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Exopolysaccharide Production from Marine Bacteria and Its Applications
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Prashakha J. Shukla, Shivang B. Vhora, Ankita G. Murnal, Unnati B. Yagnik, Maheshwari Patadiya
Several studies have concluded that EPSs mediated biofilm formation is closely associated with quorum-sensing (QS) systems for the production of autoinducers (Di Donato et al., 2016). These QS mechanisms have been very well studied in the marine strain of Vibrio fischeri with two QS systems, ain and lux (Lupp and Ruby, 2005).
Cell-Cell Communication in Lactic Acid Bacteria
Published in Marcela Albuquerque Cavalcanti de Albuquerque, Alejandra de Moreno de LeBlanc, Jean Guy LeBlanc, Raquel Bedani, Lactic Acid Bacteria, 2020
Emília Maria França Lima, Beatriz Ximena Valencia Quecán, Luciana Rodrigues da Cunha, Bernadette Dora Gombossy de Melo Franco, Uelinton Manoel Pinto
The mechanism of quorum sensing was first observed in Aliivibrio fischeri (formely Vibrio fischeri), a Gram-negative marine bacterium that produces bioluminescence and lives in symbiosis with the Hawaiian squid Euprymna scolopes(Lazdunski et al. 2004). In this microorganism, the communication is mediated by the N-3-oxohexanoyl-L-homoserine lactone (OHHL), which is produced by a LuxI-type enzyme. When OHHL molecules are in high concentration due to bacterial high cell density, they bind to LuxR-receptor proteins, activating the transcription of genes responsible for bioluminescence (Fuqua and Greenberg 2002). In absence of AHL, the LuxR transcriptional factor is unstable and is rapidly degraded by intracellular proteases (Nealson and Hastings 1979, Miller and Bassler 2001). In other words, the bioluminescence process is associated with the high cell density of V. fisheri.
Genetic Engineering of Clostridial Strains for Cancer Therapy
Published in Ananda M. Chakrabarty, Arsénio M. Fialho, Microbial Infections and Cancer Therapy, 2019
Maria Zygouropoulou, Aleksandra Kubiak, Adam V. Patterson, Nigel P. Minton
In the case where the imaging functionality is introduced de novo into the clostridial vector, the options could extend beyond those discussed above. For fluorescence imaging, the clostridial host can be engineered to express oxygen-independent fluorescent proteins, which unlike the green fluorescent protein (GFP) do not require oxygen for chromophore maturation [120, 121]. For bioluminescence imaging, luminescence constructs such as the reshuffled luxABCDE operon optimized for expression in grampositive strains can be introduced in the clostridial host of interest [122]. Introduction of the entire operon would result in continuous luciferase-catalyzed light emission without the need of exogenous substrates, apart from molecular oxygen [123]. In the context of an anaerobic organism and the hypoxic environment of the tumor, the fulfillment of the oxygen requirement may pose a challenge. Nevertheless, it has been shown that the lux operon is functional even at very low oxygen tensions [6]. In support of this, bioluminescence imaging has been successfully applied in this fashion for the imaging of the tumor-colonizing anaerobic Bifidobacterium breve [122]. Also, high levels of Vibrio fischeri luciferase has been expressed in C. perfringens under strictly anaerobic conditions, thereby also providing confidence that the operon can be correctly expressed in a clostridial host [124, 125].
