Extraction, Optimization and Characterization of Chitosan from Penicillium chrysogenum

Chitosan is a derivative of chitin, the second most abundant natural polymer on earth after cellulose. It is the major component of skeletal or exoskeletal structure of lower animals, particularly crustacea, molluscs and insects. It is also present in a vast majority of fungi as the principle fibrillar polymer of the cell wall. Fungal cell walls and septa of Extraction of chitosan from fungi is gaining significant importance in the world of industrial Mycology. Fungi are thus the promising alternative sources of chitosan. Chitosan extracted from fungi are found to be more consistent and have desired physiochemical properties when compared to the product from crustacean sources. In the present study, P. chrsogenum cultured in Czapex Dox broth and its wet mycelia after benzyl penicillin fermentation were selected for chitosan extraction. For the purpose of comparing the yields, commercial chitin obtained from shrimp shells was also used for chitosan extraction. The yield percentage of chitosan extracted from broth culture was found to be higher than that produced by wet mycelia and commercial chitin. Different acids were used for chitosan extraction and it was observed that acetic acid treatment was studied to give highest yield with all the three sources, followed by hydrochloric acid and sulphuric acid. It was also studied that when incubation period after acetic acid treatment during chitosan extraction was altered without changing the concentration, the yield was found to decrease drastically. When different ages of broth culture were used for chitosan extraction, 70 h culture gave a maximum yield. The extracted chitosan was then characterized based on properties such as nature, colour and solubility in water and different acids. The extracted chitosan from broth culture, wet mycelia and commercial chitin were analysed using FT-IR spectrophotometry and the results were found to be similar to the standard absorbance peak of chitosan. Colorimetric estimation of glucosamine units in chitosan from three sources were performed and it revealed higher glucosamine content (54%) in chitosan from broth culture than that extracted from wet mycelia (38%) and commercial chitin. International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Special Issue-3 (February-2016) pp. 19-26 Journal homepage: http://www.ijcmas.com