Sandra Torriani

University of Verona | UNIVR · Department of Biotechnology

The evaluation of cell parietal components of yeasts is an important criterium for the selection of wine starters since they play a key role in the vinification process. The aim of this study was to characterize and compare the cell wall composition of four industrial (BM45, D47, EC1118, K1) and three native Saccharomyces cerevisiae (MY8, MY11, PED...

Metschnikowia pulcherrima is an important yeast species that is attracting increased interest thanks to its biotechnological potential, especially in agri-food applications. Phylogenetically related species of the so-called ‘pulcherrima clade’ were first described and then reclassified in one single species, which makes the identification an intrig...

Kombucha is a fermented tea with a long history of production and consumption. It has been gaining popularity thanks to its refreshing taste and assumed beneficial properties. The microbial community responsible for tea fermentation—acetic acid bacteria (AAB), yeasts, and lactic acid bacteria (LAB)—is mainly found embedded in an extracellular cellu...

Glutathione (GSH) is a non-protein thiol naturally present in grape berries and produced by yeasts during fermentation. It has a strong antioxidant activity; thus, the addition of pure GSH during winemaking is recommended to limit the oxidative phenomena of wine, preserving sensory characteristics and stability, ultimately promoting a healthier pro...

Currently, consumption of spontaneously fermented milks is common in Algeria, making it a feasible source of diverse lactic acid bacteria (LAB) with the potential to be used as adjunct cultures to improve quality and safety of fermented dairy products. In this context, to select eligible indigenous strains which could be applied as bioprotective an...

Propionic Acidemia (PA) is a rare inherited metabolic disorder caused by the enzymatic block of propionyl-CoA carboxylase with the consequent accumulation of propionic acid, which is toxic for the brain and cardiac cells. Since a considerable amount of propionate is produced by intestinal bacteria, interest arose in the attempt to reduce propionate...

Lactic acid bacteria (LAB) perform the process of malolactic fermentation (MLF) in wine. Availability of oxygen and nitrogen nutrients could influence LAB growth, malolactic activity, and other metabolic pathways, impacting the subsequent wine quality. The impact of these two factors has received limited investigation within LAB, especially on a tr...

Wine quality is strongly affected by chemical composition and microbial population of grape must, which, in turn, are influenced by several post-harvest treatments, including grape withering. Different strategies have been suggested to manage the fermenting must microbiota, as it plays a central role in the outcomes of both spontaneous and guided f...

Leuconostoc spp. are environmental microorganisms commonly associated with fermented foods. Absence of antibiotic resistance (AR) in bacteria is a critical issue for global food safety. Herein, we updated the occurrence of AR genes in the Leuconostoc genus through in silico analyses of the genomes of 17 type strains. A total of 131 putative AR trai...

Background and Aims Glutathione (GSH), a strong antioxidant naturally present in grape berries and produced by yeasts during fermentation, can be added by winemakers to control oxidative deterioration of wine. A promising approach is the inoculation of starter or co‐starter yeasts that are strong producers of GSH in situ. Since little is known abou...

Glutathione (GSH) is the most abundant non-protein thiol in yeasts and plays an important role as antioxidant in wine. Application of selected GSH-accumulating strains can improve wine sensorial quality and stability, but most selection programs have been conducted on Saccharomyces cerevisiae. Therefore, the aim of the study was to evaluate the abi...

Gray mold caused by Botrytis cinerea is a fungal disease that can determine significant economic losses of apple during the storage phase. An alternative to reduce the use of traditional synthetic fungicides is to employ the yeast Starmerella bacillaris as biological control agent (BCA), also with positive effect on apple juice fermentation for the...

Non-conventional yeasts are increasingly applied in fermented beverage industry to obtain distinctive products with improved quality. Among these yeasts, Lachancea thermotolerans has multiple features of industrial relevance, especially the production of L(+)-lactic acid (LA), useful for the biological acidification of wine and beer. Since few info...

This research investigated the technological and safety effects of the nisin Z producer Lactococcus lactis subsp. lactis CBM 21, tested as an adjunct culture for the making of Squacquerone cheese in a pilot-scale plant. The biocontrol agent remained at a high level throughout the cheese refrigerated storage, without having a negative influence on t...

Within this chapter, we provide the taxonomic framework of genera involved in dairy technology, discussing the Lactobacillus genus reclassification and focusing on the novel genera of lactobacilli that play an important role in dairy industry. Their metabolism and technological properties at the basis of the starter selection are described, includi...

