scholarly journals Engineering of a borneol dehydrogenase from P. putida for the enzymatic resolution of camphor

2021 ◽  
Vol 105 (8) ◽  
pp. 3159-3167
Author(s):  
Michael Hofer ◽  
Julia Diener ◽  
Benjamin Begander ◽  
Robert Kourist ◽  
Volker Sieber
Keyword(s):  
Kinetic Resolution ◽  
Enzyme Engineering ◽  
Medical Applications ◽  
Natural Sources ◽  
Alpha Pinene ◽  
Enzymatic Kinetic Resolution ◽  
Key Points ◽  
Reliable Source ◽  
Ancient Times

Abstract Several thousand different terpenoid structures are known so far, and many of them are interesting for applications as pharmaceuticals, flavors, fragrances, biofuels, insecticides, or fine chemical intermediates. One prominent example is camphor, which has been utilized since ancient times in medical applications. Especially (−)-camphor is gaining more and more interest for pharmaceutical applications. Hence, a commercial reliable source is needed. The natural sources for (−)-camphor are limited, and the oxidation of precious (−)-borneol would be too costly. Hence, synthesis of (−)-camphor from renewable alpha-pinene would be an inexpensive alternative. As the currently used route for the conversion of alpha-pinene to camphor produces a mixture of both enantiomers, preferably catalytic methods for the separation of this racemate are demanded to yield enantiopure camphor. Enzymatic kinetic resolution is a sustainable way to solve this challenge but requires suitable enzymes. In this study, the first borneol dehydrogenase from Pseudomonas sp. ATCC 17453, capable of catalyzing the stereoselective reduction of camphor, was examined. By using a targeted enzyme engineering approach, enantioselective enzyme variants were created with E-values > 100. The best variant was used for the enzymatic kinetic resolution of camphor racemate, yielding 79% of (−)-camphor with an ee of > 99%. Key points • Characterization of a novel borneol dehydrogenase (BDH) from P. putida. • Development of enantioselective BDH variants for the reduction of camphor. • Enzymatic kinetic resolution of camphor with borneol dehydrogenase. Graphical abstract

scholarly journals Dry mechanosynthesis and characterization of carbonate apatite based on Indonesian natural sources

2021 ◽  
Author(s):  
Herlina Damayanti ◽  
Kristanto Wahyudi ◽  
Karlina Noordiningsih ◽  
Ayu Ratnasari ◽  
Devi Rianti
Keyword(s):  
Carbonate Apatite ◽  
Natural Sources

scholarly journals Gut microbiota profiles and characterization of cultivable fungal isolates in IBS patients

2021 ◽  
Author(s):  
Piero Sciavilla ◽  
Francesco Strati ◽  
Monica Di Paola ◽  
Monica Modesto ◽  
Francesco Vitali ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Gut Microbiota ◽  
Healthy Subjects ◽  
Fungal Isolates ◽  
Key Points ◽  
Health Promoting ◽  
Irritable Bowel

Abstract Studies so far conducted on irritable bowel syndrome (IBS) have been focused mainly on the role of gut bacterial dysbiosis in modulating the intestinal permeability, inflammation, and motility, with consequences on the quality of life. Limited evidences showed a potential involvement of gut fungal communities. Here, the gut bacterial and fungal microbiota of a cohort of IBS patients have been characterized and compared with that of healthy subjects (HS). The IBS microbial community structure differed significantly compared to HS. In particular, we observed an enrichment of bacterial taxa involved in gut inflammation, such as Enterobacteriaceae, Streptococcus, Fusobacteria, Gemella, and Rothia, as well as depletion of health-promoting bacterial genera, such as Roseburia and Faecalibacterium. Gut microbial profiles in IBS patients differed also in accordance with constipation. Sequence analysis of the gut mycobiota showed enrichment of Saccharomycetes in IBS. Culturomics analysis of fungal isolates from feces showed enrichment of Candida spp. displaying from IBS a clonal expansion and a distinct genotypic profiles and different phenotypical features when compared to HS of Candida albicans isolates. Alongside the well-characterized gut bacterial dysbiosis in IBS, this study shed light on a yet poorly explored fungal component of the intestinal ecosystem, the gut mycobiota. Our results showed a differential fungal community in IBS compared to HS, suggesting potential for new insights on the involvement of the gut mycobiota in IBS. Key points • Comparison of gut microbiota and mycobiota between IBS and healthy subjects • Investigation of cultivable fungi in IBS and healthy subjects • Candida albicans isolates result more virulent in IBS subjects compared to healthy subjects

Development and characterization of electrospun curcumin-loaded antimicrobial nanofibrous membranes

