Total suspended solids and their impact in a biofloc system: current and potentially new management strategies.

SOAUDY M; GHONIMY A; LOPEZ GRECO L.S; CHEN Z; DYZENCHAUZ A; LI J

AQUACULTURE

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2023

0044-8486

Heterotrophic bacterial activity generatesa load of total suspended solids (TSS) in biofloc systems (BF). This ac-cumulation affects animal health and product quality in terms of the gills blocked function and flesh off-flavor,but TSS elimination causesa sudden change in microbial composition and nutrients concentration, leading toadecreased nitrifying bacterial load and facilitating pathogenic bacterial growth. The accumulated or drained TSSfrom BF system results in an increased of pathogenic bacterial abundance, in this review, we suggest novel man-agement strategies to manipulate the TSS level by manipulating the heterotrophic and nitrifying bacterial activi-ties. Hybrid activity between heterotrophic and nitrifying bacteria may decrease the bacterial intensity and car-bon source supplement in BF. Based on this complex interaction we suggested novel management strategies of ni-trifying activity induction and heterotrophic activity manipulation. Nutrient availability (Ca+2 and alkalinity ascarbon sources, for example lime), biofilm induction (homoserine lactone supplementation asa quorum sensingagent), and environmental conditions (temperature, anda complex carbon source asa substrate carrier) may in-duce nitrifying bacterial activity. Decreasing C/N ratio may inducea low C/N dependent heterotrophic activity,whereas increased algal abundance would providea photosynthetic carbon for heterotrophic activity and wouldrecycle the nitrogenous compounds (NO3). The hybrid bacterial activities may result in an increased productiv-ity, zero mortality, stable water quality, longer culture capacity, anda free off-flavor product.