International Journal of Environmental & Agriculture Research (IJOEAR) ISSN:[2454-1850] [Vol-7, Issue-9, September- 2021] Page | 37 Testing the ability against Bacillus cereus of actinobacteria strains isolated from sponges in Kien Giang Sea, Vietnam Tran Vu Phuong 1* , Cao Ngoc Diep 2 Biotechnology R&D Institute, Can Tho University, Can Tho City, Vietnam *Corresponding Author Abstract— This study aimed to test the antibacterial activity of Bacillus cereus of actinobacterial isolates isolated from marine sponges in the Kien Giang Sea, Vietnam. That can select the strains with high resistance to identify them. There were 198 actinobacterial isolates tested. Based on the ability of antimicrobial activity to B. cereus, 82/198 had the against B. cereus, in which there were six isolates with high (7.3%), 52 medium (25.6%), and 21 weak resistance (67.1%). Selection of six isolates with the best resistance to B. cereus (ND1.7a, ND2.7c, HD1-3e, HD1-6a, HD2.3b, and H6b) identified by PCR and 16S rRNA gene sequencing. The results identified five strains of Streptomyces (Streptomyces tateyamensis ND1.7a, Streptomyces althioticus HD1.3e, Streptomyces flaveolus HD1.6a, Streptomyces olivaceus HD2.3d, and Streptomyces albidoflavus H6b) and one strain of genus Microbacterium (Microbacterium tumbae ND2.7c). Keywords— Antimicrobial activity, Bacillus cereus, Kien Giang Sea, sponge, Streptomyces. I. INTRODUCTION According to the World Health Organization [1], more than 80% of the world's population relies on traditional medicine for their primary healthcare needs. Microorganisms have the potential to cause diseases. The human body is very prone to viral, bacterial, and fungal infections. The discovery of antibiotics in the early twentieth century provided an increasingly important tool to combat bacterial diseases. However, due to the indiscriminate use of commercial antibacterial drugs treated for infectious diseases, resistance is becoming more common and severe [2]. Microbial natural products have been the source of most of the antibiotics in current use for the treatment of various infectious diseases. Bacillus cereus, family Bacillaceae, order Bacillales, class Bacilli, phylum Firmicutes, is a Gram-positive, rod-shaped, facultative, an anaerobic, motile, beta- hemolytic, spore-forming bacterium commonly found in soil and food. Some strains are harmful to humans and cause foodborne illness, while others can be beneficial as probiotics for animals [3]. Until recently, the majority of antimicrobial compounds were isolated from terrestrial microorganisms. The aquatic environment is now becoming increasingly appreciated as a rich and untapped reservoir of useful novel natural products. The marine environment alone is known to contain taxonomically diverse bacterial groups which exhibit unique physiological and structural characteristics that enable them to survive in extreme environmental conditions, with the potential production of novel secondary metabolites not observed in terrestrial microorganisms [4]. Marine bacteria are considered to play a central role as symbionts of most marine invertebrates and also represent one of the most novel biomedical resources remaining to be explored [5). Marine microorganisms have been an important study in recent years because of the production of novel metabolites which represent various biological properties such as antiviral, antitumor, or antimicrobial activities. These secondary metabolites serve as model systems in the discovery of new drugs [6]. The studies of the secondary substances produced by marine microorganisms have obtained many significant achievements in the world [7]. Among the secondary metabolites from marine microorganisms, many compounds are having interesting biological activities that should be useful for development for their pharmaceutical uses. Therefore, in this study, the presence of potent antimicrobial metabolite-producing microorganisms with Bacillus cereus was reposted, a human pathogenic, especially microbes symbiosis in sponges at Kien Giang Sea, that is a resource not studied yet. Received:- 09 September 2021/ Revised:- 18 September 2021/ Accepted:- 24 September 2021/ Published: 30-09-2021 Copyright @ 2021 International Journal of Environmental and Agriculture Research This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted Non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.