A Natural Gas Fermentation Bacterial Meal (FeedKind®) as a Functional Alternative Ingredient for Fishmeal in Diet of Largemouth Bass, Micropterus salmoides

Abstract

A 10-week growth study was conducted to evaluate the effect of a natural gas fermentation bacterial meal (FeedKind®, FK) as a fishmeal (FM) alternative in largemouth bass (Micropterus salmoides) (48.0 ± 0.03 g). Four isonitrogenous and isoenergetic diets were formulated including one commercial control (C, 42% FM) and three experimental diets with gradient FK of 3% (FK3, 29%FM), 6% (FK6, 26%FM) and 9% (FK9, 23%FM), respectively. FK-fed groups showed significantly higher SR than that of C group. The WGR and SGR of fish fed FK3 and FK6 were significantly higher than those of FK9, but not statistical different from the C group. FK-fed groups showed higher apparent digestibility coefficients of dry matter and nutrients. Further, FK-fed groups increased the ratio of SOD/MDA in the plasma and liver, and the upregulation of intestinal Keap1 and downregulation of HIF1α was found in FK3. Furthermore, FK-fed groups showed higher microbial richness and diversity. Pearson correlation analysis found that antioxidant relevant biomarkers were negatively correlated with the relative abundance of certain potential beneficial bacteria. In conclusion, supplemented up to 3–6% FK replacing FM in a low FM diet of largemouth bass could increase growth, survival rate, antioxidant capacity, and improve gut microbiota.

Fishmeal, plant protein, and fish oil substitution with single-cell ingredients in organic feeds for European sea bass (Dicentrarchus labrax)

“…This result cannot be correlated with lower digestibility of fish meal trimmings compared to premium fishmeal as other studies reported ( Dam et al, 2019 ) since all the diets included this type of fishmeal. However, this result is in accordance with the findings of Guo et al (2022) in largemouth bass where all dietary inclusion levels (3%, 6%, and 9%) of bacterial protein showed higher digestibility of protein compared to the fishmeal diet. The same trend was detected for the digestibility of starch where all bacterial protein diets demonstrated significantly higher digestibility coefficients of starch compared to the fishmeal diet.…”

“…Bacterial protein has been used in several studies as a replacement for fishmeal. In most of the cases, the bacterial protein was produced by M. capsulatus and was tested with different levels of inclusion for several species such as largemouth bass ( Micropterus salmoides ), sea bream ( Sparus aurata ), and spotted seabass ( Lateolabrax maculatus ) ( Guo et al, 2022 ; Zhang et al, 2022 ; Carvalho et al, 2023 ; Yu et al, 2023 ). The inclusion levels of bacterial protein in the aforementioned studies were between 3% and 21.5%.…”

“…The results detected a nutritional tolerance limit of this protein source for most species which was dependent on fishmeal inclusion. For largemouth bass, the inclusion of bacterial protein in moderate fishmeal diets (26%) reached up to 6% with positive effects on final body weight ( Guo et al, 2022 ) while at the 9% inclusion level, a low feed intake was recorded which was possibly related to palatability issues. In another study for largemouth bass, it was observed that higher fishmeal inclusion (31%) increased the tolerance of the specific species for bacterial protein up to 12.9%, resulting in similar growth parameters as fishmeal diets ( Zhang et al, 2022 ).…”

Effects of paraprobiotics on bile acid metabolism and liver health in largemouth bass (Micropterus salmoides) fed a cottonseed protein concentrate-based diet

“…One recent study revealed that the species Romboutsia ilealis could have the potential genic function of expressing bile salt hydrolase ( Gerritsen et al., 2017 ) suggesting that a lower relative abundance of genus Romboutsia might slow down intestinal bile acid hydrolysis and in turn influence the bile acid profile in fish fed the CPC diet. Of note, the characterization of the associations between physiological functions and intestinal microbial clades is a fundamental method of finding the physiological functions of bacteria, which could benefit fish health and welfare ( Guo et al., 2022 ; Wang et al., 2022b ; Wang et al., 2021a ; Wang et al., 2022c ). However, studies on the correlation between Romboutsia and bile acid metabolism in fish are still rare and need further investigation.…”

Alternative proteins as fish meal substitution in diets for largemouth bass (Micropterus salmoides): a mini review

“…A combination of shrimp hydrolysate (6.80 g kg −1 ) and FSBM (13.45 g kg −1 ) can replace almost 33% FM (15 g kg −1 ) and achieved an obvious improvement of the growth performance (Li et al., 2021b). Similarly, 38.1% of FM replaced by FeedKind ® (60 g kg −1 ) and soy protein concentrated (250 g kg −1 ) in a low FM inclusion diet of LMB (IBW: 48.0 ± 0.03 g) could increase growth, survival rate, antioxidant capacity, as well as improve intestinal homeostasis (Guo et al., 2022). Moreover, a total of 80% FM could be substituted by combination of poultry by‐product meal (196 g kg −1 ) and CPC (172 g kg −1 ) in diet of LMB (IBW: 24.0 ± 0.3 g), which significantly reduced feed cost without increasing negative effect on growth and environment (Wang et al., 2021).…”