Dwi Suryanto

Partial Characterization of Keratinolytic Activity of Local Novel Bacteria Isolated from Feather Waste

Three keratinolytic bacterial isolates were characterized partially for their keratinase activity. Bacterial isolates were grown in feather meal agar. Ammonium sulfate precipitation followed by dialysis was performed to know the bacterial isolate keratinase activity in differet pH and temperature. Identification of the bacteria was done by using their 16S rRNA gene sequences. The result showed that bacterial growth was coinciding with keratinase activity. Precipitation with ammonium sulfate showed that keratinae activity of isolate A4 was optimum at 20% of ammonium sulphate, while B4 and B6 were more active at 70%. Keratinase activity increased after dialysis. Keratinase of A4 showed to have optimum activity at temperature of 45oC and pH=8, B4 was optimum at temperature of 35oC and pH=7, while B6 was optimum at temperature of 40oC and pH=7, respectively. Identification of the bacterial isolates using 16S rRNA gen showed that A4, B4, and B6 were closed to Leclercia adecarboxylata strain M-X17B, Azotobacter chroococcum strain ABA-1, and Stenotrophomonas maltophilia strain BIW by 97%, 99%, and 98%, respectively. Two bacteria L. adecarboxylata and A. chroococcum were firstly reported to produce keratinase.

BACTERIA EXTRACT ACTIVITY ASSOCIATED WITH SPONGESHaliclonasp.2 ANDAxinellid sp.AS ANTIBACTERIAL.

Endang Sulistyarini Gultom 1 , Dwi Suryanto 2 , Erman Munir 2 and Diky Setya Diningrat 1 . 1. Biology Department, FMIPA, Medan State University. Jl. Willem Iskandar Pasar V, Medan 20221, Indonesia. 2. Biology Department, FMIPA, University of North Sumatera. Jl. Bioteknologi 1, Medan 20155, Indonesia. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History

Penapisan Jamur Penghasil Senyawa Antimikroba dari Tanah Bangka dan Taman Wisata Alam Sibolangit serta Potensinya Menghambat Pertumbuhan Beberapa Jamur Patogen Tanaman

Kajian tentang penapisan jamur tanah penghasil senyawa antimikroba yang diisolasi dari Bangka dan Taman Wisata Alam Sibolangit dan kemampuannya menghambat pertumbuhan jamur penyakit tanaman telah dilakukan. Tiga puluh isolat jamur diisolasi dari tanah menggunakan agar dektrosa kentang. Jamur yang ditemukan termasuk genus Penicillium, Aspergillus, Fusarium, Curvularia, Rhizomucor, Paecilomyces, Moniliella, Eupenicillium, dan Trichoderma, dan empat jamur tidak dapat diidentifikasi yaitu sp.1, sp.2, sp.3, dan sp.4. Jamur yang paling sering ditemukan dari genus Aspergillus dan Penicillium. Empatbelas isolat berpotensi menghambat pertumbuhan pertumbuhan Ganoderma boninense dan Fusarium oxysporum. Tidak ada isolat yang mampu menghambat pertumbuhan Penicillium citrinum. Ekstrak methanol Penicillium sp.1 menunjukkan kemampuan terbesar dalam menghambat pertumbuhan G. Boninense, sedangkan Penicillium sp.8 menghambat pertumbuhan F. oxysporum.