Anna Lavecchia - Academia.edu (original) (raw)

Papers by Anna Lavecchia

Applied and Environmental Microbiology, Jun 15, 2015

In order to identify antifungal compounds from natural sources to be used as ingredients in the b... more In order to identify antifungal compounds from natural sources to be used as ingredients in the bakery industry, water/salt-soluble extracts (WSE) from different legume flour hydrolysates obtained by the use of a fungal protease were assayed against Penicillium roqueforti DPPMAF1. The agar diffusion assays allowed the selection of the pea (Pisum sativum) hydrolysate as the most active. As shown by the hyphal radial growth rate, the WSE had inhibitory activity towards several fungi isolated from bakeries. The MIC of the WSE was 9.0 mg/ml. Fungal inhibition was slightly affected by heating and variations in pH. The antifungal activity was attributed to three native proteins (pea defensins 1 and 2 and a nonspecific lipid transfer protein [nsLTP]) and a mixture of peptides released during hydrolysis. The three proteins have been reported previously as components of the defense system of the plant. Five peptides were purified from WSE and were identified as sequences encrypted in leginsulin A, vicilin, provicilin, and the nsLTP. To confirm antifungal activity, the peptides were chemically synthesized and tested. Freeze-dried WSE were used as ingredients in leavened baked goods. In particular, breads made by the addition of 1.6% (wt/wt) of the extract and fermented by baker's yeast or sourdough were characterized for their main chemical, structural, and sensory features, packed in polyethylene bags, stored at room temperature, and compared to controls prepared without pea hydrolysate. Artificially inoculated slices of a bread containing the WSE did not show contamination by fungi until at least 21 days of storage and behaved like the bread prepared with calcium propionate (0.3%, wt/wt).

Biomolecules, Mar 28, 2024

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

Scientific Reports

Reproductive dysfunctions have been recently documented in male greater amberjack Seriola dumeril... more Reproductive dysfunctions have been recently documented in male greater amberjack Seriola dumerili caught from the wild and reared in captivity. In the present study, we compared testis transcriptome in wild fish (WILD), hatchery-produced fish with apparently normal spermatogenesis (Normal Farmed; NormalF) and hatchery-produced fish with evident reproductive dysfunction (Dysfunctional Farmed; DysF). Gene expression analysis identified 2157, 1985 and 74 differentially expressed genes (DEGs) in DysF vs WILD, NormalF vs DysF and NormalF vs WILD comparisons, respectively. In DysF, a dysregulation of several interconnected biological processes, including cell assembly, steroidogenesis and apoptosis was found. Gene enrichment of progesterone-mediated oocyte maturation, oocyte meiosis and cell cycle pathways were identified in the DysF vs NormalF comparison. Most of the DEGs involved in the enriched pathways were downregulated in DysF. The comparison of NormalF vs WILD showed that most of ...

Microbiome, Mar 7, 2024

Background Macroalgae, especially reds (Rhodophyta Division) and browns (Phaeophyta Division), ar... more Background Macroalgae, especially reds (Rhodophyta Division) and browns (Phaeophyta Division), are known for producing various halogenated compounds. Yet, the reasons underlying their production and the fate of these metabolites remain largely unknown. Some theories suggest their potential antimicrobial activity and involvement in interactions between macroalgae and prokaryotes. However, detailed investigations are currently missing on how the genetic information of prokaryotic communities associated with macroalgae may influence the fate of organohalogenated molecules. Results To address this challenge, we created a specialized dataset containing 161 enzymes, each with a complete enzyme commission number, known to be involved in halogen metabolism. This dataset served as a reference to annotate the corresponding genes encoded in both the metagenomic contigs and 98 metagenome-assembled genomes (MAGs) obtained from the microbiome of 2 red (Sphaerococcus coronopifolius and Asparagopsis taxiformis) and 1 brown (Halopteris scoparia) macroalgae. We detected many dehalogenation-related genes, particularly those with hydrolytic functions, suggesting their potential involvement in the degradation of a wide spectrum of halocarbons and haloaromatic molecules, including anthropogenic compounds. We uncovered an array of degradative gene functions within MAGs, spanning various bacterial orders such as Rhodobacterales, Rhizobiales, Caulobacterales, Geminicoccales, Sphingomonadales, Granulosicoccales, Microtrichales, and Pseudomonadales. Less abundant than degradative functions, we also uncovered genes associated with the biosynthesis of halogenated antimicrobial compounds and metabolites. Conclusion The functional data provided here contribute to understanding the still largely unexplored role of unknown prokaryotes. These findings support the hypothesis that macroalgae function as holobionts, where the metabolism of halogenated compounds might play a role in symbiogenesis and act as a possible defense mechanism against environmental chemical stressors. Furthermore, bacterial groups, previously never connected with organohalogen metabolism, e.g., Caulobacterales, Geminicoccales, Granulosicoccales, and Microtrichales, functionally characterized through MAGs reconstruction, revealed a biotechnologically relevant gene content, useful in synthetic biology, and bioprospecting applications.

