Hasil Pencarian  ::  Simpan CSV :: Kembali

"Penyakit busuk pangkal batang dan busuk akar yang disebabkan oleh jamur patogen Ganoderma merupakan penyakit yang menyebabkan kerugian pada komoditas Hutan Tanaman Industri seperti Kelapa Sawit. Pertumbuhan Ganoderma dapat dikendalikan dengan menggunakan mikroba biokontrol. Bakteri kelompok actinomycetes, dari genus Streptomyces telah banyak diteliti kemampuannya untuk menghasilkan senyawa metabolit sekunder yang bersifat antibiosis. Penelitian dilakukan untuk mengetahui pengaruh masa delayed antagonistic test yang diperpanjang, medium dan lama fermentasi isolat S. cellulosae terhadap Ganoderma sp. TB3 dan TB4. Uji Antagonistis dilakukan dengan penundaan inokulasi selama 9 hari. Aktivitas antifungal dari S.cellulosae diujikan menggunakan filtrat fermentasi berumur 10 dan 14 hari pada medium CSM broth dan PDB yang disterilisasi dengan autoklaf dan membrane filter. Filtrat fermentasi terpilih dengan hambatan terbaik diekstraksi dan diujikan terhadap Ganoderma sp. pada konsentrasi 5.000, 10.000, 20.000 dan 40.000 ppm menggunakan metode paper disc diffusion. Aktivitas antagonistis S.cellulosae dapat menghambat pertumbuhan Ganoderma sp. TB3 (83%) dan Ganoderma sp. TB4 (85%). Filtrat S.cellulosae menunjukkan hambatan paling optimal terhadap pertumbuhan Ganoderma sp. TB3 (94%) dan TB4 (93%) bila ditumbuhkan di medium CSM broth selama 14 hari dengan teknik sterilisasi membrane filter. Uji Antibiosis dengan ekstrak kasar mulai memperlihatkan hambatan terhadap pertumbuhan terhadap Ganoderma sp. TB3 (68%) dan TB4 (47%) pada konsentrasi 20.000 ppm.

---

Basal stem rot and root rot diseases caused by pathogenic fungi Ganoderma are threatening diseases that can cause severe loss in industrial tree plantation commodities, including oil palm. The mycelial growth of Ganoderma can be managed using biological control microorganism. Bacteria from the group of Actinomycetes, namely Streptomyces has been widely researched because of their ability to produce various kinds of secondary metabolites which have antibiosis activity. This research was done to show the effect of prolonged delay antagonistic test, media and incubation period of S. cellulosae towards Ganoderma sp. TB3 and TB4. Antagonistic activity was assayed using the prolonged delay antagonistic test with a 9 days delay for Ganoderma inoculation. Antifungal activity of S.cellulosae was tested using fermentation filtrate of the isolate which had been grown for 10 and 14 days in CSM broth and PDB media by still culture method. Filtrates were sterilized using autoclave and membrane filter. The filtrate with highest inhibition activity was extracted and tested against Ganoderma at a concentration of 5.000, 10.000, 20.000 and 40.000 ppm using the paper disc diffusion method. Antagonistic activity of S.cellulosae can inhibit the growth of Ganoderma sp. TB3 (83%) and TB4 (85%). Culture filtrate from CSM broth at 14 days fermentation with membrane filter sterilization technique exhibited the maximum inhibition to Ganoderma sp. TB3 (94%) and TB4 (93%). Antibiosis assay of crude extract started to show 68% inhibition of Ganoderma sp. TB3 and 47% of Ganoderma sp. TB4 at a concentration of 20.000 ppm."

