enzymatic modifications of chitin and chitosan

... respectively, the chitin and protein contents of head and shell are largely different The chitin content of shell and head of white shrimp were 27.37 and 11.40%, respectively The chitin content ... fishmeal and chitin were produced This way of treatment caused the recovery of useful compounds to be lost the efficiency and to pollute environment concurrently The industry of chitin and chitosan ... Germay) and has the frequency of 37kHz and RMS of 35W CHAPTER III: RESULTS AND DISCUSSION 3.1 Characteristics of the white leg shrimp by - product The mass average ratio of head and shell of shrimp...

Ngày tải lên: 15/08/2015, 22:14

... synthetic, chitin and chitosan are of interest in that they offer most of the above characteristics Chitin and chitosan are natural polyaminosaccharides [14–28], chitin being one of the world’s ... immobilization supports chitin- and chitosanbased materials are used in the form of powders, flakes and gels of different geometrical configurations Chitin/ chitosan powders and flakes are available ... Determination of glucose Chitin powder ␤ -Chitin membrane (coagulation) Chitin film (coagulation) Chitosan beads Chitosan membrane (a) Chitosan membrane (a, c, d) Sol–gel /chitosan membrane (c) Chitosan- organosilane...

Ngày tải lên: 24/08/2016, 16:38

... differences in the IR spectra of chitin can be used to distinguish between a -chitin and b -chitin (i) Due to the different arrangement between a -chitin and b -chitin, amide I band in a -chitin spectrum splits ... organization and dense structure was observed clearly for a -chitin, whereas the surface of b -chitin appears less crystalline and different from a -chitin 3.3 Deacetylation of chitin 3.3.1 Preparation of chitosan ... electron microscopy (SEM) The surface morphology of chitin and chitosan was observed using SEM The dried sample of chitin and chitosan was ground and then coated with gold under vacuum using a...

Ngày tải lên: 25/08/2016, 11:21

... configurations of Chitin (A)
-chitin, (B) ß -chitin and (C)  -Chitin known These are the heterogeneous deacetylation of solid chitin and the homogeneous deacetylation of pre-swollen chitin under ... levels of transfection Lavertu et al studied several combinations of Mw and DA of chitosan finding two combinations of high transfection efficiency using a chitosan of 10 kDa and DD of 92 and 80%, ... easily to chitosan The adsorption of cells on chitin and chitosan has also been studied Strand et al studied the effect of the chemical composition and Mw of chitosan on the adsorption and flocculation...

Ngày tải lên: 25/08/2016, 11:35

... sprouts On the other hand, the initiation of and its acceleration seem to be linked to enzyme changes (GDH and growth Protein content decreased because of the synthesis of non-protein substances ... Correlatively, activities of G6PDH (pentose phosphate pathway) and GDH (cellular detoxification of NH+) increased and ensured, respectively, the production of NADPH and NADH which are needed ... discriminant analysis (Jay-Allemand et al., 1988) The evolution of these compounds during elongation of adult and rejuvenation shoots is described in Fig A high level of compound A (undetermined...

Ngày tải lên: 09/08/2014, 02:21

... 337 Chitin and Chitosan – Chitin and Chitosan in Life Science, edited by T Uragami, K Kurita and T Fukamizo (Kodansha Scientific Ltd, Tokoyo, Japan) 2001 Lim S & Hudson S M, Review of chitosan and ... mammalian and microbial cells aggresively, Derivatives of Chitin and Chitosan Chitosan may be readily derivatized by utilizing the reactivity of the primary amino group and the primary and secondary ... hair sprays, and hair tonics Several derivatives of chitosan and chitin have potential applications in hair care They include glyceryl chitosan, an adduct of an oligomer of hydrolyzed chitosan, ...

Ngày tải lên: 24/08/2016, 16:29

... Abstract The use of infrared spectroscopy for characterization of the composition of chitin and chitosan covering the entire range of degree of acetylation (DA) and a wide variety of raw materials ... fraction of N-acetylglucosamine) 3.2 Chitin and chitosan analysis In Figs and are given the IR spectra of the two polymers (samples 24 and 1, respectively) with the aim to show the role of the ... independent of the technique and state of the material This evidence supports the use of A1320/A1420 ratio, as being only sensitive to the chemical composition of chitin (or chitosan) irrespectively of...

