Isolation, identification and diversity of oleaginous yeasts from Kuching, Sarawak, Malaysia

Vincent M, Hung MC, Baran PRM, Azahari AS, Adeni DSA. 2018. Isolation, identification and diversity of oleaginous yeasts from Kuching, Sarawak, Malaysia. Biodiversitas 19: 1266-1272. The present study was performed to isolate, identify and determine the diversity of oleaginous yeasts from various sources in Kuching, Sarawak (Malaysia). Microscopic observations via light and scanning electron microscope (SEM) indicated that the yeast isolates were in sizes ranging from 2-3 µm in width and 4-8 µm in length, typical of most unicellular ascomycotic fungi. Polymerase Chain Reaction (PCR) and molecular identification performed on the yeast isolates, targeting the D1/D2 region of the 26S rDNA, identified 6 yeast species from the 21 isolates, namely Pichia manshurica (5/21), Candida krusei (8/21), Candida parapsilosis (1/21), Pichia guilliermondii (2/21), Clavispora lusitaniae (1/21) and Kluyveromyces marxianus (4/21). All 21 yeast isolates accumulated intracellular lipids when grown in nitrogen-limited medium, as tested via Sudan IV staining. The present study is the first to document the production of lipids bodies in C. krusei, C. parapsilosis, and C. lusitaniae. Further investigations to assess the growth kinetics, lipid production efficiencies and lipids profiles of these oleaginous yeasts may provide insights into the possible utilization of these isolates for a variety of scientific, technical and industrial applications

Growth Kinetics of Ethidium Bromide Mutagenized Lipomyces starkeyi Strains

Micky Vincent1,*, Latifah Suali1, Afizul Safwan Azahari1, Patricia Rowena Mark Baran1, Elexson Nillian1, Lesley Maurice Bilung

Rapid detection and quantification of vibrio parahaemolyticus in cockles (anadara granosa) by using real-time PCR

Vibrio parahaemolyticus (V. parahaemolyticus) is acknowledged as one of the most significant disease-causing foodbome pathogen that causes the gastroenteritis resulting in diarrhea from vulnerable patients. The pathogenicity genes of V. parahaemolyticus are thermostable direct hemolysin (tdh) and thermostable direct hemolysin related hemolysin (trh). However, targeting a gene of thermolabile hemolysin (tlh) gene in this study, is described in total V. parahaemolyticus which may play its role in affecting the host and contribute to human health risks. This research aims for V. parahemolyticus in rapidly detecting and quantitatively determines the present and the level of the bacteria from 30 samples of cockles (Anadara granosa) purchased from Kuching7'~-Mile wet market by utilizing the Real-Time PCR. In this study, the primer MV2B-tl (tlh-gene based) and the SYBR Green PCR mastermix were used in Real-Time PCR assay and among all the 30 samples of cockles isolated, there were no detectable quantification of V. parahaemolyticus. Quantification of V. parahaemolyticus could be determined by the standard curve result obtained. Spiking of 'Ti/apia' fish with Ixl07 CFU/mL V. parahaemolyticu aids in determining the sensitivity of the study by Real-Time PCR assay by standard curve plot obtained with ~ value of 0.99 which showed a good correlation. Furthermore, the specificity of the assay was confinned by testing with 7 non -Vibrio strains by specific PCR. The SYBR Green PCR mastermix and primer set were developed as quantification tool of V. parahaemolyticus to the traditional PCR method which needed post-peR result and is time consuming. Therefore, the development of Real-Time peR assay in analyzing the presence of bacteria in seafood is crucial to both seafood industries as well as to the consumers