Saccharomyces cerevisiae starter cultures are largely used in winemaking to repress the wild microorganisms and achieve more predictable and desired outcomes. Notwithstanding, alternative microbial resources received increasing attention for their potential to produce wines with more distinctive and typical features. Our previous survey revealed a...

Background: Synbiotic foods, which combine the action of prebiotics and probiotics along the gastrointestinal tract, can affect inflammatory and glucose-related markers. Objective: The aim of this study was to investigate the effects on inflammatory and glycemia-related markers of a whole-grain pasta containing barley β-glucans and Bacillus coag...

The inoculation of Saccharomyces cerevisiae starter cultures in grape musts is a common practice in wineries worldwide; however, native non-Saccharomyces yeast species are increasingly investigated as co-starters to augment the complexity and regionality of wine. In this study, an extensive collection of non-Saccharomyces yeasts from high-sugar mat...

Diet-related modulation of gut microbiota and its metabolic activity represents an intriguing research context, particularly in the case of disorders related to imbalances in gut microbial communities. We here explored the effects of Bacillus coagulans GBI-30, 6086 (BC30), β-glucans, and innovative whole-grain pastas, with or without these function...

Bacteriophages are responsible for significant material and time losses in the dairy industry. This because these viruses infect the selected lactic starter cultures used for milk fermentation, i.e., the first stage toward cheese production. Standard detection techniques are time-and labor-consuming, causing huge costs related to production plant s...

Bacteriocins have attracted great attention as potential alternatives to antibiotics and chemical food additives. In the present study, 243 Staphylococcus isolates from milk samples (n = 110) of goat and sheep herds located in Fars province, Iran, were screened for antimicrobial substance production. Twenty-eight isolates showed an antagonistic act...

Lactobacillus species are generally considered to be nonpathogenic and are used in a wide variety of foods and products for humans and animals. However, many of the species examined in this study have antibiotic resistance levels which exceed those recommended by the EFSA, suggesting that these cutoff values should be reexamined in light of the gen...

The genus Debaryomyces comprises generalist species of saltand cold-tolerant ascomycetous yeasts able to colonize extreme environments, diverse ecological niches (eg, soil, fruits, seawater, plants, insects, and air) and also the base of Arctic polythermal glaciers as well as a variety of fermented food products. 1, 2 The most representative specie...

In this study, 28 bacteriocinogenic Staphylococcus strains isolated from goat and sheep milk were subjected to the PCR detection of enterotoxin genes (sea-see), enterotoxin-like toxin Q gene (selq), toxic shock syndrome toxin gene (tst1), and antibiotic resistance genes. They were also evaluated for phenotypic resistance against 10 antibiotics and...

In order to investigate the possible implications of the trophic supply in the distribution and adaptation of the organisms in caves, we analysed the gut microbiota composition of Neobathyscia pasai and Neobathyscia mancinii, two subterranean Leptodirini endemic to Lessini Mountains (NE-Italy). The two species exhibit different distribution inside...

Four batches of Milano-type dry fermented sausages were industrially produced to evaluate the effects of two different lactic acid bacteria starter cultures (Lactobacillus sakei and Pediococcus pentosaceus) and diameter on physico-chemical, microbiological and aroma characteristics during processing and in the final products. Values of aw and pH we...

This chapter describes different aspects of genome-wide studies on strains relevant for dairy and probiotic products. Knowledge of the complete genome sequence is useful not only in discovering novel genes and new properties, but also in determining the absence at the genetic level of undesirable traits. In addition, it is of much help in character...

The lactic acid bacterium Oenococcus oeni is the most important species involved in malolactic fermentation due to its capability to survive in presence of ethanol and in the acidic environment of wine. In order to identify novel genes involved in adaptation to wine, a new approach using genome-wide analysis based on stress-related genes was perfor...

Lactobacillus casei,Lactobacillus paracasei and Lactobacillusrhamnosus form a closely related taxonomic group (the L. casei group) within the facultatively heterofermentative lactobacilli. Strains of these species have been used for a long time as probiotics in a wide range of products, and they represent the dominant species of nonstarter lactic a...

The natural or induced development of noble rot caused by the fungus Botrytis cinerea during the late stages of grapevine (Vitis vinifera L.) berry ripening is used in some traditional viticulture areas to produce high-quality wines such as Sauternes and Tokaji. In this research, we wanted to verify if by changing the environmental conditions durin...

