Biology subjects

Mydland, L. T.

Publications and source records attributed to Mydland, L. T..

5 recordsLinked to original sources

bioRxiv2024

Microbial alginate foraging is conserved in geographically and taxonomically distinct ruminant microbiomes

Seaweed plays a crucial role in carbon cycling and is expected to be a valuable resource for sustainable biomass, with applications in biofuel production, human nutrition, and animal feed. Although seaweed has historically been used as a feed source for livestock grazing near coastlines, the process by which it is digested in the rumen remains unknown. Here, we show how the brown algae Saccharina latissima is catabolized in the rumen ecosystem of two different species using in vivo and in vitro experimental systems. We determined that the ruminal decomposition of alginate, a prominent component of the brown algae cell wall, requires microbial catabolic pathways complete with alginate lyases and transport proteins. Evidence of digestion was obtained through a combination of animal models, bacterial imaging, multilayered meta-omics, and enzyme biochemistry. The evolution of and implications for acquisition of alginate utilization loci within geographically and taxonomically distinct ruminants are considered. Graphical abstractSaccharina latissima is a brown alga commonly found in the North Atlantic, Arctic and Pacific oceans. S. latissima was collected from the west coast and Canada and Norway for microbiome studies. Alginate constitutes a substantial portion of the cell wall of S. latissima (SL), and its digestion requires a specific set of enzymes, alginate lyases. We investigated if and how S. latissima is metabolized in geographically distinct rumen ecosystems through in vivo lamb feeding experiments (2.5 and 5% inclusion, DM basis) and in vitro cattle-based rumen simulation technique, RUSITEC, experiments (up to 50% inclusion). Evidence supporting ruminal degradation of alginate was explored using a combination of multilayered meta-omics, physiology (fluorescently labelled S. latissima hot water extracts (FLA-SLAT)) and biochemical characterization of PL6 alginate lyases. O_FIG O_LINKSMALLFIG WIDTH=161 HEIGHT=200 SRC="FIGDIR/small/628917v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@eebe40org.highwire.dtl.DTLVardef@c6fb8org.highwire.dtl.DTLVardef@7a9b1borg.highwire.dtl.DTLVardef@15d30d7_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2021

SALARECON connects the Atlantic salmon genome to growth and feed efficiency

Atlantic salmon (Salmo salar) is the most valuable farmed fish globally and there is much interest in optimizing its genetics and rearing conditions for growth and feed efficiency. Marine feed ingredients must be replaced to meet global demand, with challenges for fish health and sustainability. Metabolic models can address this by connecting genomes to metabolism, which converts nutrients in the feed to energy and biomass, but such models are currently not available for major aquaculture species such as salmon. We present SALARECON, a model focusing on energy, amino acid, and nucleotide metabolism that links the Atlantic salmon genome to metabolic fluxes and growth. It performs well in standardized tests and captures expected metabolic (in)capabilities. We show that it can explain observed hypoxic growth in terms of metabolic fluxes and apply it to aquaculture by simulating growth with commercial feed ingredients. Predicted limiting amino acids and feed efficiencies agree with data, and the model suggests that marine feed efficiency can be achieved by supplementing a few amino acids to plant- and insect-based feeds. SALARECON is a high-quality model that makes it possible to simulate Atlantic salmon metabolism and growth. It can be used to explain Atlantic salmon physiology and address key challenges in aquaculture such as development of sustainable feeds. Author summaryAtlantic salmon aquaculture generates billions of euros annually, but faces challenges of sustainability. Salmon are carnivores by nature, and fish oil and fish meal have become scarce resources in fish feed production. Novel, sustainable feedstuffs are being trialed hand in hand with studies of the genetics of growth and feed efficiency. This calls for a mathematical-biological framework to integrate data with understanding of the effects of novel feeds on salmon physiology and its interplay with genetics. We have developed the SALARECON model of the core salmon metabolic reaction network, linking its genome to metabolic fluxes and growth. Computational analyses show good agreement with observed growth, amino acid limitations, and feed efficiencies, illustrating the potential for in silico studies of potential feed mixtures. In particular, in silico screening of possible diets will enable more efficient animal experiments with improved knowledge gain. We have adopted best practices for test-driven development, virtual experiments to assay metabolic capabilities, revision control, and FAIR data and model management. This facilitates fast, collaborative, reliable development of the model for future applications in sustainable production biology.