Ngày tải lên: 24/08/2016, 16:48

... modelling: (a) of a chitin chain with two H bonds (1) betweenOH and O 5, (2) betweenOH and O of CQO; and (b) of a chitosan chain with two H bonds (1) betweenOH and O 5, and (2) betweenOH and N modeling ... obtains chitosan, which is the most important chitin derivative in terms of applications This review aims to present state -of- the-art knowledge of the morphology of chitin and chitosan and to ... temperature, and the presence of excess free CD or AD [229] 3.5 Applications of chitosan and chitosan derivatives Table 10 summarizes the main properties of chitosan and potential biomedical and other...

Ngày tải lên: 25/08/2016, 11:09

... content of esterified and etherified p-coumaric acids is 3.78 and 1.72% respectively, and the content of esterified and etherified ferulic acid is 1.02 and 2.2%, respectively [23] Dimerization of ... removal of 70% of hemicelluloses and 65% lignin and a subsequent 90% enzymatic hydrolysis yield [85] Aqueous methanol percolation (1:1 v/v, 1min, 10 ml/min) of wheat straw and a subsequent enzymatic ... hydrolysis of cellulose by respective enzymes (modified from [96]) Enzymatic saccharification of cellulose takes place at optimum temperature of 45-50ºC and pH of 5.0 Cellulase loading range of 10-15...

Ngày tải lên: 05/09/2013, 15:28

... broad selection of insoluble carbohydrates (e.g ChbB, which binds both a- and b -chitin [21], and Chb3 from St coelicolor, which binds a -chitin, b -chitin, colloidal chitin and chitosan [22]), ... b -chitin The degradation rates of a- and b -chitin were assayed with LlChi18A in the presence or absence of LlCBP33A As both chitin variants, and especially a -chitin, are highly resistant to enzymatic ... all cases Degradation of a- and b -chitin Determination of the enzyme activity towards insoluble chitin was performed using b -chitin from a squid pen (France Chitin) and a -chitin isolated from...

Ngày tải lên: 18/02/2014, 08:20

... (Asn) and serine (Ser) [4,12] In the active center of silicatein, the hydroxyl group of Ser26 and the imidazole of His165 (catalytic diad) have been shown to play key roles in the condensation of ... displacement of p-aminophenol and formation of a (alkoxyl)-monosilane This reaction is facilitated by hydrogen bonding between the imidazole nitrogen of the conserved histidine (His) and the hydroxyl of ... range between 20 and 250 lm of BAPD silane After cleavage of one of the silica ester bonds, the concentration of the released product p-aminophenol was determined at a wavelength of 300 nm, which...

Ngày tải lên: 18/02/2014, 16:20

... capacity of fish xenobiotic metabolism [28] and raises the possibility of arachidonic acid based signalling Zebrafish express both cyclooxygenase (cox)-1 and -2 and the primary prostaglandin end ... DNA and RNA were performed as described previously [57] Isolation and cloning of the SynMGST and E.coliMGST The coding sequence for the SynMGST, corresponding to the complementary strand of the ... Characterization of MAPEG members BamHI and EcoRI and then the reformatted BamHI-EcoRI fragment was subcloned into BamHI and EcoRI sites of the pYeDP60 vector The nucleotide sequence of the cDNA was...

Ngày tải lên: 19/02/2014, 17:20

... the isolation of chitinase A from a marine bacterium, V carchariae [24] Chitinase A is highly expressed upon induction with chitin and is active as a monomer of Mr 62 700 Analysis of chitin hydrolysis ... viscosity assay and HPLC-ESI MS suggested that the newly isolated chitinase acts as an endochitinase [25] We also reported isolation of the gene encoding chitinase A and functional expression of the recombinant ... the present study, the hydro- Enzymatic properties of chitinase A from Vibrio carchariae lytic activity of chitinase A resulting in the production of a broad range of chitooligosaccharide products...

