مقاله انگلیسی رایگان در مورد فساد غذایی در شبه موناس فلورسنس سپرماهی – اسپرینگر 2018

Food is an impressionable commodity bound to decompose timely (Gram et al. 2002). Usually, apart from the concerned factors (e.g., physicochemical alterations, variety of food, environment, etc.), microbial growth is critical for food spoilage. At the onset of spoilage, the product contains some bacteria that are involved in spoilage, the socalled specific spoilage organism, which produce a variety of extracellular enzymes (proteases, lipases, etc.) and other metabolites role in the food matrix. The SSOs are not only involved in the food spoilage, but also are the organisms responsible for the food spoilage to occur (Loureiro 2000; Ragaert et al. 2007). Pseudomonas is a sort of Gram negative bacterium, a psychrotroph bacterium which causes the spoilage of high-protein food, and it plays a key role in aquatic products spoilage (Lund et al. 2000). Various Gram negative bacteria have been reported to result in the decay of foodstuffs, and N-acylhomoserine lactones (AHLs) have been found in decomposed food (Bruhn et al. 2004; Pinto et al. 2007). Quorum sensing (QS), intercellular communication system in bacteria, was used as a tool to monitor microbial population density and to control their physiological process (Ferkinghoff-Borg and Sams 2014). The supervision of specific behaviors depends on the production of the signaling molecule (Autoinducer, AI). In the present research, some kinds of AI have been reported. Gram negative bacteria usually utilize AHLs as AI-1 whereas the oligopeptide is the most common AI-2 in Gram positive bacteria (Chen et al. 2012; Kalia 2013; Papenfort and Bassler 2016), and the AI-3/epinephrine/norepinephrine and diketopiperazines (DKPs) signaling system. Various biological habits and physiological processes are controlled by QS system, including biofilm formation, bioluminescence, production of antibiotics and expression of virulence factors (Kim et al. 2008; Reading and Sperandio 2006; Wang et al. 2013). The autoinducers-1(AHLs) system was the first time to be discovered in the bioluminescence in Vibrio fischeri (Nealson et al. 1970). AHL signal molecule has a conserved homoserine lactone ring whereas the acyl side chain length varies from four to eighteen carbons and the substituent pattern (carbonyl group, hydroxyl or fully reduced) at the third position in the acyl side chain. AHL system is regulated by two proteins, LuxI, which is an AHL synthase, LuxR, which is the AHL receptor protein (Li Ying Tan and Chan 2012). AHL is a small molecular mass which can penetrate the cytomembrane and accumulate in the environment. When the density of signal molecules reaches a critical threshold, it combines with the LuxR-Type proteins and regulates the transcription genes in a variety of phenotypes (Reading and Sperandio 2006). These actions include anti-resistance, virulence factors in Pseudomonas aeruginosa, and swarming migration in Rhizobium, Bacillus subtilis and Serratia liquefaciens (Daniels et al. 2004; Schuster and Greenberg 2006; Høiby et al. 2010).