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  • Chitin
  • Horizontal gene transfer
  • Tehran, Iran  (5)
  • Springer Nature  (1)
  • American Institute of Physics
  • 2015-2019  (6)
  • 1960-1964
  • 1945-1949
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  • 1
    Publication Date: 2022-05-25
    Description: © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gruen, D. S., Wolfe, J. M., & Fournier, G. P.. Paleozoic diversification of terrestrial chitin-degrading bacterial lineages. BMC Evolutionary Biology, 19, (2019): 34, doi:10.1186/s12862-019-1357-8.
    Description: Background Establishing the divergence times of groups of organisms is a major goal of evolutionary biology. This is especially challenging for microbial lineages due to the near-absence of preserved physical evidence (diagnostic body fossils or geochemical biomarkers). Horizontal gene transfer (HGT) can serve as a temporal scaffold between microbial groups and other fossil-calibrated clades, potentially improving these estimates. Specifically, HGT to or from organisms with fossil-calibrated age estimates can propagate these constraints to additional groups that lack fossils. While HGT is common between lineages, only a small subset of HGT events are potentially informative for dating microbial groups. Results Constrained by published fossil-calibrated studies of fungal evolution, molecular clock analyses show that multiple clades of Bacteria likely acquired chitinase homologs via HGT during the very late Neoproterozoic into the early Paleozoic. These results also show that, following these HGT events, recipient terrestrial bacterial clades likely diversified ~ 300–500 million years ago, consistent with established timescales of arthropod and plant terrestrialization. Conclusions We conclude that these age estimates are broadly consistent with the dispersal of chitinase genes throughout the microbial world in direct response to the evolution and ecological expansion of detrital-chitin producing groups. The convergence of multiple lines of evidence demonstrates the utility of HGT-based dating methods in microbial evolution. The pattern of inheritance of chitinase genes in multiple terrestrial bacterial lineages via HGT processes suggests that these genes, and possibly other genes encoding substrate-specific enzymes, can serve as a “standard candle” for dating microbial lineages across the Tree of Life.
    Description: This work was supported by a National Science Foundation (NSF) Graduate Research Fellowship Program Award to DSG., and Simons Collaboration on the Origins of Life Award #339603 and NSF Integrated Earth Systems Program Award #1615426 to GPF. The funding agencies for this study had no role in study design, data collection, data analysis and interpretation, or in writing the manuscript.
    Keywords: Horizontal gene transfer ; Chitinase ; Chitin ; Bacteria ; Fungi ; Arthropods
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 2
    Publication Date: 2021-05-19
    Description: Chitin nanofibers are prepared from the exoskeletons of shrimp by a simple mechanical treatment after a series of purification steps. The nanofibers have fine nanofibers networks with a uniform width of approximately 10 nm. Grinders and highpressure water jet systems are effective for disintegrating chitin into nanofibers. Acidic conditions are the key factor to facilitate mechanical fibrillation. Ultrafine fibers were successfully fabricated chitosan and fish skinextracted gelatin via electrospinning (ES). Important ES parameters, such as concentration of aqueous acid and fish gelatin solutions, and electric field intensity were examined to investigate the effects on the morphology of the gelatin nanofibers. Due to the poor mechanical properties of the fish gelatin membranes, composite nanofibers made of fish gelatin and poly(L-lactide)(PLLA) were produced with a novel solution. The introduction of PLLA remarkably improved the mechanical properties of the gelatin membranes. With a combination of good biocompatibility and mechanical properties, fish gelatin/PLGA blending non-woven mats are considered to be very promising in fish fillet coating application.. in this study, we fabricated a novel nanofibers composed of fish collagen (FC) and polycaprolactone (PCL) blends by using the electrospinning method. Nanofibers were characterized using a scanning electron microscope (SEM), and it was revealed that the diameter of nanofibers decreases as FC content was increased in the FC/PCL composite nanofibers. Several modifications to the chitin NF surface are achieved, including acetylation, deacetylation and maleylation. The results of this study revealed that: 1 –It is possible to produce Nanofibers from chitosan and fish gelatin. 2 – Covering and coating of processed fish by nanofibers are applicable and increasing the possibility of shell life for the processed fish. 3 – Nanofibers which have been produced from chitosan and fish gelation not only is environmentally friendly but also it will be eatable while has been covered for fish fillets. biocompatible chitosan and gelatin made from fish, fresh fish fillets do not have the ability to cover and packaging, but is edible and used.
