The cost of raw materials has been known to be the major limitation on the economic feasibility of acetone-butanol-ethanol (ABE) production. About 60-70% of the total ABE production cost is the cost for substrates (Madihah et al. 2001). Therefore, many researches have been conducted to find the most economical substrates for ABE production, for examples those who used simple sugars such as glucose, lactose, galactose, and xylose (Shinto et al.2008;Keis et al. 2001;Bahl et al. 1986), or moreIn the effort of developing bioenergy source materials, a laboratorium study was performed to investigate the effects of substrate types and concentrations on the production of acetone-butanol-ethanol (ABE) from various substrates by Clostridium saccharoperbutylacetonicum N1-4 (ATCC 13564) in defined TYA (Tryptone-Yeast extract-Acetate) media. The results demonstrated that the ABE ratios produced by the strain N1-4 were greatly influenced by the types of substrate and the concentrations being used. It was also shown that fermentation of disaccharides (cellobiose and dextrin) by the strain N1-4 could give relatively as high butanol and ABE yields as glucose fermentation after 24 h fermentation time. The strain N1-4 was also found to be able to ferment xylans from birchwood sources producing a relatively high ABE concentration, especially at a prolonged incubation time (after 48 h incubation period). A subsequent experiment using several different concentrations of glucose or cellobiose revealed that the higher the concentration of the substrate being used, then the higher the total ABE concentration or productivity could be obtained but not necessarily in the same increasing ratio. To the best of our knowledge, there was no other previous study about the effect of substrate type and concentration on the ABE ratio by C. saccharoperbutylacetonicum N1-4 (ATCC 13564) using various substrates in defined TYA media, specifically by using xylans and dextrin substrates.Key words: ABE ratio, acetone-butanol-ethanol fermentation, biomass substrate effect, Clostridium saccharoperbutylacetonicum N1-4Dalam rangka mendapatkan bahan baku bioenergi, sebuah studi laboratorium dilakukan untuk mengetahui pengaruh dari jenis dan konsentrasi substrat biomasa terhadap proses fermentasi langsung yang menghasilkan aseton, butanol, dan etanol oleh bakteri Clostridium saccharoperbutylacetonicum N1-4 (ATCC 13564) dalam media TYA (Tryptone-Yeast extract-Acetate) yang terdefinisi. Hasil penelitian menunjukkan bahwa rasio dari aceton:butanol:etanol (rasio ABE) ternyata sangat dipengaruhi oleh jenis substrat biomass dan konsentrasi yang dipergunakan dalam proses fermentasinya. Data menunjukkan bahwa dengan menggunakan substrat disakarida (yang diwakili oleh dextrin dan cellobiose), strain N1-4 mampu menghasilkan ABE dengan yield yang relatif sama tinggi dengan menggunakan glukosa setelah masa fermentasi 24 jam. Strain N1-4 ternyata juga mampu memproduksi ABE dengan konsentrasi yang cukup tinggi dengan menggunakan substrat xylan yang diekstraksi dari kayu, wa...