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Abstrak :
The objectives of this research were to obtain coconut vinegar with acetic acid concentrate more than 4% and to determine the ABSTRAK
Penelitian bertujuan untuk menghasilkan asam cuka air kelapa dengan kadar asam lebih dari 4% dan mengetahui kandungan total polifenol dari asam cuka tersebut. Cuka air kelapa dibuat melalui dua tahap fermentasi yaitu fermentasi alkohol dan fermentasi asam asetat. Penambahan sukrosa sebanyak 15% (b/v) dan 20% (b/v) terhadap substrat diperlukan untuk mendukung fermentasi alkohol. Penambahan jumlah inokulum A. aceti fermentasi asam asetat dilakukan dengan tiga variasi 10% (v/v), 15% (v/v) dan 20% (v/v). Kadar asam asetat tertinggi yaitu 4,28±0,12 % diperoleh pada hari ke-49 fermentasi asam asetat dengan penambahan sukrosa 15% (b/v) dan 10% (v/v) inokulum A. aceti. Hasil pengukur total polifenol berkisar antara 467,38±49,14 dan 572,31±3,05 mgGAE/100ml.

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ABSTRACT
concentration of total polyphenol in the vinegar. Coconut vinegar was made through alcohol and acetic acid fermentation. Sucrose addition 15% (b/v) and 20% (b/v) were needed to support alcohol fermentation. Three concentrations of Acetobacter aceti inoculums were applied: 10% (v/v), 15% (v/v) and 20% (v/v). The highest acid concentration produced was 4,28±0,12 % in day 49 of the acetic acid fermentation, with 15% (b/v) sucrose and 10% (v/v) A. aceti inoculums addition. Total polyphenol’s concentration were ranged between 467,38±49,14 and 572,31±3,05mgGAE/100ml.

Abstrak :
[Aspergillus flavus UICC 360 merupakan fungi yang mampu menghasilkan senyawa metabolit sekunder berupa lovastatin. Penelitian bertujuan untuk mengetahui pengaruh variasi konsentrasi urea terhadap kemampuan Aspergillus flavus UICC 360 dalam menghasilkan lovastatin. Proses fermentasi menggunakan konsentrasi inokulum Aspergillus flavus UICC 360 sebesar 1,96% (v/v) dalam medium Czapek’s Dox Broth (CDB) modifikasi dengan variasi konsentrasi urea (0 mM, 33 mM, 42 mM, 50 mM, 58 mM, dan 67 mM) dan inkubasi selama 7 hari pada suhu ruang (27--300C) dengan kecepatan agitasi 90 rpm. Ekstrak hasil fermentasi dalam etil asetat diuji terhadap Candida albicans UICC Y-29 menggunakan metode difusi agar cara cakram. Ekstrak hasil fermentasi dari konsentrasi urea 42 mM mempunyai indeks penghambatan rata-rata tertinggi sebesar 0,54 ± 0,15. Hasil Kromatografi Lapis Tipis (KLT) menunjukkan bahwa nilai Rf ekstrak hasil fermentasi dari konsentrasi urea 42 mM sama dengan lovastatin standar, yaitu 0,42 yang mengindikasikan ekstrak mengandung lovastatin. Uji Least Significant Difference (LSD) (P < 0,05) menunjukkan terdapat perbedaan nyata variasi konsentrasi urea terhadap kemampuan Aspergillus flavus UICC 360 dalam menghasilkan lovastatin. Hal tersebut menunjukkan bahwa pemberian variasi konsentrasi urea berpengaruh terhadap kemampuan Aspergillus flavus UICC 360 dalam menghasilkan lovastatin.;Aspergillus flavus UICC 360 is capable of producing secondary metabolites such as lovastatin. The study aims to determine the effect of variations of urea concentration on the ability of Aspergillus flavus UICC 360 to produce lovastatin. The fermentation process using 1.96% (v/v) inoculum concentration of Aspergillus flavus UICC 360 in the Czapek’s Dox Broth (CDB) medium modified with urea concentration variations (0 mM, 33 mM, 42 mM, 50 mM, 58 mM, and 67 mM) and incubated for 7 days at room temperature (27--30 °C) with agitation speed of 90 rpm. Ethyl acetate extracts were tested against Candida albicans UICC Y-29 using agar disc diffusion method. The extract from fermentation medium of 42 mM urea has the highest average of inhibition index of 0.54 ± 0.15. Results of Thin Layer Chromatography (TLC) showed that the extract from fermentation medium of 42 mM urea has the same Rf value with lovastatin standard Rf 0.42 which indicated that the extract contained lovastatin. Least Significant Difference (LSD) test showed that there were significant differences in the urea concentration variation in the ability of Aspergillus flavus UICC 360 to produce lovastatin. It shows that variation of urea concentrations affect the ability of Aspergillus flavus UICC 360 to produce lovastatin., Aspergillus flavus UICC 360 is capable of producing secondary metabolites such as lovastatin. The study aims to determine the effect of variations of urea concentration on the ability of Aspergillus flavus UICC 360 to produce lovastatin. The fermentation process using 1.96% (v/v) inoculum concentration of Aspergillus flavus UICC 360 in the Czapek’s Dox Broth (CDB) medium modified with urea concentration variations (0 mM, 33 mM, 42 mM, 50 mM, 58 mM, and 67 mM) and incubated for 7 days at room temperature (27--30 °C) with agitation speed of 90 rpm. Ethyl acetate extracts were tested against Candida albicans UICC Y-29 using agar disc diffusion method. The extract from fermentation medium of 42 mM urea has the highest average of inhibition index of 0.54 ± 0.15. Results of Thin Layer Chromatography (TLC) showed that the extract from fermentation medium of 42 mM urea has the same Rf value with lovastatin standard Rf 0.42 which indicated that the extract contained lovastatin. Least Significant Difference (LSD) test showed that there were significant differences in the urea concentration variation in the ability of Aspergillus flavus UICC 360 to produce lovastatin. It shows that variation of urea concentrations affect the ability of Aspergillus flavus UICC 360 to produce lovastatin.]

