Ngo Thi Tuong Chau, Le Thi Ha Thanh, Nguyen Huu Thuan Anh

Main Article Content

Abstract

Abstract: A new emerged lethal disease that termed EMS (Early Mortality Syndrome) or AHPNS (Acute Hepatopancreatic Necrosis Syndrome) caused by Vibrio parahaemolyticus had been added to list of shrimp diseases during last recent years. However, there are no currently available methods to treat EMS. Given this circumstance, developing an alternative strategy to control infections, especially in countries found that antibiotics are not effective against EMS as Vietnam, is urgent need. In this study, a Streptomyces sp. A8 strain isolated from shrimp pond sediments in Thừa Thiên Huế showed the high activity against V. parahaemolyticus V6 and production of extracellular enzymes to decompose organic compounds which reveals the potential to involve in mineralization and nutrient cycles in the shrimp culture ponds. The Streptomyces sp. A8 strain was only resistant to several common antibiotics as ampicillin, tetracycline and penicillin-G. Selected cultivative conditions for biomass production and antagonistic activity to V. parahaemolyticus V6 of Streptomyces sp. A8 were 96 hours, pH 8.0, 35oC in SCB medium with concentrations of starch, casein, NaCl, DL-α-alanine and vitamin B6 were 13%, 0.6%, 16%, 0.6% and 0.02%, respectively. When being selected fermented, a large amount of Streptomyces sp. A8 biomass (15.0 g/L) was harvested.

Keywords: Actinomycetes, Streptomyces sp. A8, shrimp ponds, Vibrio parahaemolyticus, early mortality syndrome.

References

[1] Zorriehzahra M.J., Banaederakhshan R., Early mortality syndrome (EMS) as new emerging threat in shrimp industry, Adv. Anim. Vet. Sci. 3(2S) (2015) 64.
[2] Sonia A. Soto-Rodriguez, Bruno Gomez-Gil, Rodolfo Lozano-Olvera, Miguel Betancourt-Lozano, Maria Soledad Morales-Covarrubias, Field and experimental evidence of Vibrio parahaemolyticus as the causative agent of acute hepatopancreatic necrosis disease of cultured shrimp (Litopenaeus vannamei) in Northwestern Mexico, Appl. Environ. Microbiol. 81(5) (2015) 1689.
[3] Noor Uddin GM., Larsen M.H., Christensen H., Aarestrup F.M., Phu T.M., Dalsgaard A., Identification and antimicrobial resistance of bacteria isolated from probiotic products used in shrimp culture, PLoS ONE 10 (7) (2015), e0132338. doi:10.1371/ journal.pone.0132338
[4] Oskay M., Tamer A.U. and Azeri C., Antibacterial activity of some actinomycetes isolated from farming soils of Turkey, Afr. J. Biotechnol. 3(9) (2004) 441.
[5] Barcina I., Iriberri J. and Egea L., Enumeration isolation and some physiological properties of actinomycetes from sea water and sediment, Syst. Appl. Microbiol. 10 (1987) 85.
[6] Kesarcodi W.A., Kaspar H., Lategan M.J., Gibson L., Probiotics in aquaculture: The need, principles and mechanisms of action and screening processes, Aquaculture 274(1) (2008) 1.
[7] Yang J., Chen L., Sun L., Yu J., Jin Q., VFDB 2008 release: an enhanced web–based resource for comparative pathogenomics, Nucleic. Acids. Res. 36 (2007) 539.
[8] Barrow G.I., Feltham R.K.A., Cowan and Steel’s Manual for the Identification of Medical Bacteria. 3rd ed. Cambridge University Press, 1993.
[9] Baumann P., Schubert R.H.W., Vibrionaceae. In: Krieg NR, Holt GJ (eds.) Bergey’s manual of systematic bacteriology, Vol. 1. The Williams & Wilkins Co., Baltimore, Md: 516-550, 1984.
[10] Sambrook J., Russell D.W, Molecular Cloning: A Laboratory Manual, 3th ed., Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 2001.
[11] You J., Cao L.X., Liu G.F., Zhou S.N., Tan H.M., Lin Y.C, Isolation and characterization of actinomycetes antagonistic to pathogenic Vibrio spp. from nearshore marine sediments, World. J. Microb. Biot. 21(5) (2005) 679.
[12] Das S., Ward R.L., Burke C., Prospects of using marine actinobacteria as probiotics in aquaculture, Appl. Microbiol. Biotechnol. 81(3) (2008) 419.