Deciphering Physio-Biochemical Basis of Tolerance Mechanism for Sesame (Sesamum indicum L.) Genotypes under Waterlogging Stress at Early Vegetative Stage.

Waterlogging represents a substantial agricultural concern, inducing harmful impacts on crop development and productivity. In the present study, 142 diverse sesame genotypes were examined during the early vegetative phase to assess their response under waterlogging conditions. Based on the severity of symptoms observed, 2 genotypes were classified as highly tolerant, 66 as moderately tolerant, 69 as susceptible, and 5 as highly susceptible. Subsequent investigation focused on four genotypes, i.e., two highly tolerant (JLT-8 and GP-70) and two highly susceptible (R-III-F6 and EC-335003). These genotypes were subjected to incremental stress periods (0 h, 24 h, 48 h, 72 h, and 96 h) to elucidate the biochemical basis of tolerance mechanisms. Each experiment was conducted as a randomized split-plot design with three replications, and the statistical significance of the treatment differences was determined using the one-way analysis of variance (ANOVA) followed by the Fisher least significant difference (LSD) test at p ≤ 0.05. The influence of waterlogging stress on morphological growth was detrimental for both tolerant and susceptible genotypes, with more severe consequences observed in the latter. Although adventitious roots were observed in both sets of genotypes above flooding levels, the tolerant genotypes exhibited a more rapid and vigorous development of these roots after 48 h of stress exposure. Tolerant genotypes displayed higher tolerance coefficients compared to susceptible genotypes. Furthermore, tolerant genotypes maintained elevated antioxidant potential, thereby minimizing oxidative stress. Conversely, susceptible genotypes exhibited higher accumulation of hydrogen peroxide (H2O2) and malondialdehyde content. Photosynthetic efficiency was reduced in all genotypes after 24 h of stress treatment, with a particularly drastic reduction in susceptible genotypes compared to their tolerant counterparts. Tolerant genotypes exhibited significantly higher activities of anaerobic metabolism enzymes, enabling prolonged survival under waterlogging conditions. Increase in proline content was observed in all the genotypes indicating the cellular osmotic balance adjustments in response to stress exposure. Consequently, the robust antioxidant potential and efficient anaerobic metabolism observed in the tolerant genotypes served as key mechanisms enabling their resilience to short-term waterlogging exposure. These findings underscore the promising potential of specific sesame genotypes in enhancing crop resilience against waterlogging stress, offering valuable insights for agricultural practices and breeding programs.

The Potential of Traditional Norwegian KVEIK Yeast for Brewing Novel Beer on the Example of Foreign Extra Stout.

The development of craft brewing has spurred huge interest in unusual and traditional technologies and ingredients allowing the production of beers that would fulfil consumers' growing demands. In this study, we evaluated the brewing performance of traditional Norwegian KVEIK yeast during the production of Foreign Extra Stout beer. The content of alcohol of the KVEIK-fermented beer was 5.11-5.58% v/v, the extract content was 5.05-6.66% w/w, and the pH value was 4.53-4.83. The KVEIK yeast was able to completely consume maltose and maltotriose. The mean concentration of glycerol in KVEIK-fermented beers was higher than in the control sample (1.51 g/L vs. 1.12 g/L, respectively). The use of KVEIK-type yeast can offer a viable method for increasing the concentration of phenolic compounds in beer and for boosting its antioxidative potential. The beers produced with KVEIK-type yeast had a total phenol content of 446.9-598.7 mg GAE/L, exhibited antioxidative potential of 0.63-1.08 mM TE/L in the DPPH• assay and 3.85-5.16 mM TE/L in the ABTS•+ assay, and showed a ferric ion reducing capacity (FRAP) of 3.54-4.14 mM TE/L. The KVEIK-fermented bears contained various levels of volatile compounds (lower or higher depending on the yeast strain) and especially of higher alcohols, such as 3-metylobutanol, 2-metylobutanol, and 1-propanol, or ethyl esters, such as ethyl acetate or decanoate, compared to the control beers. In addition, they featured a richer fruity aroma (apricot, dried fruit, apples) than the control beers fermented with a commercial US-05 strain.

Proteomics Reveals an Increase in the Abundance of Glycolytic and Ethanolic Fermentation Enzymes in Developing Sugarcane Culms During Sucrose Accumulation.

