Chitin Heterodisaccharide, Released from Chitin by Chitinase and Chitin Oligosaccharide Deacetylase, Enhances the Chitin-Metabolizing Ability of Vibrio parahaemolyticus

Abstract

Vibrio parahaemolyticus RIMD2210633 secretes both chitinase and chitin oligosaccharide deacetylase and produces β-N-acetyl-d-glucosaminyl-(1,4)-d-glucosamine (GlcNAc-GlcN) from chitin. Previously, we reported that GlcNAc-GlcN induces chitinase production by several strains of Vibrio harboring chitin oligosaccharide deacetylase genes (T. Hirano, K. Kadokura, T. Ikegami, Y. Shigeta, et al., Glycobiology 19:1046–1053, 2009). The metabolism of chitin by Vibrio was speculated on the basis of the findings of previous studies, and the role of chitin oligosaccharide produced from chitin has been well studied. However, the role of GlcNAc-GlcN in the Vibrio chitin degradation system, with the exception of the above-mentioned function as an inducer of chitinase production, remains unclear. N,N′-Diacetylchitobiose, a homodisaccharide produced from chitin, is known to induce the expression of genes encoding several proteins involved in chitin metabolism in Vibrio strains (K. L. Meibom, X. B. Li, A. Nielsen, C. Wu, et al., Proc Natl Acad Sci U S A 101:2524–2529, 2004). We therefore hypothesized that GlcNAc-GlcN also affects the expression of enzymes involved in chitin metabolism in the same manner. In this study, we examined the induction of protein expression by several sugars released from chitin using peptide mass fingerprinting and confirmed the expression of genes encoding enzymes involved in chitin metabolism using real-time quantitative PCR analysis. We then confirmed that GlcNAc-GlcN induces the expression of genes encoding many soluble enzymes involved in chitin degradation in Vibrio parahaemolyticus. Here, we demonstrate that GlcNAc-GlcN enhances the chitin-metabolizing ability of V. parahaemolyticus. IMPORTANCE We demonstrate that β-N-acetyl-d-glucosaminyl-(1,4)-d-glucosamine (GlcNAc-GlcN) enhances the chitin-metabolizing ability of V. parahaemolyticus. Members of the genus Vibrio are chitin-degrading bacteria, and some species of this genus are associated with diseases affecting fish and animals, including humans (F. L. Thompson, T. Iida, and J. Swings, Microbiol Mol Biol Rev 68:403–431, 2004; M. Y. Ina-Salwany, N. Al-Saari, A. Mohamad, F.-A. Mursidi, et al., J Aquat Anim Health 31:3–22, 2019). Studies on Vibrio are considered important, as they may facilitate the development of solutions related to health, food, and aquaculture problems attributed to this genus. This report enhances the current understanding of chitin degradation by Vibrio bacteria.

gbpAandchiAgenes are not uniformly distributed amongst diverseVibrio cholerae

“…Since VPA1177 has been shown to be transcribed [75] and to produce a translated protein in V. parahaemolyticus [35], we sought to determine whether the product of chiA-3 from V.…”

“…The pathways by which chitin is degraded and utilised by V. cholerae have been described in detail [30], as it has been in other members of the genus (e.g., [31][32][33][34][35][36][37][38]). Although a comprehensive review of the chitin utilisation pathway is beyond the scope of this manuscript, it is important to appreciate the complexity of this pathway.…”

“…Both ChiA-1 and ChiA-2 are essential for V. cholerae to grow in media supplemented with colloidal chitin [23]. Once chitin oligomers have been digested by extracellular chitinases, the resultant oligosaccharides are thought to enter the bacterial periplasm via the chitoporin ChiP (encoded by VC_0972 , accession # AAF94134.1) and by other as-yet-uncharacterised porins [23, 35, 48], and subsequently transported to the cytoplasm via PTS and ABC-type transporters [19, 35] (Figure 1).…”

“…Schematic summarising the principal stages in chitin degradation and import by V. cholerae . Comprehensive descriptions of this pathway are reported in [19, 35]. The MSHA adhesin has not been included in this diagram.…”

Effects of salinity and shaking condition on the growth and virulence of Vibrio parahaemolyticus

“…Chitinase, on the other hand, generally plays an important role in the degradation of the crustacean rich biopolymer chitin, converting it into nutrients for marine bacteria (Frederiksen et al, 2013). It is of course not present in all V. parahaemolyticus strains (Hirano et al, 2019). However, the absence of chitinase in AHPND V. parahaemolyticus XN9 indicated that chitinase might not be essential in shrimp pathogenesis or induced in vitro.…”