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"Kelompok Actinobacteria berfilamen merupakan bakteri Gram positif yang beberapa anggotanya diketahui memiliki kemampuan mendegradasi selulosa dengan menghasilkan selulase. Penelitian ini bertujuan untuk mengetahui kemampuan tumbuh isolat Actinobacteria-like GL1-2, GL1-9, dan GL1-12 pada variasi media agar (ISP 1, ISP 2, ISP 3, dan modified Bennett’s) dan suhu (25, 30, 35, 40, 45, 50, dan 55°C), serta mengetahui kemampuan selulolitiknya pada substrat 1% CMC di berbagai suhu (30, 35, 40, 45, 50, dan 55°C). Kemampuan selulolitik diuji dengan menginokulasi biakan pada medium agar minimal (Mm) dengan penambahan 1% CMC, kemudian diinkubasi pada berbagai suhu selama 3, 7, dan 14 hari. Kemampuan selulolitik diamati dengan terbentuknya zona bening di sekitar koloni setelah ditetesi 0,1% Congo red dan dibilas dengan larutan NaCl 1 M. Isolat GL1-2 dan GL1-9 menunjukkan pertumbuhan miselium substrat dalam jumlah banyak pada semua medium yang diuji, namun sporulasi penuh hanya teramati pada medium ISP 1 agar dan MBA. Isolat GL1-12 menunjukkan pertumbuhan miselium substrat yang baik kecuali pada medium ISP 2 agar, namun sporulasi hanya teramati pada medium ISP 3 agar. Suhu pertumbuhan isolat GL1-2 dan GL1-9 berkisar antara 30--55°C, sedangkan GL1-12 berkisar antara 35--55°C. Hasil uji kemampuan selulolitik menunjukkan bahwa isolat GL1-2 dan GL19 memiliki kemampuan mendegradasi 1% CMC pada suhu 30, 35, 40, 45, 50, dan 55°C. Isolat GL1-12 memiliki kemampuan selulolitik pada suhu 40, 45, 50, dan 55°C. Hasil penelitian menunjukkan bahwa ketiga isolat Actinobacteria-like dari serasah di kawasan sumber air panas gunung Galunggung memiliki potensi menghasilkan enzim selulase di berbagai suhu yang diuji.

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Members of Gram-positive filamentous Actinobacteria are some recognized for their ability to degrade cellulose by producing cellulase. This study aimed to determine the growth ability of three Actinobacteria-like isolates (designated isolates GL1-2, GL19, and GL1-12) obtained from litter samples of mount Galunggung hot spring, Tasikmalaya, West Java, on various agar media (ISP 1, ISP 2, ISP 3, and modified Bennett’s) and temperatures (25, 30, 35, 40, 45, 50, 55°C), along with their cellulolytic ability on 1% carboxymethyl cellulose (CMC) as substrate. Cellulolytic ability was tested by inoculating the cultures on minimal (Mm) agar plates with the addition of 1% CMC, and incubated at various temperatures (30, 35, 40, 45, 50, and 55°C) for 3, 7, and 14-days. Cellulolytic ability was observed as formation of clear zone surrounding the colonies after being flooded with 0.1% Congo red and rinsed with 1 M NaCl solution. The results showed that isolates GL1-2 and GL1-9 have abundant substrate mycelia formation on all media tested, while optimal sporulation was only observed on ISP 1 agar and MBA. Isolate GL1-12 showed good growth of substrate mycelia except on ISP 2 agar, however sporulation was poorly observed only on ISP 3 agar. Growth temperatures of isolates GL1-2 and GL1-9 were ranging from 30 to 55°C, while GL112 was ranging from 35 to 55°C. Isolates GL1-2 and GL1-9 have the ability to degrade 1% CMC at 30, 35, 40, 45, 50, and 55°C. Isolate GL1-12 has celulolytic ability at temperatures of 40, 45, 50, and 55°C. This study revealed that Actinobacteria-like isolates obtained from litter samples of mount Galunggung hot spring, Tasikmalaya are potential cellulase-producers on various tested temperatures.

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"Kelompok Actinobacteria berfilamen merupakan bakteri Gram positif yang beberapa anggotanya diketahui memiliki kemampuan mendegradasi selulosa dengan menghasilkan selulase. Penelitian ini bertujuan untuk mengetahui kemampuan tumbuh isolat Actinobacteria-like GL1-2, GL1-9, dan GL1-12 pada variasi media agar (ISP 1, ISP 2, ISP 3, dan modified Bennett’s) dan suhu (25, 30, 35, 40, 45, 50, dan 55°C), serta mengetahui kemampuan selulolitiknya pada substrat 1% CMC di berbagai suhu (30, 35, 40, 45, 50, dan 55°C). Kemampuan selulolitik diuji dengan menginokulasi biakan pada medium agar minimal (Mm) dengan penambahan 1% CMC, kemudian diinkubasi pada berbagai suhu selama 3, 7, dan 14 hari. Kemampuan selulolitik diamati dengan terbentuknya zona bening di sekitar koloni setelah ditetesi 0,1% Congo red dan dibilas dengan larutan NaCl 1 M. Isolat GL1-2 dan GL1-9 menunjukkan pertumbuhan miselium substrat dalam jumlah banyak pada semua medium yang diuji, namun sporulasi penuh hanya teramati pada medium ISP 1 agar dan MBA. Isolat GL1-12 menunjukkan pertumbuhan miselium substrat yang baik kecuali pada medium ISP 2 agar, namun sporulasi hanya teramati pada medium ISP 3 agar. Suhu pertumbuhan isolat GL1-2 dan GL1-9 berkisar antara 30--55°C, sedangkan GL1-12 berkisar antara 35--55°C. Hasil uji kemampuan selulolitik menunjukkan bahwa isolat GL1-2 dan GL1- 9 memiliki kemampuan mendegradasi 1% CMC pada suhu 30, 35, 40, 45, 50, dan 55°C. Isolat GL1-12 memiliki kemampuan selulolitik pada suhu 40, 45, 50, dan 55°C. Hasil penelitian menunjukkan bahwa ketiga isolat Actinobacteria-like dari serasah di kawasan sumber air panas gunung Galunggung memiliki potensi menghasilkan enzim selulase di berbagai suhu yang diuji.