Sugarcane is an economically important crop contributing to the sugar and ethanol production of the world with 80 and 40%, respectively. Despite its importance as the main crop for sugar production, the mechanisms involved in the regulation of sucrose accumulation in sugarcane culms are still poorly understood. The aim of this work was to compare the quantitative changes of proteins in juvenile and maturing internodes at three stages of plant development. Label-free shotgun proteomics was used for protein profiling and quantification in internodes 5 (I5) and 9 (I9) of 4-, 7-, and 10-month-old-plants (4M, 7M, and 10M, respectively). The I9/I5 ratio was used to assess the differences in the abundance of common proteins at each stage of internode development. I9 of 4M plants showed statistically significant increases in the abundance of several enzymes of the glycolytic pathway and proteoforms of alcohol dehydrogenase (ADH) and pyruvate decarboxylase (PDC). The changes in content of the enzymes were followed by major increases of proteins related to O2 transport like hemoglobin 2, ROS scavenging enzymes, and enzymes involved in the ascorbate/glutatione system. Besides, intermediates from tricarboxylic acid cycle (TCA) were reduced in I9-4M, indicating that the increase in abundance of several enzymes involved in glycolysis, pentose phosphate cycle, and TCA, might be responsible for higher metabolic flux, reducing its metabolites content. The results observed in I9-4M indicate that hypoxia might be the main cause of the increased flux of glycolysis and ethanolic fermentation to supply ATP and reducing power for plant growth, mitigating the reduction in mitochondrial respiration due to the low oxygen availability inside the culm. As the plant matured and sucrose accumulated to high levels in the culms, the proteins involved in glycolysis, ethanolic fermentation, and primary carbon metabolism were significantly reduced.

Dynamics of microbial contaminants is driven by selection during ethanol production.

Brazil is the second largest ethanol producer in the world and largest using sugarcane feedstock. Bacteria contamination is one of the most important issues faced by ethanol producers that seek to increase production efficiency. Each step of production is a selection event due to the environmental and biological changes that occur. Therefore, we evaluated the influence of the selection arising from the ethanol production process on diversity and composition of bacteria. Our objectives were to test two hypotheses, (1) that species richness will decrease during the production process and (2) that lactic acid bacteria will become dominant with the advance of ethanol production. Bacterial community assemblage was accessed using 16S rRNA gene sequencing from 19 sequential samples. Temperature is of great importance in shaping microbial communities. Species richness increased between the decanter and must steps of the process. Low Simpson index values were recorded at the fermentation step, indicating a high dominance of Lactobacillus. Interactions between Lactobacillus and yeast may be impairing the efficiency of industrial ethanol production.

Characterization of microbial communities in ethanol biorefineries.

Bacterial contamination of corn-based ethanol biorefineries can reduce their efficiency and hence increase their carbon footprint. To enhance our understanding of these bacterial contaminants, we temporally sampled four biorefineries in the Midwestern USA that suffered from chronic contamination and characterized their microbiomes using both 16S rRNA sequencing and shotgun metagenomics. These microbiotas were determined to be relatively simple, with 13 operational taxonomic units (OTUs) accounting for 90% of the bacterial population. They were dominated by Firmicutes (89%), with Lactobacillus comprising 80% of the OTUs from this phylum. Shotgun metagenomics confirmed our 16S rRNA data and allowed us to characterize bacterial succession at the species level, with the results of this analysis being that Lb. helveticus was the dominant contaminant in this fermentation. Taken together, these results provide insights into the microbiome of ethanol biorefineries and identifies a species likely to be commonly responsible for chronic contamination of these facilities.

Energetics of acclimation to NaCl by submerged, anoxic rice seedlings.

BACKGROUND AND AIMS: Our aim was to elucidate how plant tissues under a severe energy crisis cope with imposition of high NaCl, which greatly increases ion fluxes and hence energy demands. The energy requirements for ion regulation during combined salinity and anoxia were assessed to gain insights into ion transport processes in the anoxia-tolerant coleoptile of rice. METHODS: We studied the combined effects of anoxia plus 50 or 100 mm NaCl on tissue ions and growth of submerged rice (Oryza sativa) seedlings. Excised coleoptiles allowed measurements in aerated or anoxic conditions of ion net fluxes and O2 consumption or ethanol formation and by inference energy production. KEY RESULTS: Over 80 h of anoxia, coleoptiles of submerged intact seedlings grew at 100 mm NaCl, but excised coleoptiles, with 50 mm exogenous glucose, survived only at 50 mm NaCl, possibly due to lower energy production with glucose than for intact coleoptiles with sucrose as substrate. Rates of net uptake of Na+ and Cl- by coleoptiles in anoxia were about half those in aerated solution. Ethanol formation in anoxia and O2 uptake in aerobic solution were each increased by 13-15 % at 50 mm NaCl, i.e. ATP formation was stimulated. For acclimation to 50 mm NaCl, the anoxic tissues used only 25 % of the energy that was expended by aerobic tissues. Following return of coleoptiles to aerated non-saline solution, rates of net K+ uptake recovered to those in continuously aerated solution, demonstrating there was little injury during anoxia with 50 mm NaCl. CONCLUSION: Rice seedlings survive anoxia, without the coleoptile incurring significant injury, even with the additional energy demands imposed by NaCl (100 mm when intact, 50 mm when excised). Energy savings were achieved in saline anoxia by less coleoptile growth, reduced ion fluxes as compared to aerobic coleoptiles and apparent energy-economic ion transport systems.