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ABSTRAK
Telah dilakukan studi mengenai penggunaan Achromobacter insolitus dengan penambahan pupuk kandang, yakni pupuk kotoran ayam, pupuk kotoran kambing, pupuk kotoran sapi, dan pupuk urin kelinci, untuk mengontrol Pythium aphanidermatum pada mentimun (Cucumis sativus). Tujuan penelitian untuk mengetahui: potensi Achromobacter insolitus sebagai agen biokontrol untuk menekan penyakit rebah kecambah akibat Pythium aphanidermatum, mekanisme bakteri dalam menekan penyakit tersebut, pengaruh penambahan pupuk kandang pada penggunaan A. insolitus dalam menekan penyakit rebah kecambah, dan kombinasi bakteri-pupuk kandang yang memiliki efek paling efektif. Penelitian dilakukan di Lembaga Ilmu Pengetahuan Indonesia (LIPI), Mikrobiologi, Pusat Penelitian Biologi pada bulan November 2014 sampai April 2015. Metode yang digunakan: uji biokontrol in planta yang diamati selama 14 hari, uji aktivitas protease, uji aktivitas selulase, dan uji in vitro daya hambat. Persentase kelayuan mentimun didapat sebagai berikut: kelompok dengan pemberian Achromobacter insolitus 40%, A. insolitus dan pupuk kotoran ayam 20%, A. insolitus dan pupuk kotoran kambing 30%, A. insolitus dan pupuk kotoran sapi serta A. insolitus dan pupuk urin kelinci masing-masing 35%. Achromobacter insolitus menghasilkan enzim protease ekstraseluler dengan indeks proteolitik (IP) sebesar 1,4, enzim selulase ekstraseluler dengan indeks selulolitik (IS) sebesar 1,7, dan persentase daya hambat terhadap P. aphanidermatum sebesar 28%. Kombinasi bakteri-pupuk kotoran ayam merupakan kombinasi yang paling efektif dalam menekan penyakit rebah kecambah.

