Lactobacillus salivarius BGHO1 and Lactobacillus reuteri BGGO6-55 modify nutritive profile of Artemia franciscana nauplii in a strain ratio, dose and application timing-dependent manner

Abstract

This study aimed to analyze an impact of Lactobacillus salivarius BGHO1 and Lactobacillus reuteri BGGO6-55 supplemented to Artemia franciscana cultivation medium on biochemical profile of hatched nauplii. Impacts of different BGHO1:BGGO6-55 ratios (75:25, 50:50 and 25:75) and their total concentrations (250 and 500 g/kg of Artemia cysts) at different timings of bacteria application (pre- and post-hatching) were examined. The effects were evaluated by quantification of naupliar peptide, soluble protein, phospho-, neutral and unsaturated lipid content. Uni and multi-factorial analysis of variance (ANOVA) were used to estimate the effects of treatments relative to control and to model factor interactions, respectively Statistical analysis indicated that post-hatching application of 75:25 strain ratio at high dose was associated with an increase of neutral lipid amount. Furthermore, factor interaction profiling identified positive correlation of lactobacilli concentration with the level of free amino acids/short peptides, phospho-, neutral and unsaturated lipids, but only at 50:50 strain ratio combination. Application of lower lactobacilli dose at 75:25 strain ratio caused an increase of soluble protein and phospholipid amount. Hypothetically, graded response of Artemia nauplii to lactobacilli supplementation was induced with different BGHO1 doses. It assumedly ranged from stress-response protein synthesis at lower doses to membrane permeability alterations and triglyceride-mediated defense mechanism activation at higher BGHO1 doses. In contrast to lactobacilli supplementation after Artemia hatching, pre-hatching application of lactobacilli was not associated with an increase of Artemia nutritive profile, though again there was a positive association of lactobacilli concentration with nutrient amount. This implicates interference of lactobacilli with the hatching process. Results presented here facilitate the design of future studies aiming to modify Artemia nutritive profile in accordance with nutritional demands of cultivated fish species.