Chitin: New Facets of Research

Austin, PR; Brine, C.J.; Castle, J. E.; Zikakis, John P.

doi:10.1126/science.7221561

Cited by 320 publications

(146 citation statements)

References 14 publications

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“…In Norwegian aquaculture, astaxanthine has been utilized for a long time to give colour to the flesh of salmonids. Additionally, there may be surprising indirect effects when some chitin is included in the food, an example of which is reported by Austin et al (1981): They found in feeding experiments that chitin at 2 % in the food enhances the development of bifido-bacteria in the intestines of chickens, which in tum synthesize the enzyme lactase. Thus, the lactose in the food mixture becomes digestible and the growth of the chickens is encouraged.…”

Section: Discussionmentioning

confidence: 99%

Digestibility of chitin in cod,Gadus morhua, in vivo

Danulat¹

1987

Helgolander Meeresunters

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Sixteen cod, Gadus morhua (L.), were individually fed a single ration of shrimps, Crangon allmanni. Four fish were killed and examined 6, 12, 24 and 48 h after the fish had been fed.Chitinase activities were measured in the extracts of stomach contents, stomach tissue, pyloric caecae, intestinal contents and intestinal tissue. The level of enzyme activity in different parts of the digestive tract was shown to be dependent on the phase of the digestive process. High concentrations of the chitin degradation product N-acetyl-D-glucosamine were determined in the stomach and in the intestinal contents. Based on the chitin concentration in the food organisms and the individual food uptake, the amount of chitin consumed by each fish could be calculated. Only up to 9 % of the ingested chitin was recovered from the intestinal contents of the fish at any given time after feeding (6, 12, 24 and 48 h). In addition, only 2.4 % of the chitin consumed with the food could be recovered in the collected faeces of the fish. The 4 cod killed 48 h after feeding had completely emptied their stomach. Chitin digestion in these fish was calculated to have been 90 %.

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Section: Discussionmentioning

confidence: 99%

Digestibility of chitin in cod,Gadus morhua, in vivo

Danulat¹

1987

Helgolander Meeresunters

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“…Chitin, a fi-1,4-linked polymer of N-acetylglucosamine, is a major component of the cell wall of many fungi (Austin et al, 1981;Peberdy, 1990). The enzymic degradation of chitin by micro-organisms occurs in two consecutive steps : first the hydrolysis by chitinase [ poly( 1,4-(N-acetyl-fi-~-glucosaminide)) glycanohydrolase; EC 3.2.1.141 to oligomers, mainly dimers, followed by their degradation to free N-acetylglucosamine by chitobiase (N-acetyl-fi-glucosaminidase; EC 3.2.1.30).…”

Section: Introductionmentioning

confidence: 99%

Regulation of chitinase synthesis in Trichoderma harzianum

Ulhôa

Peberdy

1991

Journal of General Microbiology

102

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The production of chitinase by Trichoderma species is of interest in relation to their use in biocontrol and as a source of mycolytic enzymes. Fourteen isolates of the genus were screened to identify the most effective producer of chitinase. The best strain for chitinase was Trichoderma hurziunum 39.1, and this was selected for study of the regulation of enzyme synthesis. Washed mycelium of T. hurziunum 39.1 was incubated with a range of carbon sources. Chitinase synthesis was induced on chitin-containing medium, but repressed by glucose and Nacetylglucosamine. Production of the enzyme was optimal at a chitin concentration of 0.5 %, at 28 "C, pH 6.0 and was independent of the age of the mycelium. The synthesis of chitinase was blocked by both 8-hydroxyquinoline and cycloheximide, inhibitors of RNA and protein synthesis, respectively. The mode of chitinase synthesis in this fungus is discussed.

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“…Despite their biological interest and potential agronomical usefulness, CHOS with well-defined structures remain poorly accessible. CHOS with 2 to 6 degrees of polymerization (DP) were obtained from chitin by chemical or enzymatic depolymerization or metabolic engineering (2,17,30). Most biological activities require CHOS DP of Ն4 (12), but the synthesis of oligomers with Ն6 DP has been a daunting task.…”

mentioning

confidence: 99%

Synthesis of Long-Chain Chitooligosaccharides by a Hypertransglycosylating Processive Endochitinase of Serratia proteamaculans 568

Purushotham

Podile

2012

J Bacteriol

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We describe the heterologous expression and characterization of a 407-residue single-domain glycosyl hydrolase family 18 chitinase (SpChiD) from Gram-negative Serratia proteamaculans 568 that has unprecedented catalytic properties. SpChiD was optimally active at pH 6.0 and 40°C, where it showed a K m of 83 mg ml ؊1 , a k cat of 3.9 ؋ 10 2 h ؊1 , and a k cat /K m of 4.7 h mg ؊1 ml ؊1 on colloidal chitin. On chitobiose, the K m , k cat , and k cat /K m were 203 M, 1.3 ؋ 10 2 h ؊1 , and 0.62 h ؊1 M ؊1 , respectively. Hydrolytic activity on chitooligosaccharides (CHOS) and colloidal chitin indicated that SpChiD was an endo-acting processive enzyme, with the unique ability to convert released chitobiose to N-acetylglucosamine, the major end product. SpChiD showed hyper transglycosylation (TG) with trimer-hexamer CHOS substrates, generating considerable amounts of long-chain CHOS. The TG activity of SpChiD was dependent on both the length and concentration of the oligomeric substrate and also on the enzyme concentration. The length and amount of accumulated TG products increased with increases in the length of the substrate and its concentration and decreased with increases in the enzyme concentration. The SpChiD bound to insoluble and soluble chitin substrates despite the absence of accessory domains. Sequence alignments and structural modeling indicated that SpChiD would have a deep substrate-binding groove lined with aromatic residues, which is characteristic of processive enzymes. SpChiD shows a combination of properties that seems rare among family 18 chitinases and that may resemble the properties of human chitotriosidase.

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Chitin: New Facets of Research

Cited by 320 publications

References 14 publications

Digestibility of chitin in cod,Gadus morhua, in vivo

Digestibility of chitin in cod,Gadus morhua, in vivo

Regulation of chitinase synthesis in Trichoderma harzianum

Synthesis of Long-Chain Chitooligosaccharides by a Hypertransglycosylating Processive Endochitinase of Serratia proteamaculans 568

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