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Abstrak :
Tofu waste can be used as a raw material for bioethanol production due to its high carbohydrate content in the form of starch. A microbial consortium, consisting of Aspergillus niger and Saccharomyces cerevisiae. The study’s first objective wasto capture the amount of sugar produced from starch hydrolysis using single cultures of Aspergillus niger.The study’s second objective wasto determine the amount of ethanol produced by the SSF technique. Aspergillus niger was used to produce an amylase enzyme that hydrolyzes starch into simple sugar.Then, Saccharomyces cerevisiae was used to produce bioethanol from the sugar produced earlier.The synthesis of bioethanol consists of two main stages, hydrolysis and fermentation. In previous studies, the hydrolysis and fermentation processes were performed separatelyusing a separated hydrolysis and fermentation (SHF)technique. This studyprocesses via a simultaneous saccharification and fermentation (SSF) technique which produced higher substrate efficiency, cell yield, and product yield compared to the SHF process.The characterization process showed that tofu waste flour was mainly composed of carbohydrates, which comprised 52.82±0.01% (dw) and had a starch content of 35.1±0.2% (dw). Sugar from the starch of the tofu waste was produced by batch system cultivation for 84 hours using Aspergillus niger. The highest sugar production (14.48 g/L) was achieved during the 48th hour. Then, Saccharomyces cerevisiae was used to convert the produced sugar into bioethanol. The production of bioethanol by SSF using a microbial consortium for 72 hours was 7.69 g/L of bioethanol, with a yield of bioethanol per substrate use (Yp/s) of 0.23 g ethanol/g substrate and a substrate conversion efficiency of 88%.

Abstrak :
Salah satu prioritas dalam agenda jangka panjang pengembangan energi baru dan terbarukan yang tertuang dalam Agenda Riset Nasional (ARN) adalah pengembangan bioetanol dari material lignoselulosa. Masalah yang mendasar dalam proses peningkatan produksi etanol dari material lignoselulosa termasuk bagas adalah bagaimana mengkonversi secara menyeluruh polisakarida menjadi monosakarida dengan memanfaatkan enzim-enzim yang spesifik. Untuk material bagas, yang dimaksud konversi menyeluruh adalah konversi selulosa, xylan dan selobiosa. Selain itu, keberadaan lignin dalam bagas dapat menghambat akses enzim dalam memecah polisakarida menjadi monosakarida, sehingga menyebabkan produksi etanol tidak optimal. Pada penelitian ini, telah dilakukan penelitian dengan teknologi proses baru untuk meningkatkan produksi etanol dari bagas melalui proses sakarifikasi dan fermentasi serempak (SSF). Penelitian yang dilakukan adalah mencakup proses menyeluruh perlakuan awal dengan beberapa jamur pelapuk putih (Ceriporiopsis subvermispora, Lentinus edodes dan Pleurotus ostreatus) dan steaming, hidrolisis menggunakan kombinasi multi enzim selulase, selobiasedan xylanase serta proses fermentasi dengan Saccharomyces cerevisiae AM 12 yang dilakukan secara serempak. Kombinasi enzim selulase-selobiase, selulase-xylanase dan selulase-selobiase-xylanase meningkatkan produksi etanol dari bagas dalam proses SSF. Konsentrasi etanol tertinggi yang dihasilkan dengan kombinasi enzim selulase-selobiase, selulase-xylanase dan selulase-selobiase-xylanase berturut-turut 6,9 g/L, 8,6 g/L dan 9,8 g/L, sedangkan dengan enzim selulase saja sebesar 6,0 g/L. Persentase ethanol yield (berbasis berat bagas) yang dihasilkan dengan kombinasi enzim tersebut berturut-turut sebesar 13,9%, 17,2% dan 19,7%, sedangkan dengan enzim selulase saja sebesar 11,95%. Pencapaian