Lignocellulolytic enzymes are the main enzymes to saccharify lignocellulose from renewable plant biomass in the bio-based economy. The production of these enzymes is transcriptionally regulated by multiple transcription factors. We previously engineered Penicillium oxalicum for improved cellulase production via manipulation of three genes in the cellulase expression regulatory network. However, the potential of combinational engineering of multiple regulators and their targets at protein abundance and activity levels has not been fully explored. Here, we verified that a point mutation XlnRA871V in transcription factor XlnR enhanced the expression of lignocellulolytic enzymes, particularly hemicellulases, in P. oxalicum. Then, overexpression of XlnRA871V with a constitutive PDE_02864 promoter was combined with the overexpression of cellulase transcriptional activator ClrB and deletion of carbon catabolite repressor CreA. The resulted strain RE-7 showed 8.9- and 51.5-fold increased production of cellulase and xylanase relative to the starting strain M12, respectively. Further overexpression of two major cellulase genes cbh1-2 and eg1 enabled an additional 13.0% improvement of cellulase production. In addition, XlnRA871V led to decreased production of β-glucosidase and amylase, which could be attributed to the reduced transcription of corresponding enzyme-encoding genes. The results illustrated that combinational manipulation of the involved transcription factors and their target genes was a viable strategy for efficient production of lignocellulolytic enzymes in filamentous fungi. The striking negative effect of XlnRA871V mutation on amylase production was also highlighted.

The liver of hens bears a very heavy workload in handling lipogenesis as well as carbohydrate, protein, and other nutrient metabolism to maintain a high laying rate. D-glucuronolactone (DGL) is a naturally occurring chemical metabolite produced from glucose and exhibits a hepatoprotective effect as a food ingredient. This study aimed to evaluate the effect of DGL on production performance, egg quality, and liver health in laying hens during their peak period. Four hundred and eighty Hy-Line brown hens (aged 42 weeks), with comparable high-laying performance, were randomly assigned to four groups, with each group consisting of eight replicates. The control group was fed a basal diet, while the treatment groups were supplemented with DGL at 70, 140, and 280 mg/kg in the basal diet, respectively. The results indicated that DGL supplementation significantly increases the laying rate and egg mass of hens (p < 0.05). The brown color of the eggshell was significantly deepened by DGL administration (p < 0.05). Additionally, DGL supplementation significantly decreased the serum levels of aspartate aminotransferase and γ-glutamyl transpeptidase (p < 0.05). The liver index, liver fat, and triglyceride levels in the liver had also significantly decreased (p < 0.05). Liver histopathological results showed that the control group exhibited yellow coloration with large gaps and numerous vacuolar cells, while DGL supplementation improved the compactness of liver parenchyma. Antioxidant activity was enhanced, showing a significant increase in the activity of total antioxidant capacity and catalase in the liver (p < 0.05). The inflammatory response was alleviated, with a significant decrease in expressions of interleukin-β, tumor necrosis factor-α, interferon-α, interleukin-6, and interleukin-8 genes in the liver (p < 0.05). Moreover, DGL supplementation significantly reduced cell apoptosis-related genes, including factor-related apoptosis, Caspase 7, and BCL2 associated X protein in the liver (p < 0.05). Overall, these findings indicate that dietary DGL enhanced the laying performance of hens by maintaining liver health, with the best results achieved at a dose of 280 mg/kg in this trial.

A novel species of the genus Gramella , designated ASW11-100T, was isolated from a tidal flat sediment in the Yellow Sea, PR China. Phylogenetic analysis based on 16S rRNA gene sequences and single-copy orthologous clusters revealed that strain ASW11-100T belonged to the genus Gramella , and exhibited 16S rRNA gene sequence similarities of 98.9, 98.8 and 98.7 % to Gramella sabulilitoris HSMS-1T, Gramella sediminilitoris GHTF-27T and Gramella forsetii KT0803T, respectively. The genome of strain ASW11-100T harbours 2950 protein-coding genes and 105 carbohydrate-active enzymes including 38 glycoside hydrolases. Seventeen of the glycoside hydrolases are organized in five distinct polysaccharide utilization loci, which are predicted to involve in the degradation of starch, glucans, arabinoxylans, arabinomannan, arabinans and arabinogalactans. The genomic DNA G+C content was 37.3 mol%. The digital DNA–DNA hybridization and average nucleotide identity values between strain ASW11-100T and its closely related relatives were in ranges of 19.8–23.9% and 76.6–80.9 %, respectively. Cells of the isolate were Gram-negative, aerobic, non-flagellated and short rod-shaped. Carotenoid pigments were produced, but flexirubin-type pigments were absent. The major fatty acids (>10 %) were iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c). The sole respiratory quinone was menaquinone-6 and the major polar lipid was phosphatidylethanolamine. Based on the above polyphasic evidence, strain ASW11-100T should be considered to represent a novel Gramella species, for which the name Gramella sediminis sp. nov. is proposed. The type strain is ASW11-100T (=KCTC 82502T=MCCC 1K05580T).

This study aimed to investigate the effects of supplementing broiler feed with high-yield protease Bacillus subtilis strain FRE76 on growth performance, slaughter performance, apparent digestibility, intestinal morphology, and intestinal microbiota. One-day-old Arbor Acres broilers (n = 240) were randomly assigned to four groups (n = 6 replicates; 10 animals per replicate), in which their basal diet was supplemented with B. subtilis strain FRE76 at 0 CFU/kg (group C), 3.60 × 10⁸ CFU/kg (group L), 1.08 × 10⁹ CFU/kg (group M), and 1.80 × 10⁹ CFU/kg (group H). The experiment lasted for 42 d and comprised two phases: Days 1–21 and days 22–42. The broilers’ body weight at 21 d and the average daily gain at 1–21 d in the L and H groups increased significantly relative to those in group C (p < 0.05). The half-bore weight, half-bore percentage, and breast muscle percentage in group L were significantly higher (p < 0.05) than those in group C. The apparent digestibility of crude protein in group L and the ether extract in groups L, M, and H were significantly increased at 22–42 d compared with those in group C (p < 0.05). In group L, the jejunal villus height and villus height/crypt depth increased significantly relative to those in group C (p < 0.05). The chymotrypsin and trypsin activities tended to increase in the B. subtilis FRE76 groups (p = 0.072 and p = 0.056, respectively) relative to those in group C. Additionally, the abundance of Bacteroidota, Proteobacteria, Alistipes, Clostridia_vadinBB60_group, and Parabacteroides increased significantly in the B. subtilis FRE76 groups (p < 0.05). In conclusion, dietary B. subtilis FRE76 could improve broilers’ body weight, average daily gain, apparent digestibility, protease activity, intestinal morphology, and gut microbiota.