Effect of different levels of bioflocs on bacterial diversity in intensive shrimp farming

• Grant number: 17/24583-6
• Support Opportunities: Scholarships in Brazil - Master
• Start date: April 01, 2018
• End date: July 31, 2020
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Aquaculture
• Agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Rodrigo Schveitzer
• Grantee: Fabrini Copetti Temistocles de Oliveira Alves
• Host Institution: Instituto de Saúde e Sociedade (ISS). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil
• Associated scholarship(s): 19/17521-0 - Ecological theory as a management strategy of microbial community in microbial-based systems for culture of fish and shrimp, BE.EP.MS

Abstract

The biofloc culture technology is a production system that has gained importance in recent years and has been used for both shrimp and fish farming. Briefly, it is a production system where dense microbial communities are manipulated in order to control the ammonia excreted by the farmed organisms. The growth of these microorganisms occurs as microbial flakes (bioflocs), which serve as food for the farmed species. The main characteristics of this cultivation system are the high storage density and the intense aeration. This form of nitrogen compounds control demands no water exchange or demands only a little water exchange, which increases farming biosecurity and reduces effluent emissions. One of the factors that can affect performance in this culture system is the diversity of bacteria. The dynamic nature of the microbial ecosystem in biofloc cultures means that this system may be susceptible to changes that impact the stability of the microorganism community. This instability may lead to proliferation of opportunistic pathogenic species, which may compromise the performance of the farmed organisms. In this project the bacterial diversity in the biofloc culture will be evaluated from molecular techniques. Diversity will be evaluated in water tanks of superintensive shrimp culture systems kept under different amounts of bioflocs in water, expressed as total suspended solids (TSS). In one treatment the TSS will be maintained with a maximum of 300 mg L-1, while in another the level of bioflocs will be between 400 and 600 mg L-1. Our hypothesis is that in environments with more TSS the bacterial diversity would be greater, and it would be less favorable to the development of pathogenic bacteria, such as those of the genus Vibrio. The research of bacterial diversity in biofloc cultures is the initial step in attempting to "domesticate" these microorganisms and to obtain more microbiologically predictable systems. The results obtained will help in understanding the variables that affect bacterial diversity in this production system, allowing a greater microbial control in biofloc cultures. Although this project is directed to shrimp cultures, the knowledge generated will be applicable to biofloc cultures of other organisms. This project will be implemented at the facilities of the Department of Marine Sciences (DCMAR) of the Federal University of São Paulo, which was created in 2012 as part of the Federal Universities' Restructuring and Expansion Program, and it will result in an increase of the production of researches applied to biotechnology in the aquaculture area. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

COPETTI, FABRINI; GREGORACCI, GUSTAVO BUENO; VADSTEIN, OLAV; SCHVEITZER, RODRIGO. Management of biofloc concentrations as an ecological strategy for microbial control in intensive shrimp culture. Aquaculture, v. 543, OCT 15 2021. (17/24583-6)