hasil teori (theoretical yield) tertinggi dengan menggunakan kombinasi enzim selulase-selobiase-xylanase sebesar 49,5%, sedangkan dengan enzim selulase saja pencapaian hasil teori sebesar 42,0%. Peningkatan produksi etanol dengan enzim selulase-selobiase membuktikan bahwa selain glukosa, selobiosa juga terbentuk dalam proses hidrolisis parsial selulosa oleh enzim selulase. Selobiosa yang terbentuk kemudian secara simultan dikonversikan menjadi glukosa oleh enzim selobiase, yang dibuktikan dengan peningkatan glukosa sebesar 16,2% setelah proses dihidrolisis dengan enzim selulase-selobiase. Selanjutnya glukosa yang terbentuk secara simultan dikonversi menjadi etanol oleh S. cerevisiae. Selain itu, pengingkatan jumlah etanol yang dihasilkan dengan kombinasi selulase-selobiase-xylanase juga membuktikan bahwa reaksi multi enzim dengan masing-masing substrat yang spesifik dapat terjadi dalam proses SSF. Reaksi multi enzim tersebut yaitu reaksi hidrolisis selulosa dengan selulase menjadi glukosa, hidrolisis xylan dengan xylanase menjadi xylosa dan hidrolisis selobiosa menjadi glukosa dengan enzim selobiase. Selanjutnya secara simultan glukosa dan xylosa yang terbentuk dikonversi menjadi etanol dengan S. cerevisiae. Hal ini dibuktikan dengan menurunnya kadar selulosa dan hemiselulosa setelah proses SSF berlangsung yaitu dari 50% dan 20% menjadi 22% dan 10%. Peningkatan sangat signifikan pada produksi etanol dari bagas dengan kombinasi enzim selulase-selobiase, selulase-xylanase dan selulase-selobiase-xylanase setelah dilakukan kombinasi perlakuan awal C. subvermispora dan steaming 180_C. Konsentrasi etanol yang dihasilkan dengan kombinasi enzim dan perlakuan awal tersebut berturut-turut sebesar 12,9 g/L, 13,5 g/L dan 18,2 g/L. Dengan persentase ethanol yield yang dihasilkan berbasis berat bagas sebesar 25,7%, 26,9% dan 36,4%. Peningkatan etanol yang dihasilkan setelah perlakuan awal dengan C. subvermispora dan steaming disebabkan adanya proses biodegradasi lignin oleh C. subvermispora dan pelarutan kristal-kristal selulosa dan hemiselulosa selama proses perlakuan dengan steaming berlangsung. Hal ini dibuktikan dengan adanya penurunan kadar lignin sebesar 26,5%, selulosa sebesar 9,4% dan hemiselulosa 14,1% setelah kombinasi perlakuan awal C. subvermispora dan steaming pada suhu 180_C. Ethanol yield tertinggi 36,4% dengan pencapaian theoretical yield sebesar 91,4%, yaitu dengan enzim selulase-selobiase-xylanase yang dikombinasikan dengan perlakuan awal C. subvermispora dan steaming 180_C. Pencapaian hasil teori ini meningkat sangat signifikan dibandingkan dengan etanol yang dihasilkan jika hanya menggunakan enzim selulase saja (42,03%). Peningkatan tersebut membuktikan bahwa kombinasi perlakuan awal C. subvermispora dan steaming yang dipadukan dengan hidrolisis multi enzim selulase-selobiase-xylanase sangat efektif dalam mengkonversi bagas menjadi etanol dalam proses SSF. Hal ini dibuktikan dengan menurunnya kadar selulosa dan hemiselulosa pada residu bagas setelah proses SSF berlangsung yaitu dari 50% dan 20% menjadi 4,5% dan 3,5%. One of priority in the long term National Research Agenda for renewable energy development is bioethanol production from lignocellulosic materials. The problem in increasing ethanol production from lignocellulosic material, including bagasse, is how to convert completely polysaccharide to monosaccharide using specific enzymes. Complete conversion of bagasse includes how to convert cellulose, xylan and cellobiose. Another problem is the existence of lignin in bagasse, which makes it difficult for enzyme to access and, thus to convert polysaccharide to monosaccharide. It causes unoptimal