Antibacterial Activity Screening Of Bacterial Isolates Associated With Seaweed Eucheuma cottonii From Coastal Area In Buleleng, Bali

Abstract

Seaweeds like other marine organisms develop a strong association with prokaryotic communities, especially bacteria. Many of these associated bacteria play an important role in synthesizing secondary metabolites which are beneficial for their host, especially against predation or infection. In Indonesia, Eucheuma cottonii is one of the seaweed species that has been cultivated widely. However, only limited study has been reported on bacterial isolates and their antibacterial activity from E. cottonii. Bacterial isolates from E. cottonii were cultivated in six agar media namely Zobell Marine Agar, Nutrient Agar, Plate Count Agar, ISP-1, ISP-2, and Starch-M protein agar. Cultivation of bacterial isolates yielded 23 isolates with nine bacterial isolates were classified as Gram-positive bacteria and 14 isolates were grouped among Gram-negative bacteria. All the bacterial isolates were screened for their antibacterial activity against six bacterial indicator strains namely Staphylococcus aureus ATCC 25923, Streptococcus mutans FNCC 0405, Escherichia coli ATCC 25922, and Klebsiella pneumoniae ATCC 700603 using perpendicular streak and agar block method. Six out of 23 bacterial isolates displayed antibacterial activity against at least one of the bacterial indicator strains. The bacterial isolate ISP1RL4 showed the highest antibacterial activity with average inhibition of > 20 mm against all bacterial indicators. Overall, our result indicated the potential of bacterial isolates associated with E. cottonii as an antibacterial producer.

Isolasi Bakteri Dari Rumput Laut Eucheuma spinosum dan Skrining Aktivitas Antibakteri Terhadap Beberapa Bakteri Gram Positif dan Negatif

“…Sejumlah penelitian melaporkan bahwa Aktinobakteria yang berasosiasi dengan rumput laut menunjukkan aktivitas antibakteri terhadap sejumlah bakteri patogen (Ulfah et al, 2018). Selain kelompok Aktinobakteria, aktivitas antibakteri dari isolat yang berasosiasi dengan rumput laut juga banyak dilaporkan dari jenis bakteri lain seperti Bacillus sp ., Purnami et al,2022.…”

Isolation and identification of bacterial pathogens causing ice-ice disease in Eucheuma cottonii seaweed at Seira Island Waters, Tanimbar Islands District, Maluku, Indonesia

“…This can have negative impacts on seaweed farming industry (Brakel et al 2021). Despite the presence of harmful bacteria, studies showed that bacteria associated with E. cottonii was a source of antibacterial substances, but investigations on this aspect were still limited (Purnami et al 2022). Several studies on the isolation and identification of bacteria in E. cottonii seaweed infected with ice-ice disease showed the presence of bacteria such as Vibrio sp., Pseudomonas sp., and Bacillus sp.…”

Antibacterial Activity of Pseudomonas Aeruginosa ISP1RL3 Against Multidrug Resistance Bacteria

“…Seaweed-associated bacteria contribute in growth, morphogenesis, and protection by synthesizing various bioactive molecules including antibacterial compounds (Singh & Reddy, 2014). Unlike its host, studies on E. cottonii-associated bacteria are still limited (Hafsan et al, 2019;Purnami et al, 2022). A previous study reported isolation of Aeromonas sp.…”

“…that inhibit S. aureus and E. coli. Furthemore, a recent study has reported 23 bacterial isolates from E. cottonii collected at the coastal waters of Buleleng, Bali with six of these isolate displayed antibacterial activity against S. aureus, S. mutans, E. coli, and K. pneumoniae (Purnami et al, 2022).…”

“…Among these six bacterial isolates that was previously described (Purnami et al, 2022), an isolate encoded as ISP1RL3 is one of the isolate with a strong antibacterial activity. However, up to know only a limited information is available on the bacterial isolate with regards to its species.…”