Undergraduate Research Journal for
Biomolecular Sciences and Biotechnology Kesan Mononatrium Glutamat (MSG) Terhadap Penghasilan Lipid oleh Aurantiochytrium sp. SW1 Menggunakan Fermentasi Kultur Suap-Kelompok Yong Jin Tung, Vidyah Manikan, Aidil Abdul Hamid & Herryawan Ryadi Eziwar Dyari* Pusat Pengajian Biosains dan Bioteknologi, Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia * Mel-e pengarang rujukan:
[email protected]
Abstrak: Aurantiochytrium sp. SW1 merupakan mikroorganisma oleaginus yang berpotensi menghasilkan asid lemak poli tidak tepu (PUFA) sehingga 50% dari berat keseluruhan di mana 90% daripada kandungannya adalah asid dokosaheksanoik (DHA). Mononatrium glutamat atau MSG ialah garam natrium berasaskan asid glutamik di mana formula struktur umum ialah C5H8NO4Na. Dari segi penyelidikan dan pembangunan, MSG merupakan sumber nitrogen yang memainkan peranan kritikal dalam pertumbuhan dan pengumpulan biojisim mikroalga di mana MSG membantu dalam pembentukan asid amino dan proliferasi sel. Dalam penyelidikan ini, fermentasi kultur kelompok digunakan untuk menentukan kepekatan MSG yang optimum bagi pertumbuhan dan pengumpulan lipid oleh Aurantiochytrium sp. SW1. Seterusnya, keberkesanan kultur kelompok dan kultur suap-kelompok juga dibandingkan. Pengkulturan dijalankan dalam kelalang Erlenmeyer 250 mL yang mengandungi 200 mL kultur pembenihan, dieram dan digoncang dengan kelajuan 200 rpm pada suhu 30 ˚C selama 5 hari. Penyediaan kultur penghasilan adalah sama dengan kultur pembenihan dalam fermentasi kultur kelompok kecuali kepekatan MSG yang dimasukkan berbeza iaitu 4 gL-1, 8 gL-1, 12 gL-1 dan 16 gL-1. Kepekatan MSG yang mempunyai produktiviti lipid terbaik dalam kultur kelompok akan dipilih untuk diaplikasikan dalam fermentasi kultur suap-kelompok. Kajian ini telah menunjukkan bahawa penggunaan 8 gL-1 MSG dalam fermentasi kultur kelompok menghasilkan produktiviti lipid yang paling tinggi dan seragam di mana 45.47% lipid dikumpulkan. Bagi fermentasi kultur suap-kelompok, penyuapan MSG pada jam ke-60 telah mendorong penghasilan biojisim yang lebih tinggi dan secara berterusan sehingga hari kelima pengkulturan. Namun bagi profil produktiviti lipid, penurunan berlaku di mana peratus lipid tertinggi yang dikumpulkan adalah 33.66% sahaja pada masa tuaian 96 jam (t=4). Kajian ini telah menunjukkan penyuapan MSG di dalam fermentasi kultur suap kelompok telah mengehadkan penghasilan lipid dalam kultur Aurantiochytrium sp. SW1. Kata kunci: Mononatrum glutamat, lipid, Aurantiochytrium sp. SW1, kultur suap-kelompok Abstract: Aurantiochytrium sp. SW1 is an oleaginous microorganism that can generate up to 50% polyunsaturated fatty acids (PUFA) intracellularly, where 90% of it is Docosahexaenoic acid (DHA). Monosodium glutamate or MSG is known as sodium salt of glutamic acid where the general structural formula is C5H8NO4Na. In terms of research and development, MSG is a source of nitrogen that plays a critical role in the growth and accumulation of microalgae biomass where MSG helps the formation of amino acids and cell proliferation. In this research, the batch culture fermentation was used to determine the optimal concentration of MSG for the growth and lipid productivity by Aurantiochytrium sp. SW1. The effectiveness of batch culture and fed-batch culture were also compared. Cultivation was carried out using batch culture in a 250 mL Erlenmeyer flask containing 200 mL of seedling culture and incubated at 30 °C with 200 rpm agitation for 5 days. The preparation of the production culture and the seedling culture only differed in the concentration of MSG in which 4 gL-1, 8 gL-1, 12 gL-1 and 16 gL-1 of MSG were applied and the optimum MSG concentration was investigated via fed-batch culture fermentation. This study showed that the use of
8 gL-1 of MSG in batch culture had the highest and most uniform lipid productivity, in which 13.35 gL-1 biomass and 45.47% of lipid had been accumulated. For fed-batch culture fermentation, the feeding of MSG at the 60th hour increased the biomass up to the fifth day of cultivation with 14.93 gL-1 produced. However, for lipid productivity, the percentage of lipid produced dropped sharply in which the highest percentage of lipid collected was only 33.66% on the 4th day of the cultivation. This study has shown that the feeding of MSG at its optimal concentration in fed-batch culture has restricted the lipid accumulation of Aurantiochytrium sp. SW1. Keywords: Monosodium glutamate, lipid, Aurantiochytrium sp. SW1, fed-batch culture
