Effect of different bio-augmentation agents on the biochemical composition of bacterial floc and growth of juvenile <i>Penaeus monodon</i> cultured in concrete tanks

Abstract

The effect of bio-augmentation agents on the biochemical composition of biofloc, growth ofjuvenile Penaeus monodon, and antimicrobial activity of BFT water against <i>Vibrio harveyi</i> was investigated. <i>P. monodon</i> juveniles were cultured in pond soil-lined concrete tanks for 150 d using biofloc technology with bio-augmentation. Three commercial bio-augmentation agents (Pond Protect™, Pond Dtox™, BZT Waste Digester™) were tested against a control with no bio-augmentation agent application. At the end of the culture period, floc and shrimp collected for proximate analysis, and biofloc water tested for activity against V. harveyi. Average body weight (ABW), food conversion ratio (FCR), and specific growth rate (SGR) of the shrimp were computed. Bio augmentation with Pond Protect™ resulted in significantly higher (p < 0.05) crude protein content of the biofloc although this did not translate to higher shrimp yield nor growth performance. BZT Waste Digester™ as bio-augmentation agent significantly increased (p < 0.05) shrimp ABW. No apparent relationship between floc composition and shrimp carcass composition was observed. BFT water, with and without bioaugmentation agents, completely inhibited <i>V. harveyi</i> within 24 h. This study demonstrates that bio-augmentation agents could enhance the biochemical composition offloc and affect shrimp growth. BFT water was also shown to have potent antimicrobial properties against <i>V. harveyi</i>.