The main aim of this work was to evaluate, at pilot scale in an industrial environment, the effects of the biocontrol agent Lactococcus lactis CBM21 and thyme essential oil compared to chlorine, used in the washing step of fresh-cut lamb’s lettuce, on the microbiota and its changes in relation to the time of storage. The modification of the microbi...

Background: The gut microbiome is the full set of microbes living in the gastrointestinal tract and is emerging as an important dynamic/fluid system that, if altered by environmental, dietetic or pharmacological factors, could considerably influence drug response. However, the immunosuppressive drug-induced modifications of this system are still p...

List of pathways that had an unadjusted p-value<0.05 but did not meet the log 2 fold change threshold. (DOCX)

Most abundant functional genes (A) and pathways (B) in the two groups of patients. (DOCX)

Percentage distribution of sugar consumption in the samples. (DOCX)

Life style and simplified food frequency questionnaire. (DOCX)

List of the OTUs that had an unadjusted p-values <0.05 and absolute log 2 fold change>1. (DOCX)

Aims: The tyraminogenic potential of the strains Enterococcus faecalis EF37 and ATCC 29212 was investigated in a synthetic medium containing defined amounts of tyrosine and phenylalanine at different temperatures. Methods and results: The enterococci growth and the production of biogenic amines was evaluated in relation to their pre-grown in med...

During the vinification process, we can generally separate four main phases associated with specific microbial dominances: (i) first stages of alcoholic fermentation (AF) (non-Saccharomyces), (ii) most part of AF, up to the end (Saccharomyces), (iii) malolactic fermentation (MLF) (lactic acid bacteria or LAB), and (iv) undesired changes associated...

The microbiota of Serrano dry-cured ham of different chemical composition, subjected or not to high-pressure processing (HPP), was investigated using culture-dependent and culture-independent methods. Microbial counts were submitted to analysis of variance with physicochemical parameters (aw, NaCl concentration, salt-in-lean ratio and intramuscular...

Here, we report the draft genome sequence of Kluyveromyces marxianus fragilis B0399, the first yeast approved as a probiotic for human consumption not belonging to the genus Saccharomyces The genome is composed of 8 chromosomes, with a total size of 11.44 Mb, including mitochondrial DNA.

The thioredoxin system protects against oxidative stress through the reversible oxidation of the thioredoxin active centre dithiol to a disulphide. The genome of Oenococcus oeni PSU-1 contains three thioredoxin genes (trxA1, trxA2, trxA3), one thioredoxin reductase (trxB) and one ferredoxin reductase (fdr) which, until recently, was annotated as a...

Few information is available about the tyraminogenic potential of the species Enterococcus mundtii. In this study, two plant-derived strains of E. mundtii were selected and investigated to better understand the phenotypic behaviour and the genetic mechanisms involved in tyramine accumulation. Both the strains accumulated tyramine from the beginning...

In this study nine strains of Enterococcus faecalis and 12 strains of E. faecium, isolated from different sample types in the swine meat chain and previously characterized for the presence of antibiotic resistance genes, were examined for phenotypic tolerance to seven biocides (chlorexidine, benzalkonium chloride, triclosan, sodium hypochlorite, 2-...

Vitis vinifera L. cv. Corvina grape forms the basis for the production of unique wines, such as Amarone, whose distinctive sensory features are strongly linked to the post-harvest grape withering process. Indeed, this process increases sugar concentration and changes must characteristics. While microorganisms involved in must fermentation have been...

Probiotics are microorganisms that confer beneficial effects on the host; nevertheless, before being allowed for human consumption, their safety must be verified with accurate protocols. In the genomic era, such procedures should take into account the genomic-based approaches. This study aims at assessing the safety traits of Bacillus coagulans GBI...

Fresh tofu is a traditional Asian soybean-derived food product which has become increasingly popular worldwide, however, little is known on its microbial ecology and the microbial groups that can cause its deterioration. In this study, the microbiological characteristics of ready-to-eat fresh tofu produced by a small company in Northern Italy were...

Background: Pancreatic organ-specific autoimmunity in subjects at risk for type 1 diabetes (T1D) is associated with increased intestinal permeability and an aberrant gut microbiota; but these factors have not yet been simultaneously investigated in the same subjects. Thus, the aim of this study was to assess both intestinal permeability and gut mi...

