Detection of quorum sensing molecules from <i>Vibrio harveyi</i> and use of synthetic furanone to control <i>V. harveyi</i> during shrimp larviculture

Abstract

This paper explores the extraction and detection processes of quorum sensing molecules such as N-aceyl homoserine lactone compounds (AHL) from marine Vibrio harveyi. The spent culture of V. harveyi was solvent partitioned for AHL, rotary evaporated and re-suspended in 50% acetonitrile then detected with reporter strain using Luminometer. Furanone was tested for antagonism against V. harveyi and an inhibitory zone of 9.0 ± 0.25 mm was observed. When, V. harveyi grew in Lysogeny broth (LB) with furanone, the growth was decreased from 0.2 to 0.03 optical density (OD) in 16 h. In control, V. harveyi growth was increased from 1.33 to 2.3 OD. When furanone was challenged against V. harveyi among shrimp post larvae, the cumulative percentage mortality was increased in the control from 0.85 to and 80% for the period of 5th to 30th days. But in the treatment tank the mortality varied from 0.53 to 1.26, 5.51, 8.17, 10.72 and 13.37% till the 30th day. The differences in the cumulative percentage mortalities in the treatment tank were 0.32, 2.34, 28.63, 51.50, 59.20 and 66.71% respectively as compared to the control. The results suggest that furanone can be used as non-antibiotic agent to control shrimp disease caused by V. harveyi.

Key words: Vibrio harveyi, detection of N-aceyl homoserine lactone compounds (AHL), furanone, antagonism, shrimp larviculture.