Sonication of chitin–glucan, preparation of water-soluble fractions and characterization by HPLC

Abstract

A water-insoluble chitin-glucan complex, isolated from the mycelium of Aspergillus niger, was swollen in various aqueous media and treated subsequently by high-energy sonication. The concentration of the resulting water-soluble polysaccharide fractions was dependent on the swelling medium, the amount of the chitin-glucan complex in the suspension, and on the time of sonication. The yields of water-soluble chitin-glucan were within the range 13.6 to 24.4% relative to the mass of the original chitin-glucan. The nitrogen content obtained for the samples of water-soluble chitin-glucan indicated a higher content of chitin (3.45% of nitrogen in high-molecular fraction) than in the original water-insoluble chitin-glucan sample (1.8%). The distribution of the molecular weights of the water-soluble fractions prepared was determined by high-performance liquid chromatography.

Short-Chain Chitin Oligomers: Promoters of Plant Growth

“…Taking into account previous works [41,42,43,44,45,46], we produced a low-molecular-weight chitin mix (CHL) using combined thermal treatment and sonication on a high-molecular-weight chitin mix (CHH, see the Material and Methods Section). In order to characterize this CHL mix, several analyses were performed.…”

“…The mainstream process for obtaining chitin- or chitosan-derived oligomers involves acid hydrolysis, several deproteinization steps (depending on the natural origin of the chitin), deacetylation and purification by high-performance liquid chromatography, which can lead to the production of oligomers with very high levels of purity. In addition, if chitin oligomers are required, chitosan oligomers need to be re-acetylated [41,42]. As we were interested in producing a mixture of chitin fragments with as high a degree of acetylation as possible and a low molecular weight, we optimized a protocol based on previous work that indicated that chitin biopolymers can be fragmented using sonication.…”

Isolamento de polímeros da parede celular de Saccharomyces cerevisiae e avaliação da atividade antioxidante da manana-proteína isolada

“…Tratamento das glucanas bruta e purificada com ultrassom O tratamento com ultrassom e a hidratação da glucana foram realizados segundo Mislovicová et al, 26 com algumas modificações. Utilizou-se uma mistura de 100 mg de glucana (bruta ou purificada) em 25 mL de água, com pH ajustado para 7,0, e submeteu-se ao tratamento com ultrassom (Unique, mod.…”

“…Misloviscová et al 26 verificaram que o tratamento da glucanaquitina de Aspergillus niger com ultrassom durante 20 min aumentou a solubilização de carboidratos de 7,6 para 12,2% quando a concentração inicial foi de 50 mg/25 mL. Para a glucana de levedura (Tabela 3) observou-se o aumento na solubilidade de 10,3 para 14,2% quando a glucana purificada foi submetida a um tratamento idêntico.…”

An improved sonochemical reactor

“…While numerous applications of ultrasound have been published to physically modified chitosan (e.g. to favor its swelling and dissolution [15], to prepare polymeric vesicles [16,17] etc.) to the best of our knowledge no sonochemical modifications of this polysaccharide have been reported to-date.…”