化石燃料常為家庭供暖、交通工具、工業生產提供能量，以及提供電力等。然而，由於持續使用使得地球上所剩餘的化石燃料不斷減少。因此需要研究開發替代性能源以供使用。近年藉由發酵有機物製備的生質乙醇成為一項理想替代方案。於本研究中，使用不同水解及發酵策略，將Ulva lactuca作為生產乙醇的原料，進行探討生產過程和不同條件影響乙醇的生合成量。於本研究結果顯示，靜置培養Kluyveromyces marxianusK-21(K-21)之乙醇產量（7.80±0.40g/L)稍高於分別以50rpm及150rpm轉速下培養之乙醇產量（6.10±0.70g/L和5.90±0.23g/L)之組別。而以Pichia stipitis BCRC21777(BCRC21777)進行靜置、50rpm及150rpm轉速下培養之乙醇產量分別為5.21±0.37g/L、4.90±0.19g/L和4.80±0.35g/L。以反應曲面法進行對K-21及BCRC21777之最適化生產，為培養溫度35t、pH6且使用基質濃度10%條件下靜置培養，分別可得10.60±0.31g/L和6.80±0.20g/L之乙醇產量。共培養則具11.5±0.7g/L之乙醇總產量。此研究結果顯示Ulva lactuca具有作為生質乙醇生產之原材料的潛力。

Fossil fuels heat our homes, run our vehicles, power industry and manufacturing, and provide us with electricity. However, as a result of our continual use the planets supply is diminishing, an alternative fuel source should thus be researched. Bioethanol is the ideal substitute as it is made up from the fermentation of organic substrates. In this study, Ulva lactuca was used as a feedstock for production of ethanol following different hydrolysis and fermentation strategies used to demonstrate the process ethanol production and influences of different conditions. The results of the agitation experiments revealed that static culture produced slightly higher ethanol (7.80 ± 0.40 g/L) than agitations at 50 rpm and 150 rpm (6.10 ± 0.70 g/L and 5.90 ± 0.23 g/L) for Kluyveromyces marxianus K-21 (K-21) and static culture, 50, 150 rpm for Pichia stipitis BCRC 21777 (BCRC 21777) was 5.21 ± 0.37 g/L, 4.90 ± 0.19 g/L, and 4.80 ± 0.35 g/L respectively, 10% substrate loading was the optimum for both yeast K-21 and BCRC 21777 with ethanol concentrations of 10.60 ± 0.31 g/L and 6.80 ± 0.20 g/L was obtained at optimized fermentation conditions of 35oC, static culture and a pH of 6. For the result of the co-culture a total amount of 11.5 ± 0.7 g/L bioethanol was produced. The results of this research proposes that Ulva lactuca could be used as a feedstock for bioethanol production.