    Description: Iranian Fisheries Science Research Institute
    Description: Published
    Keywords: Chitin ; Chitosan ; Nanofiber ; Chemical modification ; Fish ; Aquatic ; Maintenance
    Repository Name: AquaDocs
    Type: Report , Refereed
    Format: 66pp.
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  • 3
    Publication Date: 2021-05-19
    Description: Cyst shell of Artemia urmiana was collected from the Urmia Lake......
    Description: Iranian Fisheries Science Research Institute
    Description: Published
    Keywords: Artemia urmiana ; Lake ; Chitin ; Chitosan
    Repository Name: AquaDocs
    Type: Report , Not Known
    Format: 115pp.
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  • 4
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    Iranian Fisheries Science Research Institute | Tehran, Iran
    Publication Date: 2021-05-19
    Description: Sea is one the great resources of food stuffs, chemicals and industrial materials, shrimp, crab, lobster because of good taste and lots of protein and minerals are very worthy.....
    Description: Iranian Fisheries Science Research Institute
    Description: Published
    Keywords: Chitin ; Shrimp ; Crabs ; Lobster ; Chemical
    Repository Name: AquaDocs
    Type: Report , Not Known
    Format: 83pp.
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  • 5
    Publication Date: 2021-05-19
    Description: Chitin and chitosan are 2 very important products of biopolymer that enjoy high consumption in industry, but their production sources are very limited. In this study, Artemia urmiana cyst shells were obtained from previously collected and stored ones in Iranian Artemia Research Center. 20 kg of Artemia urmiana cyst shells were sampled, cleaned, separated, dried and transferred to Iranian Artemia Research Center Laboratory to extract their Chitin and chitosan. Their chitin and chitosan initially were extracted using optimized common chemical methods. Their properties were compared to 2 other types of Chitin and chitosan obtained from crab and shrimp manufactured by Vietnam and China, respectively. To determine their quality, elemental analysis device , infrared spectrophotometry, x –ray radiography , determination of viscosity , molecular weight, crystallinity percent , color, de stylization measure , empirical and molecular formulas were made . The results showed that the percentage of chitin obtained from Artemia cyst Shells in Chemical method was 28 ± 3 % by weight and efficiency into chitosan (grade steel relief) in this method was 50 ± 5 %. To optimize the extraction procedure and the removal of proteins of chitin by biological practices that were done by sodium hydroxide in the chemical method, it was replaced by the bacterium Bacillus subtilis. And in the bio- phase of chitosan de steelation fungus Aspergillus niger enzyme was replaced instead of sodium hydroxide at high temperatures. The results showed that chitin and chitosan can be extracted from Artemia cyst shell using biological method and their characteristics included as in chitin49.6% C , 8.2 % N , 7.5 % H, and 34.5 % O . Also the same levels for chitosan were 44.4 %, 8.9, 7.2 and 39.5 %, respectively. Their other quality characteristics were included chitin average molecular weight 4.9 × 10 6 Dalton , crystallinity percentage of 36.4 , viscosity at 20 ° C 31 centipoise and its color was gray to brown . In the biologic method, the average molecular weight of chitosan, crystallinity percentage, viscosity at 20 ° C, were 5.1 × 105 Dalton, 94.5, and 18 centipoises, respectively. Also, its color was pale brown. Chemical structure of extracted chitin and chitosan from the shell of Artemia urmiana cysts were C_7H_12NO_4 and C_6H_11 NO_4c , respectively . The comparison of chitin and chitosan obtained from each chemical and biological method revealed that replacing biological methods instead of chemical methods is possible in achieving these products at suitable condition and better quality . This can eliminate the use of chemicals damaging the environment such as sodium hydroxide and decrease environmental pollution.
    Description: Iranian Fisheries Science Research Institute
    Description: Published
    Keywords: Artemia urmiana cyst shell ; Chitin ; Chitosan ; Chemical ; Biological methods ; Crab shell ; Shrimp shell ; Biotechnology
    Repository Name: AquaDocs
    Type: Report , Refereed
    Format: 82pp.
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  • 6
    Publication Date: 2021-05-19
    Description: Without Abstract.
    Description: Iranian Fisheries Science Research Institute
    Description: Published
    Keywords: Survey ; Medical fibers ; Chitin ; Chitosan ; Shrimp
    Repository Name: AquaDocs
    Type: Report , Refereed
    Format: 90pp.
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