Antagonistic Properties of Some Halophilic Thermoactinomycetes Isolated from Superficial Sediment of a Solar Saltern and Production of Cyclic Antimicrobial Peptides by the Novel Isolate<i> Paludifilum halophilum</i>

Dammak, Donyez Frikha; Zarai, Ziad; Najah, Soumaya; Abdennabi, Rayed; Belbahri, Lassaâd; Rateb, Mostafa E.; Mejdoub, Hafedh; Maâlej, Sami

doi:10.1155/2017/1205258

Cited by 16 publications

(8 citation statements)

References 56 publications

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“…Our results indicate that the number of keystone taxa affected by, or affecting other members in the microbial mat community within site B is equivalent, being the majority members of both RB and microbial mat core. An interesting example within these hubs is the family Thermoactinomycetaceae, which is known for its protein degradative capacities, strong lipolytic activity, and alpha-amylase activity, as well as antimicrobial activity ( Frikha Dammak et al, 2017 ).…”

Section: Resultsmentioning

confidence: 99%

Understanding the Mechanisms Behind the Response to Environmental Perturbation in Microbial Mats: A Metagenomic-Network Based Approach

et al. 2018

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To date, it remains unclear how anthropogenic perturbations influence the dynamics of microbial communities, what general patterns arise in response to disturbance, and whether it is possible to predict them. Here, we suggest the use of microbial mats as a model of study to reveal patterns that can illuminate the ecological processes underlying microbial dynamics in response to stress. We traced the responses to anthropogenic perturbation caused by water depletion in microbial mats from Cuatro Cienegas Basin (CCB), Mexico, by using a time-series spatially resolved analysis in a novel combination of three computational approaches. First, we implemented MEBS (Multi-genomic Entropy-Based Score) to evaluate the dynamics of major biogeochemical cycles across spatio-temporal scales with a single informative value. Second, we used robust Time Series-Ecological Networks (TS-ENs) to evaluate the total percentage of interactions at different taxonomic levels. Lastly, we utilized network motifs to characterize specific interaction patterns. Our results indicate that microbial mats from CCB contain an enormous taxonomic diversity with at least 100 phyla, mainly represented by members of the rare biosphere (RB). Statistical ecological analyses point out a clear involvement of anaerobic guilds related to sulfur and methane cycles during wet versus dry conditions, where we find an increase in fungi, photosynthetic, and halotolerant taxa. TS-ENs indicate that in wet conditions, there was an equilibrium between cooperation and competition (positive and negative relationships, respectively), while under dry conditions there is an over-representation of negative relationships. Furthermore, most of the keystone taxa of the TS-ENs at family level are members of the RB and the microbial mat core highlighting their crucial role within the community. Our results indicate that microbial mats are more robust to perturbation due to redundant functions that are likely shared among community members in the highly connected TS-ENs with density values close to one (≈0.9). Finally, we provide evidence that suggests that a large taxonomic diversity where all community members interact with each other (low modularity), the presence of permanent of low-abundant taxa, and an increase in competition can be potential buffers against environmental disturbance in microbial mats.

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Section: Resultsmentioning

confidence: 99%

Understanding the Mechanisms Behind the Response to Environmental Perturbation in Microbial Mats: A Metagenomic-Network Based Approach

et al. 2018

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“…In the present study, we targeted the isolation of actinomycetes because it produces about 70-80 % of the available natural antibiotics in the world. The chance is the discovery of strains of rare actinomycetes producing novel antimicrobial compounds [76].…”

Section: Antimicrobial Activitymentioning

confidence: 99%

Thermoflavimicrobium dichotomicum as a novel thermoalkaliphile for production of environmental and industrial enzymes

