scholarly journals Marine Actinomycetes, New Sources of Biotechnological Products

Marine Drugs ◽  
2021 ◽  
Vol 19 (7) ◽  
pp. 365
Author(s):  
Sveta V. Jagannathan ◽  
Erika M. Manemann ◽  
Sarah E. Rowe ◽  
Maiya C. Callender ◽  
William Soto
Keyword(s):  
Secondary Metabolites ◽  
Pathogenic Bacteria ◽  
Applied Research ◽  
Antitumor Agents ◽  
Current Knowledge ◽  
Industrial Applications ◽  
Future Research ◽  
Marine Actinomycetes ◽  
Food Preservatives ◽  
New Compounds

The Actinomycetales order is one of great genetic and functional diversity, including diversity in the production of secondary metabolites which have uses in medical, environmental rehabilitation, and industrial applications. Secondary metabolites produced by actinomycete species are an abundant source of antibiotics, antitumor agents, anthelmintics, and antifungals. These actinomycete-derived medicines are in circulation as current treatments, but actinomycetes are also being explored as potential sources of new compounds to combat multidrug resistance in pathogenic bacteria. Actinomycetes as a potential to solve environmental concerns is another area of recent investigation, particularly their utility in the bioremediation of pesticides, toxic metals, radioactive wastes, and biofouling. Other applications include biofuels, detergents, and food preservatives/additives. Exploring other unique properties of actinomycetes will allow for a deeper understanding of this interesting taxonomic group. Combined with genetic engineering, microbial experimental evolution, and other enhancement techniques, it is reasonable to assume that the use of marine actinomycetes will continue to increase. Novel products will begin to be developed for diverse applied research purposes, including zymology and enology. This paper outlines the current knowledge of actinomycete usage in applied research, focusing on marine isolates and providing direction for future research.

scholarly journals The Coordinated Positive Regulation of Topoisomerase Genes Maintains Topological Homeostasis in Streptomyces coelicolor

2016 ◽  
Vol 198 (21) ◽  
pp. 3016-3028 ◽  
Author(s):  
Marcin Jan Szafran ◽  
Martyna Gongerowska ◽  
Paweł Gutkowski ◽  
Jolanta Zakrzewska-Czerwińska ◽  
Dagmara Jakimowicz
Keyword(s):  
Secondary Metabolites ◽  
Topoisomerase I ◽  
Elevated Temperatures ◽  
Antitumor Agents ◽  
Streptomyces Coelicolor ◽  
Optimal Level ◽  
Industrial Applications ◽  
Biologically Active ◽  
Content Type ◽  
Number Of Genes

ABSTRACTMaintaining an optimal level of chromosomal supercoiling is critical for the progression of DNA replication and transcription. Moreover, changes in global supercoiling affect the expression of a large number of genes and play a fundamental role in adapting to stress. Topoisomerase I (TopA) and gyrase are key players in the regulation of bacterial chromosomal topology through their respective abilities to relax and compact DNA. Soil bacteria such asStreptomycesspecies, which grow as branched, multigenomic hyphae, are subject to environmental stresses that are associated with changes in chromosomal topology. The topological fluctuations modulate the transcriptional activity of a large number of genes and inStreptomycesare related to the production of antibiotics. To better understand the regulation of topological homeostasis inStreptomyces coelicolor, we investigated the interplay between the activities of the topoisomerase-encoding genestopAandgyrBA. We show that the expression of both genes is supercoiling sensitive. Remarkably, increased chromosomal supercoiling induces thetopApromoter but only slightly influencesgyrBAtranscription, while DNA relaxation affects thetopApromoter only marginally but strongly activates thegyrBAoperon. Moreover, we showed that exposure to elevated temperatures induces rapid relaxation, which results in changes in the levels of both topoisomerases. We therefore propose a unique mechanism ofS. coelicolorchromosomal topology maintenance based on the supercoiling-dependent stimulation, rather than repression, of the transcription of both topoisomerase genes. These findings provide important insight into the maintenance of topological homeostasis in an industrially important antibiotic producer.IMPORTANCEWe describe the unique regulation of genes encoding two topoisomerases, topoisomerase I (TopA) and gyrase, in a modelStreptomycesspecies. Our studies demonstrate the coordination of topoisomerase gene regulation, which is crucial for maintenance of topological homeostasis.Streptomycesspecies are producers of a plethora of biologically active secondary metabolites, including antibiotics, antitumor agents, and immunosuppressants. The significant regulatory factor controlling the secondary metabolism is the global chromosomal topology. Thus, the investigation of chromosomal topology homeostasis inStreptomycesstrains is crucial for their use in industrial applications as producers of secondary metabolites.

