scholarly journals Actinobacteria From Desert: Diversity and Biotechnological Applications

2021 ◽  
Vol 12 ◽  
Author(s):  
Feiyang Xie ◽  
Wasu Pathom-aree

Deserts, as an unexplored extreme ecosystem, are known to harbor diverse actinobacteria with biotechnological potential. Both multidrug-resistant (MDR) pathogens and environmental issues have sharply raised the emerging demand for functional actinobacteria. From 2000 to 2021, 129 new species have been continuously reported from 35 deserts worldwide. The two largest numbers are of the members of the genera Streptomyces and Geodermatophilus, followed by other functional extremophilic strains such as alkaliphiles, halotolerant species, thermophiles, and psychrotolerant species. Improved isolation strategies for the recovery of culturable and unculturable desert actinobacteria are crucial for the exploration of their diversity and offer a better understanding of their survival mechanisms under extreme environmental stresses. The main bioprospecting processes involve isolation of target actinobacteria on selective media and incubation and selection of representatives from isolation plates for further investigations. Bioactive compounds obtained from desert actinobacteria are being continuously explored for their biotechnological potential, especially in medicine. To date, there are more than 50 novel compounds discovered from these gifted actinobacteria with potential antimicrobial activities, including anti-MDR pathogens and anti-inflammatory, antivirus, antifungal, antiallergic, antibacterial, antitumor, and cytotoxic activities. A range of plant growth-promoting abilities of the desert actinobacteria inspired great interest in their agricultural potential. In addition, several degradative, oxidative, and other functional enzymes from desert strains can be applied in the industry and the environment. This review aims to provide a comprehensive overview of desert environments as a remarkable source of diverse actinobacteria while such rich diversity offers an underexplored resource for biotechnological exploitations.

Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 411
Author(s):  
Maxence Quemener ◽  
Marie Dayras ◽  
Nicolas Frotté ◽  
Stella Debaets ◽  
Christophe Le Meur ◽  
...  

Among the different tools to address the antibiotic resistance crisis, bioprospecting in complex uncharted habitats to detect novel microorganisms putatively producing original antimicrobial compounds can definitely increase the current therapeutic arsenal of antibiotics. Fungi from numerous habitats have been widely screened for their ability to express specific biosynthetic gene clusters (BGCs) involved in the synthesis of antimicrobial compounds. Here, a collection of unique 75 deep oceanic crust fungi was screened to evaluate their biotechnological potential through the prism of their antimicrobial activity using a polyphasic approach. After a first genetic screening to detect specific BGCs, a second step consisted of an antimicrobial screening that tested the most promising isolates against 11 microbial targets. Here, 12 fungal isolates showed at least one antibacterial and/or antifungal activity (static or lytic) against human pathogens. This analysis also revealed that Staphylococcus aureus ATCC 25923 and Enterococcus faecalis CIP A 186 were the most impacted, followed by Pseudomonas aeruginosa ATCC 27853. A specific focus on three fungal isolates allowed us to detect interesting activity of crude extracts against multidrug-resistant Staphylococcus aureus. Finally, complementary mass spectrometry (MS)-based molecular networking analyses were performed to putatively assign the fungal metabolites and raise hypotheses to link them to the observed antimicrobial activities.


2019 ◽  
Vol 57 (3B) ◽  
pp. 144
Author(s):  
Thi Hang Nguyen Vu ◽  
Quang Huy Nguyen ◽  
Thi Thu Hang Le ◽  
Son Chu-Ky ◽  
Quyet Tien Phi

This study determined the optimal nutrient and environmental conditions for the production of antimicrobial and cytotoxic agents by Streptomyces cavourensis YBQ59 during the fermentation process. The antimicrobial and cytotoxic activities of eluted fractions based gradient solvents via silica gel column of chromatograph were also evaluated. S. cavourensis YBQ59 exhibited strong, board-spectrum antimicrobial activities under fermentation conditions as follows: MT6 medium with soluble starch and soybean powder as carbon and nitrogen sources, respectively, temperature 30oC, initial pH 7.0, 20% DO concentration and with 5% initial seed culture. The kinetic of fermentation showed that the antimicrobial and cytotoxic activities were highest at between 72h and 78h. The fraction 25/1 D-M (dichloromethane –methanol) exhibited the highest antimicrobial effect against methicillin-resistant Staphylococcus aureus ATCC 33591 and methicillin-resistant Staphylococcus epidermidis ATCC 35984 with minimum inhibitory concentrations of 9.4 µg/ml and 6.4 µg/ml, respectively. The fraction 10/1 D-M had strong cytotoxic effects towards multidrug-resistant A459 and H1299 lung carcinoma cell lines with the cell viability of 11.3% and 12.4%, respectively. In conclusion, S. cavourensis YBQ59 would be a potential producer of valuable bioactive compounds that may have a board application in pharmaceutical industry and agriculture (biocontrol, livestock, food safety and quality management)


Mindfulness ◽  
2021 ◽  
Author(s):  
Karin Matko ◽  
Ulrich Ott ◽  
Peter Sedlmeier

Abstract Objectives Meditation is an umbrella term for a vast range of contemplative practices. Former proposals have struggled to do justice to this variety. To our knowledge, there is to date no comprehensive overview of meditation techniques spanning all major traditions. The present studies aimed at providing such a comprehensive list of meditation techniques. Methods In a qualitative study, we compiled a collection of 309 meditation techniques through a literature search and interviews with 20 expert meditators. Then, we reduced this collection to 50 basic meditation techniques. In a second, quantitative study, 635 experienced meditators from a wide range of meditative backgrounds indicated how much experience they had with each of these 50 meditation techniques. Results Meditators’ responses indicated that our choice of techniques had been adequate and only two techniques had to be added. Our additional statistical and cluster analyses illustrated preferences for specific techniques across and within diverse traditions as well as sets of techniques commonly practiced together. Body-centered techniques stood out in being of exceptional importance to all meditators. Conclusions In conclusion, we found an amazing variety of meditation techniques, which considerably surpasses previous collections. Our selection of basic meditation techniques might be of value for future scientific investigations and we encourage researchers to use this set.


2021 ◽  
Vol 22 (7) ◽  
pp. 3299
Author(s):  
Damian Neubauer ◽  
Maciej Jaśkiewicz ◽  
Marta Bauer ◽  
Agata Olejniczak-Kęder ◽  
Emilia Sikorska ◽  
...  

Ultrashort cationic lipopeptides (USCLs) and gemini cationic surfactants are classes of potent antimicrobials. Our recent study has shown that the branching and shortening of the fatty acids chains with the simultaneous addition of a hydrophobic N-terminal amino acid in USCLs result in compounds with enhanced selectivity. Here, this approach was introduced into arginine-rich gemini cationic surfactants. L-cystine diamide and L-lysine amide linkers were used as spacers. Antimicrobial activity against planktonic and biofilm cultures of ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) strains and Candida sp. as well as hemolytic and cytotoxic activities were examined. Moreover, antimicrobial activity in the presence of human serum and the ability to form micelles were evaluated. Membrane permeabilization study, serum stability assay, and molecular dynamics were performed. Generally, critical aggregation concentration was linearly correlated with hydrophobicity. Gemini surfactants were more active than the parent USCLs, and they turned out to be selective antimicrobial agents with relatively low hemolytic and cytotoxic activities. Geminis with the L-cystine diamide spacer seem to be less cytotoxic than their L-lysine amide counterparts, but they exhibited lower antibiofilm and antimicrobial activities in serum. In some cases, geminis with branched fatty acid chains and N-terminal hydrophobic amino acid resides exhibited enhanced selectivity to pathogens over human cells.


2021 ◽  
Vol 9 (1) ◽  
pp. 171
Author(s):  
Yitayal S. Anteneh ◽  
Qi Yang ◽  
Melissa H. Brown ◽  
Christopher M. M. Franco

The misuse and overuse of antibiotics have led to the emergence of multidrug-resistant microorganisms, which decreases the chance of treating those infected with existing antibiotics. This resistance calls for the search of new antimicrobials from prolific producers of novel natural products including marine sponges. Many of the novel active compounds reported from sponges have originated from their microbial symbionts. Therefore, this study aims to screen for bioactive metabolites from bacteria isolated from sponges. Twelve sponge samples were collected from South Australian marine environments and grown on seven isolation media under four incubation conditions; a total of 1234 bacterial isolates were obtained. Of these, 169 bacteria were tested in media optimized for production of antimicrobial metabolites and screened against eleven human pathogens. Seventy bacteria were found to be active against at least one test bacterial or fungal pathogen, while 37% of the tested bacteria showed activity against Staphylococcus aureus including methicillin-resistant strains and antifungal activity was produced by 21% the isolates. A potential novel active compound was purified possessing inhibitory activity against S. aureus. Using 16S rRNA, the strain was identified as Streptomyces sp. Our study highlights that the marine sponges of South Australia are a rich source of abundant and diverse bacteria producing metabolites with antimicrobial activities against human pathogenic bacteria and fungi.


Diversity ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 337
Author(s):  
Sergio de los Santos-Villalobos ◽  
Alondra María Díaz-Rodríguez ◽  
María Fernanda Ávila-Mascareño ◽  
Andrea Denisse Martínez-Vidales ◽  
Fannie Isela Parra-Cota

COLMENA is a microbial culture collection dedicated to the characterization, classification, preservation, and transferal of native microorganisms isolated from various agro-systems and other ecosystems in Mexico. This collection aims to protect microbial diversity, reducing soil degradation, but also exploiting its agro-biotechnological potential. So far, COLMENA has isolated and cryopreserved soil microorganisms from different crops in two major agricultural regions in Mexico, the Yaqui Valley, Sonora, and the Fuerte Valley, Sinaloa. COLMENA has specialized in the identification and characterization of microbial strains with metabolic capacities related to the promotion of plant growth and the biocontrol of phytopathogens. Thus, COLMENA has identified several promising plant growth-promoting microbial (PGPM) strains due to their metabolic and genetic potentials and their beneficial effects in vivo and field trials. These findings demonstrate the biotechnological potential of these strains for their future use in profitable agricultural alternatives focused on enhancing global food security. To share the knowledge and results of the COLMENA team’s scientific research, a virtual platform was created, where the database of the studied and preserved microorganisms is available to professionals, researchers, agricultural workers, and anyone who is interested.


This exciting new Handbook offers a comprehensive overview of the contemporary state of the field. The editors’ introduction and forty-five essays cover feminist critical engagements with philosophy and adjacent scholarly fields, as well as feminist approaches to current debates and crises across the world. Authors cover topics ranging from the ways in which feminist philosophy attends to other systems of oppression, and the gendered, racialized, and classed assumptions embedded in philosophical concepts, to feminist perspectives on prominent subfields of philosophy. The first section contains chapters that explore feminist philosophical engagement with mainstream and marginalized histories and traditions, while the second section parses feminist philosophy’s contributions to with numerous philosophical subfields, for example metaphysics and bioethics. A third section explores what feminist philosophy can illuminate about crucial moral and political issues of identity, gender, the body, autonomy, prisons, among numerous others. The Handbook concludes with the field’s engagement with other theories and movements, including trans studies, queer theory, critical race, theory, postcolonial theory, and decolonial theory. The volume provides a rigorous but accessible resource for students and scholars who are interested in feminist philosophy, and how feminist philosophers situate their work in relation to the philosophical mainstream and other disciplines. Above all it aims to showcase the rich diversity of subject matter, approach, and method among feminist philosophers.


Author(s):  
D. Muthuselvam ◽  
Kathick Kathick

Delonix elata L., belongs to family Fabaceae used by the traditional various medicinal practices to cure jaundice, skin disease, heart disease, cancer cell formation, physiological abnormalities, heptoprotective, bronchial and rheumatic problems. The present study was screen the antimicrobial and phytochemical activity of alkaloid leaf extracts. This extracts was assessed on multidrug resistant clinical isolated from both gram positive, gram negative and antifungal strains including Bacillus subtilis, Staphylococcus aureus, Escherchia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger. The zone of inhibition was determined by Agar well diffusion method with various concentration. GC- MS analysis was performed to identify major bioactive compounds present in the extracts. The GC – MS studies shown the present of 25 compound were identified in the leaf extract composition. The antimicrobial analysis revealed that C. albicans showed a highest zone of inhibition 25mm at 100 mg/ml of extracts. Present finding suggest that D. elata as plant pharmaceutical and pharmacological importance.


Author(s):  
María Villanueva Fernández ◽  
Héctor García-Diego

Resumen: A partir de 1920 Le Corbusier comenzó a elaborar un cuerpo teórico sobre el diseño de objetos que iría difundiendo a través de sus escritos y conferencias. Libros como Vers une architecture, L´art décoratif d´aujourd´hui o Précisions sur un état présent de l'architecture et de l'urbanisme han constituído un rico legado de ideas e imágenes interrelacionadas que permiten analizar la propuesta del arquitecto desde el plano de la teoría. Sin embargo, el poder de sus postulados fue continuamente experimentado y corroborado por su obra en materia de mobiliario, hasta el punto de establecerse relaciones directas entre teoría y obra. Esta evolución conjunta proporciona una completa visión del concepto de mobiliario moderno desarrollado por Le Corbusier. Por tanto, esta investigación persigue, por un lado, sacar a la luz un verdadero cuerpo teórico de cuño 'corbuseriano' y específico del equipamiento moderno, haciendo especial mención a los postulados y dibujos originales del arquitecto y, por otro, comprobar la correspondencia real entre sus teorías y sus obras mediante el análisis de una escogida selección de obras del arquitecto pertenecientes al periodo de entreguerras, para, finalmente, ofrecer una caracterización 'corbuseriana' del mobiliario moderno. Abstract: From 1920 Le Corbusier began to develop a theoretical body on the objects design that went spreading through his writings and lectures. Books like Vers une architecture, L'art décoratif d'aujourd'hui or Précisions sur un état présent de l'architecture et de l'urbanisme have constituted a rich legacy of interlinked ideas and images to analyze the proposal of the architect from the level of theory. However, the power of its principles was continuously experienced and corroborated by his work in furniture, to the point of establishing direct relations between theory and work. This joint development provides a comprehensive overview of modern furniture concept developed by Le Corbusier. Therefore, this research aims on the one hand, to expose a 'Corbusian' and specific theoretical body of modern equipment, with special reference to the principles and original drawings by the architect; and, secondly, to check the real correspondence between his theories and works by analyzing a choice selection of works by the architect belonging to the interwar period, to finally offer a 'Corbusian' characterization of modern furniture.Palabras clave: Teoría; mobiliario; moderno; escritos. Keywords: Theory; furniture; modern; writings. DOI: http://dx.doi.org/10.4995/LC2015.2015.569 


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