Sakarifikasi pati ubi kayu menggunakan amilase Aspergillus niger ITB CC L74

Abstract

Saccharification of cassava starch using amilase Aspergillus niger ITB CC L74 Bioethanol is a derivative product from cassava that is thoroughly developed nowadays. One of the bioethanol research program of the Chemical Engineering Product Design and Development Research Group, Faculty of Industrial Technology, Institut Teknologi Bandung in the year of 2008 was to increase productivity and the performance of α-amylase and glucoamylase from Aspergillus niger ITB CC L74 for saccharification of cassava starch in bioethanol production. In conjunction with the optimum condition of saccharification process, research on the effect of pH, temperature, Ca²⁺ concentration, substrate concentration, and enzyme volume percentage have been carried out. The performance of α-amylase was determined by the iodine method while the performance of glucoamylase was done by the Somogyi-Nelson method. Research variable to determine the optimum performance condition of amylase extract were pH (3.15–7.0), temperature (30–89 ^oC), Ca²⁺ concentration (0–200 ppm), substrate concentration (0.5–20 %-w/v), and enzyme volume percentage (1.0–50 %-v). The results of this research showed that the optimum performance of amylase complex were pH 4.5, temperature 60 ^oC, Ca²⁺ concentration 75 m/L, and substrate concentration 7 %-w/v. The performances of amylase complex increased with the increase in the amount of enzyme percentage, but the increase was limited by the amount of glucose that could inhibit enzyme activity.

Keywords: amylase, glucoamylase, Aspergillus niger, saccharification, starch

Abstrak

Bioetanol merupakan produk turunan ubi kayu yang sekarang sedang giat dikembangkan. Salah satu program riset bioetanol Kelompok Keahlian Perancangan dan Pengembangan Produk Teknik Kimia, FTI, ITB tahun 2008 adalah peningkatan produktivitas dan kinerja enzim α-amilase dan glukoamilase Aspergillus niger ITBCC L74 untuk proses sakarifikasi pati ubi kayu pada produksi bioetanol. Sehubungan dengan kondisi optimum proses sakarifikasi, penelitian tentang pengaruh pH, temperatur, konsentrasi Ca²⁺, konsentrasi substrat, dan persentase volume enzim, telah dilakukan. Analisis kinerja kompleks amilase yang dilakukan meliputi analisis kinerja enzim α-amilase dengan metode iodin dan analisis kinerja enzim glukoamilase dengan metode Somogyi-Nelson. Variabel yang diteliti untuk menentukan kondisi optimum kinerja ekstrak amilase adalah pH (3,5–7,5), temperatur (25–80 ^oC), konsentrasi Ca²⁺ (25–200 ppm) konsentrasi substrat (0,5–20 %-b/v) dan persentase volume enzim (1-50 %-v). Hasil penelitian menunjukkan bahwa kinerja kompleks enzim amilase optimum berada pada pH 4,5, temperatur 60 ^oC, konsentrasi Ca²⁺ 75 ppm, dan konsentrasi substrat 7 %-b/v. Kinerja kompleks amilase makin baik seiring dengan peningkatan persentase volume enzim, namun peningkatan ini dibatasi oleh kandungan glukosa dalam enzim yang dapat menyebabkan inhibisi terhadap aktivitas enzim.

Kata kunci: amilase, glukoamilase, Aspergillus niger, sakarifikasi, pati