"Isolat Actinomycetes BCy diisolasi dari lamun Cymodocea rotundata di Prapat Agung, Bali Barat dan telah diidentifikasi menggunakan gen 16S rRNA menunjukkan kemiripan 99,00 dengan Streptomyces sp. Isolat tersebut difermentasi dalam Production Medium 4 PM4 , diinkubasi selama 1 dan 2 minggu. Medium difiltrasi dengan etil asetat lalu biomassa dikeringkan. Hasil biomassa kering minggu 1 dan 2 1,68 g, 2,79 g . Ekstrak kasar minggu 1 68,30 mg lebih tinggi dibandingkan minggu 2 62,35 mg . Metode uji antimikroba menggunakan Kirby-Bauer. Hasil uji menunjukkan ekstrak kasar senyawa antimikroba tidak mampu menghambat Escherichia coli NBRC 3301, namun mampu menghambat Staphylococcus aureus NBRC100910 pada konsentrasi 5 mg/mL dan apabila konsentrasi ditingkatkan menjadi 15 mg/mL maka mampu menghambat Candida albicans UICC Y-29 dan Staphylococcus aureus NBRC100910.

---

Isolate Actinomycetes BCy was isolated from seagrass Cymodocea rotundata in Prapat Agung, Bali Barat and was identified using 16S rRNA gene showing similarities 99,00 with Streptomyces sp. The isolates were fermented in Production Medium 4 PM4 , incubated for 1 and 2 weeks. Medium was filtered with ethyl acetate then the biomass was dried. Total dried biomass during the 1st and 2nd weeks were 1,68 g and 2,79 g respectively. The crude extract of the 1st week 68,30 mg was higher than 2nd week 62,35 mg. Antimicrobial test was done using the Kirby Bauer method. The results show that crude extract can not inhibit Escherichia coli NBRC 3301, but inhibit Staphylococcus aureus NBRC100910 in 5 mg mL and if the concentration was added into 15 mg mL, it can inhibits Candida albicans UICC Y 29 and Staphylococcus aureus NBRC100910. "

"Penelitian ini mencakup rangkaian oksidasi kolesterol berupa studi oksidasi kolesterol, oksidasi dengan menggunakan substrat hewani, oksidasi dengan enzim terimobilisasi material magnetit silikon dioksida (M-SiO2)/magnetit kitosan (M-Chit) dan oksidasi dengan protein rekombinan Rhodococcus erythropolis BL21(DE3) (RhoChoA). Enzim kolesterol oksidase yang diproduksi dengan metode submerged fermentation dari Streptomyces sp memiliki nilai aktivitas sebesar 5,12 U/mL dan aktivitas RhoChoA sebesar 17,9 U/mL. Studi kinetika dilakukan dengan menggunakan orde satu dengan reaksi irreversible. Optimasi produksi enzim dilakukan dengan memperhatikan faktor suhu dan jenis substrat. Untuk meningkatkan karakteristik enzim, imobilisasi dilakukan pada enzim kolesterol oksidase Streptomyces sp. Material magnetit disintesis dengan metode sol-gel dengan modifikasi menggunakan magnetit silikon dioksida dan magnetit kitosan yang diberi kode M-SiO2 dan M-Chit secara berurutan. Enzim hasil produksi diimobilisasi dengan menggunakan teknik cross-linking. Hasil karakterisasi FTIR dari material magnetit menunjukkan gugus fungsi M-O di bilangan gelombang 559,88; 598,91 dan 680,1 cm‑1 , gugus Si-O di bilangan gelombang 1615,78 dan 1761,65 cm-1.Uji oksidasi dilakukan dengan beberapa variabel bebas yaitu konsentrasi enzim (0,5; 1; 2 mg/mL), konsentrasi substrat (0,75; 1,25; 2,5 mg/mL), waktu oksidasi (5, 30, 60, 120, 180 menit), serta bentuk enzim (ekstrak kasar enzim kolesterol oksidase dan enzim kolesterol oksidase terimobilisasi). Hasil uji oksidasi dikuantifikasi dengan menggunakan HPLC untuk menganalisis konsentrasi substrat dan konsentrasi enzim yang optimum dalam oksidasi yang dijadikan sebagai referensi dalam penentuan uji biosensor kolesterol. Oksidasi kolesterol dengan menggunakan substrat hewani dilakukan dengan ekstraksi dengan pelarut lemak. Kuantifikasi kadar kolesterol dalam sampel menunjukkan susbtrat dari lemak hewani memiliki konsentrasi kolesterol tertinggi dari kuning telur dengan konsentrasi 1,94 mg/mL, hati ayam (0,93 mg/mL), daging sapi (0,25 mg/mL) dan daging ayam (0,23 mg/mL). Enzim kolesterol oksidase dengan konsentrasi 2 mg/mL dapat mengoksidasi ekstrak kasar kolesterol dari kuning telur, hati ayam dan daging ayam hingga teroksidasi 20%, sedangkan ekstrak kasar kolesterol dari daging sapi teroksidasi sebesar 10%. Hasil uji oksidasi dengan menggunakan HPLC diperoleh konsentrasi substrat secara optimal dioksidasi oleh enzim terimobilisasi M-SiO2 dengan konsentrasi 20 mg/mL serta konsentrasi kolesterol 1,94 mM sebesar 90%, sedangkan enzim kolesterol oksidase bebas mengoksidasi kolesterol sebesar 80%. Uji oksidasi kolesterol menggunakan enzim kolesterol oksidase terimobilisasi magnetit kitosan (M-Chit) ditemukan konsentrasi substrat yang optimum adalah 2,5 mg/mL dan konsentrasi enzim yang paling efektif adalah 2 mg/mL. Reaksi oksidasi kolesterol dengan kondisi optimum dan menggunakan enzim terimobilisasi M-Chit dapat mengoksidasi kolesterol sampai 10%. Uji penggunaan kembali material M-Chit dalam proses imobilisasi dapat digunakan sebanyak 2 kali.