scholarly journals Transformation of Helicobacter pylori into Coccoid Forms as a Challenge for Research Determining Activity of Antimicrobial Substances

Pathogens ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 184 ◽  
Author(s):  
Paweł Krzyżek ◽  
Rossella Grande
Keyword(s):  
Helicobacter Pylori ◽  
Applied Research ◽  
Morphological Variability ◽  
Alternative Methods ◽  
Future Research ◽  
Antimicrobial Substances ◽  
Coccoid Form ◽  
Current Review ◽  
H Pylori ◽  
New Compounds

Morphological variability is one of the phenotypic features related to adaptation of microorganisms to stressful environmental conditions and increased tolerance to antimicrobial substances. Helicobacter pylori, a gastric mucosal pathogen, is characterized by a high heterogeneity and an ability to transform from a spiral to a coccoid form. The presence of the coccoid form is associated with the capacity to avoid immune system detection and to promote therapeutic failures. For this reason, it seems that the investigation for new, alternative methods combating H. pylori should include research of coccoid forms of this pathogen. The current review aimed at collecting information about the activity of antibacterial substances against H. pylori in the context of the morphological variability of this bacterium. The collected data was discussed in terms of the type of substances used, applied research techniques, and interpretation of results. The review was extended by a polemic on the limitations in determining the viability of coccoid H. pylori forms. Finally, recommendations which can help in future research aiming to find new compounds with a potential to eradicate H. pylori have been formulated.

scholarly journals The Biology of Colicin M and Its Orthologs

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1109
Author(s):  
Dimitri Chérier ◽  
Delphine Patin ◽  
Didier Blanot ◽  
Thierry Touzé ◽  
Hélène Barreteau
Keyword(s):  
Pathogenic Bacteria ◽  
Current Knowledge ◽  
Antibacterial Properties ◽  
Multidrug Resistant ◽  
Public Health Issue ◽  
Sequence Alignments ◽  
Food Preservatives ◽  
E Coli ◽  
Lipid Ii ◽  
Colicin M

The misuse of antibiotics during the last decades led to the emergence of multidrug resistant pathogenic bacteria. This phenomenon constitutes a major public health issue. Consequently, the discovery of new antibacterials in the short term is crucial. Colicins, due to their antibacterial properties, thus constitute good candidates. These toxin proteins, produced by E. coli to kill enteric relative competitors, exhibit cytotoxicity through ionophoric activity or essential macromolecule degradation. Among the 25 colicin types known to date, colicin M (ColM) is the only one colicin interfering with peptidoglycan biosynthesis. Accordingly, ColM develops its lethal activity in E. coli periplasm by hydrolyzing the last peptidoglycan precursor, lipid II, into two dead-end products, thereby leading to cell lysis. Since the discovery of its unusual mode of action, several ColM orthologs have also been identified based on sequence alignments; all of the characterized ColM-like proteins display the same enzymatic activity of lipid II degradation and narrow antibacterial spectra. This publication aims at being an exhaustive review of the current knowledge on this new family of antibacterial enzymes as well as on their potential use as food preservatives or therapeutic agents.

scholarly journals Enterococci from Raw-Milk Cheeses: Current Knowledge on Safety, Technological, and Probiotic Concerns

Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2753
Author(s):  
Amarela Terzić-Vidojević ◽  
Katarina Veljović ◽  
Nikola Popović ◽  
Maja Tolinački ◽  
Nataša Golić
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Resistance Genes ◽  
Pathogenic Bacteria ◽  
Current Knowledge ◽  
Antibiotic Resistance Genes ◽  
Raw Milk ◽  
Starter Cultures ◽  
Food Preservatives ◽  
Hypocholesterolemic Action

The present study is focused on the safety, technological characteristics, and probiotic evaluation of Enterococcus species from different artisanal raw milk dairy products, mainly cheeses with ripening. Apart from proteolytic and lipolytic activities, most enterococci show the ability to metabolize citrate and convert it to various aromatic compounds. Long-ripened cheeses therefore have a specific flavor that makes them different from cheeses produced from thermally treated milk with commercial starter cultures. In addition, enterococci are producers of bacteriocins effective against spoilage and pathogenic bacteria, so they can be used as food preservatives. However, the use of enterococci in the dairy industry should be approached with caution. Although originating from food, enterococci strains may carry various virulence factors and antibiotic-resistance genes and can have many adverse effects on human health. Still, despite their controversial status, the use of enterococci in the food industry is not strictly regulated since the existence of these so-called desirable and undesirable traits in enterococci is a strain-dependent characteristic. To be specific, the results of many studies showed that there are some enterococci strains that are safe for use as starter cultures or as probiotics since they do not carry virulence factors and antibiotic-resistance genes. These strains even exhibit strong health-promoting effects such as stimulation of the immune response, anti-inflammatory activity, hypocholesterolemic action, and usefulness in prevention/treatment of some diseases.

scholarly journals Antimicrobial Activity of Metabolites Extracted from Marine Actinomycetes

2021 ◽  
Vol 14 (4) ◽  
pp. 1673-1679
Author(s):  
Jehan Alrahimi
Keyword(s):  
Antimicrobial Activity ◽  
Secondary Metabolites ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Chemical Compositions ◽  
Marine Actinomycetes ◽  
Biological Drugs ◽  
Soil System ◽  
New Antibiotics ◽  
Promising Source

Actinomycetes are free-living bacteria that are widely distributed and found in several habitats. These bacteria are essential organism in soil system, they contribute to agroindustry as the origin of active compounds. Their economical and biotechnological importance lies in the production of bioactive secondary metabolites including anticancer, insecticides, and antibiotic agents, such Actinomycetes–derived agents have been commonly used in both medical and industrial fields. Mainly, different Actinomycetes species isolated from coastal habitats are found to be novel sources of antibiotics. Thus, further investigating Actinomycetes will provide a better understanding of the physiological features and chemical composition of marine Actinomycetes. It also enables to use of large synthetic libraries of derived molecules (e.g., secondary metabolites) to develop biological drugs to combat advanced bacterial infections. Actinomycetes can produce more powerful biological compounds of medicinal and economic importance; moreover, it can provide insight into new antibiotics against different types of pathogens that cause infection to humans and support human health by overcoming complications caused by pathogenic bacteria and drug resistance. In particular, Actinomycetes of marine origin are a promising source of biomedical microbial products and natural products with an interesting microbial activity against many other pathogenic causing microorganisms. They are diverse in nature and have unique chemical compositions. During the past years, many new anti-microbial agents were discovered and deemed powerful therapeutic agents. The discovery of bioactive compounds continues to increase. However, the underlying potential of Actinomycetes has yet to be found. Therefore, this work conducts a review of the antimicrobial activity of metabolites extracted from marine Actinomycetes.