Microbiology Resource Announcements, 2018

The genome sequences of three new strains of Staphylococcus arlettae named Bari1, Bari2, and Bari... more The genome sequences of three new strains of Staphylococcus arlettae named Bari1, Bari2, and Bari3 are presented. The strains exhibited tolerance to hexavalent chromium ions. An sprC gene encoding a putative chromium transporter was present in each of the three draft genome sequences.

Space Farming. Un ponte tra fantascienza e realtà dell’agricoltura del terzo millennio, 2013

Biology

Fire events in agricultural soils can modify not only soil properties but also the structure of s... more Fire events in agricultural soils can modify not only soil properties but also the structure of soil microbial communities, especially in soils containing high concentrations of potentially toxic elements (PTEs). The recolonization of burned soils can in fact favor the proliferation of certain microorganisms, more adaptable to post-fire soil conditions and higher PTE availability, over others. In this study, we simulated with laboratory experiments the microbial recolonization of an agricultural soil containing high Cr concentrations after heating at 500 °C for 30 min, to mimic the burning of crop residues. Changes in soil properties and Cr speciation were assessed, as well as soil microbial structure by means of 16S rRNA gene sequencing. Both altered soil conditions and increased Cr availability, especially Cr(VI), appeared to be responsible for the reduction in species diversity in heated soils and the proliferation of Firmicutes. Indeed, already after 3 days from the heat treatme...

Microorganisms

Coagulase Negative Staphylococci (CoNS) are becoming increasingly recognized as an important caus... more Coagulase Negative Staphylococci (CoNS) are becoming increasingly recognized as an important cause of human and animal infections. Notwithstanding their clinical relevance, annotation of genes potentially involved in pathogenicity and/or antibiotic resistance in the CoNS species Staphylococcus arlettae (SAR) is currently very limited. In the current work we describe the genome of a novel methicillin resistant isolate of SAR, which we named Bari, and present a comprehensive analysis of predicted antibiotic resistance profiles and virulence determinants for all the 22 currently available SAR genomes. By comparing predicted antibiotic resistance and virulence-associated genes with those obtained from a manual selection of 148 bacterial strains belonging to 14 different species of staphylococci and to two “outgroup” species, Bacillus subtilis (BS) and Macrococcus caseoliticus (MC), we derived some interesting observations concerning the types and number of antibiotic resistance-related ...

Soil Science

Wildfires are a driving factor of forest soils and their biota, especially in fire-prone ecosyste... more Wildfires are a driving factor of forest soils and their biota, especially in fire-prone ecosystems. Fire effects on soil microbial community are complex and still largely unknown. Greater knowledge is needed as fire frequency is expected to increase with human-induced climate change. This study aims at assessing the effects of a single moderately severe wildfire on microbial community diversity and activity in a Mediterranean forest soil by DNA molecular screening (polymerase chain reaction–denaturing gradient gel electrophoresis). For this purpose, the soil of a burned area was sampled 3 days and 10months after the fire and compared with the soil of an unburned contiguous area. For the DNA fingerprinting, we analyzed both extracellular and intracellular DNA fractions of the soil metagenome. The fire impact on soil was also rated in terms of selected enzyme activities, as reliable bioindicators of biogeochemical cycles. An immediate fire-induced general decrease in enzyme activities and more durable changes in the bacterial and fungal communities structure were found, although microbial biomass was not significantly affected. Litter layer was completely turned to char and ash by the fire, but after 10 months, it showed a fair amount of DNA, a structured microbial community, and a good enzymatic activity. Overall, such relatively fast recovery was likely caused by the microbial biomass that survived the fire, which evidently adapted to the new soil conditions.

Italian Journal of Forest and Mountain Environments, Sep 2, 2012

È noto a tutti come questo millennio abbia ereditato dal precedente diverse sfide ambientali che ... more È noto a tutti come questo millennio abbia ereditato dal precedente diverse sfide ambientali che devono urgentemente trovare una risposta a livello politico ed una soluzione a livello scientifico. La gran parte di tali sfide è dovuta all'opera dell'uomo la cui influenza sull'ambiente ha subìto dall'inizio dell'era industriale un'accelerazione esponenziale da diventare talmente rilevante che per caratterizzare questa era di dominio dell'uomo sul pianeta è stata coniata la definizione di "Antropocene". Un esempio è rappresentato dall'effetto serra con alterazione del clima a livello planetario che sta portando ad una pericolosa estremizzazione dei fenomeni atmosferici, con sempre più frequenti e prolungati periodi siccitosi (con elevato rischio di insorgenza di fenomeni di desertificazione e salinizzazione) alternati da eventi piovosi, sempre più spesso caratterizzati dall'essere di breve durata ma di tale intensità da ingenerare fenomeni di forte erosione, con frequenti frane, e di esondazione dei corsi d'acqua. Tali fenomeni ingenerano gravi fenomeni di dissesto idro-geologico che rappresentano ad oggi un serio problema in vaste aree del mondo, Italia compresa. Un ulteriore effetto dell'attività dell'uomo proviene dalla progressiva urbanizzazione ed utilizzazione per agricoltura intensiva di vaste aree che ingenerano anche rilevanti problematiche in termini di perdita di zone "verdi" (foreste), di biodiversità sia procariotica che eucariotica (erosione genetica), e di fertilità dei suoli. Da ricordare infine il progressivo inquinamento dell'aria, dell'acqua e del suolo che oltre a comportare notevoli rischi per la salute pubblica concorrono a ridurre fortemente la disponi

