Modulating gut microbiota and digestive enzyme activities of Artemia urmiana by administration of different levels of Bacillus subtilis and Bacillus licheniformis

Abstract

The aim of this study was to evaluate the effects of Bacillus subtilis and Bacillus licheniformis on growth, gut microbiota, and digestive enzyme activities of Artemia urmiana. Three diets containing 10 2 (T 1 ), 10 4 (T 2 ), 10 6 (T 3 ) CFU of probiotics/g feed, and a control diet (C) without probiotic were used through a completely randomized design (treatments with triplicates). Twelve plastic tanks with the capacity of 60-l and density of 20 nauplii/ml were used and the trial continued for 15 days. Results showed that probiotics significantly increased the total length of A. urmiana (P \ 0.05). Although the total aerobic gastrointestinal bacteria count showed no significant differences among the treatments, the total Bacillus count significantly increased in experiments (P \ 0.05). The ratio of TCBS to total aerobic bacteria count was significantly lower in T 1 (0.31 ± 0.05), T2 (0.27 ± 0.15), and T 3 (0.25 ± 0.05) compared to the control (0.76 ± 0.34) (P \ 0.05). The probiotics were able to increase the protease and amylase activities (P \ 0.05). No significant effect on lipase activity. The study determined T 2 and T 3 as the most effective treatments for improving growth, bacterial flora, and digestive enzyme activities. As less probiotic needed in T 2 , using 10 4 bacteria per g diet is recommended for rearing Artemia up to the maturity stage.

Vibrio Species in an Urban Tropical Estuary: Antimicrobial Susceptibility, Interaction with Environmental Parameters, and Possible Public Health Outcomes

“…from clinical and environmental samples, some studies may classify total bacterial counts on TCBS as Vibrio spp. [48,49]. However, our results revealed that at least 19.0% of the bacteria isolated on TCBS agar submitted to MALDI-TOF MS identification did not belong to the genus Vibrio, being Photobacterium and Aeromonas the most frequently identified genera.…”

Nutrient L-Alanine-Induced Germination of Bacillus Improves Proliferation of Spores and Exerts Probiotic Effects in vitro and in vivo

“…Probiotic Bacillus species are beneficial for modulating the intestinal microflora and micro-ecological balance ( Motlagh et al, 2012 ; Wang et al, 2017 ; Luo et al, 2020 ). In the present study, the increased intestinal microbiota barrier by the L-alanine-induced spores was further confirmed in the SD rats ( Figure 7 ).…”

Effect of commercial probiotic on the population dynamics of selected rotifers ( Brachionus angularis , Plationus patulus ) and cladocerans ( Moina cf. macrocopa and Simocephalus mixtus )

“…LAB is recognized as a part of the microflora of rotifers (Gatesoupe, 1994), but its specific role is not yet fully understood. Applied to zooplankton cultures, B. subtilis acts as a growth promoter (Hirata et al, 1998;Murillo & Villamil, 2011;Zink et al, 2013); as a digestive enzyme promoter (Motlagh, Farhangi, Rafiee, & Noori, 2012); and as a pathogen inhibitor (Giarma et al, 2017;Murillo & Villamil, 2011).…”