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ABSTRAKBakteri kitinolitik memiliki kemampuan menghasilkan enzim kitinase dan banyak dilaporkan sebagai agens biokontrol. Penelitian ini bertujuan memperoleh bakteri kitinolitik yang bersifat antagonis terhadap pertumbuhan Ganoderma boninense penyebab busuk pangkal batang pada kelapa sawit. Sebanyak 63 galur bakteri penghasil enzim kitinase berhasil diisolasi dari tanah di Taman Nasional Bukit Dua Belas dan dari perkebunan kelapa sawit di Provinsi Jambi. Seluruh galur diseleksi untuk melihat potensinya menghambat pertumbuhan G. boninense secara in vitro. Tiga galur TB04-05, SW01-11, dan SW02-08 paling potensial menekan dan menghambat pertumbuhan miselium G. boninense secara in vitro. Berdasarkan uji aktivitas spesifik, ketiganya memiliki aktivitas masing-masing sebesar 6.3072 U mg -1 protein, 6.0385 U mg -1 protein, dan 6.1279 U mg -1 protein setelah diinkubasi 24 jam. Identifikasi 16S RNA menunjukkan galur TB04-05 berkerabat dekat dengan Bacillus cereus, sedangkan SW01-11 dan SW02-08 berkerabat dekat dengan Bacillus thuringiensis.Kata kunci: busuk pangkal batang, Elaeis guineensis, kelapa sawit, kitinase, 16S RNA ABSTRACT Chitinolytic bacteria have been reported as biocontrol agents and have the ability to produce chitinase enzymes. The objective of the research was to obtain chitinase producing bacteria that had antagonistic activity to Ganoderma boninense, a causal agent of basal stem rot on oil palm. A total of 63 isolates of chitinase producing bacteria were isolated from soil of Bukit Dua Belas National Park and oil palm plantation in Jambi Province; all was screened for their potency in inhibiting G. boninense in vitro. Three isolates designated TB04-05, SW01-11, and SW02-08 were potentially suppressed and inhibited the mycelium growth of G. boninense in vitro. Based on their specific chitinase activity, these three isolates produced the highest level of chitinase enzyme of 6.3072 U mg -1 protein, 6.0385 U mg -1 protein and 6.1279 U mg -1 protein, respectively after 24 hr incubation. Based on 16S RNA identification, strain TB04-05 had similarity with Bacillus cereus, whereas strains SW01 and SW02-08 had similarity with Bacillus thuringiensis.

Sponges are the subject of interesting antibiotic development studies because the sponges form associations with various microbes and are rich in bioactive compounds. Bacteria associated with sponges are able to produce bioactive compounds, which have the potential to be antimicrobial such as, antibacterial, antifungal and antiviral. Antifungal compounds are bioactive compounds that have the ability to inhibit the growth of pathogenic fungi of Candida albicans. This fungal is an opportunistic pathogen fungi that can cause candidiasis. This study aimed to examine the antifungal activity of bacteria associated Aplysina sp. sponge from Enggano Island, North Bengkulu, Indonesia against Candida albicans. Antagonistic tests were carried out in three stages, by using isolates, pellets and supernatants respectively. The antagonistic assay results showed that four isolates were able to inhibit the growth of the fungus Candida albicans in Vitro, i.e APD3, APD10, APD11 and APD15. The highest inhibitory activity was resulted by APD10 isolate with a clear zone area of 14.9 mm in culture, 14,0 mm in pellets and 15.1 mm in supernatants. The morphological, Gram staining and biochemical characterization showed that the four isolates had a close relationship with the genus of Bacillus.

Pulau Enggano merupakan salah satu pulau terluar di Indonesia yang memiliki keragaman biota yang cukup tinggi, salah satunya adalah hewan spons. Spons adalah sekelompok hewan multiseluler, memiliki ciri tubuh berpori, dan organisme invertebrata berguna dalam memproduksi senyawa bioaktif. Bakteri yang terkait dengan spons dapat menjadi sumber alternatif senyawa bioaktif baru, terutama antimikrob. Penelitian ini bertujuan untuk mengetahui potensi bakteri yang terkait dengan Aplysina sp. asal Pulau Enggano sebagai penghasil senyawa antimikrob melawan mikrob patogen. Total 263 isolat berhasil diisolasi pada media agar-agar Sea water Complete (SWC). Isolat bakteri potensial selanjutnya diidentifikasi dengan pengamatan morfologi, pewarnaan Gram, serta dilanjutkan dengan uji biokimia. Hasil uji aktivitas antimikrob dari 16 isolat terpilih melalui uji antagonis, supernatan dan pelet terhadap mikrob patogen Escherichia coli, Staphylococcus aureus, Pseudomonas aeroginosa dan Candida albicans menunjukkan bahwa isolat ENG-4 memiliki kemampuanmenghambat pada dua mikrob pathogen yaitu E. coli, S. aureus. Isolat ENG-4 termasuk ke dalam bakteri gram positif dan merujuk pada genus Bacillus berdasarkan uji biokimia.POTENTIAL OF ISOLATE Bacillus sp. ENG-4 ASSOCIATED WITH MARINE SPONGE Aplysina sp. PRODUCING ANTIMICROBIAL COMPOUNDS FROM ENGGANO ISLAND. Enggano Island is one of the outer islands in Indonesia that has a high diversity of marine biota, one of them are sponges. Sponge is a group of multicellular animals, has a characteristic porous body, and invertebrate organisms are useful in producing bioactive compounds. Bacteria associated with sponges can be an alternative source of new bioactive compounds, especially antimicrobial. This study aims to determine the potential of bacteria associated with Aplysina sp. from Enggano island as a producer of antimicrobial compounds against pathogenic microbes. Total 263 isolates were successfully isolated in Sea water Complete (SWC) agar media. Potential isolates were further identified morphologically, Gram staining, and also biochemical tests. The results of the antimicrobial activity test of 16 selected isolates through antagonist, supernatant and pellet tests on pathogenic microbes of Escherichia coli, Staphylococcus aureus, Pseudomonas aeroginosa and Candida albicans showed that the ENG-4 isolate had the ability to inhibit two spesies of pathogens which are E. coli and S. aureus. ENG-4 isolate belong to gram-positive bacteria and refer to the genus Bacillus based on biochemical tests.

Penelitian tentang analisis ekologi relung amfibi belum pernah dilakukan di Indonesia. Secara umum genus Fejervarya memiliki dua spesies yaitu Fejervarya cancrivora dan Fejervarya limnocharis. Di habitatnya, kedua spesies ini ditemukan tumpang tindih. Pengamatan dilakukan pada rentang waktu aktif amfibi dalam mencari makan yaitu dari pukul 18:00 sampai dengan pukul 06:00 pagi. Penelitian ini bertujuan untuk mengetahui pola kehadiran katak simpatik Fejervarya berdasarkan waktu aktif makan. Hasil penelitian menunjukkan keberadaan katak yang paling banyak terjadi pada pukul 03:00 pagi. Keberadaan Fejervarya cancrivora lebih dominan dibandingkan jenis Fejervarya limnocharis.