Antibacterial activity in secondary metabolite extracts of heterotrophic bacteria against Vibrio alginolyticus, Aeromonas hydrophila,and Pseudomonas aeruginosa.

Jarod Setiaji,Iesje Lukistyowati,Zainal Abidin Muchlisin,Hilwan Yuda Teruna,Feli Feliatra,Indra Suharman,Teuku Iskandar Johan

doi:10.12688/f1000research.26215.1

Jarod Setiaji, Iesje Lukistyowati + Show 5 more

Open Access

https://doi.org/10.12688/f1000research.26215.1

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Abstract

Background: Disease causing bacteria such as Vibrio alginolyticus, Aeromonas hydrophila, and Pseudomonas aeruginosa present a problem for fish farming. Treatment to remove them are generally carried out using antibiotics which have side effects on fish, the environment and humans. However, the use of antibacterial compounds derived from heterotrophic bacteria serve as a good alternative for antibiotics. Therefore, this study aimed to explore antibacterial activity in the secondary metabolite extracts of heterotrophic bacteria against Vibrio alginolyticus, Aeromonas hydrophila, and Pseudomonas aeruginosa. Methods: Heterotrophic bacteria namely Bacillus sp. JS04 MT102913.1, Bacillus toyonensis JS08 MT102920.1, Bacillus cereus JS10 MT102922.1, Bacillus sp. JS11 MT102923.1, Pseudoalteromonas sp. JS19 MT102924.1, Bacillus cereus JS22 MT102926.1, and Bacillus sp. strain JS25 MT102927.1 were used in this study. The sequences of these bacteria have been deposited and are available from NCBI GenBank. Each heterotrophic bacterium was cultured on 6L nutrient broth for 8 days, and extracts produced using ethyl acetate to obtain their secondary metabolites. These extracts were tested for their phytochemical contents using FT-IR and also tested for their inhibitory property in pathogenic bacteria by agar diffusion method. Results: Phytochemical test results showed that the seven heterotrophic bacterial isolates produced terpenoid compounds. Based on the inhibitory test, the secondary metabolite extracts from Bacillus sp strain JS04 had the highest inhibitory effect on the growth of pathogenic bacteria namely, V. alginolyticus (17.5 mm), A. hydrophila (16.8 mm), and P. aeruginosa (17.3 mm). Conclusion: It was concluded that the secondary metabolite extracts of heterotrophic bacteria inhibit the growth of V. alginolyticus, A. hydrophila, and P. aeruginosa.

Highlights

Bacteria diseases in fish stocks constitute a major problem for fish farming, since they cause significant economic losses[1,2,3]
This study aims to explore antibacterial activity in secondary metabolite extracts of heterotrophic bacteria isolated from Riau sea water, against pathogenic bacteria namely, V. alginolyticus, A. hydrophila, and P. aeruginosa
Bacterial culture The heterotrophic bacteria isolates were collected from sea waters in Sungai Pakning Bengkalis Regency Riau Province Indonesia (North latitude 01o21’36,8” and East longitude 102o09’34,1”). 1 liter of the sea water was collected at 50 cm depth by using a water sampler (Tiolan Lab, type: WSV-BIT22), was transferred into a sample bottle and was put into a coolbox filled with ice at 15°C, before being transported by car for 1 hour to the laboratory

Summary

Introduction

Bacteria diseases in fish stocks constitute a major problem for fish farming, since they cause significant economic losses[1,2,3]. P. aeruginosa is found to infect freshwater and marine fish[27,28], with infection being characterized by the expression of red spots due to bleeding, skin darkens, loose scales, protruding eyes, fin erosion[29], behavioural changes due to disruption of locomotor activity[30], and abnormal swimming[31] Disease causing bacteria such as Vibrio alginolyticus, Aeromonas hydrophila, and Pseudomonas aeruginosa present a problem for fish farming. This study aimed to explore antibacterial activity in the secondary metabolite extracts of heterotrophic bacteria against Vibrio alginolyticus, Aeromonas hydrophila, and Pseudomonas aeruginosa. Each heterotrophic bacterium was cultured on 6L nutrient broth for 8 days, and extracts produced using ethyl acetate to obtain their secondary metabolites These extracts were tested for their phytochemical contents using FT-IR and tested for their inhibitory property in pathogenic bacteria by agar diffusion method. Based on the inhibitory test, the secondary metabolite extracts from Bacillus sp strain JS04 had the highest inhibitory effect on the growth

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