Identification of intestinal microbiota and microbiological quality of the king weakfish (Macrodon ancylodon)

Abstract

The king weakfish (Macrodon ancylodon) has a wide geographic distribution in South America and provides a positive economic outlook for the fishing industry in Brazil. The present study aimed to identify the intestinal microbiota and bacterial strains that can increase during storage of the king weakfish. Characterization of the microbiological quality was performed on samples to identify the microflora through isolation on culture media and identification using BD BBL kits for Gram-negative and Gram-positive bacteria. The growth of isolated strains was tested at conventional storage temperatures of 7 and 3°C used to limit the expansion of pathogenic bacteria populations. All king weakfish samples were within the limits established by Brazilian law for microbiological standards. Twenty strains that were isolated from the intestinal microbiota of M. ancylodon were identified; five stood out and may play a role in the safety and/or shelf-life of this fish species: Staphylococcus cohnii subsp. urealyticum, Burkholderia cepacia, Pseudomonas stutzeri, Pseudomonas fluorescens and Corynebacterium sp. However, only the first two strains showed significant growth at 3°C after three days of storage, mainly B. cepacia which is also considered an opportunistic pathogen.