The need is always found for effective substitution of chemical and synthetic food preservatives with effective and powerful alternatives from natural origins. Chitosan is an amazing biopolymer with a very wide range of applications. Chitosan could be produced microbiologically from the fungal cell walls. The nature, occurrence, antimicrobial activity and other potential applications of chitosan are illustrated in this book. Successful production of chitosan from Aspergillus brasiliensis mycelia, using agricultural waste as a substrate, is pointed out in this study. The application of produced fungal chitosan as a biopreservative, for the protection and maintaining the quality of minced meat, are also highlighted in this book. This book will provide readers; researchers and food industry overseers with an interesting and innovative topic for the enhancement of food safety.