Ancestim

The economic feasibility of lignocellulosic ethanol production depends on obtaining high yields and productivity. This condition requires extensive research to identify strategies that maximize yield and productivity in lignocellulosic ethanol production. Self-cycling fermentation (SCF) has been shown to increase ethanol productivity. To validate whether the SCF system could enhance productivity during ethanol fermentation, we simulated the process using experimental results obtained from six cycles in a stirred bioreactor and compared the outcomes with separate hydrolysis and fermentation (SHF) and simultaneous saccharification-fermentation (SSF) for ethanol production from wheat straw using Kluyveromyces marxianus SLP1. The volumetric ethanol productivity (Q_p) was 1.11 g/Lh, 1.13 g/Lh, and 0.42 g/Lh for SCF, SHF, and SSF, respectively. The system with the highest global productivity (Q_g) was SCF with 0.65 g/Lh. Moreover, the estimated annual ethanol productivity for SCF (P_SCF) improved by 21.7% compared with SHF and by 3.1-fold improvement over SSF. This result confirms that SCF can be an effective strategy for increasing productivity during lignocellulosic ethanol production. However, the SCF system is limited by the physiological states of the yeasts.

Concurrent consumption of dietary fiber and n-3 polyunsaturated fatty acids reduces colon tumor formation. However, their combined effects on colorectal cancer risk remain unexplored in human trials.

This study investigated the synergistic effects of fish oil (FO) and fermentable fiber on the gut transcriptional profiles and microbiome composition in older adults.

In a randomized controlled crossover pilot study, 30 adults (ages 50-75 y), received fermentable fiber (33 g/d soluble corn fiber; SCF) plus eicosapentaenoic acid and docosahexaenoic acid (EPA + DHA as FO, 7.7 g/d) or a comparator (similar doses of maltodextrin plus corn oil; MD + CO) for 30 d, followed by a 60-d washout period before crossing over to the alternate intervention. Serum phospholipid fatty acids, stool exfoliome [ribonucleic acid sequencing (RNAseq)], microbiome (16S ribosomal ribonucleic acid gene sequencing), butyrate kinase (but) gene abundance (digital droplet polymerase chain reaction), and fecal short-chain fatty acids were analyzed. Linear mixed models were used for the majority of outcome analyses. Differential expression and pathway enrichment analyses were applied to RNAseq data, whereas microbiome diversity was assessed using α and β diversity.

Serum EPA and DHA concentrations were higher after SCF + FO than MD + CO supplementation [EPA: β = 0.51; 95% confidence interval: 0.31, 0.72; DHA: β = 0.18; 95% confidence interval: 0.10, 0.27; P < 0.0001]. Analysis of host gut transcriptional networks revealed that SCF + FO supplementation inhibited the glucose-insulin receptor-phosphatidylinositol-3 kinase-signaling axis. Microbiome analysis revealed significant intervention differences in β-diversity (F = 4.4, R² = 0.08, P = 0.001), and 27 of 73 genera analyzed, several known short-chain fatty acid producers, differed between the 2 interventions (false discovery rate <0.05). Abundance of the but gene from Roseburia sp (P < 0.001) and the genera Roseburia (P = 0.006) were lower in the SCF + FO compared to MD + CO intervention, although fecal butyrate concentrations did not differ.

Thirty-day supplementation of SCF + FO compared with MD + CO showed significant shifts in intestinal cell pathways relevant to colorectal cancer with concomitant differences in gut microbial community structure and butyrate-producing taxa.