Amruthapala (Decalepis arayalpathra (J. Joseph and V. Chandras.) Venter): A Comprehensive Review on Diversity, Therapeutic Uses, and Valorization of Bioactive Constituents

2019 ◽  
Vol 20 (5) ◽  
pp. 376-389 ◽  
Author(s):  
Sonali Mishra ◽  
Nupur Srivastava ◽  
Velusamy Sundaresan ◽  
Karuna Shanker
Keyword(s):  
Secondary Metabolite ◽  
Current Knowledge ◽  
Experimental Studies ◽  
Critical Discussion ◽  
Future Research ◽  
Bioactive Constituents ◽  
Medicinal Uses ◽  
Comprehensive Review ◽  
Therapeutic Uses ◽  
Decalepis Arayalpathra

Background: Decalepis arayalpathra (J. Joseph and V. Chandras.) Venter is used primarily for nutrition besides its therapeutic values. Traditional preparations/formulations from its tuber are used as a vitalizer and blood purifier drink. The folklore medicinal uses cover inflammation, cough, wound healing, antipyretic, and digestive system management. A comprehensive review of the current understanding of the plant is required due to emerging concerns over its safety and efficacy. Objective: The systematic collection of the authentic information from different sources with the critical discussion is summarised in order to address various issues related to botanical identity, therapeutic medicine, nutritional usage, phytochemical, and pharmacological potentials of the D. arayalpathra. Current use of traditional systems of medicine can be used to expand future research opportunities. Materials and Methods: Available scripted information was collected manually, from peered review research papers and international databases viz. Science Direct, Google Scholar, SciFinder, Scopus, etc. The unpublished resources which were not available in database were collected through the classical books of ‘Ayurveda’ and ‘Siddha’ published in regional languages. The information from books, Ph.D. and MSc dissertations, conference papers and government reports were also collected. We thoroughly screened the scripted information of classical books, titles, abstracts, reports, and full-texts of the journals to establish the reliability of the content. Results: Tuber bearing vanilla like signature flavor is due to the presence of 2-hydroxy-4-methoxybenzaldehyde (HMB). Among five other species, Decalepis arayalpathra (DA) has come under the ‘critically endangered’ category, due to over-exploitation for traditional, therapeutic and cool drink use. The experimental studies proved that it possesses gastro-protective, anti-tumor, and antiinflammatory activities. Some efforts were also made to develop better therapeutics by logical modifications in 2-Hydroxy-4-methoxy-benzaldehyde, which is a major secondary metabolite of D. arayalpathra. ‘Amruthapala’ offers the enormous opportunity to develop herbal drink with health benefits like gastro-protective, anti-oxidant and anti-inflammatory actions. Results: The plant has the potential to generate the investigational new lead (IND) based on its major secondary metabolite i.e. 2-Hydroxy-4-methoxy-benzaldehyde. The present mini-review summarizes the current knowledge on Decalepis arayalpathra, covering its phytochemical diversity, biological potentials, strategies for its conservation, and intellectual property rights (IPR) status. Chemical Compounds: 2-hydroxy-4-methoxybenzaldehyde (Pubchem CID: 69600), α-amyrin acetate (Pubchem CID: 293754), Magnificol (Pubchem CID: 44575983), β-sitosterol (Pubchem CID: 222284), 3-hydroxy-p-anisaldehyde (Pubchem CID: 12127), Naringenin (Pubchem CID: 932), Kaempferol (Pubchem CID: 5280863), Aromadendrin (Pubchem CID: 122850), 3-methoxy-1,2-cyclopentanedione (Pubchem CID: 61209), p-anisaldehyde (Pubchem CID: 31244), Menthyl acetate (Pubchem CID: 27867), Benzaldehyde (Pubchem CID: 240), p-cymene (Pubchem CID: 7463), Salicylaldehyde (Pubchem CID: 6998), 10-epi-γ-eudesmol (Pubchem CID: 6430754), α -amyrin (Pubchem CID: 225688), 3-hydroxy-4-methoxy benzaldehyde (Pubchem CID: 12127).

