Integrating Microbial Protein Production and Harvest Systems into Pilot-Scale Recirculating Aquaculture Systems for Sustainable Resource Recovery: Linking Nitrogen Recovery to Microbial Communities

Author(s):  
Min Deng ◽  
Zhili Dai ◽  
Kang Song ◽  
Yuren Wang ◽  
Xugang He
2019 ◽  
pp. 145-161 ◽  
Author(s):  
Alyssa Joyce ◽  
Mike Timmons ◽  
Simon Goddek ◽  
Timea Pentz

AbstractThe growth rates and welfare of fish and the quality of plant production in aquaponics system rely on the composition and health of the system’s microbiota. The overall productivity depends on technical specifications for water quality and its movement amongst components of the system, including a wide range of parameters  including factors such as pH and flow rates which ensure that microbial components can act effectively in nitrification and remineralization processes. In this chapter, we explore current research examining the role of microbial communities in three units of an aquaponics system: (1) the recirculating aquaculture system (RAS) for fish production which includes biofiltration systems for denitrification; (2) the hydroponics units for plant production; and (3) biofilters and bioreactors, including sludge digester systems (SDS) involved in microbial decomposition and recovery/remineralization of solid wastes. In the various sub-disciplines related to each of these components, there is existing literature about microbial communities and their importance within each system (e.g. recirculating aquaculture systems (RAS), hydroponics, biofilters and digesters), but there is currently limited work examining interactions between these components in aquaponics system, thus making it an important area for further research.


Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3000
Author(s):  
Wujie Xu ◽  
Yu Xu ◽  
Haochang Su ◽  
Xiaojuan Hu ◽  
Keng Yang ◽  
...  

Ammonia is the main pollution factor of the aquatic environment in marine shrimp culture systems. In order to demonstrate the feasibility of the combination of biofloc technology and nitrifying biofilter for the ammonia removal, a 70-day production trial was conducted in a simplified pilot-scale hybrid biofloc-based recirculating aquaculture system (biofloc-RAS) with the intensive culture of Litopenaeus vannamei. Nitrogen dynamics and nitrifying microbial communities were investigated in three replicated systems simultaneously under the conditions of high feed loading and zero water exchange. Along with biofloc development in the culture tank and biofilm formation in the nitrifying biofilter during the trial, nitrification could be fastly and effectively established in the system, which was indicated by the dynamics of total ammonia nitrogen (TAN), NO2–-N, NO3–-N, and total nitrogen (TN) concentrations. Meanwhile, similar nitrifying microorganisms could be found between biofloc and biofilm, despite some differences in abundance, diversity, and composition of ammonia-oxidizing archaea and bacteria and nitrite-oxidizing bacteria. High TAN removal rate could be achieved and was significantly and positively correlated with abundances of these nitrifying microbial communities in both biofloc and biofilm, further indicating that both biofloc and biofilm could contribute highly to nitrification performance of the biofloc-RAS. The results of this study indicate a potential application of the biofloc-RAS in coastal intensive aquaculture.


Archaea ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xiaona Ma ◽  
Xingqiang Song ◽  
Xian Li ◽  
Songzhe Fu ◽  
Meng Li ◽  
...  

Microorganisms play an essential role in the performance of constructed wetlands (CWs) for wastewater treatment. However, there has been limited discussion on the characteristics of microbial communities in CWs for treatment of effluents from marine recirculating aquaculture systems (RAS). This study is aimed at characterizing the microbial communities of pilot-scale CWs with Salicornia bigelovii for treatment of saline wastewater from a land-based Atlantic salmon RAS plant located in Northern China. Illumina high-throughput sequencing was employed to identify the profile of microbial communities of three CWs receiving wastewater under different total ammonia nitrogen (TAN) concentrations. Results of this study showed remarkable spatial variations in diversity and composition of microbial communities between roots and substrates in three CWs, with distinct response to different TAN concentrations. In particular, Proteobacteria, Firmicutes, Cyanobacteria, and Bacteroidetes were predominant in roots, while Cyanobacteria, Proteobacteria, Firmicutes, Verrucomicrobia, and Bacteroidetes were prevalent in substrates. Moreover, redundancy analysis indicated that specific functional genera, such as Nitrosopumilus, Vibrio, Pseudoalteromonas, Nitrospina, and Planctomyces, played key roles in the removal of nitrogen/phosphorus pollutants and growth of wetland plants. From a microorganism perspective, the findings of this study could contribute to better understanding of contaminants’ removal mechanism and improved management of CWs for treatment of effluents from land-based marine aquaculture.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Blanca M. Gonzalez-Silva ◽  
Kjell Rune Jonassen ◽  
Ingrid Bakke ◽  
Kjetill Østgaard ◽  
Olav Vadstein

