Date Palm Waste Compost Application Increases Soil Microbial Community Diversity in a Cropping Barley (Hordeum vulgare L.) Field.

Application of date palm waste compost is quite beneficial in improving soil properties and crop growth. However, the effect of its application on soil microbial communities is less understood. High-throughput sequencing and quantitative real-time PCR (qPCR) were used to evaluate the effect of compost application on the soil microbial composition in a barley field during the tillering, booting and ripening stages. The results showed that compost treatment had the highest bacterial and fungal abundance, and its application significantly altered the richness (Chao1 index) and α-diversity (Shannon index) of fungal and bacterial communities. The dominant bacterial phyla found in the samples were Proteobacteria and Actinobacteria while the dominant fungal orders were Ascomycota and Mortierellomycota. Interestingly, compost enriched the relative abundance of beneficial microorganisms such as Chaetomium, Actinobacteriota, Talaromyces and Mortierella and reduced those of harmful microorganisms such as Alternaria, Aspergillus and Neocosmospora. Functional prediction based on Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) showed that amplicon sequence variant (ASV) sequences related to energy metabolism, amino acid metabolism and carbohydrate metabolism were associated with compost-treated soil. Based on Fungi Functional Guild (FUNGuild), identified fungi community metabolic functions such as wood saprotroph, pathotroph, symbiotroph and endophyte were associated with compost-treated soil. Overall, compost addition could be considered as a sustainable practice for establishing a healthy soil microbiome and subsequently improving the soil quality and barley crop production.

Carnosine content in the porcine longissimus thoracis muscle and its association with meat quality attributes and carnosine-related gene expression.

Muscle carnosine has pH-buffering, antioxidant and carbonyl scavenging properties, which may affect pork quality attributes. Study objectives were to: (1) compare muscle carnosine content and carnosine-related gene mRNA abundance in purebred pigs (n=282), (2) study the effect of muscle carnosine content on pork quality attributes and gene expression across breeds, and (3) study transcript abundance of carnosine-related genes in various tissues. Pigs were raised under similar conditions and slaughtered at 120±4.5kg. Longissimus thoracis muscles were sampled on the dressing line for gene expression and at 24h for meat quality measurements. Muscle carnosine content and carnosine-related gene mRNA abundance were modulated according to pig breeds. Greater pH24h, better water holding capacity and improved meat color values were found in pigs with high muscle carnosine content. Data suggest that high muscle carnosine is associated with improved pork meat quality attributes. The pig genetic background may be a key determinant for muscle carnosine content regulation.

Identification of single nucleotide polymorphisms in carnosine-related genes and effects of genotypes on pork meat quality attributes.

Carnosine has pH-buffering and antioxidant properties that may bring advantages in terms of meat quality attributes. This study aimed at identifying polymorphisms in carnosine-related genes (CARNS1, SLC6A6, SLC15A3, SLC15A4) that might associate with muscle carnosine content and meat quality traits in pigs (Duroc, Landrace, Yorkshire). Twenty seven SNPs were identified and association analyses performed for SLC15A3 c.*35C>T and c.*52C>T (3' UTR region), and SLC15A4 c.658A>G (Ile220Val) and c.818G>A (Ser273Asn) SNPs. Associations were observed for SNP c.658A>G with carnosine content, color b* and L*, drip and cooking losses, pH24h and glycolytic potential values (P≤0.05). The same associations were observed for SNP c.818G>A, but they were not significant after FDR correction. Results suggest that specific SLC15A4 gene variants might increase muscle carnosine content and improve meat quality. With a minor allele frequency of 0.17 for SNP c.658A>G in Yorkshire pigs, selection in favor of the c.658A allele may be considered as a mean to improve pork quality attributes.