Mannanoligosaccharides as a Carbon Source in Biofloc Boost Dietary Plant Protein and Water Quality, Growth, Immunity and Aeromonas hydrophila Resistance in Nile Tilapia (Oreochromis niloticus)

Abstract

The aim of the present study was to evaluate mannan oligosaccharides (MOS) or glycerol (GLY) as a carbon source on biofloc systems of Nile tilapia (O. niloticus) juveniles. Fish (n = 750) were reared in open flow (Controls) or biofloc systems (B-GLY and B-MOS) fed with a plant or fish protein source over a period of twelve weeks. Total ammonia nitrogen and nitrate decreased in the biofloc groups, while biofloc volume increased in B-MOS. Compared to the controls, B-MOS and B-GLY exhibited higher weight gain and improved feed conversion, irrespectively of the diet. Serum level of C-reactive protein was reduced, while IgM and lysozyme activity was higher in the B-MOS fish, compared to other groups. Intestinal Bacillus spp. count was increased, whereas Vibrio, Aeromonas and Pseudomonas spp. counts decreased in B-MOS reared groups, compared to the other groups. The proinflammatory cytokine (IL-8 and IFN-γ) transcript expression was upregulated in B-MOS more than B-GLY reared groups. Compared to the controls, the virulence of Aeromonas hydrophila was decreased in the B-MOS and B-GLY groups. The results indicate several benefits of using MOS as a carbon source in a biofloc Nile tilapia system; a cost benefit analysis is required to assess the economic viability of this.

Study on floc characteristics and bacterial count from biofloc‐based genetically improved farmed tilapia culture system

“…In this study, total presumptive Vibrio, total coliform and Aeromonas count were significantly lower in BFT water and fish gut compared with CWS at the end of study. These results were coherent with previous findings (Kishawy et al., 2020; Kumar et al., 2018; Luis‐Villasenor et al., 2015; Martins et al., 2020; Panigrahi., 2017, 2018, 2019). Water samples collected from White leg shrimp and Nile tilapia culture tanks, a sugar cane‐based biofloc system, showed lower relative abundance of vibrionacea using next‐generation sequencing (Martins et al., 2020).…”

“…Similar growth pattern was observed in Nile tilapia reared in BFT by Kishavy et al. (2020). Besides this, weight gain and FCR of the present study were found to be better than the Durigon et al.…”

“…Kishawy et al. (2020) found decreased Vibrio and Aeromonas counts in the BFT reared fish gut samples than the control group. However, the present study showed higher values of Vibrio (10 5 ) and Aeromonas (10 5 ) loads in fish gut samples compared with Kishawy et al.’s (2020) report, who used mannan‐oligosaccharides and glycerol as carbon sources in Nile tilapia biofloc system.…”

“…Equally, the present study found significantly higher LAB count in the intestinal tract of fish reared at BFT system than CWS. Similarly, biofloc system, using mannan‐oligosaccharides and glycerol as carbon source, produced a better LAB count in the gut of Nile tilapia (Kishawy et al., 2020). Moreover, the study found a positive correlation ( r ‐0.92) between the THB count of water and fish gut which confirmed the biofloc colonization in the GIT of fish.…”

Yucca schidigera Usage for Healthy Aquatic Animals: Potential Roles for Sustainability

“…The overall results provide impressive outcomes regarding using Y. schidigera in terms of potential interest in open-flow pond aquaculture and closed aquaculture systems. Correspondingly, Y. schidigera can be complementary to biofloc technology, which can also improve the growth and immune status of farmed fish via improving water quality parameters [ 96 ].…”