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Members of Gram-positive filamentous Actinobacteria are some recognized for their ability to degrade cellulose by producing cellulase. This study aimed to determine the growth ability of three Actinobacteria-like isolates (designated isolates GL1-2, GL1- 9, and GL1-12) obtained from litter samples of mount Galunggung hot spring, Tasikmalaya, West Java, on various agar media (ISP 1, ISP 2, ISP 3, and modified Bennett’s) and temperatures (25, 30, 35, 40, 45, 50, 55°C), along with their cellulolytic ability on 1% carboxymethyl cellulose (CMC) as substrate. Cellulolytic ability was tested by inoculating the cultures on minimal (Mm) agar plates with the addition of 1% CMC, and incubated at various temperatures (30, 35, 40, 45, 50, and 55°C) for 3, 7, and 14-days. Cellulolytic ability was observed as formation of clear zone surrounding the colonies after being flooded with 0.1% Congo red and rinsed with 1 M NaCl solution. The results showed that isolates GL1-2 and GL1-9 have abundant substrate mycelia formation on all media tested, while optimal sporulation was only observed on ISP 1 agar and MBA. Isolate GL1-12 showed good growth of substrate mycelia except on ISP 2 agar, however sporulation was poorly observed only on ISP 3 agar. Growth temperatures of isolates GL1-2 and GL1-9 were ranging from 30 to 55°C, while GL1- 12 was ranging from 35 to 55°C. Isolates GL1-2 and GL1-9 have the ability to degrade 1% CMC at 30, 35, 40, 45, 50, and 55°C. Isolate GL1-12 has celulolytic ability at temperatures of 40, 45, 50, and 55°C. This study revealed that Actinobacteria-like isolates obtained from litter samples of mount Galunggung hot spring, Tasikmalaya are potential cellulase-producers on various tested temperatures."

"Penelitian ini bertujuan untuk memperoleh isolat Actinobacteria termofilik potensial dari tanah di sekitar geiser Cisolok yang dapat mendegradasi xylan dan mengetahui hubungan kekerabatannya dengan taksa terdekat dari Actinobacteria penghasil xylanase. Tujuh belas isolat Actinobacteria termofilik diisolasi dari tanah di sekitar geiser Cisolok, Jawa Barat. Penapisan kemampuan 17 isolat Actinobacteria dan type strain Actinomadura keratinilytica NBRC 105837T mendegradasi xylan dilakukan menggunakan medium Minimal (Mm) padat dengan penambahan substrat xylan 0,5, inkubasi selama 7 hari. Pewarnaan dengan Congo red 0,2 (b/v) menunjukkan terbentuknya zona bening di sekitar koloni isolat Actinobacteria yang dapat mendegradasi xylan 0,5 pada suhu 45 C (15 isolat), 50 C (14 isolat), 55 C (4 isolat), dan 60 C (3 isolat). Type strain NBRC 105837T dapat mendegradasi xylan 0,5 pada suhu 45 C hingga 60 C. Tiga isolat (SL1- 2-R-2, SL1-2-R-3, dan SL1-2-R-4) yang mendegradasi xylan 0,5 hingga suhu 60 C dipilih sebagai isolat potensial. Tiga isolat potensial dan type strain NBRC 105837 dapat mendegradasi substrat Remazol Brilliant Blue R-xylan (RBB-xylan) 0,1 pada medium Mm padat setelah 3 hari inkubasi pada suhu 45 hingga 60 C. Tiga isolat potensial telah diidentifikasi pada penelitian sebelumnya sebagai Actinomadura keratinilytica berdasarkan karakter genotip dan fenotip. Crude enzyme dari tiga isolat potensial dan type strain NBRC 105837 dapat mendegradasi xylan 0,5 dan RBB-xylan 0,1 pada medium Mm padat setelah 24 jam inkubasi pada suhu 45 hingga 60 C. Berdasarkan analisis filogenetik sequence gen 16S rRNA menggunakan metode neighbor-joining, minimum evolution, dan maximum likelihood, 3 isolat potensial membentuk clade yang monofiletik dengan dua spesies Actinomadura termofilik yang dapat mendegradasi xylan (A. keratinilytica dan A. miaoliensis). Tiga isolat potensial membentuk clade yang monofiletik dengan empat spesies Actinomadura termofilik (A. keratinilytica, A. miaoliensis, A. rubrobrunea, dan A. viridilutea). Tiga isolat potensial menghasilkan miselium substrat yang bercabang dan tidak berfragmen, serta miselium aerial yang menghasilkan spora pada medium modified Bennetts padat setelah 14 hari inkubasi pada suhu 45 C. Penelitian ini memberikan informasi tambahan mengenai kemampuan typestrain A. keratinilytica NBRC 105837 mendegradasi xylan.