2019

Biointerface Res Appl Chem

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Thermoalkaliphilic actinomycetes enzymes have many important applications in many industrial, biotechnological and environmental aspects. So, the current study aimed to obtain the thermoalkali-enzymes producing actinomycetes. A novel thermoalkaliphilic actinomycete strain was isolated from Egyptian Siwa oasis and identified according to its morphological, physiological and biochemical characters as Thermoflavimicrobium dichotomicum. And then confirmed by phylogenetic analysis and the partial sequence was deposited in GenBank under accession number of KR011193 and name of Thermoflavimicrobium dichotomicum HwSw11. It could produce amylase, cellulase, lipase, pectinase and proteinase enzymes. Also, this strain exhibited anti-bacterial activities against P. aeruginosa and E. coli with inhibition zones of 14 and 20 mm, respectively. Consequently, it has antifungal activity against A. niger, A. flavus and Penicillium notatum with inhibition zones of 17, 14 and 14 mm, respectively. For that, it may be concluded that Thermoflavimicrobium dichotomicum HwSw11 as a novel thermoalkaliphile has a wide range of biological activities against a broad spectrum of pathogenic bacteria and fungi, in addition to produce many enzymes (amylase, cellulase, lipase, pectinase and proteinase). So, this isolate could be applied as manufactory for many industrial, biotechnological and environmental sectors.

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“…Actinobacteria are widely present in the rhizosphere of plants and produce various agro-active compounds. In the recent years, this group of bacteria, based on its high antimicrobial potential and its dominant saprophytic nature in the soil, has attracted much attention [ 15 ]. Actinobacteria promote plant growth by producing phytohormones (Indole Acetic Acid; IAA), siderophores and solubilizing phosphate.…”

Section: Introductionmentioning

confidence: 99%

Improvement of Medicago sativa Crops Productivity by the Co-inoculation of Sinorhizobium meliloti–Actinobacteria Under Salt Stress

et al. 2021

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Biotic and abiotic stresses are severely limiting plant production and productivity. Of notable importance is salt stress that not only limits plant growth and survival, but affects the soil fertility and threatens agricultural ecosystems sustainability. The problem is exacerbated in fragile arid and semi-arid areas where high evaporation, low precipitation and the use of salty water for irrigation is accelerating soil salinization. Legumes, considered very nutritious foods for people and providing essential nutrients for ecosystems are a fundamental element of sustainable agriculture. They can restore soil health by their ability to fix nitrogen in a symbiotic interaction with the rhizobia of the soil. However, salt stress is severely limiting productivity and nitrogen fixation ability in legumes. Plant growth-promoting rhizobacteria (PGPR) and mainly actinobacteria promote plant growth by producing phytohormones, siderophores, antibiotics and antifungal compounds, solubilizing phosphate and providing antagonism to phytopathogenic microorganisms. In addition, actinobacteria have beneficial effects on nodulation and growth of legumes. In this study, actinobacteria isolated from different niches and having PGP activities were used in co-inoculation experiments with rhizobia in Medicago sativa plants rhizosphere submitted to salt stress. The results indicate that drought- and salinity-tolerant Actinobacteria with multiple PGP traits can potentially increase alfalfa growth under saline conditions, in the presence or absence of symbiotic rhizobial bacteria. Actinobacteria discovered in this study can, therefore, be suitable biofertilizers in the formulation of agricultural products improving plant development, health and productivity in saline soils, a necessary alternative for modern agriculture and sustainable development.

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Antagonistic Properties of Some Halophilic Thermoactinomycetes Isolated from Superficial Sediment of a Solar Saltern and Production of Cyclic Antimicrobial Peptides by the Novel Isolate Paludifilum halophilum

Cited by 16 publications

References 56 publications

Understanding the Mechanisms Behind the Response to Environmental Perturbation in Microbial Mats: A Metagenomic-Network Based Approach

Understanding the Mechanisms Behind the Response to Environmental Perturbation in Microbial Mats: A Metagenomic-Network Based Approach

Thermoflavimicrobium dichotomicum as a novel thermoalkaliphile for production of environmental and industrial enzymes

Improvement of Medicago sativa Crops Productivity by the Co-inoculation of Sinorhizobium meliloti–Actinobacteria Under Salt Stress

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