---

This research includes a series of cholesterol oxidation in the form of cholesterol oxidation studies, oxidation using animal substrates, oxidation with immobilized enzymes of magnetite silicon dioxide (M-SiO2) / magnetite chitosan (M-Chit) and oxidation with recombinant protein Rhodococcus erythropolis BL21 (DE3) ( RhoChoA). Cholesterol oxidase enzyme produced by the submerged fermentation method from Streptomyces sp has an activity value of 5.12 U / mL and a RhoChoA activity of 17.9 U / mL. The kinetic study was carried out using first order with an irreversible reaction. Optimization of enzyme production is carried out by controlling the temperatur and type of substrate. To improve the characteristics of the enzyme, immobilization was carried out on the cholesterol oxidase enzyme Streptomyces sp. The magnetite material was synthesized by the sol-gel method with modification using magnetite silicon dioxide and magnetite chitosan which were coded M-SiO2 and M-Chit, respectively. The immobilized enzymes are produced using a cross-linking technique. The FTIR characterization results of the magnetite material showed the M-O functional group at wave number 559.88; 598.91 and 680.1 cm-1, the Si-O group at wave numbers 1615.78 and 1761.65 cm-1.

The oxidation test was carried out with several independent variables, namely enzyme concentration (0.5; 1; 2 mg / mL), substrate concentration (0.75; 1.25; 2.5 mg / mL), oxidation time (5, 30, 60, 120, 180 minutes), as well as the form of the enzyme (crude extract of the cholesterol oxidase enzyme and the immobilized cholesterol oxidase enzyme). The results of the oxidation test were quantified using HPLC to analyze the optimum substrate concentration and enzyme concentration in oxidation which were used as references in determining the cholesterol biosensor test. Cholesterol oxidation using animal substrates was carried out by extraction with fat solvents. The quantification of cholesterol levels in the sample showed that the animal fat substrate had the highest cholesterol concentration from egg yolks with a concentration of 1.94 mg / mL, chicken liver (0.93 mg / mL), beef (0.25 mg / mL) and chicken meat. (0.23 mg / mL). Cholesterol oxidase enzyme with a concentration of 2 mg / mL can oxidize the crude extract of cholesterol from egg yolk, chicken liver and chicken meat up to 20%, while the crude extract of cholesterol from beef is oxidized only 10%. The results of the oxidation test using HPLC showed that the optimal substrate concentration was oxidized by the immobilized enzyme M-SiO2 with a concentration of 20 mg / mL and a cholesterol concentration of 1.94 mM of 90%, while the free cholesterol oxidase enzyme was 80% oxidized. Cholesterol oxidation test using immobilized cholesterol oxidase enzyme magnetite chitosan (M-Chit) found that the optimum substrate concentration was 2.5 mg / mL and the most effective enzyme concentration was 2 mg / mL. Cholesterol oxidation reaction under optimum conditions and using the immobilized enzyme M-Chit can oxidize cholesterol up to 10%. The M-Chit reuse test in the immobilization process can be used for 2 times."

