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Chitin

About: Chitin is a research topic. Over the lifetime, 6590 publications have been published within this topic receiving 253993 citations.


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TL;DR: The results suggest that chitin-binding peptides, especially the 53-kDa chitIn- binding peptide and chit inase and perhaps the 150-KDa peptide, mediate the specific attachment of V. harveyi to ch itin.
Abstract: We examined the mechanism of attachment of the marine bacterium Vibrio harveyi to chitin. Wheat germ agglutinin and chitinase bind to chitin and competitively inhibited the attachment of V. harveyi to chitin, but not to cellulose. Bovine serum albumin and cellulase do not bind to chitin and had no effect on bacterial attachment to chitin. These data suggest that this bacterium recognizes specific attachment sites on the chitin particle. The level of attachment of a chitinase-overproducing mutant of V. harveyi to chitin was about twice as much as that of the uninduced wild type. Detergent-extracted cell membranes inhibited attachment and contained a 53-kDa peptide that was overproduced by the chitinase-overproducing mutant. Three peptides (40, 53, and 150 kDa) were recovered from chitin which had been exposed to membrane extracts. Polyclonal antibodies raised against extracellular chitinase cross-reacted with the 53- and 150-kDa chitin-binding peptides and inhibited attachment, probably by sterically hindering interactions between the chitin-binding peptides and chitin. The 53- and 150-kDa chitin-binding peptides did not have chitinase activity. These results suggest that chitin-binding peptides, especially the 53-kDa chitin-binding peptide and chitinase and perhaps the 150-kDa peptide, mediate the specific attachment of V. harveyi to chitin.

75 citations

Journal ArticleDOI
TL;DR: The structural properties of chitin, and its derivatives are presented and their biomedical implications including, tissue engineering, drug delivery, diagnosis, molecular imaging, antimicrobial activity, and wound healing are highlighted.

75 citations

Journal ArticleDOI
TL;DR: From these results, chitin accelerates the migration of MN and PMN cells to the NWF site with rapid follow-up organization of theNWF accompanied by angiogenesis.
Abstract: Analyses on the effects of polymeric N-acetyl-D-glucosamine (chitin), which was obtained from squid pen, on histogenic activation in dogs were carried out with subcutaneous implants (5×5 cm2) of polyester non-woven fabric (NWF) supplemented with chitin (chitin group) and NWF (control group). These materials were implanted at 4 sites, on the lumbodorsal and lumbosacral subcutaneous tissues on both sides of the midline in each dog under general anesthesia. The implants and their surrounding tissues were isolated on post-implantation days (PIDs) 2, 4, 8, and 18 under general anesthesia. In the chitin group, the implant was organized gradually and its organization was completed on PID 18, when obvious angiogenesis toward the NWF was observed. On the other hand, in the control group, obvious angiogenesis toward the NWF was not observed macroscopically. Numbers of mononuclear (MN) and polymorphonuclear (PMN) cells concentrated around the implants on PID2 were larger in the chitin than control group. In the chitin group, formation of granulating tissue around the implant was indicated on PID 4, whereas such a phenomenon was not observed in the control group. From these results, chitin accelerates the migration of MN and PMN cells to the NWF site with rapid follow-up organization of the NWF accompanied by angiogenesis.

75 citations

Journal ArticleDOI
TL;DR: The enzymatic hydrolysis of native and pretreated chitin by the culture filtrate of Myrothecium verrucaria NCIM 903 indicated that the swelling of the ordered structure results in efficient hydrolyzing.
Abstract: The enzymatic hydrolysis of native and pretreated chitin by the culture filtrate of Myrothecium verrucaria NCIM 903 was studied. Also, factors which influence the enzymatic hydrolysis such as pH, temperature, enzyme and substrate concentration and enzyme adsorption characteristics (n-value) were studied. Chitin hydrolysate was also used as a substrate for Single Cell Protein (SCP) production using Saccharomyces cerevisiae NCIM 3052. With M. verrucaria chitinase complex, native and acid swollen chitin were hydrolyzed at pH 5.0 and 40°C, 12.7% and 39.6% respectively. The n values which is a measure of adsorption characteristics of an enzyme were 0.4 and 0.63 for native and acid swollen chitin, respectively. This indicates that the swelling of the ordered structure results in efficient hydrolysis. As the end-product of hydrolysis of chitin was mainly N-acetyl-D-glucosamine, its further utilization as a substrate for SCP production was investigated. A biomass of 9.5g/l with a growth yield of 0.27g/g of substrate utilized was obtained. The total protein and nucleic acid content of the biomass was 61% and 3.1%, respectively.

75 citations

Journal ArticleDOI
TL;DR: Calcium phosphate growth on chitin phosphorylated fibres was studied using scanning electron microscopy and energy dispersive X-ray analysis, micro-Fourier transform infrared spectroscopy, and solid state magic angle spinning nuclear magnetic resonance (MAS NMR) techniques to suggest ammonium hydrogen phosphate formed during the phosphorylation procedure.
Abstract: Calcium phosphate growth on chitin phosphorylated fibres was studied using scanning electron microscopy and energy dispersive X-ray analysis (SEM, EDX), micro-Fourier transform infrared spectroscopy (FTIR), and solid state magic angle spinning nuclear magnetic resonance (MAS NMR) techniques. The C6 chemical shift positions of 13C MAS NMR in the chitin fibres phosphorylated using urea and H3PO4 are obvious indicating that phosphorylation takes place not in the C1 but in the C6 region. Micro-FTIR and 31P MAS NMR suggested that ammonium hydrogen phosphate formed during the phosphorylation procedure. Chitin fibres phosphorylated using urea and H3PO4 and then soaked in saturated Ca(OH)2 solution at ambient temperature, which lead to the formation of thin coatings formed by partial hydrolysis of the PO4 functionalities, were found to stimulate the growth of a calcium phosphate coating on their surfaces after soaking in 1.5×SBF solution for as little as one day. The thin layer after Ca(OH)2 treatment functioned as a nucleation layer for further calcium phosphate deposition after soaking in 1.5×SBF solution. EDX-measured Ca : P ratios of the coatings of Ca(OH)2-treated phosphorylated chitin in 1.5×SBF solution suggested that calcium-deficient apatite was formed.

75 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023434
2022868
2021271
2020354
2019333
2018271