scholarly journals A Review on Mangrove Actinobacterial Diversity: The Roles of Streptomyces and Novel Species Discovery

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Jodi Woan-Fei Law ◽  
Priyia Pusparajah ◽  
Nurul-Syakima Ab Mutalib ◽  
Sunny Hei Wong ◽  
Bey-Hing Goh ◽  
...  

In the class Actinobacteria, the renowned genus Streptomyces comprised of a group of uniquely complex bacteria that capable of synthesizing a great variety of bioactive metabolites. Streptomycetes are noted to possess several special qualities such as multicellular life cycle and large linearized chromosomes. The significant contribution of Streptomyces in microbial drug discovery as witnessed through the discovery of many important antibiotic drugs has undeniably encourage the exploration of these bacteria from different environments, especially the mangrove environments. This review emphasizes on the genus Streptomyces and reports on the diversity of actinobacterial population from mangroves at different regions of the world as well as discovery of mangrove-derived novel Streptomyces species. Overall, the research on diversity of Actinobacteria in the mangrove environments remains limited. A total of 19 novel Streptomyces spp. isolated from mangroves between the year 2009 - early 2019, notably from China, India, Malaysia, and Thailand. Hence, it will be worthwhile to encourage the study of these bacteria from mangroves of different locations.

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 588
Author(s):  
Kunjukrishnan Kamalakshi Sivakala ◽  
Karina Gutiérrez-García ◽  
Polpass Arul Jose ◽  
Thangadurai Thinesh ◽  
Rangasamy Anandham ◽  
...  

Searching for new bioactive metabolites from the bacterial genus Streptomyces is a challenging task. Combined genomic tools and metabolomic screening of Streptomyces spp. native to extreme environments could be a promising strategy to discover novel compounds. While Streptomyces of desertic origin have been proposed as a source of new metabolites, their genome mining, phylogenetic analysis, and metabolite profiles to date are scarcely documented. Here, we hypothesized that Streptomyces species of desert environments have evolved with unique biosynthetic potential. To test this, along with an extensive characterization of biosynthetic potential of a desert isolate Streptomyces sp. SAJ15, we profiled phylogenetic relationships among the closest and previously reported Streptomyces of desert origin. Results revealed that Streptomyces strains of desert origin are closer to each other and relatively distinct from Streptomyces of other environments. The draft genome of strain SAJ15 was 8.2 Mb in size, which had 6972 predicted genes including 3097 genes encoding hypothetical proteins. Successive genome mining and phylogenetic analysis revealed the presence of putative novel biosynthetic gene clusters (BGCs) with low incidence in another Streptomyces. In addition, high-resolution metabolite profiling indicated the production of arylpolyene, terpenoid, and macrolide compounds in an optimized medium by strain SAJ15. The relative abundance of different BGCs in arid Streptomyces differed from the non-arid counterparts. Collectively, the results suggested a distinct evolution of desert Streptomyces with a unique biosynthetic potential.


2016 ◽  
Vol 106 (2) ◽  
pp. 123-131 ◽  
Author(s):  
Joanna K. Fyans ◽  
Luke Bown ◽  
Dawn R. D. Bignell

Potato common scab (CS) is an economically important crop disease that is caused by several members of the genus Streptomyces. In this study, we characterized the plant-pathogenic Streptomyces spp. associated with CS-infected potato tubers harvested in Newfoundland, Canada. A total of 17 pathogenic Streptomyces isolates were recovered from potato scab lesions, of which eight were determined to be most similar to the known CS pathogen S. europaeiscabiei. All eight S. europaeiscabiei isolates were found to produce the thaxtomin A phytotoxin and to harbor the nec1 virulence gene, and most also carry the putative virulence gene tomA. The remaining isolates appear to be novel pathogenic species that do not produce thaxtomin A, and only two of these isolates were determined to harbor the nec1 or tomA genes. Of the non-thaxtomin-producing isolates, strain 11-1-2 was shown to exhibit a severe pathogenic phenotype against different plant hosts and to produce a novel, secreted phytotoxic substance. This is the first report documenting the plant-pathogenic Streptomyces spp. associated with CS disease in Newfoundland. Furthermore, our findings provide further evidence that phytotoxins other than thaxtomin A may also contribute to the development of CS by Streptomyces spp.


2016 ◽  
Vol 22 ◽  
pp. 21-29
Author(s):  
FO Ekundayo ◽  
KA Oyeniran ◽  
AD Adedokun