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The aims of this study were to obtain the potential xylan-degrading thermophilic Actinobacteria isolates from soil of Cisolok geysers and to understand their relationship with the closely related taxa of xylanase-producing Actinobacteria. Seventeen thermophilic Actinobacteria isolates were isolated from soil collected around Cisolok geysers, West Java. Xylan-degrading ability of 17 Actinobacteria isolates and type strain Actinomadura keratinilytica NBRC 105837T were screened by using Minimal (Mm) agar medium with the addition of 0.5 xylan substrate, incubated for 7 days. Clear zone was formed around the colony of Actinobacteria isolates which showed xylan-degrading ability at 45 C (15 isolates), 50 C (14 isolates), 55 C (4 isolates), and 60 C (3 isolates) after staining by 0.2 (w/v) Congo red. Type strain NBRC 105837T was able to degrade 0,5 xylan at 45 to 60 C. Three isolates (SL1-2-R-2, SL1-2-R-3, dan SL1-2-R-4) that showed xylan-degrading ability at 45 to 60 C were choosen as potential isolates. Three potential isolates and type strain NBRC 105837T were able to degrade 0,1 Remazol Brilliant Blue R-xylan (RBB-xylan) substrate on Mm agar after 3 days incubation at 45 to 60 C. In the previous study, these potential isolates were identified as Actinomadura keratinilytica based on genotypic and phenotypic characters. Crude enzyme of 3 potential isolates and type strain NBRC 105837T were able to degrade both 0.5 xylan and 0.1 RBB-xylan on Mm agar after 24 hours at 45 to 60 C. Phylogenetic analyses based on 16S rRNA gene using neighbor-joining, minimum evolution, and maximum likelihood methods showed the 3 potential isolates formed monophyletic clade with two thermophilic xylan-degrading Actinobacteria species (A. keratinilytica and A. miaoliensis). Three potential isolates formed monophyletic clade with four thermophilic Actinobacteria species (A. keratinilytica, A. miaoliensis, A. rubrobrunea, and A. viridilutea). These isolates produced non-fragmented branched substrate mycelia and spores produced from aerial mycelia after 14 days incubation at 45 C. This study reports a new information regarding the xylan-degrading ability of A. keratinilytica NBRC 105837."

"Tujuan dari penelitian ini adalah untuk memperoleh isolat 'Actinobacteria' termofilik dari tanah di sekitar geiser Cisolok, Jawa Barat yang memiliki aktivitas selulolitik pada suhu tinggi serta mengetahui posisi filogenetik isolat terpilih terhadap spesies-spesies terdekatnya berdasarkan gen 16S rRNA. Penapisan kemampuan degradasi selulosa 17 isolat dilakukan secara kualitatif pada 'Minimal medium' (Mm) padat yang ditambahkan substrat yaitu 'carboxymethyl cellulose' (CMC) 1% (b/v) atau  'microcrystalline cellulose' (MCC) 1% (b/v) kemudian diinkubasi selama 7 hari. Pengamatan dilakukan dengan pewarnaan 'Congo red' 0,2% (b/v) dan zona bening pada sekitar koloni mengindikasikan degradasi substrat. Hasil penapisan menunjukkan bahwa 15 isolat mendegradasi CMC 1% dan 12 isolat mendegradasi MCC 1% pada suhu 45 ^oC, 14 isolat mendegradasi CMC 1% dan MCC 1% pada suhu 50 ^oC, 4 isolat mendegradasi CMC 1% dan MCC 1% pada suhu 55 ^oC, dan 3 isolat mendegradasi CMC 1% dan MCC 1% pada suhu 60 ^oC. Tiga isolat (SL1-2-R-2, SL1-2-R-3, dan SL1-2-R-4) yang mendegradasi CMC 1% dan MCC 1% hingga 60 ^oC merupakan isolat terpilih. Identifikasi dan karakterisasi telah dilakukan pada penelitian sebelumnya dan melaporkan tiga isolat terpilih memiliki kekerabatan terdekat dengan 'Actinomadura keratinilytica' WCC-2665^T(=NBRC 105837^T). Hasil pengujian menunjukkan 'type strain' NBRC 105837^T mendegradasi CMC 1% dan MCC 1% pada medium Mm padat dengan suhu 45, 50, 55, dan 60 ^oC setelah inkubasi 7 hari. 'Crude enzyme' dari tiga isolat potensial dan 'type strain' NBRC 105837^T menunjukkan aktivitas selulolitik pada medium Mm padat yang ditambahkan CMC 1% atau MCC 1% pada suhu 45, 50, 55, dan 60 ^oC. Analisis filogenetik tiga isolat terpilih berdasarkan gen 16S rRNA menggunakan metode 'Neighbor-Joining' (NJ), 'Minimum Evolution' (ME), dan 'Maximum Likelihood' (ML) menunjukkan bahwa tiga isolat terpilih berada pada satu 'clade' monofiletik dengan 'Actinomadura' 'keratinilytica' WCC-2665^T. Analisis filogenetik juga menunjukkan dua kelompok yang terpisah berdasarkan kemampuan menghasilkan selulase pada anggota famili 'Thermomonosporaceae'.

