Evaluation of Biodiesel Productivity from Candida parapsilosis Isolated from Marine Sediments of Khor Al-Zubair in Basra, Iraq

Introduction: The increasing environmental impact of fossil fuel consumption has intensified the search for sustainable biofuel alternatives. Oleaginous yeasts are promising microbial sources for biodiesel production due to their ability to accumulate intracellular lipids. This study evaluated lipid production and biodiesel potential of Candida parapsilosis isolated from marine sediments of Khor Al-Zubair, Basrah, Iraq. Materials and Methods: Seawater samples were collected from Al-Faw Port, Khor Al-Zubair Port, and Shatt Al-Arab (Arvandrud in Persia). Yeast isolates were identified morphologically and molecularly using ITS۱–ITS۴ primers, with ۹۹.۶۰% sequence similarity to C. parapsilosis (NCBI accession PX۰۹۱۴۶۸). Lipid accumulation was induced under nitrogen-limited conditions. Dried biomass was quantified, lipids were extracted using Soxhlet with hexane, and fatty acid methyl esters (FAMEs) were produced by acid-catalyzed esterification. FAME composition was analyzed by GC-MS, and the cetane number (CN) was calculated.Results: The isolate produced ۲.۲۶۰ g/L of dried biomass and ۰.۶۷۴۰ g of extracted lipid, corresponding to ۲۹.۸۱% lipid content. Total FAME yield reached ۹۳.۱۱%. Unsaturated fatty acids accounted for ۶۹.۴۸%, with oleic acid (C۱۸:۱) predominating at ۶۱.۷۹%, whereas saturated fatty acids constituted ۲۳.۶۳%. The calculated cetane number was ۶۱.۲۹.Conclusions: Candida parapsilosis demonstrated substantial lipid accumulation and high FAME conversion efficiency, producing biodiesel-compatible fatty acid profiles with a favorable cetane number. These findings support its potential as a sustainable microbial source for biodiesel production.

کلیدواژه ها:

Biodiesel ، Candida parapsilosis ، Cetane number ، Fatty acid methyl esters ، Gas ChromatographyMass Spectrometry ، Lipid