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Papers by Alessio Giacomini

Journal of Applied Microbiology

AimComprehensive evaluation of antibiotic susceptibility patterns in Lactiplantibacillus plantaru... more AimComprehensive evaluation of antibiotic susceptibility patterns in Lactiplantibacillus plantarum strains isolated from grape marc, based on genomic and phenotypic assessment.Methods and resultsWe assessed the antibiotic resistance-susceptibility patterns of 20 L. plantarum strains for 16 antibiotics. Genomes of relevant strains were sequenced for in silico assessment and comparative genomic analysis. Results showed high MIC values for spectinomycin, vancomycin, and carbenicillin, indicating natural resistance to these antibiotics. Besides, these strains revealed MIC values for ampicillin higher than previously established by the EFSA, indicating the possible presence of acquired resistance genes in the genomes. However, genomic analysis by complete genome sequencing did not reveal presence of ampicillin resistance genes.ConclusionComparative genomic analysis between our strains and other L. plantarum genomes present in the literature showed several substantial genomic differences,...

Foods

Starmerella bacillaris is a non-Saccharomyces yeast proposed for must fermentation together with ... more Starmerella bacillaris is a non-Saccharomyces yeast proposed for must fermentation together with Saccharomyces cerevisiae because of its high glycerol and moderate volatile acidity production. Furthermore, it was demonstrated that the same S. bacillaris strains that possess interesting technological properties exhibited antifungal activity against Botrytis cinerea, suggesting the release of this yeast in the vineyard. To obtain a positive effect during the following winemaking process, the maintenance of suitable concentrations of S. bacillaris is essential. Therefore, to obtain information on the survival of S. bacillaris, a small-scale field trial was performed. One week before the harvest, two different concentrations of S. bacillaris (106 and 107 cells/mL) were sprayed on Pinot grigio bunches, and the strain concentration was monitored by means of qPCR during the subsequent fermentation process. In addition, the combined effect of different winemaking techniques was evaluated, i...

Agriculture

This paper is a microbiological voyage throughout the main discoveries and research activities of... more This paper is a microbiological voyage throughout the main discoveries and research activities of scholars who studied or taught in this field at Padova University during its 800-year history. The ancient practice of variolization, the so-called miracle of Legnaro and the pellagra debate, whose observations and investigations were driven at Padova even before microbiology was established as a scientific discipline, along with the modern era research activities in the field of agricultural, environmental and food microbiology, undoubtedly suggest the hallmark and everyday role played by microbes in overwhelmingly global, but profoundly human, adventures.

Scientific Reports

The main objective of this study was to assess the microbiota diversity in milk samples collected... more The main objective of this study was to assess the microbiota diversity in milk samples collected from Holstein cows with different estimated breeding values for predicted feed efficiency, milk coagulation, resilience to mastitis, and consequently, to study its effects on milk quality. One hundred and twenty milk samples were collected in two seasons (summer and winter) from different commercial dairy farms in the Nord-east of Italy. For each trait, 20 animals divided into two groups of the high (10 cows) and the low (10 cows) were selected to study the microbiota profile using 16S rRNA metabarcoding sequencing. The alpha and beta diversity analysis revealed significant differences between the high and the low groups for feed efficiency and resilience to mastitis, while no significant difference was detected for milk coagulation. Moreover, remarkable differences among the taxa were detected between the two seasons, where the winter was more diverse than summer when applied the Chao1...

Gli Oli essenziali: applicazioni nei settori agroalimentare, agronomico,delle produzioni animali e della medicina veterinaria, 2017

PLOS ONE, 2021

Generally, endospore contamination can occur from different sources during product manufacturing ... more Generally, endospore contamination can occur from different sources during product manufacturing in many industries and therefore lower its quality by affecting physicochemical properties and shelf-life. Bacterial endospores can germinate inside the product and produce several enzymes, which can cause several undesirable changes. This study assessed the spores thermal resistance and applied a microwave decontamination technique toward herbal extracts (Tilia tomentosa and Centella asiatica) containing ethanol or glycerol. Based on 16S rRNA analysis, the detected contaminant endospores belonged to different Bacillus species, namely B. subtilis, B. zhangzhouensis, and B. pumilus. The thermal resistance assessment using inoculated endospores in the actual products revealed B. pumilus T2 as the most resistant endospore to the heat treatments tested in both T. tomentosa and C. asiatica extracts. Finally, a high-performance microwave technique was used to decontaminate T. tomentosa extract...

Riassunto Un programma di selezione di lieviti per l’enologia prevede il reperimento di un vasto ... more Riassunto Un programma di selezione di lieviti per l’enologia prevede il reperimento di un vasto numero di ceppi da un determinato ambiente da sottoporre a test di identificazione e a varie prove per verificarne le attitudini enologiche. Nel caso di lieviti “ecotipici”, dove la popolazione microbica isolata è rappresentativa di una determinata area di produzione vitivinicola, sono di particolare importanza la biodiversità genetica, la provenienza geografica degli isolati e “l’attitudine alla tipicità” dei ceppi raccolti. Nel corso dei progetti di selezione di lieviti ecotipici condotti nelle aree di produzione delle DOC venete “Conegliano-Valdobbiadene”, “Piave” e “Lison-Pramaggiore”, sono stati collezionati lieviti da grappoli, fermentati singolarmente in laboratorio, di vitigni a bacca bianca (Prosecco e Tocai Lison) e a bacca nera (Raboso), in zone geograficamente distinte e differenti per caratteristiche geofisiche e di urbanizzazione. La caratterizzazione genetica e tecnologica...