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The aims of this study were to obtained thermophilic 'Actinobacteria' isolates from soil around Cisolok geyser, West Java with the ability to degrade cellulose at high temperatures and to analyze the phylogenetic position based on 16S rRNA gene of the selected isolates compared to closely related species. Cellulose degradation screening was performed on Minimal (Mm) medium with the addition of 1% (w/v) carboxymethyl cellulose (CMC) or 1% (w/v) microcrystalline cellulose (MCC) as substrate then incubated for 7 days. Cellulose degradations were observed by staining the plates with  0,2% (w/v) Congo red and clear zone formation around the bacterial colony would indicate the cellulose degradation. The results showed that 15 isolates were able to degrade 1% CMC and 12 isolates were able to degrade 1% MCC at 45 ^oC, 14 isolates were able to degrade 1% CMC and 1% MCC at 50 ^oC, 4 isolates were able to degrade 1% CMC and 1% MCC at 55 ^oC, and 3 isolates were able to degrade 1% CMC and 1% MCC at 60 ^oC. Three isolates (SL1-2-R-2, SL1-2-R-3, and SL1-2-R-4) were selected due to their CMC and MCC degrading ability at 60 ^oC. Molecular identification based on 16S rRNA gene and characterization in previous study showed that the three selected isolates are closely related to 'Actinomadura keratinilytica' WCC-2665^T(=NBRC 105837^T). The assay showed that type strain NBRC 105837^T was able to degrade 1% CMC and 1% MCC at 45, 50, 55, and 60 ^oC after 7 days of incubation. Cellulolytic activity show that the crude enzymes of the three selected isolates and type strain were able to degrade 1% CMC and 1% MCC at 45, 50, 55, and 60 ^oC. Phylogenetic analysis using Neighbour-Joining (NJ), Minimum Evolution (ME), and Maximum Likelihood (ML) methods showed that the  three selected isolates  were  clustered  together in monophyletic clade with 'Actinomadura keratinilytica' WCC-2265^T with 100% bootstrap value. Phylogenetic analysis also showed that cellulase  producers  and  non-cellulase  producers  in 'Thermomonosporaceae' were grouped into different clades."

"Rare-actinomycetes tersebar di berbagai habitat terutama di habitat ekstrem seperti kawasan geotermal. Penelitian mengenai rare-actinomycetes dilakukan terkait potensinya sebagai penghasil senyawa bioaktif baru yang bermanfaat dalam bidang kesehatan, industri dan farmasi. Tujuan dari penelitian ini adalah mengisolasi dan mengkarakterisasi secara fenotip dan genotip rare-actinomycetes dari sampel tanah di bawah batuan kuarsa (S3.5.3) di hutan kawasan geotermal Cisolok. Metode pengayaan sampel tanah dilakukan menggunakan medium 10% R2A (Reasoner’s 2A) cair dengan penambahan cycloheximide 100 ppm dan sodium azide 60 ppm, kemudian diinkubasi pada suhu 30°C selama 30 hari. Isolasi rare actinomycetes dilakukan dengan metode membran filter dan spread pada medium 10% R2A gellan gum yang diinkubasi pada suhu 45°C. Karakterisasi dilakukan secara genotipik (berdasarkan data sequence gen 16S rRNA, analisis homologi sequence, dan rekonstruksi pohon filogenetik dengan metode Neighbour-Joining, Maximum Likelihood, dan Minimum Evolution); dan karakterisasi fenotipik (morfologi, fisiologi, dan biokimia). Sebanyak 26 isolat diperoleh dari sampel S3.5.3. Lima isolat dengan karakter morfologi actinomycetes yang diisolasi dari suhu 45°C dengan membran filter, dipilih untuk diidentifikasi. Hasil analisis sequence gen 16S rRNA dari lima isolat menunjukkan persentase homologi sebesar 95,46-99,56% terhadap Micromonospora yasonensis DS3186T. Berdasarkan hasil analisis filogenetik dengan metode Neighbour-Joining, kelima isolat memiliki hubungan kekerabatan terdekat dengan Micromonospora yasonensis DS3186T. Kelima isolat merupakan anggota class Actinomycetes, ordo Micromonosporales, family Micromonosporaceae. Karakter fenotipik kelima isolat sesuai dengan Micromonospora yasonensis sebagai spesies terdekatnya. Kelima isolat merupakan bakteri termotoleran (tumbuh pada suhu 30-45°C dan suhu optimum 40°C), aerobik, Gram positif, menghasilkan miselium substrat tanpa adanya miselium aerial, positif katalase, dan menghasilkan soluble pigment. Penelitian ini mengungkapkan bahwa Micromonospora yasonensis dapat ditemukan di kawasan geotermal dan berasosiasi dengan batuan kuarsa.

