Identification of Proteolytic and Pectinolytic Yeasts from Civet (Paradoxorus hermaphroditus) and Evaluation of their Potential to Modify Coffee Bean Quality

Abstract

Civet coffee is one of the world’s most popular and expensive coffee types. The problem recently is the difficulty of finding natural civet coffee. The study of artificial civet coffee production using microorganisms to ferment the coffee in recent years has attracted the attention of many researchers. This study aims to characterize and identify yeast from civets and evaluate its potential as a starter in coffee fermentation. Three types of yeast isolated from civet feces have been isolated and characterized. They have varied morphological and biochemical characteristics. Only two yeast isolates Kh1 and Kh2 have the potential to be used as starters in fermentation due to the ability to degrade pectin and protein. The 18S rRNA gene fragment analysis results indicated that the isolates Kh1 and Kh2 were identified as Trichosporon asahii isolate E22922_ITS and Wickerhamomyces anomalus CNRMA10.1139. Applying both isolates as starters in coffee fermentation can improve the quality of coffee flavor and produce a higher score. Fermented coffee using W. anomalus starter provides more flavor, aftertaste, body, and overall advantages, while coffee fermentation using T. asahii isolate gives more value to the aroma. The highest cupping score was obtained for processed coffee using W. anomalus, reaching 84.42. Furthermore, it is necessary to carry out a more complex metabolite analysis to ensure the performance of the two isolates in modifying the chemical composition and taste of coffee.