"Enzim kolesterol oksidase adalah enzim oksidoreduktase yang mampu mendegradasi kolesterol. Pada percobaan ini, dilakukan produksi enzim kolesterol oksidase oleh Streptomyces sp. melalui fermentasi submerged lalu dilakukan investigasi terhadap aktivitas dan kemampuan katalisis enzim kolesterol oksidase. Pada percobaan, substrat dan enzim divariasikan pada berbagai konsentrasi, yaitu 0,15, 0,075, dan 0,0375 U/mL dan 1,25, 2,5, dan 5 mg/mL. Perbandingan konstanta laju reaksi antara ekstrak kasar enzim dan enzim komersial diperoleh dari hasil penelitian. Perbandingan konstanta laju reaksi enzimatis oleh faktor yang mempengaruhi, diantaranya imobilisasi enzim dan suhu inkubasi enzim, dengan data yang diperoleh dari literatur. Enzim dan substrat mengalami reaksi oksidasi pada waktu inkubasi 5, 30, 65, 120, dan 240, lalu konsentrasi kolesterol residu pada sampel dilakukan plotting dengan waktu inkubasi, dan konstanta laju reaksi diperoleh melalui permodelan reaksi orde 1 dengan pendekatan integrasi numerik Euler. Aktivitas ekstrak kasar enzim yaitu 1,69 U/mL dengan konstanta laju reaksi yaitu 0,01/menit untuk ekstrak kasar enzim dan 0,014/menit untuk enzim komersial. Selanjutnya, diperoleh faktor yang mempengaruhi konstanta laju reaksi oksidasi kolesterol secara enzimatik oleh enzim kolesterol oksidase, yaitu konsentrasi enzim, jenis enzim, imobilisasi, dan suhu inkubasi. Reaksi oksidasi kolesterol oleh enzim kolesterol oksidase dari Streptomyces sp. mengikuti reaksi orde 1.

---

Cholesterol oxidase well known as oxidoreductase enzyme which able to degrade the cholesterol. Here, we produced cholesterol oxidase from Streptomyces sp. by submerged fermentation and investigate the activity and cholesterol oxidation kinetics of cholesterol oxidase. The enzyme and substrate are diluted in various concentration, 0.15, 0.075, 0.0375 U mL and 1.25, 2.5, 5 mg mL, respectively. Further step was comparing crude enzyme and commercial enzyme from Streptomyces sp. by oxidation constant rate of reaction. The enzyme and substrate were through the oxidation reaction, and the amount of cholesterol residue in the sample are determined by HPLC. In this work, we also compared the oxidation constant rate of reaction of previous experiment from literature with affecting factors, such as immobilization and incubating temperature. The cholesterol residue in the sample are plotted by time reaction and the rate constant is obtained by first order rate reaction using Euler integration method. The crude enzyme activity is 1.69 U mL and the reaction constant are 0.01 U mL and 0.014 for crude extract and commercial enzyme, respectively. Furthermore, several factors affecting constant rate of enzymatic oxidation of cholesterol were enzyme concentration, enzyme type, immobilization, and incubating temperature. Cholesterol oxidation by Streptomyces sp. cholesterol oxidase was follow the first order reaction."

