A novel extracellular exoinulinase was purified and characterized from a new 
yeast strain KRF1(T), and the gene encoding the enzyme was successfully cloned. 
The enzyme was stable at low pH between 3.0 and 6.5. The K (m) and V (max) 
values of the purified enzyme for inulin were 2.3 mg/mL and 4.8 mg/min, 
respectively. The optimum temperature of the inulinase was 50 °C, and the enzyme 
remained 78 % of activity at 60 °C for 2 h. The inulinase showed an amino acid 
sequence identity of 58 % to its closest homolog in Meyerozyma (Pichia) 
guilliermondii. In the secondary structure, the domain G (VMEVH) of the enzyme 
contained three unique residues (V, M, and H). Compared with previously reported 
inulinases, the enzyme from strain KRF1(T) displayed strong acid resistance, 
notable thermostability, and high affinity for the substrate of inulin. Based on 
sequence analysis of the 26S rDNA D1/D2 domain and phenotypic characterization, 
the yeast strain KRF1(T) was found to represent a novel anamorphic, ascomycetous 
yeast species. A complete description of the species is given and the name 
Candida kutaonensis sp. nov (type strain = KRF1(T) = AS 2.4027(T) = CBS 
11388(T)) is proposed.