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Rare-actinomycetes are distributed in various habitats, particularly in extreme environments such as geothermal areas. Research on rare-actinomycetes focuses on their potential as producers of new bioactive compounds beneficial in health, industrial, and pharmaceutical fields. The aims of this study were to isolate and characterize rare-actinomycetes from soil samples beneath quartz rocks (S3.5.3) in the geothermal forest of Cisolok. Soil sample enrichment was performed using 10% R2A (Reasoner’s 2A) liquid medium supplemented with 100 ppm cycloheximide and 60 ppm sodium azide, incubated at 30°C for 30 days. Rare actinomycetes isolation was carried out using the membrane filter method and spread on 10% R2A agar with gellan gum, incubated at 45°C. Characterization included genotypic analysis based on the sequence of 16S rRNA gene, supported by phenotypic characterization (morphology, physiology, and biochemistry). A total of 26 isolates were obtained from sample S3.5.3. Five isolates with actinomycetes morphology isolated at 45°C using the membrane filter method were selected for characterization. Analysis of the 16S rRNA gene sequences from these five isolates showed homology levels of 95.46-99.56% to Micromonospora yasonensis DS3186T. Based on phylogenetic analysis using the Neighbour-Joining method, the five isolates were most closely related to Micromonospora yasonensis DS3186T. These isolates belong to the class Actinomycetes, order Micromonosporales, and family Micromonosporaceae. Phenotypic characteristics of the five isolates were consistent with Micromonospora yasonensis as their closest species. These isolates are thermotolerant bacteria (growing at temperatures of 30-45°C; optimum temperature 40°C), aerobic, Gram-positive, produce substrate mycelium without aerial mycelium, positive for catalase, and produce soluble pigment. This study reveals that Micromonospora yasonensis can be found in geothermal areas associated with quartz rocks."

"Tujuan penelitian adalah mengetahui aktivitas amilolitik 17 isolat 'Actinobacteria' termofilik pada suhu tinggi, dan memperoleh informasi spesies, dan posisi filogenetik isolat potensial berdasarkan data sekuens gen 16S rRNA, analisis filogenetik, karakterisasi morfologi, fisiologi, dan biokimia. Kemampuan tumbuh 17 isolat 'Actinobacteria' termofilik pada berbagai variasi suhu diuji menggunakan medium ISP 1 agar, dan diinkubasi pada suhu 45, 50, 55, 60 ^oC selama 7 hari. Berdasarkan hasil penelitian, 17 isolat memiliki pertumbuhan yang bervariasi pada suhu 45--60 ^oC. Tujuh belas isolat tumbuh pada suhu inkubasi 45 ^oC, 16 isolat pada suhu 50 ^oC, enam isolat pada suhu 55 ^oC, dan lima isolat pada suhu 60 ^oC terdiri atas SL1-2-R-2, SL1-2-R-3, SL1-2-R-4, SL2-2-R-15, dan SL3-1-R-16. Aktivitas amilolitik 17 isolat 'Actinobacteria' termofilik pada berbagai variasi suhu diuji dengan metode 'starch agar plate', menggunakan medium Minimal (Mm) agar dengan penambahan pati ('soluble starch') sebagai substrat sebanyak 1% (b/v), dan diinkubasi pada suhu 45, 50, 55, dan 60 ^oC selama 7 hari. Aktivitas amilolitik yang positif ditandai dengan terbentuknya zona bening di sekitar koloni bakteri setelah diteteskan larutan 'Lugol's iodine' sebanyak 1,5 ml. Hasil penelitian menunjukkan bahwa sebagian besar isolat yang diperoleh dari tanah di dekat geiser Cisolok memiliki aktivitas amilolitik yang bervariasi pada suhu 45--60 ^oC. Lima belas isolat memiliki aktivitas amilolitik pada suhu 45 ^oC, 13 isolat pada suhu 50 ^oC, empat isolat pada suhu 55 ^oC, dan hanya tiga isolat pada suhu 60 ^oC. Namun demikian, dua isolat (SL2-2-R-15 dan SL3-1-R-16) tidak memiliki aktivitas amilolitik pada suhu 45, 50, dan 55 ^oC setelah diinkubasi selama 7 hari. Tiga isolat potensial yang memiliki aktivitas amilolitik pada suhu 60 ^oC (SL1-2-R-2, SL1-2-R-3, dan SL1-2-R-4), berdasarkan data sekuens gen 16S rRNA, analisis filogenetik, dan karakterisasi fenotipik tiga isolat potensial tersebut diidentifikasi sebagai 'Actinomadura keratinilytica'.

