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Erythritol Chemical Structure, Biosynthesis Pathways, Properties, Applications, and Production
Issue:
Volume 6, Issue 3, September 2021
Pages:
59-70
Received:
21 June 2021
Accepted:
2 July 2021
Published:
9 July 2021
Abstract: Erythritol is a natural four carbon sugar alcohol present in fruits, vegetables, mushrooms and in fermented foods. It is low calorie sweetener manufactured commercially by fermentation using osmophilic yeasts and yeasts-like fungi. Some filamentous fungi and heterofermentative lactic acid bacteria demonstrated on laboratory scale the production of erythritol at lower yield. Erythritol is gaining high market share as natural sweetener with applications in low calorie foods, beverages, and as an additive in combination with high intense zero calorie artificial sweeteners to enhance sweetness, texture, and to mask these artificial sweeteners bitter after taste. Due to increasing demand of erythritol with wide applications in foods, pharmaceuticals, and chemical industries, research activities are focusing on reducing production cost by fermentation conditions optimization. and improve industrial cultures via mutation or genetic engineering to utilize cheap and abundant byproducts such as crude glycerol and lignocellulosic materials as carbon sources in replacement to the costly glucose. Erythritol production with less intermediate metabolites in the fermentation process can be achieved by microbial metabolic pathway engineering. High yield of erythritol with less intermediate metabolites at the end of fermentation process will lead to improve erythritol recovery efficiency with higher yield and specifications.
Abstract: Erythritol is a natural four carbon sugar alcohol present in fruits, vegetables, mushrooms and in fermented foods. It is low calorie sweetener manufactured commercially by fermentation using osmophilic yeasts and yeasts-like fungi. Some filamentous fungi and heterofermentative lactic acid bacteria demonstrated on laboratory scale the production of ...
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Rapid Quantitative PCR Assay for the Detection of the Three Vaginal Pathogens Candida, Gardnerella and Atopobium as well as the Commensal Lactobacillus Genera
Stephanie Bornes,
Olivier Camarès,
Marylise Paquet-Gachinat,
Philippe Veisseire,
Jacques Ravel,
Caroline Dausset,
Adrien Nivoliez
Issue:
Volume 6, Issue 3, September 2021
Pages:
71-77
Received:
12 July 2021
Accepted:
27 July 2021
Published:
4 August 2021
Abstract: The vaginal microbiota balance is quite fragile and susceptible to the development of vaginosis and candidiasis. The current diagnostic method for bacterial vaginosis relies on the evaluation of different bacterial morphotypes using the Nugent score. This method is only partially in correlation with a DNA sequencing-based diagnostic or Amsel criteria used by clinicians, suggesting the need for new molecular approaches dedicated to the diagnosis of BV. The objective of this study was to develop and validate a quantitative polymerase chain reaction (qPCR) assay for the specific and rapid detection of three vaginal pathogens, i.e. Candida, Gardnerella and Atopobium and the commensal Lactobacillus genera. For this purpose, four oligonucleotide primer pairs were designed and tested to obtain optimal amplification of the four target genera. The qPCR assay was also tested on the non-target genera and on human DNA. The designed primers allowed specific amplification of the target organisms in vitro and in clinical vaginal samples. The qPCR assay designed in this study is effective to specifically detect these genera in clinical samples as a molecular technique complementary to the Nugent score. It can be used in epidemiological studies for understanding the role of these pathogens and to follow their abundance in the microbiota in disease processes such as the development of vulvovaginal candidiasis and bacterial vaginosis.
Abstract: The vaginal microbiota balance is quite fragile and susceptible to the development of vaginosis and candidiasis. The current diagnostic method for bacterial vaginosis relies on the evaluation of different bacterial morphotypes using the Nugent score. This method is only partially in correlation with a DNA sequencing-based diagnostic or Amsel criter...