ethanol production. Novel technology to produce ethanol from bagasse by simultaneous saccharification and fermentation (SSF) was carried out. Experiments included pre-treatments of bagasse with several white rot fungi (Ceriporiopsis subvermispora, Lentinus edodes and Pleurotus ostreatus) and steaming; hydrolysis with combination cellulase, cellobiase and xylanase enzymes; followed by fermentation using Saccharomycess cerevisiae AM 12. Combination of cellulase-cellobiase, cellulase-xylanase and cellulase-cellobiase-xylanase increased the ethanol production from bagasse. The highest ethanol concentration after hydrolysis with those enzymes were 6.9 g/L, 8.6 g/L and 9.8 g/L, respectively, compared to using cellulase only which was 6.0 g/L. The highest yield of ethanol (based on bagasse) with combination of those enzymes were 13.9%, 17.2% and 19.68%, while using cellulase only was 12.0%. The highest result of ethanol production in theoretical yield with combination of enzymes cellulase-cellobiase-xylanase is 49.5%, while using cellulase only 42.0%. Beside glucose, the increase of ethanol production from bagasse with cellulase-cellobiase enzymes confirmed that cellobiose was also produced in partial hydrolysis of cellulose with cellulase enzyme. Cellobiose was then converted to glucose simultaneously with cellobiase enzyme, this was revealed by the increase of glucose content about 16.2% after hydrolysis with cellulase-cellobiase enzymes. And then glucose was converted to ethanol simultaneously with S. cerevisiae. The increase of ethanol yields with combination of cellulase-cellobiase-xylanase enzymes confirmed that multi enzymes reaction took place on specific substrates. This multiple reactions includes hydrolysis of cellulose to glucose by cellulase, hydrolysis of xylan to xylose by xylanase enzyme and hydrolysis of cellobiose to glucose by cellobiase enzyme. Then glucose and xylose were converted to ethanol simultaneously by S. cerevisiae. This phenomenon was revealed by weight loss of cellulose and hemicellulose of bagasse after SSF process from 50% and 20% to 22% and 10%, respectively. The significance increase of the ethanol production was achieved after pre-treatment with combination of C. subvermispora and steaming 180_C. The highest ethanol production at combination of cellulase-cellobiase, cellulase-xylanase and cellulase-cellobiase-xylanase after pre-treatment C. subvermispora and steaming 180_C were 12.9 g/L, 13.5 g/L and 18.2 g/L, respectively. The highest yield of ethanol (based on bagasse) with those combination were 25.7%, 26.9% dan 36.4%, respectively. The increase of ethanol yield after pre-treatment with C. subvermispora and steaming was caused by lignin biodegradation of bagasse with C. subvermispora and dissolution of cellulose and hemicelluose crystalline in steaming treatment process. This was revealed by lignin loss about 26.5%, cellulose loss about 9.4% and hemicellulose loss about 14.1% after pre-treatment with combination of C. subvermispora and steaming at 180_C. The highest achievement of ethanol production in theoretical yield with combination cellulase-cellobiase-xylanase after pre-treatment with combination of C. subvermispora and steaming at 180_C was 91.4%. This was a very significant increase compared to the ethanol production in theoretical yield when using cellulase only (42.0%). This increase of ethanol yield revealed that combination of pre-treatment and hydrolysis of multi enzymes very effectively converting bagasse to ethanol in SSF. This phenomenon was confirmed by weight loss of cellulose and hemicellulose in bagasse after SSF process from 50% and 20% to 4.5% and 3.5%.