systems biology↗

bioRxiv2021

Longitudinal analysis of the faecal microbiome in pigs fed Cyberlindnera jadinii yeast as a protein source during the weanling period followed by a rapeseed- and faba bean-based grower-finisher diet

The porcine gut microbiome is closely connected to diet and is central to animal health and growth. The gut microbiota composition in relation to Cyberlindnera jadinii yeast as a protein source in a weanling diet was studied previously. Also, there is a mounting body of knowledge regarding the porcine gut microbiome composition in response to the use of rapeseed (Brassica napus subsp. napus) meal, and faba beans (Vicia faba) as protein sources during the growing/finishing period. However, there is limited data on how the porcine gut microbiome respond to a combination of C. jadinii yeast in the weanling phase and rapeseed meal and faba beans in the growing/finishing phase. This work investigated how the porcine faecal microbiome was changing in response to a novel yeast diet with a high inclusion of yeast proteins (40% of crude protein) in a weanling diet followed by a diet based on rapeseed meal and faba beans during the growing/finishing period. The feacal microbiomes of the weanling pigs fed yeast were more diverse with higher relative abundance of Firmicutes over Bacteroidetes compared with those of soybean meal-based diet fed weanlings. Reduced numbers of Prevotella in the yeast fed faecal microbiomes remained a microbiome characteristic up until two weeks after the yeast diet was changed to the rapeseed/faba bean growing finishing diet. A number of differentially abundant bacterial phylotypes along with distinct co-occurrence patterns observed during the growing/finishing period indicated the presence of a "carry-over" effect of the yeast weanling diet onto the faecal microbiomes of the grower/finisher pigs.

microbiology↗

bioRxiv2021

Small intestine lactobacilli growth promotion and immunomodulation in weaner pigs fed Cyberlindnera jadinii yeast high inclusion diet and exposed to enterotoxigenic Escherichia coli F4+: O149

1Enterotoxigenic Escherichia coli (ETEC) F4+: O149 is a causative agent for the development of post-weaning diarrhoea (PWD) in pigs that contributes to production losses. Yeast cell wall components used as a feed additive can modulate gut immunity and help protect animals from enteric infections. This work investigated how a novel yeast diet with high inclusion of yeast proteins (40% of crude protein) affected the course of ETEC mediated diarrhoea in weaner piglets from a farm with or without a history of post-weaning diarrhoea. We found that immune response to F4ab ETEC infection and appetite of the animals were altered by high inclusion C. jadinii yeast. The results indicate that the novel diet can support the diseased animals either directly through the effect of yeast beta-glucans and mannans or indirectly through the promotion of small intestine lactobacilli or both.

microbiology↗

bioRxiv2019

Candida utilis yeast as a functional protein source for Atlantic salmon (Salmo salar L.): Local intestinal tissue and plasma proteome responses

Microbial ingredients such as Candida utilis yeast are known to be functional protein sources with immunemodulating effects whereas soybean meal causes soybean meal-induced enteritis in the distal intestine of Atlantic salmon (Salmo salar L.). Inflammatory or immunomodulatory stimuli at the local level in the intestine may alter the plasma proteome profile of Atlantic salmon. These deviations can be helpful indicators for fish health and therefore potential tools in diagnosis of fish diseases. The present work aimed to identify local intestinal tissue responses and changes in plasma protein profiles of Atlantic salmon fed inactive dry Candida utilis yeast biomass, soybean meal, or combination of soybean meal based diet with various inclusion levels of Candida utilis. A fishmeal based diet was used as control diet. Inclusion of Candida utilis yeast to a fishmeal based diet did not alter the morphology, immune cell population or gene expression of the distal intestine, but gave a plasma proteome profile different from the fishmeal based control. Lower levels of Candida utilis combined with soybean meal modulated immune cell populations in the distal intestine and reduced the severity of soybean meal-induced enteritis, while higher inclusion levels of Candida utilis were less effective. The results suggest that Candida utilis could induce systemic responses without altering intestinal morphology, and thus could be a high-quality alternative protein source with potential functional properties in diets for Atlantic salmon.

immunology↗