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Regulation and Activity Evaluation of Secondary Metabolism of an Oyster Symbiotic Fungus Schizophyllum sp. YS-08
Huannan Wang,
Maocai Yan,
Mengdi Liang,
Xiujian Wei,
Zhao Shang,
Zhen Zhang
Issue:
Volume 6, Issue 3, September 2021
Pages:
78-85
Received:
15 July 2021
Accepted:
29 July 2021
Published:
9 August 2021
Abstract: Marine microorganisms are the important resources for natural drug discovery. However, most of genes are usually in silent and could not express under the condition of traditional culture, which limits the discovery of lead compounds. In the present research, marine fungus Schizophyllum sp. YS-08 was selected as the research object, which was from Yellow Sea of China, to activate its silent genes by changing the medium of nutrients and environmental conditions. The crude extracts from metabolites of marine fungi were analyzed by HPLC, and their antioxidant activity and acetylcholinesterase (AChE) inhibitory activity were studied by DPPH radical-scavenging and Ellman's method, respectively. The results indicated that metabolic pathway of fungus was regulated effectively in different culture conditions, especially in the normal sea water medium with peptone. The antioxidant activity and AChE inhibitory activity increased significantly in comparison with wild strain and increase of the quantity of chemical constituents were even more. It is also observed that the strains showed relatively slow growth in the high salinity situation, while this adversely environmental condition could promote and produce more active metabolites. Furthermore, 6 mutant strains were obtained under salt stress and were identified. Interestingly, we found that all mutant strains had potency toward antioxidant and AChE inhibitory activity. Among them, YS-08-2 was the most potent, scavenging more than 56.02% towards DPPH free radicals, and YS-08-1, YS-08-4 and YS-08-5 exhibited more than 40% inhibition against AChE. HPLC analysis of extracts showed the metabolites of most fungi were more abundant after regulation of culture conditions.
Abstract: Marine microorganisms are the important resources for natural drug discovery. However, most of genes are usually in silent and could not express under the condition of traditional culture, which limits the discovery of lead compounds. In the present research, marine fungus Schizophyllum sp. YS-08 was selected as the research object, which was from ...
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New Phylogenetic Molecular Markers in Bacteria of the Genus Bacillus: Fibrinolytic Proteases
Nguimbi Etienne,
Soloka Mabika Faly Armel,
Dibangou Valentin,
Nzaou Stech Anomène Eckzechel,
Kayath Aimé Christian,
Moyen Rachel
Issue:
Volume 6, Issue 3, September 2021
Pages:
86-94
Received:
7 February 2021
Accepted:
16 March 2021
Published:
18 August 2021
Abstract: The fibrinolytic proteases developed by bacteria have become substances of medical interest, as they have been recognized as antithrombotic substances in the blood. It is in this context that a study has been carried out with the aim of studying the fibrinolytic proteases produced by bacteria isolated from food in the Congo. Four strains of bacteria of the genus Bacillus isolated from crushed and cooked squash seeds, namely Bacillus sp strain ASM7, Bacillus sp strain CRK, Bacillus pumilus strain ASM5, Bacillus subtilis strain ASM1, identified by their rDNA16S, were tested positive for the production of fibrinolytic proteases. The fibrin box technique was used. The diameters on the fibrin boxes prove a significant production of fibrinolytic proteases. The genes coding for these fibrinolytic proteases were amplified by PCR and 1% Agarose gel electrophoresis shows that the size of the amplicons for the four strains is between1200-1450bp. The sequences of these coding genes have been for the four strains studied submitted to GenBank and the assigned accession numbers are respectively: Bacillus sp strain ASM7 MT743004, Bacillus sp strain CRK MT743005, Bacillus pumilus strain ASM5 MT743006, Bacillus subtilis strain ASM1 MT743007. These genes show a high degree of similarity of almost 99.50% with their counterparts in the databases, are all coding and show some observable differences. The translation of these genes in coherent reading frames confirms the amino acids already known in the active sites relating to their fibrinolysis role. The fibrinolytic protease CFE1 (Id=QNJ60181) is for Bacillus sp strain ASM7, the fibrinolytic protease CFE2 (Id=QNJ60182) is for Bacillus sp strain CRK, the fibrinolytic protease CFE3 (Id=QNJ60183) is for Bacillus pumilus strain ASM5, the fibrinolytic protease CFE4 (Id=QNJ60184) is for Bacillus subtilis strain ASM1. All these fibrinolytic proteases show a strong similarity (99.51-99.76%) with the Bacillus AprX serine protease, reference sequence. The phylogenetic inference test based on these fibrinolytic proteases shows that these proteases form a highly conserved characteristic group in bacteria of the genus Bacillus. This allowed us to retain these fibrinolytic proteases as an important phylogenetic molecular marker.
Abstract: The fibrinolytic proteases developed by bacteria have become substances of medical interest, as they have been recognized as antithrombotic substances in the blood. It is in this context that a study has been carried out with the aim of studying the fibrinolytic proteases produced by bacteria isolated from food in the Congo. Four strains of bacteri...
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