Context: Streptomyces are potential sources for secondary metabolites possessing a variety of biological activities with antimicrobial activity, which is used for human and animal treatment. It is estimated these bacteria synthesize more than 7,000 metabolites. About 80% of these are made by members of the genus Streptomyces. Streptomyces spp. is known as producers of several bioactive metabolites which has antibiotic, antiparasitic, antitumor, insecticide, herbicide, etc.Objectives: Determine the antimicrobial activities of Streptomyces isolates and compare the efficacy of the antimicrobial activities of Streptomycetes with selected commercial antimicrobial agents.Materials and methods: Collection of samples and test organisms; physicochemical screening; antimicrobial assay (co-culture method); antibiotics sensitivity test (disc-diffusion assay).Result: Streptomyces griseoflavus, Streptomyces parvus and Streptomyces albidus were isolated from dry soil while Streptomyces vinaceus and Streptomyces globiosporus from moist-fresh soil and fish pond water used for cultivation of cat fish Clarias garienpinus respectively. Out of these five (5) isolates isolated, 3 isolates (60%) exhibited antibacterial activity against the following pathogenic, nosocomial organisms: Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Pseudomonas aeruginosa, Staphylococcus aureus, Candida spp, Aspergillus fumigatus, Aspergillus flavus, Aspergillus saprophyticus, and Trichoderma spp respectively. S. griseoflavus demonstrated antibacterial activity against K. pneumoniae, Trichoderma spp and Candida spp. S. albidus against S. typhi and A. fumigatus while S. parvus was inhibitory to S. aureus and A. fumigatus. The active isolates inhibited bacteria growth (0 to 39.33 mm). Commercial antimicrobials used also demonstrated inhibitory effects against the test pathogens.Conclusion: The garden soil of FUTA farm contains Streptomyces spp. with antibacterial and antifungal activities.J. bio-sci. 22: 21-29, 2014


2020 ◽  
pp. 13-22
Author(s):  
Saifudin Asrori ◽  
Ahmad Syauqi

Abstract. The Islamic education, Islamic boarding schools and madrasas, have made a very significant contribution to the implementation of education and social reform. Through the teaching process, in which the kyai as the main figure and the use of the ‘yellow book’, traditional Islamic ideas colored the early days of growing awareness as a nation and a State. When the New Order government carried out the development and modernization of society, there was a revival of a Muslim group called the “new middle class santri”, which took place in line with the modernization that occurred in the traditional Islamic educational institutions of the pesantren. Then in the era of democratization, the world of Islamic education experienced growth and development in various religious institutions and styles. Most of the pesantren are still committed to maintaining a moderate religious style, recognized as the foundation for the development of civil society and the formation of a ‘distinctive’, friendly, moderate, and tolerant social-political identity of Indonesian society. The Muslim character is different from other regions, especially the Middle East which is the axis of the Islamic world. However, a small proportion of pesantren are thought to promote the growth of religious chauvinism, teach a ‘narrow’ interpretation of Islam and provide a framework of thought and action in responding to socio-political change which often takes the form of a ‘jihad’. This article tries to explore the contribution of Islamic education to social change in the Indonesian Muslim community. Abstark. Dunia pendidikan Islam, pesantren dan madrasah, memberikan kontribusi sangat berarti dalam penyelenggaraan pendidikan dan reformasi kemasyarakatan. Melalui proses pengajaran, di mana kyai sebagai figur utama dan penggunaan ‘kitab kuning’, gagasan Islam tradisional mewarnai masa-masa awal tumbuhnya kesadaran sebagai bangsa dan Negara. Ketika pemerintah Orde Baru melakukan pembangunan dan modernisasi masyarakat, terjadi kebangkitan kelompok Muslim yang di sebut “kelas menengah santri baru”, berlangsung sejalan dengan modernisasi yang terjadi dalam lembaga pendidikan Islam tradisional pesantren. Kemudian pada era demokratisasi, dunia pendidikan Islam mengalami pertumbuhan dan perkembangan dalam beragam kelembagaan dan corak keagamaan. Sebagian besar pesantren masih tetap istiqomah dalam mempertahankan corak keagamaan yang moderat, diakui sebagai pondasi berkembangnya masyarakat sipil dan pembentukan identitas sosial-politik masyarakat Indonesia yang ‘khas’, ramah, moderat, dan toleran. Karakter Muslim yang berbeda dengan kawasan lainnya, khususnya Timur-Tengah yang merupakan poros dunia Islam. Namun ada sebagian kecil pesantren dianggap mendorong tumbuhnya chauvinisme keagamaan, mengajarkan penafsiran Islam yang ‘sempit’ dan memberikan kerangka pemikiran dan aksi dalam merespons perubahan sosial-politik yang seringkali berbentuk panggilan ‘jihad’. Artikel ini mencoba mengeksplorasi kontribusi pendidikan Islam dalam perubahan sosial masyarakat Muslim Indonesia.


2020 ◽  
Author(s):  
Iúri Novaes Luna ◽  
Valéria De Bettio Mattos

This book, comprised of 13 chapters, presents papers which discuss the processes related to the career along one’s life cycle, from adolescents’ professional choices until processes of retirement. Notwithstanding the diversity of life and work contexts, present in the different chapters, they all somewhat correspond in their central purpose, presenting both perspectives and challenges related to contemporary career interventions. Some chapters address themes that are still seldom explored in national literature, while others discuss subjects that are long established in the area, however they are innovative. The authors study them in the context of changes in the world of work in the second decade of the 21st century, of the new career models and psychosocial processes that are linked to human development throughout life. The studies and practices in vocational guidance, career development and retirement, included in this book, are the results of research and practice in recent years carried out by professionals, professors and academics that in different ways have collaborated with the activities of LIOP - Laboratory of Information and Professional Guidance, at the Federal University of Santa Catarina.