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The aims of this study were to screen for amylolytic activity of the 17 themorphilic 'Actinobacteria' at high temperature, and to obtain species information and phylogenetic position based on 16S rRNA gene sequence, phylogenetic analysis, morphological, physiological, and biochemical characterizations. The ability to grow at various temperature was carried out on ISP 1 agar medium, incubated at 45, 50, 55, 60 ^oC for 7 days. The results showed that the 17 isolates 'Actinobacteria' have varying growth at a temperature of 45--60 ^oC. Seventeen, 16, and six isolates grew at 45, 50, and 55 ^oC, respectively, and only five isolates grew at 60 ^oC, designated SL1-2-R-2, SL1-2-R-3, SL1-2-R-4, SL2-2-R-15, and SL3-1-R-16. Amylolytic activity of the 17 themorphilic 'Actinobacteria' at various temperature was carried out using the starch agar plate method on Minimal (Mm) agar medium with the addition of 1% (w/v) soluble starch as substrate, and incubated at 45, 50, 55, and 60 ^oC for up to 7 days. Amylolytic activity was detected by flooding the plates with 1.5 ml of Lugol's iodine solution. Clear zones around the colonies indicated positive results for amylolytic activity. The results showed that most of the isolates obtained from the soil near the Cisolok geyser have varying amylolytic activity at a temperature of 45--60° C. In this study, 15, 13, four, and three out of 17 isolates were positive for amylolytic activity at 45, 50, 55, and 60 ^oC, respectively. Meanwhile, two isolates, designated SL2-2-R-15 and SL3-1-R-16, showed negative results for amylolytic activity at 45, 50, and 55 ^oC, even after 7 days of incubation. Three potential isolates which have amylolytic activity at 60 ^oC (designated SL1-2-R-2, SL1-2-R-3, and SL1-2-R-4), based on 16S rRNA gene sequence, phylogenetic analysis, and phenotypic characterizations were identified as 'Actinomadura keratinilytica.'"

"Tujuan penelitian adalah mengetahui aktivitas amilolitik 17 isolat Actinobacteria termofilik pada suhu tinggi, dan memperoleh informasi spesies, dan posisi filogenetik isolat potensial berdasarkan data sekuens gen 16S rRNA, analisis filogenetik, karakterisasi morfologi, fisiologi, dan biokimia. Kemampuan tumbuh 17 isolat Actinobacteria termofilik pada berbagai variasi suhu diuji menggunakan medium ISP 1 agar, dan diinkubasi pada suhu 45, 50, 55, 60 °C selama 7 hari. Berdasarkan hasil penelitian, 17 isolat memiliki pertumbuhan yang bervariasi pada suhu 45-60 °C. Tujuh belas isolat tumbuh pada suhu inkubasi 45 °C, 16 isolat pada suhu 50 °C, enam isolat pada suhu 55 °C, dan lima isolat pada suhu 60 °C terdiri atas SL1-2-R-2, SL1-2-R-3, SL1-2-R-4, SL2-2-R-15, dan SL3-1-R-16. Aktivitas amilolitik 17 isolat Actinobacteria termofilik pada berbagai variasi suhu diuji dengan metode starch agar plate, menggunakan medium Minimal (Mm) agar dengan penambahan pati (soluble starch) sebagai substrat sebanyak 1% (b/v), dan diinkubasi pada suhu 45, 50, 55, dan 60 °C selama 7 hari. Aktivitas amilolitik yang positif ditandai dengan terbentuknya zona bening di sekitar koloni bakteri setelah diteteskan larutan Lugol's iodine sebanyak 1,5 ml. Hasil penelitian menunjukkan bahwa sebagian besar isolat yang diperoleh dari tanah di dekat geiser Cisolok memiliki aktivitas amilolitik yang bervariasi pada suhu 45-60 °C. Lima belas isolat memiliki aktivitas amilolitik pada suhu 45 °C, 13 isolat pada suhu 50 °C, empat isolat pada suhu 55 °C, dan hanya tiga isolat pada suhu 60 °C. Namun demikian, dua isolat (SL2-2-R-15 dan SL3-1-R-16) tidak memiliki aktivitas amilolitik pada suhu 45, 50, dan 55 °C setelah diinkubasi selama 7 hari. Tiga isolat potensial yang memiliki aktivitas amilolitik pada suhu 60 °C (SL1-2-R-2, SL1-2-R-3, dan SL1-2-R-4), berdasarkan data sekuens gen 16S rRNA, analisis filogenetik, dan karakterisasi fenotipik tiga isolat potensial tersebut diidentifikasi sebagai Actinomadura keratinilytica.

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The aims of this study were to screen for amylolytic activity of the 17 themorphilic Actinobacteria at high temperature, and to obtain species information and phylogenetic position based on 16S rRNA gene sequence, phylogenetic analysis, morphological, physiological, and biochemical characterizations. The ability to grow at various temperature was carried out on ISP 1 agar medium, incubated at 45, 50, 55, 60 °C for 7 days. The results showed that the 17 isolates Actinobacteria have varying growth at a temperature of 45-60 °C. Seventeen, 16, and six isolates grew at 45, 50, and 55 °C, respectively, and only five isolates grew at 60 °C, designated SL1-2-R-2, SL1-2-R-3, SL1-2-R-4, SL2-2-R-15, and SL3-1-R-16. Amylolytic activity of the 17 themorphilic Actinobacteria at various temperature was carried out using the starch agar plate method on Minimal (Mm) agar medium with the addition of 1% (w/v) soluble starch as substrate, and incubated at 45, 50, 55, and 60 °C for up to 7 days. Amylolytic activity was detected by flooding the plates with 1.5 ml of Lugol's iodine solution. Clear zones around the colonies indicated positive results for amylolytic activity. The results showed that most of the isolates obtained from the soil near the Cisolok geyser have varying amylolytic activity at a temperature of 45-60 °C. In this study, 15, 13, four, and three out of 17 isolates were positive for amylolytic activity at 45, 50, 55, and 60 °C, respectively. Meanwhile, two isolates, designated SL2-2-R-15 and SL3-1-R-16, showed negative results for amylolytic activity at 45, 50, and 55 °C, even after 7 days of incubation. Three potential isolates which have amylolytic activity at 60 °C (designated SL1-2-R-2, SL1-2-R-3, and SL1-2-R-4), based on 16S rRNA gene sequence, phylogenetic analysis, and phenotypic characterizations were identified as Actinomadura keratinilytica."

