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

Abstract

Vincent M, Hung MC, Baran PRM, Azahari AS, Adeni DSA. 2018. Isolation, identification and diversity of oleaginous yeastsfrom Kuching, Sarawak, Malaysia. Biodiversitas 19: 1266-1272. The present study was performed to isolate, identify and determine thediversity of oleaginous yeasts from various sources in Kuching, Sarawak (Malaysia). Microscopic observations via light and scanningelectron microscope (SEM) indicated that the yeast isolates were in sizes ranging from 2-3 μm in width and 4-8 μm in length, typical ofmost 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), Candidakrusei (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. Furtherinvestigations to assess the growth kinetics, lipid production efficiencies and lipids profiles of these oleaginous yeasts may provideinsights into the possible utilization of these isolates for a variety of scientific, technical and industrial applications.

Potential of Candida glabrata from ragi as a bioethanol producer using selected carbohydrate substrates

“…Another yeast species that has similar characteristics to S. cerevisiae is Candida glabrata, which can be commonly 2 found in fermented foods (Tsuyoshi et al 2005) and starters, such as ragi, a traditional fermented food starter (Kofli and Davaon 2010;Hajar et al 2012;Vincent et al 2018). In this study, C. glabrata was isolated from the samples of ragi in Sarawak and was identified by using PCR and commercial identification kit.…”

“…The desired microorganism should be robust and capable of converting substrates to ethanol effectively. The most common examples of ethanol producers are Saccharomyces cerevisiae, Zymomonas mobilis and Fusarium oxysporum (Ali et al 2016;Vincent et al 2018;Mohammad et al 2020). Among these, S. cerevisiae has been mostly used in alcoholic fermentation due to its ethanol productivity.…”

“…Therefore, several genetic engineering studies to improve sugar utilization, ethanol production, and other applications have been explored (Carrasco et al 2013;Pagliardini et al 2013;Wong and Vincent 2019). Another approach is to search for new fermenting yeasts that may perform better or are more flexible than S. cerevisiae (Vincent et al 2018).…”

Development of Rhodotorula mucilaginosa strain via random mutagenesis for improved lipid production

“…It is produced from the transesterification of triacylglycerides (TAGs) and alcohol in the presence of a catalyst such as NaOH or KOH (Moser et al, 2009). Biodiesel is highly degradable, non-toxic and could reduce the emission of harmful gases (Sitepu et al, 2013;Vincent et al, 2018). Most currently produced biodiesel is made from plant oils such as sunflower, rapeseed, peanut and palm oils (Atabani et al, 2012;Demirbas et al, 2016).…”

“…Besides the high feedstock cost, the usage of edible plant oils for biodiesel production causes the issue of food-fuel competition, therefore a cheaper raw material with high oil productivity is crucial to enhance biodiesel production (Chhetri et al, 2008;Atabani et al, 2012;Shikha and Rita, 2012). Thirdgeneration biodiesel produced from microbial oils has the potential as an excellent alternative source for biodiesel production (Soccol et al, 2017;Vincent et al, 2018).…”