Effect of different aeration units, nitrogen types and inoculum on biofloc formation for improvement of Pacific Whiteleg shrimp production

Abstract

Biofloc formation is affected by the addition of carbon sources and the adequate aeration supply with a proper arrangement of aeration units. Apart from molasses was commonly used as carbon sources, the effect of different nitrogen types was also critically important in the biofloc formation. This study aimed to evaluate the effect of different aeration units and nitrogen types on the biofloc formation using bioflocculant-producing bacteria as inoculum. Experimental set-up was prepared with two types of aeration units (i.e.: air stone and aerotube) and three nitrogen types (i.e.: fish meal, grounded pellet and pellet). Water quality parameters, water physical appearance, biofloc volume and shrimp biomass were observed within 30 days of the study period. There were no significant difference (P ≤ 0.05) between the water quality parameters, however, biofloc volume and shrimp biomass showed a significant difference with the aeration units. Nitrogen types using pellet showed positive results with the formation of biofloc, while there was no formation of biofloc in the other treatments. Consequently, injection of bioflocculant-producing bacteria for the rapid formation of biofloc was recommended with a proper installation of aerotube units and pellet as a nitrogen type.