Author(s):  
Rajesh Kumar ◽  
Seetha Harilal ◽  
Abdullah G. Al-Sehemi ◽  
Githa Elizabeth Mathew ◽  
Simone Carradori ◽  
...  

: COVID-19, an epidemic that emerged in Wuhan, has become a pandemic affecting worldwide and is in a rapidly evolving condition. Day by day, the confirmed cases and deaths are increasing many folds. SARS-CoV-2 is a novel virus; therefore, limited data are available to curb the disease. Epidemiological approaches, isolation, quarantine, social distancing, lockdown, and curfew are being employed to halt the spread of the disease. Individual and joint efforts all over the world are producing a wealth of data and information which are expected to produce therapeutic strategies against COVID-19. Current research focuses on the utilization of antiviral drugs, repurposing strategies, vaccine development as well as basic to advanced research about the organism and the infection. The review focuses on the life cycle, targets, and possible therapeutic strategies, which can lead to further research and development of COVID-19 therapy.


2020 ◽  
Vol 10 (9) ◽  
pp. 3399-3402 ◽  
Author(s):  
Dae-Kyum Kim ◽  
Jennifer J Knapp ◽  
Da Kuang ◽  
Aditya Chawla ◽  
Patricia Cassonnet ◽  
...  

Abstract The world is facing a global pandemic of COVID-19 caused by the SARS-CoV-2 coronavirus. Here we describe a collection of codon-optimized coding sequences for SARS-CoV-2 cloned into Gateway-compatible entry vectors, which enable rapid transfer into a variety of expression and tagging vectors. The collection is freely available. We hope that widespread availability of this SARS-CoV-2 resource will enable many subsequent molecular studies to better understand the viral life cycle and how to block it.


2008 ◽  
Vol 41 (2) ◽  
pp. 437-460 ◽  
Author(s):  
Olena Nikolayenko

Abstract. Regime change in Eastern Europe affords an excellent opportunity for investigating linkages between age and politics in times of social turmoil. Using data from three waves of the World Values Survey, this paper explores life cycle, generational and period effects on protest potential in Yeltsin's Russia. The study finds that an individual's position in the life cycle is the strongest predictor of protest potential in the post-communist state. Furthermore, the analysis suggests that citizens socialized during periods of relative socioeconomic stability exhibit the highest protest potential under conditions of uncertainty characteristic of the transition period.Résumé. Les changements de régime en Europe de l'Est permettent d'examiner la relation complexe entre l'âge et la politique pendant les périodes d'instabilité sociale. S'appuyant sur les données de trois vagues du World Values Survey (sondage mondial sur les valeurs), cet article explore l'incidence du cycle de vie, de la génération et de la période sur le potentiel protestataire dans la Russie d'Eltsine. L'étude démontre que la position de l'individu dans le cycle de vie est le plus puissant facteur de prédiction du potentiel protestataire dans la société postcommuniste. En outre, les citoyens socialisés pendant des périodes de relative stabilité socio-économique présentent le potentiel protestataire le plus élevé dans des conditions d'incertitude caractéristiques de la période de transition.


Antibiotics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 22
Author(s):  
Nasim Safaei ◽  
Yvonne Mast ◽  
Michael Steinert ◽  
Katharina Huber ◽  
Boyke Bunk ◽  
...  

Antibiotic producers have mainly been isolated from soil, which often has led to the rediscovery of known compounds. In this study, we identified the freshwater snail Physa acuta as an unexplored source for new antibiotic producers. The bacterial diversity associated with the snail was characterized by a metagenomic approach using cultivation-independent high-throughput sequencing. Although Actinobacteria represented only 2% of the bacterial community, the focus was laid on the isolation of the genus Streptomyces due to its potential to produce antibiotics. Three Streptomyces strains (7NS1, 7NS2 and 7NS3) were isolated from P. acuta, and the antimicrobial activity of the crude extracts were tested against a selection of Gram-positive and Gram-negative bacteria and fungi. 7NS3 showed the strongest activity against Gram-positive bacteria and, thus, was selected for genome sequencing and a phylogenomic analysis. 7NS3 represents a novel Streptomyces species, which was deposited as Streptomyces sp. DSM 110735 at the Leibniz Institute-German Collection of Microorganisms and Cell Cultures (DSMZ). Bioassay-guided high-performance liquid chromatography (HPLC) and high-resolution electrospray ionization-mass spectrometry (HR-ESI-MS) analyses of crude extract fractions resulted in the detection of four compounds, one of which matched the compound characteristics of emycin A, an angucycline-like aromatic polyketide. Genome mining studies based on the whole-genome sequence of 7NS3 resulted in the identification of a gene cluster potentially coding for emycin A biosynthesis. Our study demonstrates that freshwater snails like P. acuta can represent promising reservoirs for the isolation of new antibiotic-producing actinobacterial species.


Sign in / Sign up

Export Citation Format

Share Document