AbstractIn this study, nitrification before and after abrupt cross-transfer in salinity was investigated in two moving bed biofilm reactors inoculated with nitrifying cultures that had adaptation to freshwater (FR) and seawater salinities (SR). FR and SR MBRRs were exposed to short and long term cross-transfer in salinity, and the functional capacity of nitrifying microbial communities was quantified by the estimation of ammonia and nitrite oxidation rates. Salinity induced successions were evaluated before and after salinity change by deep sequencing of 16S rRNA gene amplicons and statistical analysis. The bacterial community structure was characterized and Venn diagrams were included. The results indicated that after salinity cross-transfer, the FR was not significantly recovered at seawater salinity whereas SR showed high resistance to stress caused by low-salt. Succession and physiological plasticity were the main mechanisms of the long-term adaption of the nitrifying communities exposed to abrupt salinity changes. Independently of salinity, some nitrifiers presented high physiological plasticity towards salinity and were very successful at both zero and full seawater salinity. SR culture is robust and suitable inoculum for ammonium removal from recirculating aquaculture systems and industrial wastewaters with variable and fast salinity changes. Our findings contradict the current perspective of the significance of salinity on the structure of nitrifying communities.


2021 ◽  
Vol 8 ◽  
Author(s):  
Marlene Lorgen-Ritchie ◽  
Michael Clarkson ◽  
Lynn Chalmers ◽  
John F. Taylor ◽  
Herve Migaud ◽  
...  

Atlantic salmon aquaculture is undergoing an expansion of land-based recirculating aquaculture systems (RAS), especially for freshwater (FW) stages of production. Juvenile salmon undergo parr-smolt transformation, also known as smoltification and become pre-adapted to tolerate seawater (SW). One aspect requiring study is the development of microbial communities during this time, especially in RAS systems. Here we analyzed temporal changes in microbiome associated with the intestine in Atlantic salmon during smolt production in a commercial RAS production facility and followed the same cohort of fish post-seawater transfer (SWT), using 16S rRNA gene sequencing. Microbial diversity and richness showed an increase over time across FW production, but declined sharply and significantly 1-week post-SWT before re-establishing itself with a completely different community structure after 4 weeks. Core microbial taxa could be assigned to three distinct categories; (1) omnipresent, (2) salinity specific, or (3) transient. By including diet and water samples in the analyses, we classified true core taxa associated with the host, those associated with the diet, and transient cores associated with microbial communities in tank water. The rising trend observed in microbial richness in the water may be a consequence of a temporal increase in organic load while dominance of Vibrionaceae may be attributed to the higher temperatures maintained during RAS production and above average natural water temperatures post-SWT. Functional analysis suggests modulation of metabolic pathways post-SWT, but downstream impacts on fish growth and health in a commercial setting remain to be elucidated. A deeper understanding of the interplay between microbial composition and functionality can play a role in optimizing fish performance in tightly regulated RAS production.


2021 ◽  
Author(s):  
Alireza Neissi ◽  
Gholamreza Rafiee ◽  
Shadi Rahimi ◽  
Hamid Farahmand ◽  
Santosh Pandit ◽  
...  

Abstract Background: The aim of this study was the enrichment of high-performance microbial communities in biofilters for removal of ammonium and nitrite from aquaculture water. Methods: Ammonium oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) were enriched from different environmental water samples. The microbial communities with higher ammonium and nitrite removal activity were selected and adapted to different temperatures [9 ºC, 15 ºC, room temperature (25 ºC), and 30 ºC]. The expression of genes involved in nitrification including ammonia monooxygenase (AMO) and nitrite oxidoreductase (NXR) were measured in temperature-adapted AOB and NOB microbiomes. The microbial species present in the selected microbiomes were identified via 16s rRNA sequencing. Results: The microbial communities containing Nitrosomonas oligotropha and Nitrobacter winogradskyi showed the highest ammonium and nitrite removal activity at all temperatures used for adaptation. Furthermore, the microbial communities do not contain any pathogenic bacteria. They also exhibited the highest expression of AMO and NXR genes. Using the enriched microbial communities, we achieved a 288% and 181% improvement in ammonium and nitrite removal over the commonly used communities in biofilters at 9 °C, respectively. Conclusions: These results suggest that the selected microbiomes allowed for a significant improvement of water quality in a recirculating aquaculture system (RAS).


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