Pengaruh Ekstrak Ganggang Terhadap Pertumbuhan Bacillus subtilis dan Pleurotus sp. Isolat HS

Abstract

Ganggang coklat dan merah banyak dibudidayakan di Indonesia. Ganggang coklat memiliki kandungan senyawa bioaktif dari produk metabolisme sekundernya seperti antimikrob, sedangkan ganggang merah memiliki potensi antioksidan dan penangkal radikal. Penelitian ini bertujuan untuk menguji ekstrak ganggang coklat (Sargassum sp.) dan merah (Gracilaria sp.) sebagai sumber senyawa antimikrob terhadap Bacillus subtilis dan dalam menghambat pertumbuhan koloni Pleurotus sp. isolat HS. Tahapan penelitian ini meliputi persiapan kultur bakteri dan cendawan, persiapan ekstrak ganggang Sargassum sp. dan Gracilaria sp. dengan metode maserasi, uji antimikrob esktrak terhadap B. subtilis dengan metode difusi cakram kertas, dan uji ekstrak terhadap pertumbuhan vegetatif Pleurotus sp. isolat HS pada media Potato Glucose Agar (PGA). Hasil uji antimikrob ekstrak Gracilaria sp. terhadap B. subtilis menghasilkan zona hambat dengan rerata diameter 5.6±1.14 mm dan menghambat pertumbuhan Pleurotus sp. isolat HS koloni sebesar 23%. Adapun ekstrak Sargassum sp. mempunyai aktivitas antimikrob dengan nilai rerata 1.2±1.10 mm terhadap B. subtilis dan menghambat pertumbuhan koloni Pleurotus sp. isolat HS sebesar 16%. Berdasarkan hasil tersebut menunjukkan bahwa ekstrak Gracilaria sp. mampu menghambat pertumbuhan B. subtilis dan Pleurotus sp. isolat HS lebih baik dibandingkan ekstrak Sargassum sp..

Brown and red algae are cultivated in Indonesia. The brown algae contains bioactive compounds from its secondary metabolic products, such as antimicrobials, and red algae has antioxidant with radical scavenging potential. This study aimed to evaluate extracts from brown algae (Sargassum sp.) and red algae (Gracilaria sp.) as sources of antimicrobial compounds against Bacillus subtilis and their inhibitory effect on the growth of Pleurotus sp. isolate HS colony. The stages include preparation of microbes growth media, the algae extracts by macerations, the antimicrobial test of extracts against B. subtilis by paper disc diffusion method, and the test of extracts against vegetative growth of Pleurotus sp. isolate HS on Potato Glucose Agar media. The research result shows that the Gracilaria sp. extract against B. subtilis produced an inhibition zone with an average diameter of 5.6±1.14 mm and inhibited the growth of Pleurotus sp. isolate HS colony by 23%. The extract of Sargassum sp. had antimicrobial activity with a mean value of 1.2±1.10 mm against B. subtilis and inhibited the growth of Pleurotus sp. HS isolate colony by 16%. These results show that the Gracilaria sp. extract can inhibit the growth of B. subtilis and Pleurotus sp. HS isolate better than the Sargassum sp. extract.