactone Quorum Signals For Growth By A Soil Pseudomonad And Pseudomonas Aeruginosa Pao1, Jean Huang, Jong-In Han, Lian-Hui Zhang, Jared Leadbetter
Jean J. Huang
Acyl-homoserine lactones (AHLs) are employed by several Proteobacteria as quorum-sensing signals. Past studies have established that these compounds are subject to biochemical decay and can be used as growth nutrients. Here we describe the isolation of a soil bacterium, Pseudomonas strain PAI-A, that degrades 3-oxododecanoyl-homoserine lactone (3OC12HSL) and other long-acyl, but not short-acyl, AHLs as sole energy sources for growth. The small-subunit rRNA gene from strain PAI-A was 98.4% identical to that of Pseudomonas aeruginosa, but the soil isolate did not produce obvious pigments or AHLs or grow under denitrifying conditions or at 42°C. The quorum-sensing bacterium P. aeruginosa, which …
Method Of Identifying Agents That Inhibit Quorum Sensing Activity Of Gamma-Proteobacteria, Jean Huang, Jared Leadbetter
Method Of Identifying Agents That Inhibit Quorum Sensing Activity Of Gamma-Proteobacteria, Jean Huang, Jared Leadbetter
Jean J. Huang
Screening assays that allow for the identification of agents that increase acyl homoserine lactone (AHL) acylase expression and/or AHL acylase activity in γ-proteobacteria such as Pseudomonas aeruginosa. Such agents are useful, for example, for inhibiting quorum sensing activity of such bacteria by increasing degradation of long chain, but not short chain, AHLs and, therefore, can be useful for treating infections by such bacteria.
Production Of Hydrogen Gas From Light And The Inorganic Electron Donor Thiosulfate By Rhodopseudomonas Palustris, Jean Huang
Jean J. Huang
A challenge for photobiological production of hydrogen gas (H2) as a potential biofuel is to find suitable electron-donating feedstocks. Here, we examined the inorganic compound thiosulfate as a possible electron donor for nitrogenase-catalyzed H2 production by the purple nonsulfur phototrophic bacterium (PNSB) Rhodopseudomonas palustris. Thiosulfate is an intermediate of microbial sulfur metabolism in nature and is also generated in industrial processes. We found that R. palustris grew photoautotrophically with thiosulfate and bicarbonate and produced H2 when nitrogen gas was the sole nitrogen source (nitrogen-fixing conditions). In addition, illuminated nongrowing R. palustris cells converted about 80% of available electrons from thiosulfate …