Optimized Utilization of Organic Carbon in Aquaculture Biofloc Systems: A Review

Abstract

Biofloc technology (BFT) as an efficient aquaculture alternative is attracting attention for boosting biosecurity with minimal water exchange and reduced feed intake. BFT relies on applying organic carbon to maintain a high C/N ratio above 10, which allows heterotrophs to assimilate toxic nitrogen. A high percentage of carbon loss is thus generated from BFT. For this review, a thorough search of the relevant literature was conducted to gather valuable information on the optimization of carbon utilization. The keywords searched included ‘BFT’, ‘carbon use efficiency’, ‘carbon conversion’, ‘carbon retention’, ‘carbon emission’, ‘carbon loss’, and ‘carbon release’. The current review discusses the possible effects of various C/N ratios, carbon types, addition strategies, and technology integration with respect to the optimized carbon utilization in BFT. Given the extreme lack of accessible research, it was concluded that the carbon utilization in BFT is still in its initial research stage. Anyhow, this review sheds light on plausible approaches for boosted carbon utilization by adopting slow-release carbon, reducing carbon input, integrating with other technologies, and enhancing interactions between functional microbes within BFT, thereby contributing to sustainable aquaculture.

Biological removal of nitrogenous waste compounds in the biofloc aquaculture system: a review

“…Microbial-based cultivation method that operates by introducing organic carbon sources into water or augmenting the carbon content in the feed to enhance the carbon-to-nitrogen ratio. This system promotes nutrient cycling and is therefore considered more eco-friendly (Yu et al, 2023;Li et al, 2023).…”

“…A balanced C/N ratio facilitates the efficient removal of nitrogenous compounds and guarantees optimal microbial growth. The ideal C/N ratio varies depending on the specific needs of the targeted aquatic organisms and the system conditions (Li et al, 2023).…”

Hermetia illucens Larvae Meal as Partial Fishmeal Replacement in Jade Perch Diet Cultured in Biofloc: Growth Performance, Feed Efficiency and Consumer Acceptance

“…Biofloc systems can either be in-situ (cultured directly with target organisms) or ex-situ (incorporated as feed ingredients) (Deng et al 2022;Menaga et al 2019). In-situ biofloc is established by creating a high carbon-to-nitrogen ratio in the water column starting from 10:1 (Dong et al 2021;Panigrahi et al 2019) by an external supply of organic carbon sources in water or increasing carbon content in feed (Li et al 2023) with a constant flow of aeration. This system benefits from minimal water change, reduced artificial feed input, and a natural establishment of microbial biomass (Mugwanya et al 2021).…”