Biology and Fertility of Soils, 2015

Driven by growing desertification and increases in the global demand for food, the necessity to a... more Driven by growing desertification and increases in the global demand for food, the necessity to adopt sustainable fertilization and crop management systems have greatly increased. In dryland soils, certain crops such as sorghum could provide important advantages. The impact of 3 years of N-fertilization with two rates of compost amendment on the composition of bacterial community of a Mediterranean soil cropped to sorghum was evaluated. The composition of bacterial communities of rhizospheric soil samples fertilized by urea (CT) or compost at single (COM1) or double doses (COM2), were compared to that of the bacterial communities from unfertilized rhizospheric soil (UF) and grassland soil (GS) by pyrosequencing. The highest number of sequences and OTUs were associated with rhizosphere soils treated with the double dose compost amendment (COM2), and analysis of alpha diversity clearly indicated a higher richness of this treated soil than other soils. Of the 16 bacterial phyla observed, Actinobacteria and Proteobacteria dominated. Actinobacteria abundance was higher in both compost-amended soils (COM1 and COM2) and GS than other investigated soils; Proteobacteria had the opposite trend. Significant differences (P < 0.05) were detected among class compositions of treatments. Most of the screened families belonged to α-Proteobacteria class. Species level analysis showed that GS and COM2-treated soil presented the highest percentage of unique OTUs; for 8 of the 14 most abundant OTUs, significant differences (P < 0.05) were found among soils. A clear distinction of bacterial communities of soil under different fertilization managements was observed from weighted as well as unweighted PCoA plots. Results from this in depth analysis clearly indicated that organic fertilization by compost, more than chemical fertilization by urea, can affect the composition of bacterial communities inhabiting the sorghum rhizosphere when compared to unfertilized soil and grassland soil.

Applied and environmental microbiology, Jan 10, 2015

Aiming at identifying antifungal compounds from natural sources to be used as ingredients in the ... more Aiming at identifying antifungal compounds from natural sources to be used as ingredients in the bakery industry, water/salt-soluble extracts (WSE) from different legume flour hydrolysates obtained by the use of a fungal protease were assayed towards Penicillium roqueforti DPPMAF1. The agar diffusion assays allowed the selection of the pea (Pisum sativum) hydrolysate as the most active. As shown by hyphal radial growth rate, the WSE showed inhibition towards several fungi isolated from bakeries. The minimal inhibitory concentration (MIC) of the WSE was 9.0 mg/ml. Fungal inhibition was slightly affected by heating and variations of pH. The antifungal activity was attributed to three native proteins (pea Defensins 1 and 2, and a non-specific lipid transfer protein [nsLTP]) and a mixture of peptides, which was released during hydrolysis. The three proteins were previously reported as components of the defense system of the plant. Five peptides were purified from WSE and identified as s...

Genome Biology and Evolution

Staphylococcus cohnii (SC), a coagulase-negative bacterium, was first isolated in 1975 from human... more Staphylococcus cohnii (SC), a coagulase-negative bacterium, was first isolated in 1975 from human skin. Early phenotypic analyses led to the delineation of two subspecies (subsp.), Staphylococcus cohnii subsp. cohnii (SCC) and Staphylococcus cohnii subsp. urealyticus (SCU). SCC was considered to be specific to humans, whereas SCU apparently demonstrated a wider host range, from lower primates to humans. The type strains ATCC 29974 and ATCC 49330 have been designated for SCC and SCU, respectively. Comparative analysis of 66 complete genome sequences—including a novel SC isolate—revealed unexpected patterns within the SC complex, both in terms of genomic sequence identity and gene content, highlighting the presence of 3 phylogenetically distinct groups. Based on our observations, and on the current guidelines for taxonomic classification for bacterial species, we propose a revision of the SC species complex. We suggest that SCC and SCU should be regarded as two distinct species: SC an...

Soil Systems

The adoption of sewage sludge as an agricultural management strategy to improve soil properties a... more The adoption of sewage sludge as an agricultural management strategy to improve soil properties and crop production is attracting great interest. Despite many positive effects on soil inorganic and organic components reported for different soil types, little information is available on sewage sludge application on Mediterranean soils, as well as on its use at different dose rates. The objectives of the present research was to evaluate, through an integrated approach, the effects of sewage sludge compost from urban wastewater on physicochemical, hydrological, biochemical parameters, and microbiota composition in soil pots under a three-year crop rotation system. Four different doses of sewage sludge compost (C3, C6, C9, C12) from municipal wastewater and a dose of them in combination with mineral fertilizer (C6N) were used. We have used 3-6-9-12 Mg/ha of sewage sludge compost for the treatments C3, C6, C9 and C12, respectively, and 6 Mg/ha of sewage sludge compost in combination with...