Antimicrobial properties of actively purified secondary metabolites isolated from different marine organisms

2020 ◽  
Vol 21 ◽  
Author(s):  
Nilushi Indika Bamunu Arachchige ◽  
Fazlurrahman Khan ◽  
Young-Mog Kim
Keyword(s):  
Secondary Metabolites ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Bacterial Species ◽  
Antimicrobial Properties ◽  
Antimicrobial Effect ◽  
Cost Effective ◽  
Resistance Mechanisms ◽  
Marine Organisms ◽  
Antimicrobial Compounds

Background: The treatment of infection caused by pathogenic bacteria becomes one of the serious concerns globally. The failure in the treatment was found due to the exhibition of multiple resistance mechanisms against the antimicrobial agents. Emergence of resistant bacterial species has also been observed due to prolong treatment using conventional antibiotics. To combat these problems, several alternative strategies have been employed using biological and chemically synthesized compounds as antibacterial agents. Marine organisms considered as one of the potential sources for the isolation of bioactive compounds due to the easily available, cost-effective, and eco-friendly. Methods: The online search methodology was adapted for the collection of information related to the antimicrobial properties of marine-derived compounds. These compound has been isolated and purified by different purification techniques, and their structure also characterized. Furthermore, the antibacterial activities have been reported by using broth microdilution as well as disc diffusion assays. Results: The present review paper describes the antimicrobial effect of diverse secondary metabolites which are isolated and purified from the different marine organisms. The structural elucidation of each secondary metabolite has also been done in the present paper, which will help for the in silico designing of the novel and potent antimicrobial compounds. Conclusion: A thorough literature search has been made and summarizes the list of antimicrobial compounds that are isolated from both prokaryotic and eukaryotic marine organisms. The information obtained from the present paper will be helpful for the application of marine compounds as antimicrobial agents against different antibiotic-resistant human pathogenic bacteria.

Pharmacological Uses of the Plants Belonging to the Genus Commiphora

2020 ◽  
Vol 18 ◽  
Author(s):  
Subbiah Latha ◽  
Palanisamy Selvamani ◽  
Thangavelu Prabha
Keyword(s):  
Secondary Metabolites ◽  
Plant Species ◽  
Dna Cleavage ◽  
Structural Information ◽  
Chemical Constituents ◽  
Future Research ◽  
Pharmacological Properties ◽  
Chemical Structures ◽  
Indigenous Uses ◽  
Available Information

: Natural products have a unique place in the healthcare industry. The genus Commiphora emerged as a potential medicinal with huge benefits as evidenced through its use in various traditional and modern systems of medicine. Therefore, we aimed to prepare a concise review on the pharmacological activities and the indigenous uses of various plant species belonging to the genus Commiphora along with the structural information of various active botanical ingredients present in these plants based on the published literatures and scientific reports. To collect the various published literatures on Commiphora in various journals; to study and classify the available information on the pharmacological uses and chemical constituents; and to present the gathered information as a precise review to serve as a potential reference for future research. Pharmacological and phytochemical data on Commiphora plant species were collected from various journals, books, reference materials, websites including scientific databases, etc for compilation. This review article describes the various pharmacological properties of plants of Commiphora species viz., Anti-arthritic and anti-inflammatory, Anti-atherogenic, Antibacterial, Anti-coagulant, Anti-dicrocoeliasis, Anti-epileptic, Anti-fascioliasis, Anti-fungal, Anti-heterophyidiasis, Anti-hyper cholesterolemic, Anti-hyperlipidemic, Anti-hypothyroidism, Anti-obesity, Anti-osteoarthritic, Anti-osteoclastogenesis, Anti-oxidant, Anti-parasitic, Anti-pyretic, Anti-schistosomiasis, Anti-septic, Anti-thrombotic, Anti-ulcer, Cardioprotective, COX enzyme inhibitory, Cytotoxic /Anti-carcinogenic/Anti-cancer, DNA cleavage, Hypotensive, Inhibits lipid peroxidation, Inhibits NO and NO synthase production, Insecticidal, Local anesthetic, Molluscicidal, Smooth muscle relaxant, Tick repellent activities along with toxicity studies. Furthermore, the review also included various secondary metabolites isolated from various species of Commiphora genus along with their chemical structures serve as a ready resource for researchers. We conclude that the plant species belonging to the genus Commiphora possesses abundant pharmacological properties with a huge treasure of diverse secondary metabolites within themselves. This review indicates the necessity of further in-depth research, pre-clinical and clinical studies with Commiphora genus which may help to detect the unidentified potential of the Commiphora plant species.

