Wai Prathumpai creator Montet, Didier Chairperson Rakshit, Sudip Kumar Examination Committee Stevens, Willem Frans Examination Committee Suwalee Chandkrachang Examination committee Pakorn Nuchnoi Examiantion Committee Virote Boonamnauyvitaya Examination committee Chiyong Limthongkul Foundation Examination committee text series technical report th Bangkok Asian Institute of Technology 1998 continuing eng 67 leaves Fungi is a better source of chitosan than other microcrustaceans as it can be separated easily and has a higher degree of deacetylation. Mycelia of G. butleri USDB 0201 is the best fungi among all of fungi in this study producing high amount of chitosan. Production of mycelia of G. butleri USDB 0201 by surface culture was 10.5 g/l for 7 days. This fungi produced 75.1 mg chitosan per gram of dried mycelia by surface culture process and 88.1 mg chitosan per gram of dried mycelia by solid state cultivation using potato. Surface culture process is a better method to produce chitosan because the separation process of mycelia is easier than solid state cultivation. Separation process of mycelia from substrate is the imp01tant criteria which determine this because of labor cost will increase the chitosan price. Degree of deacetylatylation of G. butleri USDB 0201 is 93%. This high degree of deacetylation of chitosan allows easy way of chitosan application. When amount of chitin was determined by the method of Sakurai et al (1985) for solid state cultivation, it was found that A. niger is the best fungi to produce chitin. This fungi produced 80.9 mg/g dried mycelia of chitin by solid state cultivation using sweet potato as substrate. Solid state cultivation of this fungi using potato as substrate gives better result than sweet potato even this fungi produced more chitin than on sweet potato. Separation of mycelia from potato was easier than from sweet potato. Surface culture process will not be used for production of chitin for this fungi because of low production of mycelia. Fungal chitin extraction from fungal mycelia cultivated in surface culture process was done by using 99% of formic acid as solvent, but hydrolysis was occurred after degree of deacetylation was determined. A thesis submitted in partial fulfillment of the requirement for the degree of Master of Science, School of Environment, Resources and Development Thesis (M.Sc.) - Asian Institute of Technology, 1998 Chitin Chitosan Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B13234 http://203.159.5.9/ait-thesis/detail.php?q=B13234 200499 20260817172700.0