ABSTRACT
Aims: The aim of this study was to isolate and identify the yeast and mold strains from the starter and to investigate their amylolytic activity. Methodology and results: Thirty-two yeasts were isolated from ten samples of look-paeng khao-mak, a traditional starter culture in the production of khao-mak (sweet rice) in several places in Thailand. All isolates were identified based on their morphological and biochemical characteristics including the sequencing of D1/D2 domain of large subunit (26S) ribosomal DNA analyses. They were identified as Saccharomycopsis fibuligera (9 isolates), Candida rugosa (2 isolates), C. tropicalis (1 isolate), Clavispora lusitaniae (1 isolate), Wickerhamomyces anomalus (15 isolates) and Meyerozyma guilliermondii (4 isolates). All isolates of S. fibuligera showed high amylolytic activity. One-hundred isolates of mold were isolated from twenty-one samples of look-paeng khao-mak. They were belonged to Amylomyces sp. (42 isolates), Rhizopus sp. (30 isolates), Mucor sp. (12 isolates) and Penicillium sp. (16 isolates) based on their morphological characteristics. Four isolates, LK4-1, LK8-2, LK12-5 and LK17-1 showed amylase activity ranged from 32.24 to 39.74 unit/mL by dinitrosalicylic acid (DNSA) method. The isolates LK4-1, LK8-2 and LK12-5 were identified as Amylomyces rouxii and LK17-1 was Rhizopus microsporus based on their morphological characteristics and the ribosomal RNAencoding DNA (rDNA) internal transcribed spacer (ITS) sequences. Conclusion, significance and impact study: The characterization and evaluation of yeast and mold species based on their phenotypic and genetic characteristics including their amylase activity will be useful for the diversity and sweet rice production.
ABSTRACT
Objectives Use ITS gene sequence analysis to identify 15 strains of dematiaceous fungi , to learn the types of pathogenic strains and clinical treatment. Methods By observing the colony morphology and microscope morphological of the dematiaceous fungi isolated from superficial mycoses , and identified by ITS gene sequence analysis. Results 15 strains were identified by morphological observation as dematiaceous fungi.The amplified bands were identified by Tanon-3500 gel imaging system between 500 ~ 700 bp. Blast sequencing results show that 2 strains Alternaria alternate , 2 strains Cladosporium sphaerospermum. 2 strains Exophiala dermatitis, 1 strains Cladosporium cladosporioides, Curvularia lunata, Talaromyces rugulosus, Phaeobotryon cupressi, Cladosporium tenuissimum, Fonseceea pedrosoi, Exophiala werneckii, Exophiala oligosperma and Fonsecaea monophora. Conclusion ITS gene sequence analysis can identify dematiaceous fungi effectively , avoided undetected and misdiagnose cause by the lack of clinical experience.
ABSTRACT
During our studies on the diverse endophytic fungi resident on conifer needles, many species of Cladosporium previously unreported in Korea were encountered. In this paper, we report on two species of Cladosporium from the needles of pine trees (Pinus spp.). Based on analyses of internal transcribed spacer gene sequence, and cultural and micromorphological characteristics, they were identified as C. oxysporum and C. sphaerospermum. Both species have not been hitherto reported in Korea.