The purpose of the present investigation was to study the microbiological and physicochemical characteristics of Graviera cheese from raw milk, Graviera Naxou and Graviera Kritis, made in each of the respective islands, in order to discriminate those two types of cheeses. Totally, 103 Non Starter Lactic Acid Bacteria (NSLAB) isolates were obtained...

In spite of a global concern on the transfer of antibiotic resistances (AR) via the food chain, limited information exists on this issue in species of Leuconostoc and Weissella, adjunct cultures used as aroma producers in fermented foods. In this work, the minimum inhibitory concentration was determined for 16 antibiotics in 34 strains of dairy ori...

Source of isolation of the Leuconostoc-Weissella strains of this study (Table A). Primers and positive control strains used for the detection of antibiotic resistant genes (Table B). Primers and conditions used for the identification of dairy Leuconostoc-Weissella (Table C). GenBank accession numbers for nucleotide sequences of the genes atpA and p...

The aim of this study was to investigate the diversity of tyramine production capability of four Enterococcus strains in buffered systems in relation to their genetic characteristics and environmental conditions. Cells of the strains Enterococcus faecalis EF37 and ATCC 29212, and E. faecium FC12 and FC643 were re-suspended in phosphate/citrate buff...

The intrinsic characteristics of minimally processed fruit may favor the growth of pathogens and spoilage microorganisms. In this context, the use of natural alternatives to traditional chemical sanitizer agents may represent a useful tool to increase the shelf-life and the safety of minimally processed fruit. The aim of this study was to evaluate...

Lactobacillaceae is the most numerous and heterogeneous family, as about 180 species are recognized. From an applied viewpoint, families Lactobacillaceae and Streptococcaceae represent the two most important lineages since they encompass the highest number of commercialized lactic acid bacteria (LAB). Lactobacillaceae includes the highest number of...

Leuconostoc mesenteroides is a lactic acid bacterium (LAB) commonly associated with fermented foods. Here, we report the genome sequence of three selected dairy strains, showing atypical antibiotic resistances (AR). Genome analysis provided a better understanding of the genetic bases of AR in Leuconostoc and its potential transferability among food...

Abstract A new functional pasta using a durum wheat flour rich in polyphenols, with added barley β-glucan and Bacillus coagulans GBI-30,6086 was developed. Chemical, nutritional and microbiological analyses were carried out to perform a comprehensive evaluation of the final product quality. The settled debranning process of durum wheat produced a...

The ability to accumulate tyramine and 2-phenylethylamine by two strains of Enterococcus faecalis and two strains Enterococcus faecium was evaluated in two cultural media added or not with tyrosine. All the enterococcal strains possessed a tyrDC which determined tyramine accumulation in all the conditions tested, independently on the addition of hi...

In this study the thermal resistance of seven strains of staphylococci was studied. Three of them (two Staphylococcus epidermidis and one Staphylococcus lugdunensis) were isolated from pasteurized tofu, while one Staphylococcus aureus from fermented sausages. Also the corresponding type strains were tested. Their heat resistance was assessed at 80...

Traditional dairy products harbor a complex microbiota composed by several microbial groups, including lactic acid bacteria (LAB) and yeasts. The common method to detect LAB is to culture the products on media containing cycloheximide (CHX) to prevent yeast growth by interfering with protein synthesis. However, some yeast species and strains show n...

Ultraviolet C (UV-C) irradiation is one of the emerging techniques for the inactivation of microorganisms in liquid food products, and it holds considerable promise also for treatment of wine. This application can be of particular interest to reduce or even eliminate the use of sulphur dioxide as a preservative in winemaking, given its potential he...

Bacillus coagulans GBI-30, 6086 is a safe strain, already available on the market, and characterized by certified beneficial effects. The draft genome sequence presented here constitutes the first pillar toward the identification of the molecular mechanisms responsible for its positive features and safety.

Large antibiotic resistance gene pools in the microbiota of foods may ultimately pose a risk for human health. This study reports the identification and quantification of tetracycline- and erythromycin-resistant populations, resistance genes, and gene diversity in traditional Spanish and Italian cheeses, via culturing, conventional PCR, real-time q...

Supplementary Table 1 summarizes updated tetracycline and erythromycin resistance genes which were compiled for designing primers for the qPCR analyses. Nucleotide sequences were downloaded from the GenBank database and aligned with one another using Mega 5 Software.