Sains Malaysiana 45(10)(2016): 14431451

 

Profil Pengekspresan Gen Mengekod delta 6 dan delta 12-Asid Lemak Desaturase Cunninghamella bainieri semasa Biosintesis Asid Gamma-Linolenik

(Expression Profiles of delta 6 and delta 12-Fatty Acid Desaturase Encoding Genes Cunninghamella bainieri during Gamma-Linoleneic Acid Biosynthesis)

NOOR ADILA ABDUL KARIM, ZAMRI ZAINAL, AIDIL ABDUL HAMID, FARAH DIBA ABU BAKAR & ABDUL MUNIR ABDUL MURAD*

 

Pusat Pengajian Biosains dan Bioteknologi, Fakulti Sains dan Teknologi, Universiti Kebangsaaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia

 

Received: 29 November 2015/Accepted: 10 March 2016

 

ABSTRAK

Delta 6-asid lemak desaturase dan delta 12-asid lemak desaturase merupakan enzim yang diperlukan bagi langkah desaturasi semasa proses biosintesis asid gamma-linolenik (GLA) oleh kulat oleaginus. Objektif kajian ini ialah untuk menganalisis profil pengekspresan gen mengekod enzim delta 6-asid lemak desaturase (des6) dan delta 12-asid lemak desaturase (des12) kulat oleaginus Cunninghamella bainieri semasa penghasilan GLA. Jujukan gen separa bersaiz 1372 pb bagi des6 dan 1008 pb bagi des12 telah dipencil daripada C. bainieri. Analisis pengekspresan gen menggunakan kaedah tindak balas berantai polimerase kuantitatif masa sebenar (RT-qPCR) menunjukkan perubahan kadar pengekspresan des6 adalah lebih tinggi berbanding kadar pengekspresan des12 semasa penghasilan GLA. Pengekspresan des6 adalah tertinggi selepas 24 jam dikultur dalam medium penghasilan GLA. Namun, kadar pengekspresannya menurun hingga jam ke-96 pertumbuhan tetapi meningkat semula pada jam ke-120. Bagi des12, kadar pengekspresannya adalah lebih sekata dengan pengekspresan tertinggi dikesan pada jam ke-120. Analisis penghasilan GLA menunjukkan jumlah GLA dalam sel berkolerasi dengan kadar pengekspresan des6. Hasil kajian mencadangkan bahawa aras pengekspresan des6 adalah penting dalam menentukan aras GLA dalam C. bainieri.

 

Kata kunci: Asid gamma-linolenik; Cunninghamella bainieri; delta 6-asid lemak desaturase; delta 12-asid lemak desaturase; kulat oleaginus

 

ABSTRACT

Delta 6-fatty acid desaturase and delta12-fatty acid desaturase are enzymes required for the desaturation steps during gamma-linolenic acid (GLA) biosynthesis in oleaginous fungi. The objectives of this study were to analyse the expression profiles of genes which encode for the delta 6-fatty acid desaturase (des6) and delta 12-fatty acid desaturase (des12) from an oleaginous fungus, Cunninghamella bainieri, during GLA production. Partial gene sequences with the size of 1372 bp for des6 and 1008 bp for des12, were isolated from C. Bainieri. Gene expression analyses via real-time quantitative PCR (RT-qPCR) indicate that the changes in the expression profile of des6 is higher during GLA production as compared to the expression profile of des12. The expression of des6 is the highest after 24 h of growth in the GLA-inducing medium. However, its expression showed a decreasing pattern until 96 h of growth but increased at 120 h. The expression profile of des12 is more consistent with the highest expression levels detected at 120 h of growth. GLA production analysis showed that the amount of GLA in the cell is correlated with the expression of des6. The results of this study suggested that the expression of des6 plays an important role in determining GLA production in C. bainieri.

 

Keywords: Cunninghamella bainieri; delta 6-fatty acid desaturase; delta 12-fatty acid desaturase; gamma linoleneic acid; oleaginous fungi

 

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*Corresponding author; email: munir@ukm.edu.my

 

 

 

 

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