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ABSTRACT
A study on effect of Achromobacter insolitus combined with various kinds of manures, which are manures of chicken, goat, cow, and rabbit urine, to control Pythium aphanidermatum of cucumber (Cucumis sativus) has been conducted. This research aims to evaluate: biological control activity of Achromobacter insolitus alone and its combination with the manures for suppressing damping-off caused by Pyhtium aphanidermatum and its mechanisms. Research has been conducted at Microbiology, Research Center for Biology, Indonesian Institute of Science (LIPI) from November 2014 to April 2015. The methods are biocontrol assay in planta which observed for 14 days, protease activity assay, cellulase activity assay, and in vitro inhibition assay. Result showed that A. insolitus alone resulted 40% of cucumber damping-off, A. insolitus combined with chicken manure (20%), A. insolitus combined with goat manure (30%), A. insolitus combined with cow manure (35%), and A. insolitus combined with rabbit urine (35%). In in vitro test showed that A. insolitus inhibited P. aphanidermatum growth (28%) that produced extracellular protease enzyme with proteolytic index (PI) value was 1,4 and extracellular cellulase enzyme with cellulolytic index (CI) value was 1,7. Bacteria-chicken manure combination has the most effective effect to suppress damping-off.

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ABSTRAK
Aspergillus flavus UICC 360 telah diketahui mampu menghasilkan lovastatin pada fermentasi menggunakan sumber nitrogen NaNO3. Penelitian bertujuan untuk mengetahui pengaruh variasi konsentrasi NH4NO3 terhadap kemampuan kapang tersebut dalam menghasilkan lovastatin. Fermentasi menggunakan medium Czapek’s Dox Broth modifikasi dengan variasi konsentrasi NH4NO3 (0 mM; 25,00 mM; 31,25 mM; 37,50 mM; 43,75 mM; dan 50,00 mM). Aspergillus flavus UICC 360 dengan konsentrasi inokulum sebesar 1,96% (v/v) diinokulasikan ke dalam medium, kemudian diagitasi 90 rpm, pada suhu ruang (27o--30oC) selama 7 hari untuk mendapatkan ekstrak hasil fermentasi. Pengujian ekstrak lovastatin di dalam etil asetat dilakukan terhadap Candida albicans UICC Y-29 dengan metode difusi agar cara cakram. Ekstrak hasil fermentasi dengan perlakuan 37,50 mM NH4NO3 menunjukkan indeks penghambatan tertinggi, yaitu sebesar 0,84 ± 0,07. Hasil Kromatografi Lapis Tipis (KLT) ekstrak hasil fermentasi perlakuan 25,00 mM NH4NO3 dan 37,50 mM NH4NO3 memiliki Rf (0,45), perlakuan 31,25 mM NH4NO3 dan 43,75 mM NH4NO3 memiliki Rf (0,47), sedangkan nilai Rf perlakuan 50 mM NH4NO3 (0,48). Nilai Rf ekstrak hasil fermentasi tersebut hampir sama dengan Rf lovastatin standar, yaitu (0,46), sehingga mengindikasikan adanya senyawa lovastatin di dalam ekstrak. Hasil uji perbandingan berganda Least Significant Differences (LSD) (P < 0,05) menunjukkan adanya pengaruh nyata pemberian variasi konsentrasi NH4NO3 terhadap kemampuan A. flavus UICC 360 dalam menghasilkan lovastatin.