Seasonal Variation of Carbon Metabolism in the Cambial Zone of Eucalyptus grandis.

Eucalyptus species are the most widely hardwood planted in the world. It is one of the successful examples of commercial forestry plantation in Brazil and other tropical and subtropical countries. The tree is valued for its rapid growth, adaptability and wood quality. Wood formation is the result of cumulative annual activity of the vascular cambium. This cambial activity is generally related to the alternation of cold and warm, and/or dry and rainy seasons. Efforts have focused on analysis of cambial zone in response to seasonal variations in trees from temperate zones. However, little is known about the molecular changes triggered by seasonal variations in trees from tropical countries. In this work we attempted to establish a global view of seasonal alterations in the cambial zone of Eucalyptus grandis Hill ex Maiden, emphasizing changes occurring in the carbon metabolism. Using transcripts, proteomics and metabolomics we analyzed the tissues harvested in summer-wet and winter-dry seasons. Based on proteomics analysis, 70 proteins that changed in abundance were successfully identified. Transcripts for some of these proteins were analyzed and similar expression patterns were observed. We identified 19 metabolites differentially abundant. Our results suggest a differential reconfiguration of carbon partioning in E. grandis cambial zone. During summer, pyruvate is primarily metabolized via ethanolic fermentation, possibly to regenerate NAD(+) for glycolytic ATP production and cellular maintenance. However, in winter there seems to be a metabolic change and we found that some sugars were highly abundant. Our results revealed a dynamic change in E. grandis cambial zone due to seasonality and highlight the importance of glycolysis and ethanolic fermentation for energy generation and maintenance in Eucalyptus, a fast growing tree.

Molecular identification and characterization of the pyruvate decarboxylase gene family associated with latex regeneration and stress response in rubber tree.

In plants, ethanolic fermentation occurs not only under anaerobic conditions but also under aerobic conditions, and involves carbohydrate and energy metabolism. Pyruvate decarboxylase (PDC) is the first and the key enzyme of ethanolic fermentation, which branches off the main glycolytic pathway at pyruvate. Here, four PDC genes were isolated and identified in a rubber tree, and the protein sequences they encode are very similar. The expression patterns of HbPDC4 correlated well with tapping-simulated rubber productivity in virgin rubber trees, indicating it plays an important role in regulating glycometabolism during latex regeneration. HbPDC1, HbPDC2 and HbPDC3 had striking expressional responses in leaves and bark to drought, low temperature and high temperature stresses, indicating that the HbPDC genes are involve in self-protection and defense in response to various abiotic and biotic stresses during rubber tree growth and development. To understand ethanolic fermentation in rubber trees, it will be necessary to perform an in-depth study of the regulatory pathways controlling the HbPDCs in the future.

Effects of corn meal and sulphuric acid on the production of cachaça / Efeitos do fubá e ácido sulfúrico sobre a produção de cachaça

This work was carried out to evaluate the effects of using corn meal and treating yeasts with sulfuric acid on fermentation microorganisms, wine acidity, ethanol content and cachaça yield and composition. The experiment was arranged in randomized block design, in a 2x3 factorial with five replications. The methods applied in this study are recommended by distilleries. Results showed that the yeast sulfuric acid treatment transferred acidity to the fermenting juice, without any influence on yeast viability, ethanol content and cachaça yield. On the other hand, the acid treatment controlled lactic bacteria in the inoculum. Addition of corn meal increased the concentration of lactic bacteria in the end of the fermentation and increased the levels of higher alcohols in cachaça, especially propyl and isobutyl alcohol.

Avaliou-se o efeito da adição do fubá de milho no mosto de xarope de cana e o tratamento ácido do pé-de-cuba sobre a microbiota do processo fermentativo, acidez do vinho, grau alcoólico, rendimento e composição da cachaça. O delineamento experimental utilizado foi o de blocos casualizados, no esquema fatorial 2x3 e cinco repetições. A metodologia empregada e as análises foram as recomendadas pelo setor aguardenteiro. Os resultados permitiram concluir que a adição do ácido sulfúrico no pé-de-cuba transferiu a acidez para o vinho, não influenciando na viabilidade das leveduras, rendimento e composição da cachaça. Por outro lado, a acidificação do meio controlou as bactérias láticas no pé-de-cuba. A adição do fubá aumentou a concentração de bactérias lácticas ao final do processo fermentativo e dos álcoois homólogos superiores na cachaça, particularmente, os álcoois propílico e isobutílico.