Striped catfish (Pangasianodon hypophthalmus) exploit food sources across anaerobic decomposition- and primary photosynthetic production-based food chains

Dietary information from aquatic organisms is instrumental in predicting biological interactions and understanding ecosystem functionality. In freshwater habitats, generalist fish species can access a diverse array of food sources from multiple food chains. These may include primary photosynthetic production and detritus derived from both oxic and anoxic decomposition. However, the exploitation of anoxic decomposition products by fish remains insufficiently explored. This study examines feeding habits of striped catfish (Pangasianodon hypophthalmus) at both adult and juvenile stages within a tropical reservoir, using stable carbon, nitrogen, and sulfur isotope ratios (δ¹³C, δ¹⁵N, and δ³⁴S, respectively) and fatty acid (FA) analyses. The adult catfish exhibited higher δ¹⁵N values compared to primary consumers that feed on primary photosynthetic producers, which suggests ingestion of food sources originating from primary photosynthetic production-based food chains. On the other hand, juvenile catfish demonstrated lower δ¹⁵N values than primary consumers, correlating with low δ³⁴S value and large proportions of bacterial FA but contained small proportions of polyunsaturated FA. This implies that juveniles utilize food sources from both anoxic decomposition and primary photosynthetic production-based food chains. Our results indicate that food chains based on anoxic decomposition can indeed contribute to the dietary sources of tropical fish species

Lentilactobacillus buchneri domination during the fermentation of Japanese traditional fermented fish (funazushi)

Abstract Funazushi is a Japanese traditional fermented fish made with boiled rice without the addition of microbial starter cultures. Isolates from various commercial funazushi products, as identified by 16S rDNA sequences, suggested that Lentilactobacillus buchneri strains are major lactic acid bacteria. Based on an analysis of the putative CRISPR (clustered regularly interspaced short palindromic repeat) region, the genetic diversity of L. buchneri strains was examined. The data suggested that the diversity of L. buchneri strains depended on the factories at which funazushi was produced. An analysis of samples during fermentation indicated that the transition of microbes occurred, and L. buchneri was the dominant species. To determine the factors associated with domination, bacteriocin production and environmental stress tolerance, including NaCl and organic acid (lactate and acetate) tolerance, were evaluated. L. buchneri isolates did not produce bacteriocin. Although the isolates did not exhibit NaCl tolerance, they displayed higher lactate tolerance than other lactic acid bacteria isolated during funazushi fermentation. Based on reports that L. buchneri can convert lactate to acetate, the previous and present results suggested that lactate tolerance and lactate conversion in L. buchneri could explain its domination in funazushi. Our study presented a model for the domination mechanisms of specific microbes in fermented foods by spontaneous fermentation

Polymorphisms and expression of toll-like receptors in autoimmune thyroid diseases

Graves’ disease (GD) and Hashimoto’s disease (HD) are autoimmune thyroid diseases (AITDs). Prognosis of AITDs varies in each patient. Toll-like receptors (TLRs) are pattern-recognition receptors that activate signaling pathways involved in the production of proinflammatory cytokines. UNC93B1 is a transcription factor of TLR7 and TLR9. In this study, we examined the association of TLR expression and TLR and UNC93B1 polymorphisms with the development and prognosis of AITDs. The ratio of intracellular TLR7 (iTLR7) and iTLR9 intensities in B cells was lower in patients with GD in remission than in patients with intractable GD (p = 0.0007). The frequency of G allele of TLR7 rs3853839 G/C polymorphism was significantly higher in male patients with GD and intractable GD than in control subjects (p = 0.0062 and 0.0173, respectively). The frequencies of T allele of TLR9 rs187084 C/T polymorphism and C allele of TLR9 rs352140 C/T polymorphism were significantly higher in patients with intractable GD who had GG genotype of TLR7 rs3853839 polymorphism, which is associated with higher TLR7 expression, than in patients with GD in remission (p = 0.0334 and 0.0023, respectively). The frequencies of AA genotype and A allele of UNC93B1 rs308328 polymorphism were significantly higher in patients with GD than in patients with HD (p = 0.0406 and 0.0316, respectively). These results suggested that the ratio of iTLR7 and iTLR9 intensities was associated with the development and intractability of GD and that TLR7 and UNC93B1 polymorphisms were associated with the development of GD

Striped catfish (Pangasianodon hypophthalmus) exploit food sources across anaerobic decomposition- and primary photosynthetic production-based food chains

Dietary information from aquatic organisms is instrumental in predicting biological interactions and understanding ecosystem functionality. In freshwater habitats, generalist fish species can access a diverse array of food sources from multiple food chains. These may include primary photosynthetic production and detritus derived from both oxic and anoxic decomposition. However, the exploitation of anoxic decomposition products by fish remains insufficiently explored. This study examines feeding habits of striped catfish (Pangasianodon hypophthalmus) at both adult and juvenile stages within a tropical reservoir, using stable carbon, nitrogen, and sulfur isotope ratios (δ¹³C, δ¹⁵N, and δ³⁴S, respectively) and fatty acid (FA) analyses. The adult catfish exhibited higher δ¹⁵N values compared to primary consumers that feed on primary photosynthetic producers, which suggests ingestion of food sources originating from primary photosynthetic production-based food chains. On the other hand, juvenile catfish demonstrated lower δ¹⁵N values than primary consumers, correlating with low δ³⁴S value and large proportions of bacterial FA but contained small proportions of polyunsaturated FA. This implies that juveniles utilize food sources from both anoxic decomposition and primary photosynthetic production-based food chains. Our results indicate that food chains based on anoxic decomposition can indeed contribute to the dietary sources of tropical fish species