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ABSTRACT
Aspergillus flavus UICC 360 has been reported to produce lovastatin in fermentation by using nitrogen source such as NaNO3. The research aims to determine the effect of variations of NH4NO3 concentration on the ability of A. flavus UICC 360 to produce lovastatin. Fermentation was carried out by using Czapek's Dox Broth modified with variations of NH4NO3 concentration (0 mM; 25.00 mM; 31.25 mM; 37.50 mM; 43.75 mM; and 50.00 mM). Aspergillus flavus UICC 360 with inoculum concentration of 1.96% (v/v) was inoculated into the medium and then agitated 90 rpm, at room temperature (27o--30oC) for 7 days to obtain the fermentation extract. Extract in ethyl acetate was tested with a disc diffusion method against Candida albicans UICC Y-29. The extract from the fermentation using 37.50 mM NH4NO3 showed the highest inhibition index 0.84 ± 0.07. The results of Thin Layer Chromatography (TLC) of extract from the fermentation of using 25.00 mM NH4NO3 and 37.50 mM NH4NO3 have Rf (0.45), 31.25 mM NH4NO3 and 43.75 mM NH4NO3 have Rf (0.47), and 50 mM NH4NO3 have Rf (0.48). The Rf value of extracts have nearly similiar with a lovastatin standard 0.46 which indicated there was lovastatin in the extract. The results of Least Significant Differences (LSD) (P <0.05) showed there was a significant effect of NH4NO3 concentration variation in the ability of A. flavus UICC 360 to produce lovastatin.

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Aspergillus flavus UICC 360 koleksi Universitas Indonesia Culture Collection (UICC) telah diteliti dan diuji mampu menghasilkan lovastatin. Penelitian bertujuan untuk mengetahui pengaruh variasi konsentrasi amonium sulfat (0 mM, 15,15 mM, 18,94 mM, 22,73 mM, 26,52 mM, dan 30,30 mM) sebagai sumber nitrogen terhadap kemampuan Aspergillus flavus UICC 360 menghasilkan lovastatin. Fermentasi menggunakan 1,96% (v/v) inokulum sel kapang selama 7 hari pada medium Czapek?s Dox Broth modifikasi dalam suhu ruang (27--30oC) dengan pengocokan 90 rpm. Ekstrak dalam etil asetat diuji terhadap Candida albicans UICC Y-29 dengan metode difusi agar cara cakram. Ekstrak hasil fermentasi dari perlakuan 22,73 mM amonium sulfat memiliki kemampuan tertinggi menghambat Candida albicans UICC Y-29 dengan indeks penghambatan rata-rata 0,94 ± 0,06. Hasil Kromatografi Lapis Tipis (KLT) menunjukkan bahwa ekstrak hasil fermentasi perlakuan amonium sulfat 15,15 mM memiliki nilai Rf sama dengan lovastatin standar sebesar 0,48. Ekstrak hasil fermentasi perlakuan amonium sulfat 18,94 mM, 22,73 mM, 26,52 mM, dan 30,30 mM memiliki nilai Rf hampir sama dengan nilai Rf lovastatin standar. Hasil KLT tersebut dapat mengindikasikan ekstrak mengandung lovastatin. Uji Least Significant Difference (LSD) (P<0,05) menunjukkan ada perbedaan nyata variasi konsentrasi amonium sulfat terhadap kemampuan Aspergillus flavus UICC 360 menghasilkan lovastatin. Hal tersebut menunjukkan bahwa terdapat pengaruh variasi konsentrasi amonium sulfat terhadap kemampuan Aspergillus flavus UICC 360 dalam menghasilkan lovastatin.

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ABSTRACT
The ability of Aspergillus flavus UICC 360 to produce lovastatin had been shown in previous study. The aim of this study is to determine the effect of variation in ammonium sulphate concentration at 0 mM, 15.15 mM, 18.94 mM, 22.73 mM, 26.52 mM, and 30.30 mM toward the ability of Aspergillus flavus UICC 360 in producing lovastatin. Fermentation was carried out by using 1.96% (v/v) of inoculum in modified Czapek?s Dox Broth for seven days at room temperature (27--30oC) with 90 rpm agitation. The extract in ethyl acetate was tested by disk diffusion method against Candida albicans UICC Y-29. The extract from fermentation of 22.73 mM ammonium sulphate showed the highest inhibition index of 0.94 ± 0.06. The result of Thin Layer Chromatography (TLC) showed that extract from fermentation of 15.15 mM ammonium sulphate had similar Rf value with lovastatin standard. Meanwhile, extract from fermentation of 18.94 mM, 22.73 mM, 26.52 mM, and 30.30 mM ammonium sulphate had nearly similar Rf value with lovastatin standard. The TLC result indicated that the extract contained lovastatin. Least Significant Difference test (LSD) (P<0.05) showed there was significant difference of variation in ammonium sulphate concentration toward the ability of Aspergillus flavus UICC 360 to produce lovastatin. The result of this study showed that the variation in ammonium sulphate concentration affect the ability of Aspergillus flavus UICC 360 in producing lovastatin.

