title: Quantitative analyses of the bacterial microbiota of rearing environment, tilapia and common carp cultured in earthen ponds and inhibitory activity of its lactic acid bacteria on fish spoilage and pathogenic bacteria.
abstract: The present study aimed to evaluate the bacterial load of water, Nile Tilapia and common Carp intestines from earthen ponds, isolate lactic acid bacteria (LAB) and assess their antimicrobial activity against fish spoilage and pathogenic bacteria. Following enumeration and isolation of microorganisms the antimicrobial activity of the LAB isolates was evaluated. Taxonomic identification of selected antagonistic LAB strains was assessed, followed by partial characterisation of their antimicrobial metabolites. Results showed that high counts (>4 log c.f.u ml-1or 8 log c.f.u g-1) of total aerobic bacteria were recorded in pond waters and fish intestines. The microbiota were also found to be dominated by Salmonella spp., Vibrio spp., Staphylococcus spp. and Escherichia coli. LAB isolates (5.60%) exhibited potent direct and extracellular antimicrobial activity against the host-derived and non host-derived spoilage and pathogenic bacteria. These antagonistic isolates were identified and Lactococcus lactis subsp. lactis was found as the predominant (42.85%) specie. The strains displayed the ability to produce lactic, acetic, butyric, propionic and valeric acids. Bacteriocin-like inhibitory substances with activity against Gram-positive and Gram-negative (Vibrio spp. and Pseudomonas aeruginosa) bacteria were produced by three L. lactis subsp. lactis strains. In this study, the LAB from the microbiota of fish and pond water showed potent antimicrobial activity against fish spoilage or pathogenic bacteria from the same host or ecological niche. The studied Cameroonian aquatic niche is an ideal source of antagonistic LAB that could be appropriate as new fish biopreservatives or disease control agents in aquaculture under tropical conditions in particular or worldwide in general.
authors.affiliation: Laboratory of Biochemistry, Food Science and Nutrition (LABPMAN), Department of Biochemistry, Faculty of Science, University of Dschang, Cameroon, P.O Box 67, Dschang, Cameroon. kapima79@yahoo.fr.|Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa (UAM-I), Av. San Rafael Atlixco 186, 09340, Mexico, Distrito Federal, Mexico. kapima79@yahoo.fr.
authors.forename: Pierre Marie
authors.identifier: http://orcid.org/0000-0003-0213-8858
authors.initials: PM
authors.lastname: Kaktcham
authors.affiliation: Laboratory of Biochemistry, Food Science and Nutrition (LABPMAN), Department of Biochemistry, Faculty of Science, University of Dschang, Cameroon, P.O Box 67, Dschang, Cameroon.
authors.forename: Jules-Bocamdé
authors.initials: JB
authors.lastname: Temgoua
authors.affiliation: Laboratory of Biochemistry, Food Science and Nutrition (LABPMAN), Department of Biochemistry, Faculty of Science, University of Dschang, Cameroon, P.O Box 67, Dschang, Cameroon.
authors.forename: François
authors.initials: F
authors.lastname: Ngoufack Zambou
authors.affiliation: Departamento de Alimentos y Biotecnología, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria Coyoacán, 04510, Mexico, Distrito Federal, Mexico.
authors.forename: Gloria
authors.initials: G
authors.lastname: Diaz-Ruiz
authors.affiliation: Departamento de Alimentos y Biotecnología, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria Coyoacán, 04510, Mexico, Distrito Federal, Mexico.
authors.forename: Carmen
authors.initials: C
authors.lastname: Wacher
authors.affiliation: Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa (UAM-I), Av. San Rafael Atlixco 186, 09340, Mexico, Distrito Federal, Mexico.
authors.forename: María de Lourdes
authors.initials: ML
authors.lastname: Pérez-Chabela
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology; D001419:Bacteria / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D001420:Bacteria, Aerobic / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism; D058491:Bacterial Load; D001430:Bacteriocins / Q000494:pharmacology; D002347:Carps / Q000254:growth & development / Q000382:microbiology*; D004463:Ecology; D005227:Fatty Acids / Q000378:metabolism; D005393:Fish Diseases / Q000382:microbiology; D005516:Food Microbiology; D007422:Intestines / Q000382:microbiology; D019344:Lactic Acid / Q000378:metabolism; D013294:Lactococcus lactis / Q000302:isolation & purification / Q000378:metabolism; D064307:Microbiota; D010802:Phylogeny; D061005:Ponds / Q000382:microbiology*; D017210:Tilapia / Q000254:growth & development / Q000382:microbiology*
chemical_list: D000890:Anti-Infective Agents; D001430:Bacteriocins; D005227:Fatty Acids; D019344:Lactic Acid
keywords: Bacterial load; Bacteriocins; Fish intestine; LAB’s antimicrobial activity; Pond water; Short chain fatty acids