Assessing the Pyloric Caeca and Distal Gut Microbiota Correlation with Flesh Color in Atlantic Salmon (Salmo salar L., 1758)

Abstract

The Atlantic salmon (Salmo salar L., 1758) is a temperate fish species native to the northern Atlantic Ocean. The distinctive pink–red flesh color (i.e., pigmentation) significantly affects the market price. Flesh paleness leads to customer dissatisfaction, a loss of competitiveness, a drop in product value and, consequently, severe economic losses. This work extends our knowledge on salmonid carotenoid dynamics to include the interaction between the gut microbiota and flesh color. A significant association between the flesh color and abundance of specific bacterial communities in the gut microbiota suggests that color may be affected either by seeding resilient beneficial bacteria or by inhibiting the negative effect of pathogenic bacteria. We sampled 96 fish, which covered all phenotypes of flesh color, including the average color and the evenness of color of different areas of the fillet, at both the distal intestine and the pyloric caeca of each individual, followed by 16S rRNA sequencing at the V3-V4 region. The microbiota profiles of these two gut regions were significantly different; however, there was a consistency in the microbiota, which correlated with the flesh color. Moreover, the pyloric caeca microbiota also showed high correlation with the evenness of the flesh color (beta diversity index, PERMANOVA, p = 0.002). The results from the pyloric caeca indicate that Carnobacterium, a group belonging to the lactic acid bacteria, is strongly related to the flesh color and the evenness of the color between the flesh areas.

Seasonal variations in the composition and diversity of gut microbiota in white-lipped deer (Cervus albirostris)

“…Higher abundances of Acinetobacter and Pseudomonas indicate that white-lipped deer had a higher risk of disease in the withering season, with a higher abundance of Pseudomonas compensating for the decrease of other protein-degrading microbes. Carnobacterium responds to thermal stress, resulting in more efficient feed assimilation ( Nguyen et al, 2020 ). Romboutsia is involved in the fermentation of carbohydrates and the utilization of single amino acids ( Gerritsen, 2015 ).…”

Red Cusk-Eel (Genypterus chilensis) Gut Microbiota Description of Wild and Aquaculture Specimens

“…However, it must be noted that the results obtained in this study were obtained analyzing samples of whole intestinal contents, thus corresponding to the total gut microbiota. However, the distribution and percentages described could be different if different tracts of the fish gut were analyzed separately, as previously reported by other species, such as salmonids [60][61][62].…”

Deploying new generation sequencing for the study of flesh color depletion in Atlantic Salmon (Salmo salar)

“…Several studies indicated that Fertn-M was activated to respond to many infections and oxidative stress in sh, including Atlantic salmon (39,(45)(46)(47)(48)(49)(50). In our previous studies, it was con rmed that aerobic bacteria (Pseudoalteromonadaceae, Vibrionaceae and Enterobacteriaceae families) with varying catabolic pathways that were enriched in low color sh might impact on the host physiology (16,51). These ndings are consistent with our present result and indicate that Fertn-M was downregulated in LB sh since the iron acquisition could be controlled by pathogen and used to alleviate ther stress in LB sh.…”

“…Therefore, the elevated summer temperatures experienced by Atlantic salmon grown in Tasmania may affect the sh physiology by inducing a stress response (9,12). This is evident at the molecular level by the presence of altered heat shock protein and antioxidant pathways found in salmon exposed to high water temperatures (13)(14)(15)(16). In recent years, global warming has been marked as a key factor with potential devastating impacts on the aquaculture industry, especially in cold-blooded sh (17).…”

“…In recent years, global warming has been marked as a key factor with potential devastating impacts on the aquaculture industry, especially in cold-blooded sh (17). This led to an increased focus on investigating the effect of elevated temperature on the esh color of salmonids such as Atlantic salmon (16). Recently, Grunenwald,Adams (18) were able to induce a depletion of color in Atlantic salmon muscle as a result of short term thermal stress.…”