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Penelitian biodegradasi pewarna tekstil Congo Red telah dilakukan menggunakan bakteri Enterococcus faecalis. Biodegradasi dilakukan pada medium Bushnell Haas yang ditambahkan 1.000 ppm (0,1%) Congo Red dengan konsentrasi inokulum 18 x 107 (CFU/ml) sebanyak 1%, 5% dan 10%. Persentase biodegradasi diukur dengan Spektrofotometer UV-Vis (λ 490 nm) menunjukkan bahwa persentase degradasi terbaik diperoleh pada inokulum 10% yang telah mendegradasi 98,10% Congo Red pada hari pertama. Penelitian selanjutnya 2.500 ppm (0,25%) dan 5.000 ppm (0,5%) Congo Red menunjukkan bahwa bakteri Enterococcus faecalis mampu mendegradasi 5.000 ppm (0,5%) Congo Red hingga 96,88% pada hari ke dua puluh satu. ......Research on the biodegradation of textile dye Congo Red has been carried out using Enterococcus faecalis bacteria. Biodegradation was performed in a Bushnell Haas medium containing 1.000 ppm (0,1%) of Congo Red which was inoculated with 1% , 5 % and 10 % inoculum (18 x 107 CFU/ml). The percentage of biodegradation as measured by UV - Vis Spectrophotometer (λ 490 nm ) showed that the highest degradation (98,10%) was obtained from 10% inoculum after one day incubation period. Further experiments using 2.500 ppm (0,25%) and 5.000 ppm (0,25%) Congo Red showed that the bacteria still had the ability to degrade 96,88% of 5.000 ppm (0,5%) Congo Red after twenty one day incubation period.

Abstrak :
Aspergillus flavus UICC 360 has been reported to produce lovastatin. This research was carried out to determine the effect of concentration variation of glucose technical grade on the ability of A. flavus UICC 360 to produce lovastatin. The fermentation process was carried out using inoculum 2% (v/v) modified Czapek's Dox Broth (CDB). Variation of glucose technical grade concentration used were 0 g/L, 5 g/L, 10 g/L, 15 g/L, 20 g/L, 25 g/L, 30 g/L and 35 g/L. Fermentation was carried out for 6 days at room temperature (27--30ºC) with agitation speed of 90 rpm. Extraction of lovastatin was done with ethyl acetate solvent. The extract was assayed by disk diffusion method against Candida albicans UICC Y-29. The results revealed that the fermentation extract on glucose technical grade at 15 g/L showed the highest inhibition index of 0.77 ± 0.09. Analysis using Least Significant Difference (LSD) (P < 0.05) showed there was significant difference on the ability of A. flavus UICC 360 to produce lovastatin at different glucose technical grade concentration. High Performance of Liquid Chromatography (HPLC) showed that concentration of 15 g/L glucose technical grade had the same retention time with standard lovastatin at 4.52 minutes and 54.2 mg/L concentration.

