Preparation of low-molecular-weight chitosan by enzymatic hydro-lysis for use in peliculture

2021 ◽  
pp. 31-33
Author(s):  
Элана Игоревна Ковалева ◽  
Марина Алексеевна Фролова ◽  
Алексей Иванович Албулов ◽  
Валерий Петрович Варламов ◽  
Анатолий Константинович Елисеев

Хитозан и его производные обладают множеством свойств, которые позволяют применять его в пчеловодстве. Он повышает устойчивость организма пчел к неблагоприятным факторам внешней среды и к возбудителям различных заболеваний. В результате проведенных исследований разработаны технологические параметры получения низкомолекулярного хитозана методом ферментативного гидролиза. Chitosan and its derivatives have many properties that allow them to be used in beekeeping. It increases the resistance of the bee organism to adverse environmental factors and to pathogens of various diseases. As a result of the conducted research, the technological parameters for the production of low-molecular-weight chitosan by enzymatic hydrolysis were developed.

2020 ◽  
Vol 236 ◽  
pp. 116059
Author(s):  
Jun Zhang ◽  
Zewen Mei ◽  
Xingxi Huang ◽  
Yueyue Ding ◽  
Yunxiang Liang ◽  
...  

Author(s):  
E.I. Kovaleva ◽  
A.I. Albulov ◽  
M.A. Frolova ◽  
V.P. Varlamov ◽  
A.V. Grin

Chitosan is natural high molecular weight polymer of D-glucosamine and N-acetyl - D - glucosamine connected by 1,4 - b - glycoside bond with a molecular mass of 1000 kDa (and above), practical use is difficult because of high viscosity of its aqueous solutions even at low concentrations, and lack of solubility at neutral pH and, consequently, low biological activity. To reduce viscosity, improve the solubility and enhance biological activity of high molecular weight chitosan subjected to depolymerization. Chitosan, like other polysaccharides, is characterized by a hydrolysis reaction, which is due to the presence of glycoside bonds in the molecule that are lable to hydrolyzing agents, for example, aqueous solutions of acids, alkalis, as well as to the effect of some hydrolases. During hydrolysis, glycoside bonds are broken and, as a result, the molecular weight of chitosan decreases. However, these processes are accompanied by the formation of significant amounts of toxic products and require very costly disposal of waste before it is discharged into the environment. Chitin and chitosan are natural biopolymers and their synthesis, modification and degradation are associated with enzymatic transformations. It is the biodegradability to the usual substances for the body that is one of the main advantages of chitosan. It is obvious that the most appropriate method is the enzymatic hydrolysis of chitosan. As enzyme preparations for the degradation of chitin and chitosan, enzyme complexes of various origins are used. These can be enzymes from crab or krill hepatopancreas complexes, as well as pancreatin from the pancreas of cattle. But more often for this purpose, enzymes complexes with chitinolytic activity of microbiological origin are used. In this study, low-molecular-weight chitosan was obtained by enzymatic hydrolysis using the extracellular chitinolytic complex of Streptomyces kurssanovii. The resulting chitosan had a medium-viscosity molecular weight of 25-40 kDa. Carrying out two stages of fractionation (stepwise acidification and separation on membranes) made it possible to obtain chitosan fractions with a narrow distribution by molecular weight.


2009 ◽  
Vol 379 (1) ◽  
pp. 131-138 ◽  
Author(s):  
Ning Li ◽  
Chunyang Zhuang ◽  
Mi Wang ◽  
Xiyang Sun ◽  
Shufang Nie ◽  
...  

2021 ◽  
Vol 12 (3) ◽  
pp. 035016
Author(s):  
Natalya Nikolaevna Glushchenko ◽  
Olga Alexandrovna Bogoslovskaya ◽  
Balzhima Tsyrendorzhievna Shagdarova ◽  
Alla Victorovna Il’ina ◽  
Irina Pavlovna Olkhovskaya ◽  
...  

2009 ◽  
Vol 45 (4) ◽  
pp. 374-379 ◽  
Author(s):  
A. V. Ilyina ◽  
D. S. Zagorskaya ◽  
A. N. Levov ◽  
A. I. Albulov ◽  
N. P. Kovacheva ◽  
...  

2003 ◽  
Vol 792 ◽  
Author(s):  
Rangrong Yoksan ◽  
Mitsuru Akashi ◽  
Mikiji Miyata ◽  
Siriratana Biramontri ◽  
Suwabun Chirachanchai

ABSTRACTThe present work focuses on the γ-ray irradiation doses and conditions (dry solid state, solid state dispersing in 0.5–2 % aqueous H2O2 solution, solid state dispersing in 1% aqueous acetic acid, and 2% aqueous K2S2O8) to determine the level that the molecular weight of chitosan is lowered significantly without changing its primary structure. Molecular weight of chitosan (105-106 Dalton) is reduced approximately 50% under the γ-ray dose of 20 kGy in the dry solid state. The decrease in molecular weight is enhanced up to 80% when chitosan is suspended in 0.5–2 % aqueous H2O2 solution during γ-ray irradiation. In either condition, the backbone structure of the irradiated product is maintained with little change in the terminal chain. In the cases of (i) chitosan suspended in 2% aqueous K2S2O8 and (ii) chitosan in 1% aqueous acetic acid, chitosans lose their primary structures and physical properties.


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