@article{Rusmana_Hastuti_Alfisah_Akhdiya_2021, title={Characteristics and Activity of Anti Qourum Sensing Bacillus spp. Isolated from Penaeus vannamei Shrimp Ponds }, volume={29}, url={https://journal.ipb.ac.id/index.php/hayati/article/view/37645}, DOI={10.4308/hjb.29.1.97-106}, abstractNote={<p>Certain strains of <em>V. parahaemolyticus</em> carry a gene that encodes a toxin that causes Acute hepatopancreatic necrosis disease (AHPND) in <em>P. vannamei</em>. AHPND attacks shrimp post larvae within 20-30 days after stocking causing up to 100% mortality. The expression of these virulent genes is controlled by the quorum sensing system. This system is inhibited by an anti-quorum sensing (AQS) mechanism. Several<em> Bacillus</em> strains have AQS mechanism by producing AHL-Lactonase enzyme. Therefore, this study aimed to obtain <em>Bacillus</em> spp. having AQS activity for controlling AHPND. The study was conducted from isolation and selection of <em>Bacillus</em> isolates, as well as determination of AQS activity. From 22 samples consisting of shrimp intestines, water and pond sediment samples, a total of 151 isolates of <em>Bacillus</em> spp. were isolated. The screening test for AQS activity obtained 11 isolates that showed AQS activity on <em>Cromobacterium violaceum</em>. Determination of violacein pigment in liquid cultures of <em>C. violaceum</em> showed the index value of the pigment formation was between 0.025-0.166 and 0.026-0.567 at 24-hour and between 48-hour incubations, respectively. The quantitative analysis of violacein production showed that there were six isolates of <em>Bacillus</em> could inhibit <br>the pigment production more than 75%. The isolates were identified as <em>Bacillus cereus</em> (four isolates), <em>Bacillus thuringiensis</em> (one isolate), and <em>Bacillus velezensis</em> (one isolate), respectively. The molecular analysis had confirmed that the isolates have <em>aii</em>A genes encoding AHL-lactonase enzyme. These <em>Bacillus</em> isolates have potential application for controlling AHNPD disease.</p&gt;}, number={1}, journal={HAYATI Journal of Biosciences}, author={Rusmana, Iman and HastutiYuni Puji and AlfisahRizal Khoirun and Akhdiya, Alina}, year={2021}, month={Dec.}, pages={97-106} }