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Telah dilakukan penelitian untuk mengetahui pengaruh variasi konsentrasi molase terhadap kemampuan Aspergillus flavus UICC 360 dalam menghasilkan lovastatin. Proses fermentasi dilakukan dalam medium Czapek?s Dox Broth (CDB) modifikasi dengan perlakuan variasi konsentrasi molase (0 g/L, 55 g/L, 60 g/L, 65 g/L, 70 g/L, 75 g/L, 80 g/L, dan 85 g/L) selama 7 hari pada suhu ruang (27--30˚C) dengan kecepatan agitasi 90 rpm. Ekstraksi senyawa lovastatin dilakukan dengan pelarut etil asetat. Pengujian ekstrak lovastatin dilakukan dengan metode difusi agar cara cakram terhadap Candida albicans UICC Y-29. Hasil penelitian menunjukkan bahwa nilai rata-rata indeks penghambatan tertinggi sebesar 0,49 ± 0,07 diperoleh dari ekstrak lovastatin dengan perlakuan molase 70 g/L. Analisis uji Least Significant Difference (LSD) (P < 0,05) menunjukkan bahwa terdapat pengaruh nyata perlakuan konsentrasi molase terhadap kemampuan A. flavus UICC 360 dalam menghasilkan lovastatin. Analisis kualitatif dan kuantitatif lovastatin dengan Kromatografi Cair Kinerja Tinggi (KCKT) menunjukkan keberadaan senyawa lovastatin pada perlakuan molase 70 g/L dengan waktu retensi sama dengan lovastatin standar, yaitu 4,5 menit dengan kadar 1,1 mg/L.

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ABSTRACT
This research was carried out to determine the effect of concentration variation of molasses on the ability of Aspergillus flavus UICC 360 to produce lovastatin. The fermentation process was carried out using Czapek's Dox Broth (CDB) containing variation of molasses concentrations (0 g /L, 55 g /L, 60 g/L, 65 g/L, 70 g/L, 75 g/L, 80 g/L, and 85 g/L) for 7 days at room temperature (27--30˚C) with agitation speed of 90 rpm. Extraction of lovastatin was done with ethyl acetate solvent. Lovastatin extracts were tested using agar disc diffusion method against Candida albicans UICC Y-29. The result revealed that the highest inhibition index of 0.49 ± 0.07 was obtained from lovastatin extracts-treated molasses 70 g/L. Analysis using Least Significant Difference (LSD) (P < 0.05) indicated that there was significant difference on the ability of A. flavus UICC 360 to produce lovastatin at different molasses concentration. Qualitative and quantitative analysis of lovastatin using High Performance Liquid Chromatography (HPLC) proved that lovastatin was present at 70 g/L molasses with the same retention time to lovastatin standard, which was 4.5 minutes, at concentration of 1.1 mg/L.

Abstrak :
Telah dilakukan uji aktivitas antifungi partikel nano seng oksida (NP ZnO) terhadap isolat kapang A1P dan A2C, yang di isolasi dari plafon rumah. Metode uji yang dilakukan adalah plate agar menggunakan PDA yang ditambahkan NP ZnO pada konsentrasi 0,1%; 0,25%; 0,5%; atau 1%. Pengamatan pertumbuhan kedua isolat kapang dilakukan dengan metode hanging drop menggunakan medium PDA yang mengandung NP ZnO sebesar 0,1%; 0,25%; 0,5%; 1%, 1,5%; atau 2%. Konsentrasi minimum hambatan (KMH) ditentukan dengan metode tube dilution menggunakan medium PDB dengan konsentrasi NP ZnO 0,5%; 1%; 1,5%; atau 2%. Konsentrasi minimum fungisidal (KMF) ditentukan berdasarkan jumlah sel hasil total plate count (TPC) dari perlakuan tube dilution. Hasil plate agar dan hanging drop menunjukan bahwa NP ZnO memiliki sifat fungistatik yang meningkat seiring besarnya konsentrasi. Hal tersebut diindikasikan dengan tetap adanya pertumbuhan A1P dan A2C walaupun mengalami perlambatan germinasi spora dan penurunan diameter koloni. Pada tube dilution, isolat kapang juga mengalami perlambatan pertumbuhan yang signifikan dibandingkan dengan kontrol, sesuai dengan hasil plate agar maupun hanging drop. Kedua isolat kapang tidak mengalami pertumbuhan pada cat yang ditambah NP ZnO walaupun telah di inkubasi melebihi waktu inkubasi tube dilution, selama 2 minggu. ...... Antifungal activity test of zinc oxide nanoparticle (ZnO) against molds A1P and A2C, which were isolated from ceiling, has been carried out. Agar plate method test was done using PDA added with 0,1%; 0,25%; 0,5%; or 1% ZnO. Growth of the molds on PDA medium added with 0,1%; 0,25%; 0,5%; 1%, 1,5%; or 2% ZnO was observed using hanging drop method. Minimum inhibition concentration (MIC) was determined by tube dilution method in PDB medium which contains 0,5%; 1%; 1,5%; or 2% ZnO. Minimum fungicidal concentration (MFC) was determined based on cells count from total plate count (TPC) of tube dilution. Results from plate agar and hanging drop showed that ZnO worked as fungistatic which escalated along its increased concentration. This was indicated by the growth of A1P and A2C although the spore germination was slow down and also decrease on the colony diameter. Growth of molds in tube dilution was slow down significantly compared to control, which correspond to result of plate agar and hanging drop. Both isolates did not grow on the paint test which was added with ZnO, although the incubation time has been prolonged to more than 2 weeks.