"Actinomycetes BCy berhasil diisolasi dari lamun Cymodocea rotundata, Pantai Prapat Agung Bali Barat, Indonesia. Identifikasi dengan 16S rRNA menunjukkan isolat termasuk marga Streptomyces. Penelitian bertujuan untuk mengkaji potensi aktivitas antimikroba Streptomyces sp. BCy yang ditumbuhkan pada medium Bushnell-Haas BH dengan penambahan glukosa 0,1 dan yeast extract 0,05 . Isolat diinokulasikan ke dalam 400 mL medium BH Broth lalu diinkubasi pada suhu 30oC selama 1 dan 2 minggu secara statis. Percobaan dilakukan sebanyak dua batch. Medium difiltrasi dan biomassa diukur. Filtrat diekstraksi dengan etil asetat 1:1, v/v lalu ekstrak kasar ditimbang. Ekstrak disuspensikan dengan DMSO dan akuades 1:6, v/v untuk uji antimikroba dengan metode Kirby Bauer pada konsentrasi 5 dan 15 mg/mL. Mikroba uji yang digunakan adalah Escherichia coli NBRC 3301, Staphylococcus aureus NBRC 100910, dan Candida albicans UICC Y-29. Biomassa kering meningkat dari minggu kesatu 469,9 mg ke minggu kedua 667,2 mg . Namun, berat ekstrak kasar menurun dari minggu kesatu 24,7 mg ke minggu kedua 17,05 mg . Aktivitas antimikroba dari ekstrak kasar hanya mampu menghambat Staphylococcus aureus NBRC 100910 serta ukuran zona bening meningkat pada konsentrasi 15 mg/mL.

---

Actinomycetes BCy has been isolated from seagrass Cymodocea rotundata, Prapat Agung Coastal Bali Barat, Indonesia. Identification by 16S rRNA showed that isolate belongs to genus Streptomyces. The objective of this study is to analyze antimicrobial potential of Streptomyces sp. BCy which was grown in Bushnell Haas BH medium added with 0.1 glucose and 0.05 yeast extract. The isolate was inoculated into 400 mL BH Broth then incubated at 30oC for 1 and 2 weeks using static fermentation. The experiment was carried out in two batches. Medium was filtered and dry weight of biomass was measured.

Filtrate was extracted using ethyl acetate 1 1, v v and also measured for dry weight. The dried crude extract was resuspended in DMSO and aquades 1 6, v v and used for antimicrobial testing using Kirby Bauer method in 5 and 15 mg mL. The target microbes are Escherichia coli NBRC 3301, Staphylococcus aureus NBRC 100910, and Candida albicans UICC Y 29. Biomass increased from first 469.9 mg to second week 667.2 mg. However, crude extract decreased from first 24.7 mg to second week 17.05 mg. The antimicrobial activity of crude extract was able to inhibit Staphylococcus aureus NBRC 100910 and also had larger clear zone in 15 mg mL. "

"Kolesterol terkandung di banyak bahan makanan. Kolesterol yang terkandung dalam bahan makanan diekstraksi menggunakan pelarut organik. Pembentukan produk oksidasi kolesterol dalam proses makanan dan kesehatan melibatkan reaksi kimia dan biokimia, reaksi oksidasi kolesterol ini dapat dikendalikan dalam trend oksidasi. Reaksi oksidasi kolesterol melibatkan enzim sebagai katalisator, yaitu enzim kolesterol oksidase. Bakteri yang digunakan untuk menghasilkan enzim kolesterol oksidase adalah Streptomyces sp. Reaksi oksidasi dilakukan dengan oksidasi langsung dari metode substrat. Penelitian sebelumnya jarang menggunakan bahan makanan sebagai substrat dan hanya digunakan kolesterol murni komersial. Pada penelitian ini substrat yang digunakan adalah kolesterol murni dan ekstrak kolesterol kasar dari bahan pangan. Penelitian ini bertujuan untuk mengekstrak kolesterol dari bahan makanan, memperoleh enzim oksidase kolesterol dari Streptomyces sp., Mengoksidasi ekstrak kolesterol kasar, dan membandingkannya dengan kolesterol murni komersial. Dalam penelitian ini akan dilakukan berbagai variabel bebas yaitu konsentrasi enzim (0,5; 1; 2 mg / mL), jenis substrat (kolesterol murni dan ekstrak kolesterol kasar) dan waktu reaksi (5, 30,60,120 dan 180 menit) . Uji oksidasi dilakukan pada parameter konstan tertentu dengan menghitung hasil menggunakan HPLC. Hasil ekstraksi kolesterol diperoleh konsentrasi kolesterol tertinggi dari kuning telur dengan konsentrasi 1,94 mg/mL, hati ayam (0,93 mg/mL), daging sapi (0,25 mg/mL) dan daging ayam (0,23 mg/mL)). Enzim oksidase kolesterol dengan konsentrasi 2 mg/mL dapat mengoksidasi ekstrak kasar kolesterol dari kuning telur, hati ayam dan daging ayam hingga terdegradasi 20%, sedangkan ekstrak kolesterol kasar dari daging sapi mengalami degradasi sebesar 10%.

