Production Of Fungal Chitosan Research Articles

Laboratory scale production of 13C labeled chitosan by fungi Absidia coerulea and Gongronella butleri grown in solid substrate and submerged fermentation

Nowadays, chitin and chitosan are applied in many medical and pharmaceutical products. However little is known about the metabolism of chitin and chitosan in vivo. In the human body, lysozyme will degrade chitin and chitosan into chito-oligosaccharides. 13C labeled chitosan is an essential prerequisite for the further study of the fate of chito-oligosaccharides in vivo. To fulfill this requirement, chitosans were extracted from mycelia of fungi, Absidia coerulea ATCC 14076 and Gongronella butleri USDB 0201 and ATCC 42618 grown in solid substrate fermentation (SSF) and submerged fermentation (SMF) to select the best fungus and fermentation method for the production of 13C labeled chitosan. Based on the production yield of chitosan, the SSF method is the best method for the production of fungal chitosan when compared with SMF methods (i.e., fed-batch fermentation and batch fermentation). However synthesis of 13C labeled chitosan in cell wall of G. butleri grown in SSF medium coated with 1- 13C-glucose was not observed. Alternatively, fungus A. coerulea was grown in SMF medium containing 2- 13C-glucose. The successful synthesis of 13C labeled glucosamine from 2- 13C-glucose was observed in mycelia of A. coerulea grown in SMF medium containing 2- 13C-glucose in a yield of about 13 g/100 g mycelia.

Production of fungal chitosan in liquid cultivation using apple pomace as substrate

In this work, we propose the reuse of apple pomace as a substrate for fungal chitosan production by liquid cultivation of Gongronella butleri CCT4274. Different concentrations of reducing sugars and sodium nitrate were added to the aqueous extract of apple pomace and the best result was obtained with 40 g/L of reducing sugars and 2.5 g/L of sodium nitrate. The results indicate the possibility of producing 1.19 g/L of chitosan per liter of culture medium after 72.5 hours of cultivation, representing around 21% of the biomass content.

Effect of urea on fungal chitosan production in solid substrate fermentation

The fungus Gongronella butleri USDB 0201 was grown on sweet potato pieces supplied with different amounts of urea at 26 °C for 7 days under sterilized and humidified air supply. Crude chitosan was extracted from the fungal mycelia and treated with α-amylolytic enzyme to remove bound glucan. The distribution of the molecular weight of the chitosan was studied by gel exclusion chromatography. The conditions for optimal production of fungal chitosan by solid substrate (SS) fermentation have been investigated. The initial pH and the amount of urea influence the yield of fungal mycelia and chitosan. The importance of chitosan production by fungi is discussed.

Production of fungal chitosan by solid substrate fermentation followed by enzymatic extraction

An improved method is described for the production of chitosan from mycelia of the fungus Gongronella butleri, grown by solid substrate fermentation on sweet potato. The chitosan was extracted subsequently by 11 M NaOH at 45 °C, and 0.35 M acetic acid at 95 °C. The resulting extract was clarified using a heat-stable, commercial α-amylase. The yield (4–6 g/100 g mycelia) and relative number average molecular weight (44–54 kDa) of the chitosan increased with increasing duration of fungal growth up to the sixth day.

Fungal chitosan production on food processing by-products

Four fungal strains, Aspergillus niger TISTR3245, Rhizopus oryzae TISTR3189, Zygosaccharomyces rouxii TISTR5058 and Candida albicans TISTR5239, grown on soybean and mungbean residues were investigated for their chitosan production. Their chitosan yields were in a range of 0.4–4.3 g/kg of soybean residue and 0.5–1.6 g/kg mungbean residue. The highest amount of chitosan by R. oryzae on soybean residue was 4.3 g/kg.

Production of fungal chitosan by solid state and submerged fermentation

The growth of the fungus Gongronella butleri USDB 0201 was compared in solid state fermentation (SSF) and submerged fermentation (SMF) using various nitrogen sources. The optimal production of biomass and chitosan by SMF was around 1.5–2.5 times higher than SSF. Urea is the best nitrogen source tested. SSF is to be preferred for the production of lower MW chitosan.