Bioprospecting of indigenous yeasts involved in cocoa fermentation using sensory and chemical strategies for selecting a starter inoculum

Five Saccharomyces cerevisiae strains (Chinese indigenous yeasts SC5, WC5, SC8, CC17 and commercial starter F15) were inoculated into Cabernet sauvignon grape must and fermented at pilot scale. For the first time, combination of 1H NMR, HS-SPME/GC-MS and HPLC-DAD-ESI-MS/MS metabonomic profiling techniques was performed to analyze the global chemical fingerprints of sampled wines at the end of alcoholic and malolactic fermentation respectively, then 13 non-volatile flavor compounds, 52 volatile organic aromas and 43 polyphenolic molecules were identified and determined correspondently. All principal component analysis (PCA) of two fermentation stages based on the analytical results of 1H NMR, HS-SPME/GC-MS and HPLC-DAD-ESI-MS/MS divided these strains into three clusters: (1) SC5 and SC8, (2) WC5 and F15 and (3) CC17. The wine fermented by indigenous yeast, CC17, showed a very unique chemical profile, such as low pH and high color intensity, reduced amino acids (including proline) and the lowest total higher alcohols levels, most of the fixed acids, glycerol, ethyl esters and anthocyanins concentrations. The statistical results indicate that CC17 strain possesses very special anabolism and catabolism abilities on such substances in grape juice and has potentiality to produce characteristic wines with high qualities.

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Quorum Sensing – A Stratagem for Conquering Multi-Drug Resistant Pathogens

Current Pharmaceutical Design ◽

10.2174/1381612826666201210105638 ◽

2020 ◽

Vol 26 ◽

Author(s):

Madison Tonkin ◽

Shama Khan ◽

Mohmmad Younus Wani ◽

Aijaz Ahmad

Keyword(s):

Drug Resistance ◽

Quorum Sensing ◽

Virulence Factors ◽

Biofilm Formation ◽

Cell Communication ◽

Natural Compounds ◽

Quorum Sensing Inhibitors ◽

Communication Technique ◽

Multicellular Organisms ◽

Chemical Strategies

: Quorum sensing is defined as cell to cell communication between microorganisms, which enables microorganisms to behave as multicellular organisms. Quorum sensing enables many collaborative benefits such as synchronisation of virulence factors and biofilm formation. Both quorum sensing as well as biofilm formation encourage the development of drug resistance in microorganisms. Biofilm formation and quorum sensing are causally linked to each other and play role in the pathogenesis of microorganisms. With the increasing drug resistance against the available antibiotics and antifungal medications, scientists are combining different options to develop new strategies. Such strategies rely on the inhibition of the communication and virulence factors rather than on killing or inhibiting the growth of the microorganisms. This review encompasses the communication technique used by microorganisms, how microorganism resistance is linked to quorum sensing and various chemical strategies to combat quorum sensing and thereby drug resistance. Several compounds have been identified as quorum sensing inhibitors and are known to be effective in reducing resistance as they do not kill the pathogens but rather disrupt their communication. Natural compounds have been identified as anti-quorum sensing agents. However, natural compounds present several related disadvantages. Therefore, the need for the development of synthetic or semi-synthetic compounds has arisen. This review argues that anti-quorum sensing compounds are effective in disrupting quorum sensing and could therefore be effective in reducing microorganism drug resistance.

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Synthesis of a New Dioxaspiro[bicyclo[3.3.1]nonane-oxabicyclo[6.2.0]deca- 1(10),8-dien-4-one Derivative Using Some Chemical Strategies

Letters in Organic Chemistry ◽

10.2174/1570178617666191116123359 ◽

2020 ◽

Vol 17 (5) ◽

pp. 393-402

Author(s):

Figueroa-Valverde Lauro ◽

Rosas-Nexticapa Marcela ◽

Lopez-Ramos Maria ◽

Diaz Cedillo Francisco ◽

Mateu-Armand Virginia ◽

...

