Judul: Optimization Process Of Ethanol Production From Microalgae Chlamydomonas Sp. Icbb 9113, Icbb 9114 And Synechococcus Sp. Icbb 9111
Abstrak: The production of crude oil in Indonesia is 860 thousand barrel per day. Total crude oil reserves in Indonesia today is 7,4 billion barrels, and it is estimated to be exhausted in 24 years. National energy policy targets the utilization of non-fossil energy by 5-20% in the year 2005-2020. The first generation of alternative energy materials used are crude palm oil, jatropha, cassava and corn. The potential feedstock other than terrestrial plants are aquatic organisms e.g microalgae. Components of microalgae such as lipids for biodiesel and carbohydrates to ethanol. Ethanol production from biomass of microalgae consist of two stages i.e. saccharification and fermentation. Problem often found in the saccarification process is low reducing sugar when using acid hydrolysis. Therefore, it is necessary to find an alternative approach to increase the sugar yield by using enzymes. The study consists of four stages. The first was regeneration three isolates in BG 11 medium. The second was cultivation in laboratory using N2P1, N2P2 and N3P3 medium. The commercial enzyme of α-amylase and amyloglucosidase was analyzed to determine the optimal temperature and pH of its activity. The last was evaluating ethanol production using α-amylase and amyloglucosidase. The results of hydrolysis then fermented for seven days using Saccharomyces cereviceae ICBB 8808 to produce ethanol. Microalgae Chlamydomonas sp. ICBB 9114 has the highest biomass yield of 0,44 g/L with a 14,16% starch content, whereas the biomass yield and the lowest starch content in Synechococcus sp. ICBB 9111. The results characterization of α-amylase, optimum at pH 7 and temperature of 90°C with enzyme activity of 63,69 U/mL, whereas the best characterization of amyloglucosidase obtained at pH 5,5 and temperature of 60°C with the enzyme activity of 148,59 U/mL. The hydrolysis of three types microalgae using α-amylase obtained the highest reducing sugars in the microalgae Chlamydomonas sp. ICBB 9114 (5,62 mg/mL). The lowest of reducing sugars obtained on microalgae Chlamydomonas sp. ICBB 9113 (4,39 mg/mL). The combination of the two types of enzymes α-amylase and amyloglucosidase the hydrolysis process increases the total reducing sugars (P<0,05) in all three types of microalgae. The highest reducing sugars produced in the microalgae Chlamydomonas sp. ICBB 9114 (41,83 mg / mL), whereas the lowest reducing sugar produced microalgae Synechococcus sp. ICBB 9111 (35,67 mg/mL). After fermentation for 96 hours on three types of microalgae to produce ethanol. Synechococcus sp. ICBB 9111 (920 ppm), Chlamydomonas sp. ICBB 9113 (980 ppm) and Chlamydomonas sp. ICBB 9114 (516 ppm) respectively.
Keyword: Enzyme, ethanol, fermentation, microalgae, saccharification

Judul: Seleksi dan karakterisasi ganggang mikro indigen air tawar sebagai penghasil karbohidrat untuk energi terbarukan
Abstrak: The objective of this research is to explore and isolate indigenous micro algae that have a high carbohydrate producer as potentially for bioethanol production. The exploration from indigenous fresh water fifteen micro algae carried out in a BG 11 media and resulted four different types of micro algae such as ICBB-CC (9111, 9112, 9114 and 6354 PLB). By morpholgical identification, they were identified as Crucigenia quadrata, Scenedesmus bijuga, Chlorella vulgaris, and Chlorella vulgaris respectively. They were cultivated in a 5 L reactor using three types media of BG 11, MBM and PHM. The fastest growing isolate was ICBB 9111 of C. quadrata in MBM medium. The production biomassa of four isolates were developed in the raceway of 90-100L using MBM modifications medium with TSP aims , because of media has a value of optical density (OD) which increased from 0.09 to 0,200 within 3 (three) days. Harvesting is done from the OD value ≥ 0.6 continuously and harvesting stopped at OD values ≤ 0.5. Harvesting by means of filtration and drying naturally at room temperature. Temperature micro algae in ponds ranging channel 30-35 oC and maintained volume in such a way as early cultivation (by adding water to take advantage of existing nutrients). Production of dried-biomass/L/d and the results of the proximate analysis of carbohydrates into four isolates : Crucigenia quadrata ICBB 9111, Scenedesmus bijuga ICBB 9112, Chlorella vulgaris ICBB 9114 and Chlorella vulgaris PLB 6354) is 0,038 (42.27% dry weight), 0,035 (21.30% dry weight), 0.019 (16.66% dry weight) and 0,018 (17.22% dry weight). Production of dry biomass / L / day and the results of the proximate analysis of carbohydrates into four isolates ICBB-CC (9111, 9112, 9114 and 6354 PLB) is 0,038 (42.27% dry weight), 0,035 (21.30% dry weight), 0.019 (16.66% dry weight) and 0,018 (17.22% dry weight). Result of the selection of four types of micro algae ICBB-CC (9111, 9112, 9114 and 6354 PLB,) with modifications MBM TSP aims to get local micro algae isolates that have high carbohydrate content potentially for the production of ethanol.Optimal conditions for hydrolysis process 48 hours using a commercial enzyme that includes two stages: liquefaction process using enzymes α-amylase 600U at 95 ° C with a pH of 6 while for the saccharification process using enzymes amiloglukosidase 145U at a temperature of 60 ° C, pH 4.5 and 120 rpm rotation .Ethanol content of 40-hour fermented using S. Cerevisiae each sample, namely: 9111 amounted to 50.47 ppm, 105.86 ppm for 9112, 9114 amounted to 53.38 ppm and 41.17 ppm of PLB 6354.
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Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf