scholarly journals Development of an agar-plug cultivation system for bioactivity assays of actinomycete strain collections

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0258934
Author(s):  
Nico Ortlieb ◽  
Elke Klenk ◽  
Andreas Kulik ◽  
Timo Horst Johannes Niedermeyer

Natural products are an important source of lead compounds for the development of drug substances. Actinomycetes have been valuable especially for the discovery of antibiotics. Increasing occurrence of antibiotic resistance among bacterial pathogens has revived the interest in actinomycete natural product research. Actinobacteria produce a different set of natural products when cultivated on solid growth media compared with submersed culture. Bioactivity assays involving solid media (e.g. agar-plug assays) require manual manipulation of the strains and agar plugs. This is less convenient for the screening of larger strain collections of several hundred or thousand strains. Thus, the aim of this study was to develop a 96-well microplate-based system suitable for the screening of actinomycete strain collections in agar-plug assays. We developed a medium-throughput cultivation and agar-plug assay workflow that allows the convenient inoculation of solid agar plugs with actinomycete spore suspensions from a strain collection, and the transfer of the agar plugs to petri dishes to conduct agar-plug bioactivity assays. The development steps as well as the challenges that were overcome during the development (e.g. system sterility, handling of the agar plugs) are described. We present the results from one exemplary screening campaign targeted to identify compounds inhibiting Agr-based quorum sensing where the workflow was used successfully. We present a novel and convenient workflow to combine agar diffusion assays with microtiter-plate-based cultivation systems in which strains can grow on a solid surface. This workflow facilitates and speeds up the initial medium throughput screening of natural product-producing actinomycete strain collections against monitor strains in agar-plug assays.

2020 ◽  
Vol 177 (10) ◽  
pp. 2169-2178 ◽  
Author(s):  
Angelo A. Izzo ◽  
Mauro Teixeira ◽  
Steve P.H. Alexander ◽  
Giuseppe Cirino ◽  
James R. Docherty ◽  
...  

2014 ◽  
Vol 3 (1) ◽  
pp. 1 ◽  
Author(s):  
Geoffrey A. Cordell

“Why didn’t they develop natural product drugs in a sustainable manner at the beginning of this century?”  In 2035, when about 10.0 billion will inhabit Earth, will this be our legacy as the world contemplates the costs and availability of synthetic and gene-based products for primary health care?  Acknowledging the recent history of the relationship between humankind and the Earth, it is essential that the health care issues being left for our descendants be considered in terms of resources. For most people in the world, there are two vast health care “gaps”, access to quality drugs and the development of drugs for major global and local diseases.  Consequently for all of these people, plants, in their various forms, remain a primary source of health care.  In the developed countries, natural products derived from plants assume a relatively minor role in health care, as prescription and over-the-counter products, even with the widespread use of phytotherapeutical preparations.  Significantly, pharmaceutical companies have retrenched substantially in their disease areas of focus.  These research areas do not include the prevalent diseases of the middle- and lower-income countries, and important diseases of the developed world, such as drug resistance. What then is the vision for natural product research to maintain the choices of drug discovery and pharmaceutical development for future generations?  In this discussion some facets of how natural products must be involved globally, in a sustainable manner, for improving health care will be examined within the framework of the new term “ecopharmacognosy”, which invokes sustainability as the basis for research on biologically active natural products.  Access to the biome, the acquisition, analysis and dissemination of plant knowledge, natural product structure diversification, biotechnology development, strategies for natural product drug discovery, and aspects of multitarget therapy and synergy research will be discussed.  Options for the future will be presented which may be significant as countries decide how to develop approaches to relieve their own disease burden, and the needs of their population for improved access to medicinal agents.


2021 ◽  
Author(s):  
Nadya Abbood ◽  
Tien Duy Vo ◽  
Jonas Watzel ◽  
Kenan A. J. Bozhueyuek ◽  
Helge B. Bode

Bacterial natural products in general, and non-ribosomally synthesized peptides in particular, are structurally diverse and provide us with a broad range of pharmaceutically relevant bioactivities. Yet, traditional natural product research suffers from rediscovering the same scaffolds and has been stigmatised as inefficient, time-, labour-, and cost-intensive. Combinatorial chemistry, on the other hand, can produce new molecules in greater numbers, cheaper and in less time than traditional natural product discovery, but also fails to meet current medical needs due to the limited biologically relevant chemical space that can be addressed. Consequently, methods for the high throughput generation of new-to-nature natural products would offer a new approach to identifying novel bioactive chemical entities for the hit to lead phase of drug discovery programms. As a follow-up to our previously published proof-of-principle study on generating bipartite type S non-ribosomal peptide synthetases (NRPSs), we now envisaged the de novo generation of non-ribosomal peptides (NRPs) on an unreached scale. Using synthetic zippers, we split NRPS in up to three subunits and rapidly generated different bi- and tripartite NRPS libraries to produce 49 peptides, peptide derivatives, and de novo peptides at good titres up to 145 mgL-1. A further advantage of type S NRPSs not only is the possibility to easily expand the created libraries by re-using previously created type S NRPS, but that functions of individual domains as well as domain-domain interactions can be studied and assigned rapidly.


2020 ◽  
Vol 23 (9) ◽  
pp. 862-876
Author(s):  
Hayrettin O. Gulcan ◽  
Ilkay E. Orhan

With respect to the unknowns of pathophysiology of Alzheimer’s Disease (AD)-, and Parkinson’s Disease (PD)-like neurodegenerative disorders, natural product research is still one of the valid tools in order to provide alternative and/or better treatment options. At one hand, various extracts of herbals provide a combination of actions targeting multiple receptors, on the other hand, the discovery of active natural products (i.e., secondary metabolites) generally offers alternative chemical structures either ready to be employed in clinical studies or available to be utilized as important scaffolds for the design of novel agents. Regarding the importance of certain enzymes (e.g. cholinesterase and monoamine oxidase B), for the treatment of AD and PD, we have surveyed the natural product research within this area in the last decade. Particularly novel natural agents discovered within this period, concomitant to novel biological activities displayed for known natural products, are harmonized within the present study.


2010 ◽  
Vol 5 (10) ◽  
pp. 1934578X1000501 ◽  
Author(s):  
Haining Lv ◽  
Gaimei She

Diarylheptanoids, natural products with a 1,7-diphenylheptane structural skeleton, are mainly distributed in the roots, rhizomes and bark of Alpinia, Zingiber, Curcuma and Alnus species. They have become of interest in natural product research over the past twenty years because of their remarkable anticancer, anti-emetic, estrogenic, antimicrobial and antioxidant activity. This paper compiles all 307 naturally occurring diarylheptanoids from 46 plants as reported in 137 references with their distributions, physiological activities and 13C-NMR spectral data.


2020 ◽  
Vol 15 (9) ◽  
pp. 1934578X2095143
Author(s):  
Qianqian He ◽  
Shuang Miao ◽  
Na Ni ◽  
Yuqing Man ◽  
Kaikai Gong

Marine sponges, which belong to the phylum Porifera (Metazoa), are considered the single best source of marine natural products. Among them, members of the genus Aaptos are attractive targets for marine natural product research owing to their abundant biogenetic ability to produce aaptamine derivatives. Apart from aaptamine alkaloids, there are also reports of other compounds from Aaptos sponges. This work reviews the secondary metabolites isolated from Aaptos species from 1982 to 2020, with 46 citations referring to 62 compounds (47 for aaptamines and 15 for others). The emphasis is placed on the structure of the organic molecules, relevant biological activities, chemical ecology aspects, and biosynthesis studies, which are described in the classifications of aaptamines and other compounds in the order of the published year.


2015 ◽  
Vol 18 (4) ◽  
Author(s):  
Basil D Roufogalis ◽  
Srinivas Nammi ◽  
Emanuel E Strehler

This Special Issue follows from a previous Issue entitled “Mechanism-Based Development of Natural Products for Human Health” arising from an inaugural conference on Natural Products Development held at Whistler Mountain, Canada from September 21-22, 2012. The timeliness of this issue reflects the continued growth in Natural Product research and the success of the First Issue, as judged from feedback we received and citations received. We were also encouraged by the interest in natural products research in recent years, as exemplified by the recent publication on Traditional Medicine in the prestigious journal Science (1, 2).


2019 ◽  
Author(s):  
Nicholas J. Tobias ◽  
César Parra-Rojas ◽  
Yan-Ni Shi ◽  
Yi-Ming Shi ◽  
Svenja Simonyi ◽  
...  

AbstractBacteria of the genera Photorhabdus and Xenorhabdus produce a plethora of natural products to support their similar symbiotic lifecycles. For many of these compounds, the specific bioactivities are unknown. One common challenge in natural product research when trying to prioritize research efforts is the rediscovery of identical (or highly similar) compounds from different strains. Linking genome sequence to metabolite production can help in overcoming this problem. However, sequences are typically not available for entire collections of organisms. Here we perform a comprehensive metabolic screening using HPLC-MS data associated with a 114-strain collection (58 Photorhabdus and 56 Xenorhabdus) from across Thailand and explore the metabolic variation among the strains, matched with several abiotic factors. We utilize machine learning in order to rank the importance of individual metabolites in determining all given metadata. With this approach, we were able to prioritize metabolites in the context of natural product investigations, leading to the identification of previously unknown compounds. The top three highest-ranking features were associated with Xenorhabdus and attributed to the same chemical entity, cyclo(tetrahydroxybutyrate). This work addresses the need for prioritization in high-throughput metabolomic studies and demonstrates the viability of such an approach in future research.


Sign in / Sign up

Export Citation Format

Share Document