Abstrak :
Fermentasi asam suksinat dari tandan kosong kelapa sawit (TKKS) menggunakan bakteri amobil dari rumen sapi saat ini sedand diteliti. TKKS adalah salah satu bahan baku yang dapat digunakan untuk produksi asam suksinat karena memiliki kandungan glukosa, harga rendah, serta tersedia banyak di alam. Asam suksinat dapat diproduksi dengan beberapa metode seperti fermentasi yang dianggap lebih ramah lingkungan karena mengkonsumsi CO₂ selama prosesnya sehingga berkontribusi pada pengurangan emisi CO₂. Bakteri yang digunakan dalam percobaan ini diisolasi dari rumen sapi dan akan diimobilisasi sebelum masuk ke proses produksi asam suksinat. Fermentasi dilakukan dengan teknik Semi Simurrentous Saccharification and Fermentation (SSSF). Hidrolisis dilakukan dengan menggunakan enzim selulase selama 2 - 6 jam sebelum fermentasi terjadi. Yeast extract sebagai sumber nitrogen dan MgCO₃ sebagai zat pengatur pH divariasikan kemudian akan hasil fermentasi berupa konsentrasi asam suksinat, yield, dan produktivitas akan dibandingkan. Fermentasi dilakukan selama 48 jam dalam water bath shaker dan suhunya dijaga pada suhu 37^oC. Produk fermentasi akan dianalisis menggunakan HPLC untuk mengetahui kandungan asam suksinat. Kondisi fermentasi optimal untuk produksi asam suksinat didapatkan saat: waktu hidrolisis - 6 jam, sumber pH awal - 20 g/L, konsentrasi agen pengatur pH awal - 20 g/L. Pada kondisi yang dioptimalkan ini, produksi maksimum asam suksinat ditemukan menjadi 1,43 g/L dengan hasil asam suksinat dengan konsentrasi glukosa awal dan 0,0297 g/L. produktivitas. ......The fermentation of succinic acid from oil palm empty fruit bunches (EFB) using immobilized bacteria from cow rumen were investigated. EFB is one of raw material that can be used for succinic acid production due to its cellulose content, low prices, and availability. Succinic acid can be produced effectively by several methods, one of them is fermentation which considered more environmentally friendly due to CO₂ consumed during the process, thereby potentially contributing to reduction of CO₂ emission. Bacteria used in this experiment were isolated from cow rumen which must be immobilized before getting into succinic acid production process. Fermentation is done by Semi Simultaneous Saccharification and Fermentation (SSSF) technique. Saccharification was carried out using cellulase enzyme for 2 – 6 hours before fermentation occurs. Yeast extract as nitrogen sources and MgCO₃ as pH regulating agent were varied and compared in terms of product concentration, yield, and productivity. Fermentation was carried out for 48 hours in shaker water bath and the temperature maintained at 37^oC. Fermentation product was then examined using HPLC to find out the succinic acid content. The optimum fermentation conditions for succinic acid production were found to be: saccharification time – 2 hours, initial nitrogen sources concentration – 20 g/L, initial pH regulating agent concentration – 20 g/L. At these optimized condition, the maximum production of succinic acid was found to be 1.47 g/L with 19.64 g/g yield of succinic acid to initial glucose concentration and 0.03 g/L.h productivity.

Abstrak :
This study investigates the enzymatic hydrolysis rate of Oil Palm (Elaeis guineensis) Trunk (OPT) sap in terms of the length of saccharification process with the aim to elevate sugar production. Emphasis was placed on the reaction time and addition of supplements such epsom salt (MgSO4) and alanine amino acid (C3H7NO2) to accelerate the efficiency of Saccharomyces cerevisiae containing the enzyme invertase. A whole oil palm trunk was divided into four different sections, upper, middle-1, middle-2 and bottom with separate experiments over 10 days enzymatic reaction period. The highest saccharification rate was shown as 13.47% on the tenth day. This result indicates that the increase in the saccharification rate was positively correlated with the length of hydrolysis. Moreover, the sample with nutrients achieved the highest sugar output, 17.91% on the fourth day of hydrolysis which was 4.44% higher than the hydrolysis rate of the sample without nutrients. In the presence of complex OPT sugars, together with other essential elements, epsom salt and alanine amino acid, S.cerevisiae achieved a higher hydrolysis metabolism to simple sugars as the cells strived to produce energy and regenerated the invertase. Moreover, the upper part of the OPT rendered the highest potential for sugar production with levels of 21.2% with supplements and 15.6% without. From this experimental analysis, a conventional saccharification method was optimized through the addition of nutrients and a prolonged (10 days) hydrolysis process which yielded an increase in sugar production.