Banca de DEFESA: JULIANA SOUSA TERADA NASCIMENTO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JULIANA SOUSA TERADA NASCIMENTO
DATE: 10/06/2023
TIME: 10:00
LOCAL: Campus de Rolim de Moura- sala 21
TITLE:

Monitoring of fungi in fish farm water and mycotoxins in commercial feed intended for feeding tambaqui (Colossoma macropomum) cultivated in Rondônia. 

KEY WORDS:

Fungi; Native fish; Toxicology; Economic impact.

PAGES: 74
BIG AREA: Outra
AREA: Ciências Ambientais
SUMMARY:

The consumption of fish has been growing all over the world, following the global trend that seeks a healthy diet. The state of Rondônia is considered the largest producer of native fish in Brazil. Making better quality control of the feed necessary, considering the presence of contaminants in the feed supplied to the fish. An example of this are mycotoxins that cause a wide variety of adverse effects in animals and humans. The objective was to carry out a bibliographic survey on mycotoxins in the fish production chain, as well as to evaluate the presence of fungi in the water and mycotoxins in commercial feed samples from tambaqui fish farms in the state of Rondônia. A systematic review of the last 10 years was carried out, focusing on mycotoxins in fish feed. For water analysis, water samples were collected in the supply channel, in the drainage pipe and in the water column of the nurseries, then identification of free-living fungi was carried out; along with this, a total of 21 feed samples were collected from the fish farms, where microbiological analysis, texture analysis (TPA) and high performance liquid chromatography coupled to a mass spectrometry detector were performed for 8 categories of mycotoxins. A total of 5 species of free-living fungi were identified in the water of the fish farms, Aspergillus fumigatus, Penicillium citrinum, P. implicatum, Fusarium oxysporum and Alternaria alternata. Being accounted for 35.14 CFU/mL in the rainy season and 24.69 CFU/mL in the dry season. While in the diets, 81% of the samples showed growth of some filamentous fungus, of which only one sample did not present mycotoxin, in the others, the mycotoxin fumonisin B1 + B2 (375 to 1418 μg/kg) was quantified. According to the results found in the texture analysis (TPA) of the diets, the variables hardness, compression force, fractureability, chewiness and spreadability, the fungi caused the hardening and crumbling of the pellets. There was an increase in the fracturability and spreadability of the pellets in the water in the ponds, this caused a significant reduction in the buoyancy (~50%) of the feeds, as a result the nutrients leached into the water, and therefore became a surplus of nutrients at the bottom (sediment) from the nurseries. This study supports a better understanding of the risk of exposure to mycotoxins for fish, as well as the possible economic and productivity impacts for fish farming. Control measures are necessary to mitigate feed contamination. Further studies are needed to establish the minimum dose of exposure to fumonisins capable of causing adverse effects in fish.

COMMITTEE MEMBERS:
Externo ao Programa - 2035814 - IGOR MANSUR MUNIZ - UNIRExterno à Instituição - RICARDO YSAAC GARCÍA NUÑEZ
Externo à Instituição - FRANCISCO CARLOS DA SILVA - São Lucas
Externo à Instituição - JERONIMO VIEIRA DANTAS FILHO - UNIR