"Empat belas isolat actinomycetes berhasil diisolasi dari tanah di sekitar kawasan geothermal Cisolok, Jawa Barat. Keseluruhan isolat actinomycetes dilakukan pengujian pertumbuhan pada berbagai suhu dan medium pertumbuhan untuk mengetahui pertumbuhan optimum. Hasil pengujian diperoleh bahwa empat belas isolate mampu tumbuh pada suhu 25, 30, 35, 40 dan 45 °C yang diinkubasi pada ISP 1 agar selama 7 hari, namun pertumbuhan optimal mencapai batas suhu tertinggi terjadi pada suhu 45 °C dibandingkan pada suhu 50 dan 55 °C. Pada suhu 50 °C diketahui 10 dari 14 isolat mampu tumbuh dan 14 isolat tidak mampu tumbuh apada suhu 55 °C. Uji pertumbuhan pada berbagai medium diperoleh bahwa empat belas isolat mampu tumbuh pada 6 jenis medium pertumbuhan (ISP 1 agar, ISP 2 agar, ISP 3 agar, Modiffied Bennet’s agar, Mm 1 agar, dan Mm2 agar) yang di inkubasi pada suhu 45 °C selama 7 dan 14 hari, namun tumbuh optimal pada medium ISP 1 agar dan ISP 3 agar. Penelitian ini juga bertujuan untuk diperoleh isolat actinomycetes termofilik yang potensial sebagai penghasil senyawa antimikroba dan amilase berdasarkan pendekatan OSMAC yaitu variasi medium dan suhu inkubasi. Penapisan aktivitas antimikroba dilakukan pada isolat yang ditumbuhkan di 6 jenis medium pertumbuhan yang diinkubasi pada suhu 45 °C selama 7 dan 14 hari menggunakan metode agar plug diffusion. Hasil penapisan aktivitas antimikroba diperoleh bahwa 8 dari 14 isolat menunjukkan hasil positif terhadap aktivitas antimikroba yaitu SL1-1-R-1, SL1-1-R-3, SL1-1-R-6, SL1-1-R-10, SL2-2-R-6, SL2-2-R-13, SL3-2-R-38 A2 dan SL3-2-R-38 A3. Aktivitas antibakteri terhadap S. aureus ditemukan pada tiga isolat (SL1-1-R-1, SL2-2-R-6, dan SL3-2-R-38 A3), B. subtilis pada dua isolat (SL3-2-R-38 A2 dan SL3-2-R-38 A3), dan K. rhizophila ditemukan pada tiga isolat (SL1-1-R-1, SL2-2-R-13, dan SL3-2-R-38 A3). Aktivitas antifungi terhadap C. albicans ditemukan pada empat isolat (S SL1-1-R-3, SL1-1-R-6, SL1-1-R10, dan SL2-2-R-6), A. niger pada empat isolat (SL1-1-R-1, SL1-1-R-3, SL1-1-R-6, dan SL2-2- R-6,) dan A. flavus pada satu isolat (SL2-2-R-6). Penapisan aktivitas amilolitik dilakukan dengan metode starch agar plate pada medium Mm + 1 % pati terlarut yang diinkubasi pada tiga suhu berbeda yaitu 45, 50 dan 55 °C selama 3 dan 7 hari. Hasil penapisan aktivitas amilolitik diperoleh bahwa 14 isolat positif terhadap aktivitas amilolitik. Sebanyak 14 isolat mampu mendegradasi pati pada suhu 45 °C (11 isolat mulai mendegradasi pati di hari ke-3 sedangkan 14 isolat mendegradasi pati pada hari ke-7), dua belas isolat mampu mendegradasi pati pada suhu 50 °C (9 isolat mendegradasi pati mulai dari hari ke-3 hingga hari ke-7 dan tiga isolat lainnya hanya pada hari ke-7).

