Research Information System
ABSTRACTS of the 7th Central European Forum for Microbiology , Budapest, Hungary, 6 - 08 October 2025, pp.32-33, (Summary Text)
Common carp (Cyprinus carpio) is a key species in Hungarian pond aquaculture; therefore, environmentally friendly and sustainable methods to improve reproductive performance are of great interest. One possible approach is the development of targeted probiotics in fish feed. This study analysed the initial gut and gamete microbiomes of common carp using traditional and molecular techniques to select microorganisms with potential probiotic activity for future commercial use. Sampling and microbiological analyses were conducted on 15 male and 15 female carp from a Hungarian fish farm. Microbial culturing was performed on Tryptone Soy Agar (TSA) and selective De Man-Rogosa-Sharpe (MRS) media. DNA from gut and gamete samples was extracted using commercial kits, and microbial communities were profiled by Illumina amplicon sequencing of the 16S rRNA gene (V3–V4 regions). Data were processed with the DADA2 pipeline, and Amplicon Sequence Variants were annotated using the Silva 138.1 database. Aeromonas dominated the gut microbiome of both sexes, while Cetobacterium was more abundant in male fish. Members of Erysipelotrichaceae, Desulfovibrionaceae, and Brevinema were abundant in the microbiome of some individuals. Only one ovarian fluid sample was successfully analysed by next-generation sequencing due to the low microbial DNA yield of gametes. In this sample, we found an overwhelming dominance of the Mycoplasma genus. Gamete microbiome analysis relying on cultivation combined with MALDITOF MS identified Aeromonas, Pseudomonas, Acinetobacter, Lactobacillus, and Shewanella species. In total, 125 potential probiotic isolates were obtained; the 20 most promising (Lactococcus, Lactobacillus, Liquorilactobacillus) were characterized following EFSA recommendations. Technological parameters (optimal temperature, medium, pH), safety, and effectiveness were assessed through phenotypic and molecular tests. Based on preliminary results, Lactiplantibacillus plantarum (TÉT43) was selected as the most promising candidate for probiotic feed development and was prepared for in vivo testing. This research was funded by the project 2022-1.2.6-TÉT-IPARI-TR-2022-00002 within the framework of the National Research, Development and Innovation Fund announced by the Ministry of Culture and Innovation.