The impact of perceived price justice and satisfaction on loyalty: the mediating effect of revisit intention

Purpose: The purpose of this study was to examine the relationships between perceived price justice, satisfaction, revisit intention and loyalty among restaurant customers, specially the mediating effect of revisit intention in the relationship between perceived price justice, satisfaction and loyalty. Design/methodology/approach: Data were collected from a questionnaire distributed to customer of restaurants in Turkey. A total of 304 restaurant customers participated. Findings: Results from structural equation modeling show that price justice and satisfaction positively influence their revisit intention of restaurant customers, also revisit intention positively influences loyalty of restaurant customers. Also, the empirical results indicate that while revisit intention fully mediates the effect of price justice and loyalty, it partially mediates the effect of satisfaction and loyalty. Originality/value: When the studies in the literature are examined, it is seen that there are various studies that deal with perceived price justice, customer satisfaction, revisit intention and loyalty variables from a different viewpoint. However, no study has been found on restaurants that investigate the relationship between these four variables and the mediating role of revisit intention. Furthermore, the authors’ study contributes to the hospitality and service management literature in two ways. First, the authors follow recent calls for studies on antecedents of revisit intention, with the aim of providing empirical support to uncover factor that shape customers’ revisit intentions. Second, the authors investigate the attitudinal mechanism that explains how customers’ perception of price justice and satisfaction in their loyalty by exploring the mediation effect of revisit intention. On the other hand, it is foreseen that the study will shed light on restaurant managers and provide healthy data for strategic planning. Additionally, that the results obtained are the practical purpose of the study is to contribute to the determination of product development and promotional strategies for restaurant managements. © 2019, Emerald Publishing Limited

Decolorization of the textile dyes reactive blue 220, acid red 414 and basic yellow 28 by ozone and biodegradation of oxidation products

In this study, decolorization of Reactive Blue 220, Acid Red 414 and Basic Yellow 28, decolorization kinetics, and biodegradability of intermediates after ozonolysis were studied. Effect of pH on ozonolysis was studied, and pH 3 was the best among pH values of 3, 7 and 11. The decolorization kinetics of these dyes can be described by a first-order reaction model, and the first-order rate constants ofRB 220, AR 414 and BY28 were 0.175-0.1303, 0.164-0.096 and 0.2092-0.1154 min-1, respectively. Total organic removal was determined to be 24.74, 17.15 and 23.37% for RB220, AR 414 and BY 28, respectively, after 30-min ozonation of 800 mg L-1 dye. The respirometric biologic oxygen demand of Pseudomonas putida (30-min ozone treatment of 800 mg L-1 of dye) was 490, 460 and 451 for RB220, AR 414 and BY 28, respectively. Our results showed that ozonation is an effective way to remove the color from aqueous solutions of these dyes, and that the by-products are non-toxic to P. putida. © by PSP

Cloning, purification, crystallization and preliminary crystallographic studies of NodS N-methyltransferase from Bradyrhizobium japonicum WM9

The Nod factor (NF) is a rhizobial signal molecule that is involved in recognition of a legume host and the formation of root and stem nodules. Some unique enzymes are involved in the biosynthesis of NF, which is a variously but specifically substituted lipochitooligosaccharide. One of these enzymes is NodS, an N-methyltransferase that methylates end-deacetylated chitooligosaccharide substrates. In the methylation reaction, NodS uses S-adenosyl-L-methionine (SAM) as a methyl donor. To date, no structural information is available about NodS from any rhizobium. X-ray crystallographic studies of the NodS protein from Bradyrhizobium japonicum WM9, which infects the legumes lupin and serradella, have been undertaken. The nodS gene was cloned and the recombinant protein was expressed in Escherichia coli cells using natural amino acids and as an SeMet derivative. NodS without ligands was crystallized in the presence of PEG 3350 and MgCl(2). The protein was also crystallized in complex with S-adenosyl-L-homocysteine (SAH) in the presence of PEG 8000 and MgCl(2). SAH is produced from SAM as a byproduct of the methylation reaction. The crystals of apo NodS are tetragonal and diffracted X-rays to 2.42 A resolution. The NodS-SAH complex crystallizes in an orthorhombic space group and the crystals diffracted X-rays to 1.85 A resolution

Crystal structures of NodS N-methyltransferase from Bradyrhizobium japonicum in ligand-free form and as SAH complex.

NodS is an S-adenosyl-L-methionine (SAM)-dependent N-methyltransferase that is involved in the biosynthesis of Nod factor (NF) in rhizobia, which are bacterial symbionts of legume plants. NF is a modified chitooligosaccharide (COS) signal molecule that is recognized by the legume host, where it initiates symbiotic processes leading to atmospheric nitrogen fixation. We report the crystal structure of recombinant NodS protein from Bradyrhizobium japonicum, which infects lupine and serradella legumes. Two crystal forms--ligand-free NodS and NodS in complex with S-adenosyl-L-homocysteine, which is a by-product of the methylation reaction--were obtained, and their structures were refined to resolutions of 2.43 Å and 1.85 Å, respectively. Although the overall fold (consisting of a seven-stranded β-sheet flanked by layers of helices) is similar to those of other SAM-dependent methyltransferases, NodS has specific features reflecting the unique character of its oligosaccharide substrate. In particular, the N-terminal helix and its connecting loop get ordered upon SAM binding, thereby closing the methyl donor cavity and shaping a long surface canyon that is clearly the binding site for the acceptor molecule. Comparison of the two structural forms of NodS suggests that there are also other conformational changes taking place upon the binding of the donor substrate. As an enzyme that methylates a COS substrate, NodS is the first example among all SAM-dependent methyltransferases to have its three-dimensional structure elucidated. Gaining insight about how NodS binds its donor and acceptor substrates helps to better understand the mechanism of NodS activity and the basis of its functional difference in various rhizobia