Biotesting as a modern assessment method of the aquatic environment Biofloc quality

Abstract

Studies were conducted to determine the biofloc media toxicity degree to hydrobionts by biotesting. Environment variability in which biocenosis biofloc is formed can cause optimal C/N ratio values violations in a closed water system, which is considered a critical factor affecting the formation rate of microbial communities and species ratio in them. Test objects use in this study showed no toxic effects on the bioindicator in the environment created by the bacterial communities that make up the Biofloc system. Of course, the data obtained cannot be considered exhaustive, but it should be noted that aquatic plant use as a bioindicator provides new opportunities for developing biofloc systems potential. The BFT-systems principle is to stimulate the natural growth of macroaggregate flocs, enhance culture water self-nitrification. A prerequisite for the flocs’ functioning as a biofilter analogue, along with supporting them in suspension, is the presence of an easily digestible organic carbon source, as the cultures of bacterial microorganisms in the base of flocs are heterotrophic.

Swinging between the beneficial and harmful microbial community in biofloc technology: A paradox

“…BFT culture systems are driven by biofloc, which are communities of microbes namely bacteria, algae, fungi, protozoa, rotifers, grazing macroinvertebrates, and detritus [ 141 , 142 ] performing the overlying function of saprophytes, algae grazers and pathogenic bacteria, nitrifying bacteria and floc-farming organisms [ [54] , [57] , [61] , [143] ]. In an optimally functioning BFT system, all constituent species must be suspended in the water column, carrying out their roles and in a sustainably high connections with other microorganisms [ 57 ].…”