---

Cholesterol is contained in many food ingredients. Cholesterol contained in food ingredients is extracted using organic solvents. The formation of cholesterol oxidation products in food and health processes involves chemical and biochemical reactions, these cholesterol oxidation reactions can be controlled in an oxidation trend. Cholesterol oxidation reaction involves an enzyme as a catalyst, namely the cholesterol oxidase enzyme. The bacteria used to produce cholesterol oxidase enzymes are Streptomyces sp. The oxidation reaction is carried out by direct oxidation of the substrate method. Previous studies rarely used food ingredients as a substrate and only used commercially pure cholesterol. In this study, the substrate used was pure cholesterol and crude cholesterol extract from food ingredients. This study aims to extract cholesterol from food ingredients, obtain cholesterol oxidase enzymes from Streptomyces sp., Oxidize crude cholesterol extracts, and compare it with commercial pure cholesterol. In this research, various independent variables will be carried out, namely enzyme concentration (0.5; 1; 2 mg/mL), type of substrate (pure cholesterol and crude cholesterol extract) and reaction time (5, 30,60,120 and 180 minutes). The oxidation test is carried out at certain constant parameters by calculating the results using HPLC. Cholesterol extraction results obtained the highest cholesterol concentration from egg yolk with a concentration of 1.94 mg/mL, chicken liver (0.93 mg/mL), beef (0.25 mg/mL) and chicken meat (0.23 mg/mL). Cholesterol oxidase enzyme with a concentration of 2 mg/mL can oxidize the crude cholesterol extract from egg yolk, chicken liver and chicken meat to 20% degradation, while crude cholesterol extract from beef is degraded by 10%."

"Kendala yang sering dihadapi pada pertanian adalah hama tanaman yang dapat mengganggu produktivitas tanaman pangan. Pemberantasan hama sering menggunakan pestisida kimiawi yang dapat berdampak buruk pada lingkungan dan tanaman. Salah satu alternatif mengatasi permasalahan tersebut adalah dengan menggunakan mikroorganisme sebagai biokontrol bagi hama tanaman. Mikroorganisme diketahui berpotensi sebagai agen biokontrol, dan aktivitas tersebut dapat diuji dengan  Antibiosis. Aktivitas antibiosis terlihat sebagai kemampuan menghambat pertumbuhan suatu mikroorganisme terhadap mikroorganisme lain. Pada penelitian ini dilakukan uji antibiosis dan aktivitas enzim dari empat isolat basil Gram negatif yaitu TTM, TTO, TKL, TTH, terhadap fungi Fusarium oxysporum dan Ganoderma boninense. Keempat isolat bakteri difermentasikan dalam medium Nutrient broth (NB) selama 6, 9, dan 12 hari, pada suhu inkubasi 39oC. Uji antibiosis dilakukan secara kualitatif dengan menggunakan cylinder diffusion method. Hasil uji antibiosis menunjukkan bahwa hanya isolat TTH dan TTM yang memiliki potensi untuk menghambat fungi Ganoderma boninense  dalam fermentasi hari ke 6,9, dan 12. Hasil uji aktivitas enzim menunjukkan bahwa hanya isolat TTO yang memiliki aktivitas kitinolitik.

