Peningkatan intensitas pigmen dan kadar lovastatin angkak oleh Monascus purpureus ko-kultur dengan khamir amilolitik indigenus

Abstract

Angkak is a natural food colorant while lovastatin have been reported recently as bioactive component due to its capacity lowering cholesterol biosynthesis level in rat and human. Pigment and lovastatin angkak are secondary metabolites of Monascus purpureus. The objectives of this study were to increase pigment and lovastatin productions by co-cultured with Endomycopsis burtonii. Six strains of M. purpureus (107cfu/ml) were co-cultured with various concentrations of E. burtonii (103-105) cfu/ml at three different feeding times (day 2, 4, and 6). Feeding time and concentration of E. burtonii affected the productions of both pigment and lovastatin. The highest productions of red pigment and lovastatin were achieved by the same strain (M. purpureus TOS) at 104 cfu/ml of E. burtonii added at day 6. Expression of the genes that responsible for lovastatin production were analyzed by PCR and RT-PCR method. The phenotypic character of M. purpureus TOS with high lovastatin production was conformed by the high intensity of its gene expression. The stabilities of pigment and lovastatin were studied at various temperatures (70- 121)˚C and contact times (15, 30, and 45 minutes) and various pH (3,0; 5,0 ; and 7,0) with contact times (2, 4, 6, 8 h). The results showed that both red pigment produced by mono- and co-culture were stable at 70-121˚C for 15-45 minutes and at pH 7,0 with contact times for 4-8 h. However at lower pH 3,0 and 5,0 with contact times for 2-8 h caused degradation of red pigment.produced by either monoculture or co-cultured. Heating angkak at 70-121˚C for 15-30 and at pH 7,0 for 2-8 h did not affect the lovastatin concentration, while heating at 121˚C with longer contact time (45 minutes) and at pH 3,0-5,0 for 2-8 h caused the degradation of lovastatin (by coculture). The concentration of lovastatin (by mono-culture) did not affect by heating 70-121˚C for 15-45 minutes and at pH 3,0-7,0 with contact times for 4-8 h.

Pigmen angkak merupakan produk fermentasi Monascus purpureus pada substrat beras dan sudah lama digunakan sebagai pewarna alami makanan. Beberapa penelitian terakhir melaporkan bahwa angkak juga mengandung komponen bioaktif yaitu lovastatin yang memiliki manfaat terhadap kesehatan yaitu menurunkan kadar kolesterol pada tikus dan manusia. Produk angkak dapat diunggulkan sebagai ingredien pangan fungsional. Namun demikian, kandungan lovastatin angkak relatif rendah (rata-rata 0,2-0,9%). Penelitian ini bertujuan untuk meningkatkan intensitas pigmen merah dan lovastatin angkak, melalui ko-kultur M. purpureus dengan khamir amilolitik indigenus. Penelitian dibagi dalam beberapa tahap yaitu 1) Seleksi khamir indigenus untuk mendapatkan khamir yang memiliki aktivitas amilolitik 2) Ko-kultur enam strain M. purpureus dengan khamir terseleksi pada produksi angkak, kemudian dianalisis intensitas pigmen, kadar lovastatin dan sitrinin 3) Analisis ekspresi gen penghasil lovastatin tertinggi angkak hasil ko-kultur M. purpureus dengan khamir amilolitik indigenus menggunakan RT-PCR serta 4) Analisis stabilitas pigmen dan lovastatin angkak hasil ko-kultur terhadap variasi suhu dan pH.