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Fourteen of actinomycetes isolates were successfully isolated from the soil around the Cisolok geothermal area, West Java. All actinomycetes isolates were tested for growth at various temperatures and growth mediums to determine optimum growth. The results obtained the 14 isolates were able to grow at temperatures of 25, 30, 35, 40, and 45 °C were incubated at ISP 1 agar for 7 days, but optimal growth reached the highest temperature limit at 45 °C compared to 50 and 55 °C. At 50°C, it was found that 10 out of 14 isolates were able to grow and 14 not able to growth at 55 °C. Growth tests on various media showed that fourteen isolates were able to grow on six types of growth medium (ISP 1 agar, ISP 2 agar, ISP 3 agar, Modified Bennet's agar, Mm 1 agar, and Mm2 agar) were incubated at 45 °C for 7 and 14 days, but grew optimally on ISP 1 agar and ISP 3 agar. This study also aims to obtain thermophilic actinomycetes isolates that have the potential to produce antimicrobial compounds and amylase based on the OSMAC approach (variation of medium and temperatures). The screening for antimicrobial activity was carried out on isolates grown in 6 types of growth medium which were incubated at 45 °C for 7 and 14 days using the agar plug diffusion methods. The results showed that 8 out of 14 isolates showed positive results for antimicrobial activity, namely SL1-1-R-1, SL1-1-R-3, SL1-1-R-6, SL1-1-R-10, SL2 -2-R-6, SL2-2-R-13, SL3-2-R-38 A2, and SL3-2-R-38 A3. Antibacterial activity against S. aureus was found in three isolates (SL1-1-R-1, SL2-2-R-6, and SL3-2-R-38 A3), B. subtilis in two isolates (SL3-2-R -38 A2 and SL3-2-R-38 A3), and K. rhizophila were found in three isolates (SL1-1-R-1, SL2-2-R-13, and SL3-2-R-38 A3). Antifungal activity against C. albicans was found in four isolates (S SL1-1-R-3, SL1-1-R-6, SL1-1-R-10, and SL2- 2-R-6), A. niger in four isolates (SL1-1-R-1, SL1-1-R-3, SL1-1-R-6, and SL2-2-R-6,) and A. flavus on one isolate (SL2-2-R-6). Screening for amylolytic activity using starch agar plate methods was carried out on Mm medium + 1% soluble starch and was incubated at three different temperatures; 45, 50, and 55 °C for 3 and 7 days. The results showed that 14 isolates were positive for amylolytic activity. A total of 14 isolates were able to degrade starch at 45 °C (11 isolates began to degrade starch on day 3 , while 14 isolates degraded starch on day 7), twelve isolates were able to degrade starch at 50 °C (9 isolates degraded starch from day 3 to day 7, and three other isolate only on day 7).

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"Kelimpahan mikroplastik pada perairan yang melebihi ambang batas aman perlu dilakukan remediasi. Bentuk-bentuk remediasi mikroplastik salah satunya adalah menggunakan agen biologis seperti bakteri. Bakteri dari sampel mikroplastik berhasil diisolasi dari air di inlet dan outlet Situ Kenanga, Kampus UI, Depok. Penelitian ini bertujuan untuk mengetahui kemampuan pertumbuhan delapan isolat bakteri pada variasi medium (ISP 1 agar, NA, dan LBA) dan suhu (25, 30, 35 dan 40°C), karakterisasi morfologi dan biokimia, serta kemampuan isolat bakteri terpilih untuk mendegradasi mikroplastik polietilena (PE). Pengujian aktivitas biokimia isolat bakteri dilakukan dengan uji fermentasi karbohidrat, oksidasi-fermentasi, produksi enzim katalase, dan sitrase. Berdasarkan pengujian variasi medium dan suhu menunjukkan bahwa keseluruhan isolat tumbuh optimum pada medium ISP 1 agar dan rentang suhu 30--35°C. Isolat KO1.1.3 positif pada uji degradasi substrat pati, sedangkan isolat KO1.3, KO2.2, KO2.3 dan KI2 dapat mendegradasi skim milk. Delapan isolat memiliki karakteristik biokimia yang bervariasi berdasarkan hasil uji. Hasil uji degradasi mikroplastik PE oleh kedua isolat terpilih menunjukkan bahwa tidak ditemukan adanya pengurangan berat granula PE setelah inkubasi selama 20 dan 45 hari. Pengamatan SEM menunjukkan adanya aktivitas degradasi pada permukaan granula PE ditandai dengan terbentuknya lubang oleh kedua isolat bakteri terpilih setelah 45 hari inkubasi. Hasil ini menunjukkan kedua isolat bakteri berpotensi dalam mendegradasi PE.

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The abundance of microplastics in water that exceeds the safety threshold needs urgent remediation. Biological agents, such as bacteria, are one of the ways for microplastics remediation. Microplastics-associated bacteria were previously isolated from water samples at the inlet and outlet of Situ Kenanga, UI Campus, Depok. This study aims to determine the growth ability of eight bacterial isolates at various media (ISP 1 agar, NA, and LBA) and temperatures (25, 30, 35 and 40°C), morphological and biochemical characteristics, and the ability of selected bacterial isolates to degrade polyethylene (PE) microplastics. Biochemical activities of bacterial isolates were carried out by carbohydrates fermentation ability, oxidation-fermentation, catalase enzyme production, and citrate utilization tests. All isolates grew optimally on ISP 1 agar and a temperatures range of 30--35°C. Isolate KO1.1.3 was positive in the starch degradation test, while isolates KO1.3, KO2.2, KO2.3 and KI2 were able to degrade skim milk. All bacterial isolates were showing various biochemical characteristics. The results of PE degradation tests by the two selected isolates showed that there was no weight reduction of PE granules after 20 and 45 days of incubation. However, SEM observations showed degradation activity on the surface of the PE granules which was indicated by the crack’s formation after 45 days of incubation. These results indicated that the two bacterial isolates were potential for PE degradation."