2020 ◽  
pp. 004051752092551
Author(s):  
Javeed A Awan ◽  
Saif Ur Rehman ◽  
Muhammad Kashif Bangash ◽  
Fiaz Hussain ◽  
Jean-Noël Jaubert
Keyword(s):  
Biological Activities ◽  
Research Work ◽  
Medical Applications ◽  
Electrospinning Technique ◽  
Naturally Occurring ◽  
Wide Range ◽  
Nanofibrous Membranes ◽  
Antimicrobial Barrier ◽  
Anti Hiv

Curcumin is a naturally occurring hydrophobic polyphenol compound. It exhibits a wide range of biological activities such as antibacterial, anti-inflammatory, anti-carcinogenic, antifungal, anti-HIV, and antimicrobial activity. In this research work, antimicrobial curcumin nanofibrous membranes are produce by an electrospinning technique using the Eudragit RS 100 (C19H34ClNO6) polymer solution enriched with curcumin. The morphology and chemistry of the membrane are analyzed using scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Kirby Bauer disk diffusion tests are carried out to examine the antibacterial effectiveness of the membrane. Experimental results show that the nanofibers produced are of uniform thickness morphology and curcumin is successfully incorporated into the nanofibrous mat, while no chemical bonding was observed between curcumin and the polymer. The antimicrobial curcumin nanofibrous membranes can be effectively applied as antimicrobial barrier in a wide variety of medical applications such as wound healing, scaffolds, and tissue engineering.

Characterization of humins from different natural sources and the effect on microbial reductive dechlorination of pentachlorophenol

Chemosphere ◽  
2015 ◽  
Vol 131 ◽  
pp. 110-116 ◽  
Author(s):  
Chunfang Zhang ◽  
Dongdong Zhang ◽  
Zhixing Xiao ◽  
Zhiling Li ◽  
Daisuke Suzuki ◽  
...  
Keyword(s):  
Reductive Dechlorination ◽  
Natural Sources ◽  
Microbial Reductive Dechlorination

Characterization of calcium oxide catalysts from natural sources and their application in the transesterification of sunflower oil

2014 ◽  
Vol 151 ◽  
pp. 207-213 ◽  
Author(s):  
Leandro Marques Correia ◽  
Rosana Maria Alves Saboya ◽  
Natália de Sousa Campelo ◽  
Juan Antonio Cecilia ◽  
Enrique Rodríguez-Castellón ◽  
...  
Keyword(s):  
Calcium Oxide ◽  
Sunflower Oil ◽  
Oxide Catalysts ◽  
Natural Sources

PRACTICAL UTILITY OF TANTRAGUNA (SHASTRA LAKSHAN) IN AYURVEDA

2020 ◽  
Vol 8 (02) ◽  
Author(s):  
Puneet Sharma Sonu
Keyword(s):  
High Standard ◽  
Scientific Paper ◽  
Research Literature ◽  
Scientific Writing ◽  
Writing System ◽  
Field Techniques ◽  
Quality Literature ◽  
Key Points ◽  
Vedic Literature ◽  
Ancient Times

"Shastra" commonly means a specific field of knowledge. In early Vedic literature, the word referred to any precept, rule, teaching, ritual instruction or direction.[1] In late and post Vedic literature of Hinduism, Shastra referred to any study, book or instrument of teaching, any manual or compilation of any subject in any field of knowledge, including religion. Tantra guna is Shastra Lakshana. The qualities of an ideal Shastra or study which would be received universally as a well documented standard reference are explained in Charak Samhita vimansthan as mentioned in Ayurveda.  The scientific paper has been developed over the last three centuries as a tool for communicating the results of scientific research. Scientific writing must be of a high standard, as it relates to the process of learning as well as new learners. In ancient times, a specific writing methodology was adopted by scientists to prepare standard and highly scientific historical documents in the field. Techniques such as Tantrayukti (Treat writing/decoding techniques), Tachchhilya (inclinations), Kalpana (compositions), etc. have been described in the classics to establish the quality requirements of research literature. Thanks to well-established writing methods, scientific mythology such as Samhita (Ayurvedic texts), Samgraha-grantha (compendia), Nighantu (lexicons), etc., has also been compiled universally and has produced some great quality literature. The Tantraguna refers to the key points of the writing, such as language, order, volume, form, etc. After reviewing and analyzing these Tantragunas, it can be concluded that the ancient writing method can be equated with certain alternatives to the current introduction, methods, results and discussion structure of scientific writing. This study can help to strengthen and reinforce the current standards of scientific writing by changing new aspects of the ancient writing system.

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