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ABSTRAK
Telah dilakukan penelitian mengenai pemanfaatan teknik adaptasi dan imobilisasi sel khamir Candida tropicalis InaCC Y799 pada fermentasi xilitol dari hidrolisat hemiselulosa daun tebu (Saccharum officinarum L.). Praperlakuan daun tebu dilakukan menggunakan 1,8% asam maleat dan iradiasi gelombang mikro pada suhu 180 C selama 5 menit. Penelitian bertujuan untuk mempelajari kemampuan khamir untuk tumbuh dan beradaptasi pada hidrolisat hemiselulosa sebelum fermentasi, dan meneliti potensi penggunaan matriks kalsium alginat untuk imobilisasi sel khamir, serta pengaruhnya dalam peningkatan produksi xilitol dari hidrolisat hemiselulosa daun tebu. Hasil menunjukkan bahwa khamir C. tropicalis InaCC Y799 teradaptasi mampu tumbuh pada media hidrolisat hemiselulosa daun tebu. Adaptasi khamir pada 75% hidrolisat menghasilkan konsentrasi dan rendemen xilitol maksimum masing-masing sebesar 11,27 1,65 g/L dan 0,56 0,05 g/g (54,98% dari nilai rendemen teoritis) selama 24 jam fermentasi, lebih tinggi daripada khamir tidak teradaptasi (kontrol). Namun demikian, imobilisasi C. tropicalis pada kalsium alginat hanya menghasilkan konsentrasi dan rendemen xilitol maksimum masing-masing sebesar 5,51 0,63 g/L dan 0,27 0,04 g xilitol/g xilosa awal (29,97% dari rendemen teroritis) selama 48 jam fermentasi. Konsentrasi dan rendemen xilitol pada sistem sel terimobilisasi setengah kali lebih rendah daripada sel bebas (kontrol).

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ABSTRACT
Research on adaptation and immobilization method of Candida tropicalis InaCC Y799 in xylitol production from sugarcane (Saccharum officinarum L.) waste hemicellulosic hydrolysate has been conducted. Sugarcane waste were pretreated with 1,8% of maleic acid and microwave at 180 C for 5 minutes. The aim of this research were to study the effects of yeast adaptation using sugarcane waste hydrolysate and the potential of using calcium alginate as immobilization matrix of yeast C. tropicalis InaCC Y799 in the xylitol production during fermentation. The results revealed that fermentation using adapted yeast in 75% concentration of hydrolysate produce higher xylitol concentration and yield than those with non adapted yeast. The highest xylitol concentration and yield obtained using adapted yeast were 11.27 1.65 g/L and 0.56 0.05 g xylitol /g initial xylose (54.98% of theoretical yield) for 24-hours fermentation. However, the highest xylitol yield obtained by immobilization method were 5.51 0.63 g/L and 0.27 0.04 g xilitol/g initial xylose (29.97% of theoretical yield) for 48-hours fermentation, which were lower than free cells system.