Disparities in Health Between Black and White Americans: Current Knowledge and Directions for Future Research

2018 ◽  
pp. 456-478
Author(s):  
Thomas E. Fuller-Rowell ◽  
David S. Curtis ◽  
Adrienne M. Duke
Keyword(s):  
Health Disparities ◽  
Current Knowledge ◽  
Public Investment ◽  
The United States ◽  
Future Research ◽  
Sociocultural Factors ◽  
White Americans ◽  
Biological Mechanisms ◽  
Black And White ◽  
Racial Ethnic

Conceptual frameworks for racial/ethnic health disparities are abundant, but many have received insufficient empirical attention. As a result, there are substantial gaps in scientific knowledge and a range of untested hypotheses. Particularly lacking is specificity in behavioral and biological mechanisms for such disparities and their underlying social determinants. Alongside lack of political will and public investment, insufficient clarity in mechanisms has stymied efforts to address racial health disparities. Capitalizing on emergent findings from the Midlife in the United States (MIDUS) study and other longitudinal studies of aging, this chapter evaluates research on health disparities between black and white US adults. Attention is given to candidate behavioral and biological mechanisms as precursors to group differences in morbidity and mortality and to environmental and sociocultural factors that may underlie these mechanisms. Future research topics are discussed, emphasizing those that offer promise with respect to illuminating practical solutions to racial/ethnic health disparities.

scholarly journals Protocol for a systematic review on the experience of informal caregivers for people with a moderate to advanced dementia within a domestic home setting

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Charles James ◽  
Catherine Walshe ◽  
Katherine Froggatt
Keyword(s):  
Systematic Review ◽  
Negative Impact ◽  
Current Knowledge ◽  
Informal Caregivers ◽  
Informal Caregiving ◽  
Bibliographic Databases ◽  
Future Research ◽  
Advanced Dementia ◽  
Home Setting ◽  
Search Terms

Abstract Background The knowledge about the experience of informal caregivers who provide care to people with moderate to advanced dementia in a domestic home setting is limited. A consequence of long hours of caregiving in addition to dealing with normal challenges of daily living is their experience of a poor quality of life. Some of their experiences may be described in terms of a feeling of powerlessness to make changes during care provision. This feeling may also suggest an experience of moral distress. The aim of this systematic review is to synthesise qualitative evidence relating to these experiences. Methods This review adopts a narrative synthesis approach. A search will be conducted for studies written in the English language in the bibliographic databases MEDLINE Complete, CINAHL, EMBASE, PsycINFO, Web of Science and Academic Search Complete covering periods from 1984 to present. Included studies will be qualitative or mixed-methods designs. The search terms will be related to dementia and caregivers, and the process will be focused on dementia at the moderate to the advanced stages within the domestic home setting. Reference lists of included papers will also be searched for additional relevant citations. Search terms and strategies will be checked by two independent reviewers. The identification of abstracts and full texts of studies will be done by the author, while the quality and the risk of bias will also be checked by the two independent reviewers. Discussion Psychological distress is cited as an experience reported within informal caregiving. For the caregiver, it is associated with a negative impact on general health. To date, no synthesis exists on the specific experience of informal caregiving for people with moderate to advanced dementia within the domestic home setting. This review considers that variation of accounts contributes to how the informal caregivers’ general experience is explored in future research. This may enable gaps in current knowledge to be highlighted within the wider context of caregiving in the domestic home setting. Systematic review registration This review is registered with PROSPERO (CRD42020183649).

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