Genotoxicity of selected pharmaceuticals, their binary mixtures, and varying environmental conditions – study with human adenocarcinoma cancer HT29 cell line
Published in Drug and Chemical Toxicology, 2021
Monika Wieczerzak, Jacek Namieśnik, Błażej Kudłak
In earlier conducted by the authors test on Vibrio fischeri bacteria, the opposite values of the MDR parameter were observed, the addition of ions rather contributed to the increase of acute toxicity of the studied drugs, it may result from various cell structure, and other defense and repair mechanisms, however without additional testing it is only conjecture (Wieczerzak et al. 2018a). In the case of previously tested yeast Saccharomyces cerevisiae (also by the authors), ions had no significant effect on the endocrine potential tested in the XenoScreen YES/YAS test, the only compound susceptible to both anions and cations was fluoxetine h., ions present in its solution contributed to the increase of its agonistic properties against estrogen receptors (Wieczerzak et al. 2018a). Raw results obtained for genotoxicity of solutions of pharmaceuticals impacted with ions addition are presented (as % of DNA in the comet tail ± SD) in supplementary materials: Supplementary Table 1.
Bacterial biofilm-derived antigens: a new strategy for vaccine development against infectious diseases
Published in Expert Review of Vaccines, 2021
Abraham Loera-Muro, Alma Guerrero-Barrera, Yannick Tremblay D.N., Skander Hathroubi, Carlos Angulo
QS systems are involved in the formation, development, and dispersal of biofilms. A classic example of QS is found in the pathogen Vibrio fischeri. In this bacterium, QS regulates the expression of the luciferase operon, which is responsible for bioluminescence through two proteins, LuxI and LuxR [41]. Another example is the AHL-dependent QS-systems found in P. aeruginosa. This pathogen uses two different LuxR/I pairs, LasR/I and RhlR/I, to sense and respond to N-(3-oxododecanoyl) homoserine lactone (3-oxo-C12-HSL) and N-butanoyl homoserine lactone (C4-HSL), respectively. Both QS systems control the expression of factors associated with biofilm formation, swarming motility, and antibiotic efflux pumps [42].
Quorum sensing: a new prospect for the management of antimicrobial-resistant infectious diseases
Published in Expert Review of Anti-infective Therapy, 2021
Mainul Haque, Salequl Islam, Md Arif Sheikh, Sameer Dhingra, Peace Uwambaye, Francesco Maria Labricciosa, Katia Iskandar, Jaykaran Charan, Alaeddin Bashir Abukabda, Dilshad Jahan
Microorganisms frequently produce chemical signal molecules or hormones to communicate with each other. This signaling mechanism of the microbial community is often called quorum sensing (QS) [2]. QS is a bacterial cell-to-cell communication method that comprises the production, detection, and response to extracellular signaling molecules called autoinducers (AIs) to coordinate the expression of specific genes, virulence factors, and the organization of biofilms [3,4]. QS signaling is not restricted to bacterial cell-to-cell communication but also permits the interaction between microorganisms and their hosts [2]. Prokaryotes and eukaryotes have cohabited for millions of years [5]. Humans uphold and maintain a symbiotic correlation with their intestinal microbial flora acting in synchrony. This collaborative relationship is essential for nutrition, vitamin generation, and the effective functioning of the innate immune system [3,6]. These mutually beneficial relationships are possible because microbes and mammals are able to interconnect via several hormones and hormone-like substances [7]. These QS signaling strategies have often been adopted by pathogenic organisms to regulate the expression of the genes associated with their virulence factors [3,8]. The QS signaling system was initially termed ‘autoinduction’ [9]. Almost fifty years ago, multiple independent groups of scientists reported autoinduction and bioluminescence in the marine gram-negative (GN) bacterium Vibrio fischeri [10]. The autoinduction of the luminescence of Vibrio fischeri transpires at the transcriptional level, and the phenomenon is controlled through extracellularly secreted molecules [10]. Dr. Steven Winnas was one of the pioneers of the field and was the author of a review manuscript on microbial autoinduction; wherein he used for the first time the expression ‘quorum sensing’ in 1994 [11]. By that time, the cross-species induction of bioluminescence became an established concept. QS controls several mechanisms essential for the survival of the microbial community including bioluminescence, sporulation, competence, motility, antibiotic production, biofilm formation, gene expression,, synthesis of proteases and siderophores, fluorescence, antibiotic resistance, and virulence factor secretion [12,13].