Papers by Marika Pellegrini
Microorganisms for Sustainability
Plant Physiology and Biochemistry
Soil Systems
This study examines culturable diazotrophs and non-culturable bacteria found in the rhizospheres ... more This study examines culturable diazotrophs and non-culturable bacteria found in the rhizospheres and root pseudonodules of wild blackberry plants (Rubus ulmifolius) that dwell on an unmanaged calcareous nitrogen-deficient soil. The DNA was extracted from the nodules and rhizospheres, and 16S rRNA gene metabarcoding was carried out. The metagenome functions were predicted with bioinformatic approaches. The soil samples were analyzed for the physico-chemical properties. The culturable diazotrophs were isolated and evaluated for the biochemical and plant growth-promoting properties. The soil was classified as nutrient-depleted calcareous soil. The microbial communities of the nodules and rhizospheres showed marked differences. The Pseudomonadota was the nodules’ dominant phyla (90%), while the Actinobacteriota was the most abundant (63%) in the rhizospheres. Stenotrophomonas was the dominant genus (55%) in the nodules, while the Streptomyces genus was widely present (39%) in the rhizos...
Sustainability
The genetic diversity of 77 Trichoderma harzianum isolates collected from sunflower rhizosphere s... more The genetic diversity of 77 Trichoderma harzianum isolates collected from sunflower rhizosphere soils in Urmia, Khoy, and Salmas in West Azerbaijan province, Iran, was evaluated by using the Universal Rice Primer (URP) molecular marker. The DNA band pattern of the isolates was developed using seven primers of this marker. These primers produced 186 gene loci, out of which 182 loci were polymorphic. Accordingly, the genetic diversity of the isolates was calculated, and their kinship relations were determined by cluster analysis using the NTSYS software package. URP-6R had the highest marker index among the studied primers, followed by URP-1F, URP-4R, and URP-25F, implying their higher efficiency in discriminating between the isolates. The results showed that the URP marker could discriminate between isolates using macroscopic morphological characteristics, such as color and colony type, potential of pigment production in the culture medium, and colony growth rate. Furthermore, there ...
Scientific Reports
This study revealed how Bacteria and Archaea communities and their metabolic functions differed b... more This study revealed how Bacteria and Archaea communities and their metabolic functions differed between two groups of black deposits identified in gorge and cave environments. Scanning electron microscopy coupled with energy dispersive spectroscopy was used to analyse the presence of microbial biosignatures and the elemental composition of samples. Metabarcoding of the V3–V4 regions of 16S rRNA was used to investigate Bacteria and Archaea communities. Based on 16S rRNA sequencing results, PICRUSt software was used to predict metagenome functions. Micrographs showed that samples presented microbial biosignatures and microanalyses highlighted Mn concretions and layers on Al-Si surfaces. The 16S rRNA metabarcoding alpha-diversity metrics showed similar Simpson's and Shannon indices and different values of the Chao-1 index. The amplicon sequence variants (ASVs) analysis at the different taxonomic levels showed a diverse genera composition. However, the communities of all samples sha...
Sustainability
The present study aimed to characterize the genetic structure of Artemisia eriantha Ten. and the ... more The present study aimed to characterize the genetic structure of Artemisia eriantha Ten. and the diversity of the rhizosphere microbiota. Plant leaves and rhizosphere soils were sampled from three areas of Central Italy, namely Monte Corvo, Monte Portella (both from the Gran Sasso massif), and Monte Focalone (Majella massif). The plant samples were subjected to genetic structure analysis by amplified fragment length polymorphism (AFLP) markers. The microbiota from the rhizosphere soils was investigated by 16S rRNA gene metabarcoding. The within and among population variability was typical of outbreeding species. The AFLP polymorphisms revealed a marked closeness among plant populations collected in Monte Focalone and Monte Corvo, despite the geographical proximity of the latter with Monte Portella, a result confirmed by cluster, STRUCTURE, and discriminant analyses. 16S rRNA gene metabarcoding showed higher values of diversity for Monte Corvo (H, 5.7; Chao1, 445) and Monte Focalone ...
Biology
The present study explored the microbial diversity of black deposits found in the “Infernaccio” g... more The present study explored the microbial diversity of black deposits found in the “Infernaccio” gorge. X-ray Powdered Diffraction (XRPD) was used to investigate the crystallinity of the samples and to identify the minerals. Scanning electron microscope and energy-dispersive X-ray spectroscopy (SEM-EDS) were used to detect the bacterial imprints, analyze microbe–mineral interactions, and highlight the chemical element distribution in the black deposits. 16S rRNA gene metabarcoding allowed the study of Archaea and Bacteria communities. Mn-oxide-solubilizing isolates were also obtained and characterized by culturable and molecular approaches. The multidisciplinary approach showed the occurrence of deposits composed of birnessite, diopside, halloysite, and leucite. Numerous bacterial imprints confirmed the role of microorganisms in forming these deposits. The Bacteria and Archaea communities associated with these deposits and runoff waters are dynamic and shaped by seasonal changes. The...