Journal of Applied Microbiology

AimComprehensive evaluation of antibiotic susceptibility patterns in Lactiplantibacillus plantaru... more AimComprehensive evaluation of antibiotic susceptibility patterns in Lactiplantibacillus plantarum strains isolated from grape marc, based on genomic and phenotypic assessment.Methods and resultsWe assessed the antibiotic resistance-susceptibility patterns of 20 L. plantarum strains for 16 antibiotics. Genomes of relevant strains were sequenced for in silico assessment and comparative genomic analysis. Results showed high MIC values for spectinomycin, vancomycin, and carbenicillin, indicating natural resistance to these antibiotics. Besides, these strains revealed MIC values for ampicillin higher than previously established by the EFSA, indicating the possible presence of acquired resistance genes in the genomes. However, genomic analysis by complete genome sequencing did not reveal presence of ampicillin resistance genes.ConclusionComparative genomic analysis between our strains and other L. plantarum genomes present in the literature showed several substantial genomic differences,...

Foods

Starmerella bacillaris is a non-Saccharomyces yeast proposed for must fermentation together with ... more Starmerella bacillaris is a non-Saccharomyces yeast proposed for must fermentation together with Saccharomyces cerevisiae because of its high glycerol and moderate volatile acidity production. Furthermore, it was demonstrated that the same S. bacillaris strains that possess interesting technological properties exhibited antifungal activity against Botrytis cinerea, suggesting the release of this yeast in the vineyard. To obtain a positive effect during the following winemaking process, the maintenance of suitable concentrations of S. bacillaris is essential. Therefore, to obtain information on the survival of S. bacillaris, a small-scale field trial was performed. One week before the harvest, two different concentrations of S. bacillaris (106 and 107 cells/mL) were sprayed on Pinot grigio bunches, and the strain concentration was monitored by means of qPCR during the subsequent fermentation process. In addition, the combined effect of different winemaking techniques was evaluated, i...

Agriculture

This paper is a microbiological voyage throughout the main discoveries and research activities of... more This paper is a microbiological voyage throughout the main discoveries and research activities of scholars who studied or taught in this field at Padova University during its 800-year history. The ancient practice of variolization, the so-called miracle of Legnaro and the pellagra debate, whose observations and investigations were driven at Padova even before microbiology was established as a scientific discipline, along with the modern era research activities in the field of agricultural, environmental and food microbiology, undoubtedly suggest the hallmark and everyday role played by microbes in overwhelmingly global, but profoundly human, adventures.

Scientific Reports

The main objective of this study was to assess the microbiota diversity in milk samples collected... more The main objective of this study was to assess the microbiota diversity in milk samples collected from Holstein cows with different estimated breeding values for predicted feed efficiency, milk coagulation, resilience to mastitis, and consequently, to study its effects on milk quality. One hundred and twenty milk samples were collected in two seasons (summer and winter) from different commercial dairy farms in the Nord-east of Italy. For each trait, 20 animals divided into two groups of the high (10 cows) and the low (10 cows) were selected to study the microbiota profile using 16S rRNA metabarcoding sequencing. The alpha and beta diversity analysis revealed significant differences between the high and the low groups for feed efficiency and resilience to mastitis, while no significant difference was detected for milk coagulation. Moreover, remarkable differences among the taxa were detected between the two seasons, where the winter was more diverse than summer when applied the Chao1...

Gli Oli essenziali: applicazioni nei settori agroalimentare, agronomico,delle produzioni animali e della medicina veterinaria, 2017

PLOS ONE, 2021

Generally, endospore contamination can occur from different sources during product manufacturing ... more Generally, endospore contamination can occur from different sources during product manufacturing in many industries and therefore lower its quality by affecting physicochemical properties and shelf-life. Bacterial endospores can germinate inside the product and produce several enzymes, which can cause several undesirable changes. This study assessed the spores thermal resistance and applied a microwave decontamination technique toward herbal extracts (Tilia tomentosa and Centella asiatica) containing ethanol or glycerol. Based on 16S rRNA analysis, the detected contaminant endospores belonged to different Bacillus species, namely B. subtilis, B. zhangzhouensis, and B. pumilus. The thermal resistance assessment using inoculated endospores in the actual products revealed B. pumilus T2 as the most resistant endospore to the heat treatments tested in both T. tomentosa and C. asiatica extracts. Finally, a high-performance microwave technique was used to decontaminate T. tomentosa extract...

Riassunto Un programma di selezione di lieviti per l’enologia prevede il reperimento di un vasto ... more Riassunto Un programma di selezione di lieviti per l’enologia prevede il reperimento di un vasto numero di ceppi da un determinato ambiente da sottoporre a test di identificazione e a varie prove per verificarne le attitudini enologiche. Nel caso di lieviti “ecotipici”, dove la popolazione microbica isolata è rappresentativa di una determinata area di produzione vitivinicola, sono di particolare importanza la biodiversità genetica, la provenienza geografica degli isolati e “l’attitudine alla tipicità” dei ceppi raccolti. Nel corso dei progetti di selezione di lieviti ecotipici condotti nelle aree di produzione delle DOC venete “Conegliano-Valdobbiadene”, “Piave” e “Lison-Pramaggiore”, sono stati collezionati lieviti da grappoli, fermentati singolarmente in laboratorio, di vitigni a bacca bianca (Prosecco e Tocai Lison) e a bacca nera (Raboso), in zone geograficamente distinte e differenti per caratteristiche geofisiche e di urbanizzazione. La caratterizzazione genetica e tecnologica...