In vitro assessment of potential probiotic characteristics of indigenous Lactococcus lactis and Weissella oryzae isolates from rainbow trout ( Oncorhynchus mykiss Walbaum)

Abstract

Aim The objective of this study was to evaluate the probiotic potential of lactic acid bacteria (LAB) isolated from the intestinal ecosystem of rainbow trout. Methods and Results Among LAB isolates, 10 of them were selected and screened for resistance to acid and bile salts, pancreatin, sodium chloride and temperature, hydrophobicity, growth profile and antimicrobial activity against fish pathogens. Then, biosafety assessments were investigated. Selected LAB tolerated to gastrointestinal physiological conditions, pancreatin and a range of sodium chloride and temperature. They also exhibited hydrophobicity and showed antagonistic activity against Streptococcus iniae and Yersinia ruckeri. Results of 16S rRNA gene sequencing showed that selected LAB belonged to the Lactococcus lactis (n = 5) and Weissella oryzae (n = 5) species. They exhibited no β‐haemolytic activity, while six selected LAB were resistant to some antibiotics. None of them harboured virulence factors. Conclusions This study revealed probiotic characteristics of indigenous LAB isolated from the intestinal ecosystem of rainbow trout. However, further studies are required to confirm the effectiveness of these isolates as probiotics in aquaculture. Significance and Impact of the Study To the best of our knowledge, for the first time, the presence of probiotic candidates belonging to W. Oryzae was confirmed in fish intestinal microbiota.

Complete Genome Sequence of Weissella confusa LM1 and Comparative Genomic Analysis

“…They have been isolated from various fermented foods, such as yoghurt, sourdough, and kimchi ( Wang et al, 2011 ; Zannini et al, 2018 ; Mun and Chang, 2020 ; Valerio et al, 2020 ), and play important roles in the process of fermentation, thereby influencing the texture and taste of foods. They also exist in the guts of humans and vertebrate animals, such as giant pandas and rainbow trout ( Xiong et al, 2019 ; Mortezaei et al, 2020 ; Wang et al, 2020 ), their functions involve reducing depressive-like behavior ( Sandes et al, 2020 ), influencing gut permeability and intestinal epithelial regeneration ( Prado et al, 2020 ), killing harmful bacteria ( Dey and Kang, 2020 ; Lee et al, 2020 ; Pelyuntha et al, 2020 ), affecting host metabolism ( Elshaghabee et al, 2020 ), and preventing cancer cell proliferation ( Le et al, 2020 ). Some Weissella species may be beneficial to plants because they inhibit the infection of plant pathogenic fungi, such as Fusarium verticillioides ( Quattrini et al, 2020 ).…”

Dietary Lipid Effects on Gut Microbiota of First Feeding Atlantic Salmon (Salmo salar L.)

“…Other Weissella spp. have been found in gut of Oncorynchus mykiss (Lyons et al, 2017;Mortezaei et al, 2020) and Atlantic salmon (Reveco et al, 2014;Godoy et al, 2015;Lokesh et al, 2019). It is worth noting that beside OTU0004, also OTU0013 and OTU0017 are associated with probiotic bacterial species (detected in all time points studied here, from EG to D93, independently of the dietary treatment).…”

Presence of Lactic Acid Bacteria in the Intestinal Tract of the Mediterranean Trout (Salmo macrostigma) in Its Natural Environment

“…Recently, some strains of Lc. lactis were selected and proposed as probiotics in the fish diet [ 35 , 60 ].…”