Ngày tải lên: 20/02/2014, 01:20

... other hand, ChiG showed activity against a -chitin and b -chitin (supplementary Fig S2), chitooligosaccharides (Figs and 3), carboxymethyl -chitin remazol–brilliant violet (CM -chitin RBV) and also ... hydrolysis of chitin led to significant production of trimers during degradation of both a -chitin and b -chitin (exoenzymes tend to almost exclusively produce dimers) Studies on the degradation of colloidal ... in the autoinjector) Analyses of the degradation of a -chitin and b -chitin were conducted by incubating 100 lL solutions containing mgÆmL)1 of b -chitin (squid pen b -chitin, lm in size; Seikagaku,...

Ngày tải lên: 07/03/2014, 11:20

... treatment of phenomena of will and also the details of his account of experiences of value See e.g Findlay, 1963, ch.9 and 10 14 Note the ambiguity in our use of the term `object' here On the one hand ... assumption, and so on The content, on the other hand, is that component of an experience which a perception and a memory of the same object may have in common and in virtue of which they are then of the ... Compare the use of the notions of standard and non-standard instances of kinds in the aesthetic theory of N Wolterstorff (1980) 11 This is also Ingarden's view in his Literary Work of Art (1931)...

Ngày tải lên: 07/03/2014, 12:20

... 10 lL of a solution of 0.2 M NaCl containing 100 lL of carrier tRNA and 40 lL of ethanol was added to the sample and kept at °C for 60 The mixture was centrifuged (15 000 g for 20 min) and the ... biosynthesis, and still in the range of the IC50 (0.03–4 nM) of type I RIPs The IC90 (the concentration of RIP causing 90% inhibition of translation) of lamjapin in the cell-free system of rabbit ... release more than one mole of adenine from each mole of ribosomes in 10 and even up to 12 mol of adenines in 40 (Fig 4B) Base and position specificity of lamjapin in depurination of SRD RNA Synthetic...

Ngày tải lên: 08/03/2014, 10:20

... inhibitory activity of this group of peptides is attributable to their effect on the turnover number of IN, and suggest a different mode of action from that of the rst group The third group of peptides, ... Comparison of the conformation of active and nonactive backbone cyclic analogs of substance P as a tool to elucidate features of the bioactive conformation: NMR and molecular dynamics in DMSO and water ... protein on the basis of the RevIN interaction [55,5863] and following the use of a Rev-derived peptide library [58] With the use of a yeast two-hybrid (Y2H) system and a random peptide library,...

Ngày tải lên: 22/03/2014, 16:21

... reference state of the network at an ATP consumption rate of 20.8 lmặs)1 and a GTP consumption rate of 0.19 lmặs)1 On the basis of the stoichiometric matrix of the network and the ux rates and metabolite ... the metabolism of this cell is controlled by the demand for energy and redox equivalents, and not by the offer of substrates Even larger variations in the concentrations of glucose and lactate give ... hybrid models composed of mechanistic and simplied rate laws for the construction of the Jacobian matrix used for the analysis of stability Enzymatic rate laws and other details of the full kinetic...

Ngày tải lên: 23/03/2014, 06:20

... EC0 and ECU represent the amount of acyl-enzyme complex formed in the absence and presence of the unlabeled antibiotic, respectively, and CU and CL are the concentrations of the unlabeled and ... range of 4.27.5 and the male urethra having a pH of 6.28.4 The pH dependence of NG PBP (pKa values of 6.9 and 10.1) therefore overlaps the alkaline side of the physiological growth range of N ... inhibitors, and pH dependence Comparison of the enzymatic properties of NG PBP with other DD-carboxypeptidases highlights both similarities and differences within these enzymes, and suggests...

Ngày tải lên: 23/03/2014, 12:20

... the one hand, and of the positive charge of the RS domain with the negatively charged ‘docking groove’ of SRPK1, on the other hand The RE-rich region of SAFB1 may interfere with any of these ... significance of enzyme–substrate contacts for catalysis This study highlights the importance of the interaction of a phosphoserine of the RS domain of the substrate with the catalytic region of the ... lanes and 1) These results confirm the direct interaction of SAFBs with the SRPK1 ⁄ 1a proteins and provide a direct link between the affinity of the SAFB–SRPK1 ⁄ 1a interaction and the extent of...

Ngày tải lên: 30/03/2014, 01:20