Frontiers in Microbiology
This study aimed to estimate the green formation lampenflora of “Stiffe” caves in order to evalua... more This study aimed to estimate the green formation lampenflora of “Stiffe” caves in order to evaluate their suitability as an isolation source of cyanobacteria useful for the production of polyhydroxyalkanoates (PHAs). The cave system was chosen as the sampling site due to its touristic use and the presence of high-impact illuminations. The biofilms and the mats of the illuminated walls were sampled. Samples were investigated by 16S rRNA gene analysis and culturable cyanobacteria isolation. The isolated strains were then screened for the production of PHAs under typical culturing and nutritional starvation. Cultures were checked for PHA accumulation, poly-β-hydroxybutyrate (PHB) presence (infrared spectroscopy), and pigment production. The 16S rRNA gene metabarcoding. Highlighted a considerable extent of the pressure exerted by anthropogenic activities. However, the isolation yielded eleven cyanobacteria isolates with good PHA (mainly PHB)-producing abilities and interesting pigment p...
The 1st International Electronic Conference on Plant Science, 2020
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Next Generation Sequencing Results of Grotta Grande dei Cervi black patinas.
In the present work, <i>Cannabis sativa</i> L. cv Futura 75 inflorescences, cultivate... more In the present work, <i>Cannabis sativa</i> L. cv Futura 75 inflorescences, cultivated in the Abruzzo territory, were characterized for their volatile fraction through SPME-GC-MS. In addition, the essential oil extracted from these inflorescences was investigated for the antioxidant potentialities and for the terpenic profile. The antibacterial activity of hemp essential oil (HEO) against some pathogenic and spoilage microorganisms isolated from food was also evaluated by determining the minimal inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). The results showed significant antioxidant capacity (DPPH: 63.38 ± 0.08 mg TE/g HEO; FRAP: 438.52 ± 6.92 mg TE/g HEO) alongside good antibacterial activity against Gram-positive bacteria such as <i>S. aureus</i> and <i>L. monocytogenes</i> (MIC 1.25-5 µL/mL). The results obtained suggest that hemp essential oil can inhibit or reduce bacterial growth, also exerting antioxidant ...
Microorganisms, 2022
The environmental conditions of caves shape microbiota. Within caves’ microbial communities, acti... more The environmental conditions of caves shape microbiota. Within caves’ microbial communities, actinomycetes are among the most abundant bacteria. Cave actinomycetes have gained increasing attention during the last decades due to novel bioactive compounds with antibacterial, antioxidant and anticancer activities. However, their potential role in soil environments is still unknown. This review summarises the literature dealing with actinomycetes from caves, underlining for the first time their potential roles in soil environments. We provide an overview of their diversity and biotechnological properties, underling their potential role in soil environments applications. The contribution of caves’ actinomycetes in soil fertility and bioremediation and crops biostimulation and biocontrol are discussed. The survey on the literature show that several actinomycetes genera are present in cave ecosystems, mainly Streptomyces, Micromonospora, and Nocardiopsis. Among caves’ actinomycetes, Strept...
Plant Sociology, 2020
Artemisia eriantha Ten., also known as "Apennines genepì", is a valuable aromatic plant... more Artemisia eriantha Ten., also known as "Apennines genepì", is a valuable aromatic plant with several medicinal properties. Among the several phytoplasma symptoms to which this plant can be subjected, the fasciation is one of the less reported and studied. In natural environments this plant is a characteristic species of the association Artemisietum erianthaeBrullo 1984. In this study, the first occurrence of fasciation in Artemisia eriantha is described. This phenomenon was observed during the ex vitro experimental cultivations, located in Assergi and Barisciano (L’Aquila, Italy), settled for the restocking of this endangered species. The fasciation occurred only in Assergi experimental field with a magnitude of 0.12%. Specific PCR analysis did not show the phytoplasma presence. This fist report allows to expand knowledge about fasciation in Apennines genepì.
Frontiers in Earth Science, 2021
The terrestrial subsurface offers privileged sites both to search for microbial life and to obser... more The terrestrial subsurface offers privileged sites both to search for microbial life and to observe still mostly unknown characteristic lithologies. In particular, caves represent natural laboratories to investigate unique minerogenetic processes and biotic interactions, connected to these phenomena. Manganese mineralization in cave environments provides a window to understand the complex Mn cycle and the development of microbial communities in special conditions, such as low constant temperature, absence of light and, in particular, low-energy environments. In the current study, we isolated and characterized Mn-samples taken from the cave “Grotta Grande dei Cervi,” L’Aquila, Central Italy, and we used a multidisciplinary approach to characterize them, with the purpose of understanding the biogeochemical processes in extreme environments. A chemical characterization of the samples was done by EDS; further investigations are underway with other multidisciplinary methodologies to unde...
Applied Sciences, 2021
The present work aimed to study suitability of a consortium of Azospirillum brasilense, Gluconace... more The present work aimed to study suitability of a consortium of Azospirillum brasilense, Gluconacetobacter diazotrophicus, Herbaspirillum seropedicae, and Burkholderia ambifaria as biofertilizers. Strains were assayed for plant growth-promoting characteristics (i.e., auxins production, phosphate solubilizing capability, and 1-aminocyclopropane-1-carboxylate deaminase activity). The consortium of four bacteria was then inoculated on carrot seeds and tested in an open field experiment. During the open field experiment, plant growth (morphological parameters, chlorophylls, and carotenoids), soil chemical analysis, and molecular and physiological profiles of soils were investigated. Each strain produced different amounts of indole-3acetic acid and several indole-derivates molecules. All strains showed phosphate solubilization capability, while 1-aminocyclopropane-1-carboxylate deaminase activity was only detected in H. seropedicae and B. ambifaria. The bacterial consortium of the four st...
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Papers by Marika Pellegrini