---

One of the common challenges in agriculture is the presence of plant pests that can disrupt the productivity of food crops. Pest control often relies on the use of chemical pesticides, which can have negative impacts on the environment and plants. One alternative to address this issue is the utilization of microorganisms as biocontrol agents for plant pests. Microorganisms are known to have the potential as biocontrol agents, and this activity can be tested through antibiosis. Antibiosis activity is observed as the ability to inhibit the growth of one microorganism by another. In this study, antibiosis and enzyme activity tests were conducted on four isolates of Gram-negative bacteria, namely TTM, TTO, TKL, and TTH, against the fungi Fusarium oxysporum and Ganoderma boninense. The four bacterial isolates were fermented in Nutrient Broth (NB) medium for 6, 9, and 12 days at an incubation temperature of 39°C. The antibiosis test was qualitatively performed using the cylinder diffusion method. The results of the antibiosis test showed that only the TTH and TTM isolates had the potential to inhibit the Ganoderma boninense fungi during the 6th, 9th, and 12th days of fermentation. The enzyme activity test results indicated that only the TTO isolate exhibited chitinolytic activity."

"Industri kelapa sawit berperan penting dalam perekonomian Indonesia. Namun, penyakit Busuk Pangkal Batang oleh Ganoderma boninense mengancam perkebunan kelapa sawit. Pengembangan agen biokontrol diperlukan sebagai alternatif dari penggunaan fungisida. Pada penelitian sebelumnya, kultur tunggal Bacillus siamensis LDR, Bacillus sp. TKA6A, dan Stenotrophomonas maltophilia G17 berhasil menghambat pertumbuhan Ganoderma boninense. Pada penelitian ini, ketiga bakteri tersebut disatukan sebagai ko-kultur. Uji Antagonis dan Antibiosis dilakukan untuk melihat kemampuan ko-kultur dalam menghambat Ganoderma boninense. Efektivitas hambatan direpresentasikan sebagai nilai Persentase Hambatan Pertumbuhan Radial (PHPR). Uji Antagonis dilakukan dengan metode pour plate dan paper disc dual culture pada medium Potato Dextrose Agar (PDA) dan Plate Count Agar (PCA). Berdasarkan pengujian, nilai PHPR pada metode pourplate mencapai 100% di kedua medium, sedangkan pada metode dual culture, nilai PHPR pada medium PCA (46,88%) lebih tinggi dibandingkan medium PDA (32,80%). Sementara itu, Fermentasi ko-kultur bakteri pada uji antibiosis dilakukan di dalam medium NB dengan dua variabel perlakuan, yakni lama fermentasi dan sumber karbon. Uji Antibiosis dengan filtrat hasil fermentasi dilakukan dengan metode Pour plate dan agar well diffusion. Uji antibiosis dengan metode pour plate memperoleh hambatan sebesar 100% pada ketiga variasi medium fermentasi, dan 94,94% pada variasi 5 hari di medium NB+Glukosa. Di samping itu, nilai PHPR pada metode agar well diffusion berkisar dalam rentang 22.57% sampai 43,74%. Perlu dilakukan analisis lebih lanjut mengenai kandungan senyawa antifungi yang dapat dihasilkan oleh ko-kultur tersebut serta pengembangan aplikasi ko-kultur pada tahap pembibitan kelapa sawit.

---

The oil palm industry is crucial to the economic growth of Indonesia. However, Basal Stem Rot disease caused by Ganoderma boninense poses a significant threat. This study aimed to develop biocontrol agents as an alternative to environmentally harmful fungicides. Previous research demonstrated that single cultures of Bacillus siamensis LDR, Bacillus sp. TKA6A, and Stenotrophomonas maltophilia G17 inhibit Ganoderma boninense. In this research, the inhibiton activities against Ganoderma boninense of these strains in co-culture were evaluated through antagonist and antibiosis assays, presenting results as Growth Inhibition Rates (GIR). Antagonistic tests, conducted using the pour plate method and paper disc dual culture on Potato Dextrose Agar (PDA) and Plate Count Agar (PCA) media, showed 100% inhibition with the pour plate method on both media. The dual culture method revealed higher GIR on PCA (46.88%) compared to PDA (32.80%). Antibiosis tests involved fermenting the co-culture in Nutrient Broth (NB) medium with varying fermentation durations and carbon sources. The pour plate method using fermentation filtrate achieved 100% inhibition across all media variations, with 94.94% in the 7-day NB+Glucose medium. GIR values from the agar well diffusion method ranged from 22.57% to 43.74%. Further analysis is required to identify antifungal compounds produced by the co-culture and to develop applications for co-culture in palm oil nurseries.

"