Production Of Important Metabolites Research Articles

Single versus dual inoculation with indigenous Saccharomyces cerevisiae strains in winemaking.

Indigenous Saccharomyces cerevisiae strains and their combinations may be used to diversify wines and add complexity to sensory profiles. Here, two S. cerevisiae strains that represent regional genetic and phenotypic specificities for two major winegrowing areas of Greece were used in single- and mixed-culture fermentations. The kinetics and metabolic activities of the strains were analysed to evaluate the influence of each strain individually or in combination on wine quality. The two strains differentially affected the kinetics and the outcome of fermentation. They showed significant differences in the production of important metabolites that strongly affect the organoleptic profile of wines, such as volatile acidity, acetaldehyde, certain esters, and terpenes. Furthermore, the chemical and sensory profiles of wines produced by single cultures were different from those fermented by mixed culture inoculum. The concentration of certain metabolites was enhanced (e.g. isoamyl acetate, 1-heptanol), while others were suppressed (e.g. hexyl acetate, octyl acetate). Results highlight the potential worth of indigenous S. cerevisiae strains to differentiate local wines. The mixed culture S. cerevisiae inoculum was shown to generate novel wine characteristics, as compared to single cultures, thus offering alternatives to further diversify wines and increase their complexity.

Advances in Genetic Tools and Their Application in Streptococcus thermophilus.

Streptococcus thermophilus is a traditional starter. Nowadays, key aspects of S. thermophilus physiology have been revealed concerning the phenotypic traits relevant for industrial applications, including sugar metabolism, protein hydrolysis, and the production of important metabolites that affect the sensory properties of fermented foods as well as the original cooperation with Lactobacillus delbrueckii subsp. bulgaricus. Moreover, significant advances have been made in the synthetic biology toolbox of S. thermophilus based on technological advances in the genome and its sequencing and synthesis. In this review, we discuss the recently developed toolbox for S. thermophilus, including gene expression toolsets (promoters, terminators, plasmids, etc.) and genome editing tools. It can be used for both functionalized foods and therapeutic molecules for consumers. The availability of new molecular tools, including the genome editing toolbox, has facilitated the engineering of physiological studies of S. thermophilus and the generation of strains with improved technical and functional characteristics.

Evaluation of Phenolic Compounds, Lignin, Amino Acids and Carbohydrates in Theobroma cacao L. from Three Different Climate Regions in Venezuela

In Venezuela, Criollo cacao crops are distributed in different regions (eastern, central and western), and under different exploitation systems, and, in each of these regions, there is a uniqueness of materials with characteristics associated to an intrinsic, differential quality that could potentially affect chocolate quality. These regions have inherent climates that are significantly different; however, there is a lack of consistent technical information about the real effects of environmental factors on the organoleptic quality of cacao. Therefore, the present work aims to evaluate the content of important components of cacao, such as phenolic compounds, lignin, amino acids, and carbohydrate, in six Theobroma cacao L clones, cultivated in three different agro-climatic locations: humid, semi-humid and dry tropical forest. It was found that production of phenolic compounds and lignin vary in clones according to their location, with the highest values found in the humid forest and the lowest in the dry climate. Non-structural carbohydrates, on the other hand, were found in greater amounts in specimens from the dry forest. The largest production of proline was found in the humid forest for most of the clones, implying that high humidity levels promote the production of amino acids, a pattern followed by phenolic compound content as well. The results presented in this study indicate that there is a climate-dependent production of important metabolites, which play an important role in the organoleptic properties of cacao, and this could potentially translate into different levels of resistance to stress and diseases.

Elicitation Based Enhancement of Secondary Metabolites in Rauwolfia serpentina and Solanum khasianum Hairy Root Cultures.

Background:Rauwolfia serpentina and Solanum khasianum are well-known medicinally important plants contained important alkaloids in their different parts. Elicitation of these alkaloids is important because of associated pharmaceutical properties. Targeted metabolites were ajmaline and ajmalicine in R. serpentina; solasodine and α-solanine in S. khasianum.Objective:Enhancement of secondary metabolites through biotic and abiotic elicitors in hairy root cultures of R. serpentina and S. khasianum.Materials and Methods:In this report, hairy root cultures of these two plants were established through Agrobacterium rhizogenes mediated transformation by optimizing various parameters as age of explants, duration of preculture, and co-cultivation period. NaCl was used as abiotic elicitors in these two plants. Cellulase from Aspergillus niger was used as biotic elicitor in S. khasianum and mannan from Saccharomyces cerevisiae was used in R. serpentina.Results:First time we have reported the effect of biotic and abiotic elicitors on the production of important metabolites in hairy root cultures of these two plants. Ajmalicine production was stimulated up to 14.8-fold at 100 mM concentration of NaCl after 1 week of treatment. Ajmaline concentration was also increased 2.9-fold at 100 mg/l dose of mannan after 1 week. Solasodine content was enhanced up to 4.0-fold and 3.6-fold at 100 mM and 200 mM NaCl, respectively, after 6 days of treatments.Conclusion:This study explored the potential of the elicitation strategy in A. rhizogenes transformed cell cultures and this potential further used for commercial production of these pharmaceutically important secondary metabolites.SUMMARY Hairy roots of Rauwolfia serpentina were subjected to salt (abiotic stress) and mannan (biotic stress) treatment for 1 week. Ajmaline and ajmalicine secondary metabolites were quantified before and after stress treatmentAjmalicine yield was enhanced up to 14.8-fold at 100 mM concentration of NaCl. Ajmaline content was also stimulated 2.9-fold at 100 mg/l dose of mannan after 1 weekHairy roots of Solanum khasianum were treated with cellulase (biotic elicitor) and salt (abiotic stress)Solasodine content was improved up to 4.0-fold and 3.6-fold at 100 mM and 200 mM NaCl, respectively, after 6.days of treatmentsThe α-solanine content increased to 1.6-fold after 24 h of treatment at 100 μg/mL cellulase concentration. Abbreviations used: MS medium: Murashige and Skoog medium, B5 medium: Gamborg B5 medium, OD: Optical Density, NaCl: Sodium Chloride.