Impact of early-life rearing history on gut microbiome succession and performance of Nile tilapia.

Background: Fish gut microbial colonisation starts during larval stage and plays an important role in host's growth and health. To what extent first colonisation could influence the gut microbiome succession and growth in later life remains unknown. In this study, Nile tilapia embryos were incubated in two different environments, a flow-through system (FTS) and a biofloc system (BFS); hatched larvae were subsequently cultured in the systems for 14 days of feeding (dof).

In-Situ Biofloc Affects the Core Prokaryotes Community Composition in Gut and Enhances Growth of Nile Tilapia (Oreochromis niloticus).

Biofloc technology is commonly applied in intensive tilapia (Oreochromis niloticus) culture to maintain water quality, supply the fish with extra protein, and improve fish growth. However, the effect of dietary supplementation of processed biofloc on the gut prokaryotic (bacteria and archaea) community composition of tilapia is not well understood. In this study one recirculating aquaculture system was used to test how biofloc, including in-situ biofloc, dietary supplementation of ex-situ live or dead biofloc, influence fish gut prokaryotic community composition and growth performance in comparison to a biofloc-free control treatment.

Exogenous enzymes and probiotics alter digestion kinetics, volatile fatty acid content and microbial interactions in the gut of Nile tilapia.

Sustainable aquafeed production requires fishmeal replacement, leading to an increasing use of plant-derived ingredients. As a consequence, higher levels of antinutritional substances, such as non-starch polysaccharides and phytate, are present in aquafeeds, with negative effects on fish performance, nutrient digestibility and overall gut health. To alleviate these negative effects, providing exogenous digestive enzymes and/or probiotics can be an effective solution.

Integration of Algae to Improve Nitrogenous Waste Management in Recirculating Aquaculture Systems: A Review.

This review investigates the performance and the feasibility of the integration of an algal reactor in recirculating aquaculture systems (RAS). The number of studies related to this topic is limited, despite the apparent benefit of algae that can assimilate part of the inorganic waste in RAS. We identified two major challenges related to algal integration in RAS: first, the practical feasibility for improving nitrogen removal performance by algae in RAS; second, the economic feasibility of integrating an algal reactor in RAS.

Using poly(β-hydroxybutyrate-β-hydroxyvalerate) as carbon source in biofloc-systems: Nitrogen dynamics and shift of Oreochromis niloticus gut microbiota.

Inorganic‑nitrogen removal is essential for the sustainable operation of aquaculture industry and also influences the health of aquatic animals, which may be accomplished by utilizing biofloc technology. In this paper, we studied the use of three different carbon sources 1) longan seed powder (LP), 2) Poly(β-hydroxybutyrate-β-hydroxyvalerate) (PHBV) and 3) synthesized PHBV and LP (PHBVL) in biofloc systems for 90days to investigate the nitrogen dynamics and gut microbiota of Nile tilapia (Oreochromis niloticus). The PHBVL and PHBV groups had higher total inorganic‑nitrogen removal efficiencies (70.

Managing the Microbial Community of Marine Fish Larvae: A Holistic Perspective for Larviculture.

The availability of high-quality juveniles is a bottleneck in the farming of many marine fish species. Detrimental larvae-microbe interactions are a main reason for poor viability and quality in larval rearing. In this review, we explore the microbial community of fish larvae from an ecological and eco-physiological perspective, with the aim to develop the knowledge basis for microbial management.

Resistance and resilience of small-scale recirculating aquaculture systems (RAS) with or without algae to pH perturbation.

The experimental set-up of this study mimicked recirculating aquaculture systems (RAS) where water quality parameters such as dissolved oxygen, pH, temperature, and turbidity were controlled and wastes produced by fish and feeding were converted to inorganic forms. A key process in the RAS was the conversion of ammonia to nitrite and nitrite to nitrate through nitrification. It was hypothesized that algae inclusion in RAS would improve the ammonia removal from the water; thereby improving RAS water quality and stability.

The impact of rearing environment on the development of gut microbiota in tilapia larvae.

This study explores the effect of rearing environment on water bacterial communities (BC) and the association with those present in the gut of Nile tilapia larvae (Oreochromis niloticus, Linnaeus) grown in either recirculating or active suspension systems. 454 pyrosequencing of PCR-amplified 16S rRNA gene fragments was applied to characterize the composition of water, feed and gut bacteria communities. Observed changes in water BC over time and differences in water BCs between systems were highly correlated with corresponding water physico-chemical properties.

The colonization dynamics of the gut microbiota in tilapia larvae.

The gut microbiota of fish larvae evolves fast towards a complex community. Both host and environment affect the development of the gut microbiota; however, the relative importance of both is poorly understood. Determining specific changes in gut microbial populations in response to a change in an environmental factor is very complicated.

Decomposition of high protein aquaculture feed under variable oxic conditions.

The microbial decomposition of nitrogen-rich organic matter in aquaculture ponds is affected by the oxic-anoxic conditions gradient at the soil-water interface as well as by resuspension practices. To investigate these interactions, the decomposition of a 49% protein fish feed was analyzed in 10 marine lab-scale systems with different exposures to aerobic and anaerobic conditions. The degree of coupling between oxic and anoxic conditions in the system had a strong effect on product accumulation and loss from the culture system.