Keyword(s):

Elemental Analysis ◽

Chemical Structure ◽

Spectroscopic Techniques ◽

Easy Method ◽

Chemical Strategies

There are several protocols for the preparation of bicyclic derivatives; however, some methods use dangerous and require special conditions. The aim of this study was to synthesize a new Dioxaspiro[ bicyclo[3.3.1]nonane-oxabicyclo[6.2.0]-deca-1(10), 8-dien-4-one (compound 8). Compound 8 was prepared using some reactions such as; i) etherification, ii) reduction, iii) amidation, iv) imination and v) 2+2 addition. The chemical structure of 8 and its intermediaries were completely characterized by spectroscopic techniques and elemental analysis. The synthesis showed a yield of 85% for compound 8. In this study, an easy method for the preparation of compound 8 is reported.

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A Brief Insight into Microbial Corrosion and its Mitigation with Eco-friendly Inhibitors

Journal of Bio- and Tribo-Corrosion ◽

10.1007/s40735-021-00563-y ◽

2021 ◽

Vol 7 (3) ◽

Author(s):

M. Lavanya

Keyword(s):

Electrochemical Impedance ◽

Wide Spectrum ◽

Present Review ◽

Electrochemical Reactions ◽

Microbial Corrosion ◽

Engineering Applications ◽

Microbially Influenced Corrosion ◽

Catastrophic Failures ◽

Chemical Strategies ◽

Insight Into

AbstractCorrosion results from the electrochemical reactions between the metal and its existing environment. Corrosion results in severe and expensive damage to a wide spectrum of industries. When microbes are involved in corrosion it is seldom possible to economically evaluate its impact. Microbially influenced corrosion is recognized to cause catastrophic failures contributing to approximately 20% of the annual losses. In many engineering applications, microbially influenced corrosion control is of prime importance. Expensive, toxicity and sometimes, even ineffectiveness of the current chemical strategies to mitigate microbially influenced corrosion have shifted the interest towards eco-friendly inhibitors. The present review discusses microbial induced corrosion in various metals and its inhibition through eco-friendly inhibitors. In addition, the study also reviews the morphological and electrochemical impedance results.

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Exploring the Capability of Yeasts Isolated from Colombian Fermented Cocoa Beans to Form and Degrade Biogenic Amines in a Lab-Scale Model System for Cocoa Fermentation

Microorganisms ◽

10.3390/microorganisms9010028 ◽

2020 ◽

Vol 9 (1) ◽

pp. 28

Author(s):

Johannes Delgado-Ospina ◽

Laura Acquaticci ◽

Junior Bernardo Molina-Hernandez ◽

Kalliopi Rantsiou ◽

Maria Martuscelli ◽

...

Keyword(s):

Biogenic Amines ◽

Yeast Species ◽

Scale Model ◽

Cocoa Beans ◽

Pichia Kudriavzevii ◽

Toxic Compounds ◽

Volatile Organic ◽

Fatty Acids Metabolism ◽

Cocoa Fermentation

Yeast starters for cocoa fermentation are usually tested according to their enzymatic activities in terms of mucilage degradation and flavor improvement, disregarding their influence on the production or elimination of toxic compounds as biogenic amines (BAs), important for human health. In this work, we tested 145 strains belonging to 12 different yeast species and isolated from the Colombian fermented cocoa beans (CB) for their capability of producing BAs in vitro. Sixty-five strains were able to decarboxylate at least one of the amino acids tested. Pichia kudriavzevii ECA33 (Pk) and Saccharomyces cerevisiae 4 (Sc) were selected to evaluate their potential to modulate BAs, organic acids, and volatile organic compounds (VOCs) accumulation during a simulated cocoa fermentation. The growth of Sc or Pk in the presence of CB caused a significant reduction (p < 0.05) of 2-phenylethylamine (84% and 37%) and cadaverine (58% and 51%), and a significant increase of tryptamine and putrescine with a strong influence of temperature in BA formation and degradation. In addition, our findings pointed out that Pk induced a major production of fatty acid- and amino acid-derived VOCs, while Sc induced more VOCs derived from fatty acids metabolism. Our results suggest the importance of considering BA production in the choice of yeast starters for cocoa fermentation.

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