Specific metagenomic asset drives the spontaneous fermentation of Italian sausages

Abstract

Metagenomics is a powerful tool to study and understand the microbial dynamics that occur during food fermentation and allows to close the link between microbial diversity and final sensory characteristics. Each food matrix can be colonized by different microbes, but also by different strains of the same species. In this study, using an innovative integrated approach combining culture-dependent method with a shotgun sequencing, we were able to show how strain-level biodiversity could influence the quality characteristics of the final product. The attention was placed on a model food fermentation process: Salame Piemonte, a Protected Geographical Indication (PGI) Italian fermented sausage. Three independent batches produced in February, March and May 2018 were analysed. The sausages were manufactured, following the production specification, in a local meat factory in the area of Turin (Italy) without the use of starter cultures. A pangenomic approach was applied in order to identify and evaluate the lactic acid bacteria (LAB) population driving the fermentation process. It was observed that all batches were characterized by the presence of few LAB species, namely Pediococcus pentosaceus, Latilactobacillus curvatus and Latilactobacillus sakei. Sausages from the different batches were different when the volatilome was taken into consideration, and a strong association between quality attributes and strains present was determined. In particular, different strains of L. sakei, showing heterogeneity at genomic level, colonized the meat at the beginning of each production and deeply influenced the fermentation process by distinctive metabolic pathways that affected the fermentation process and the final sensory aspects.

Sensory Properties and Main Differential Metabolites Influencing the Taste Quality of Dry-Cured Beef during Processing

“…Umami is a very important component for the taste of dry-cured meat products, mainly obtained from nucleotides after degradation of ATP to ADP and subsequent reduction to AMP and then IMP [ 47 ]. It can also be provided by conversion of taurine to 2-oxoglutarate, followed by the formation of glutamic acid under the action of glutamate synthase, and subsequently, glutamine under the catalysis of glutamine synthetase [ 55 ]. Meanwhile, taurine is catalyzed by taurine-pyruvate aminotransferase to produce alanine, while N-carbamoyl-L-aspartate generates aspartic acid under the action of aspartate carbamoyltransferase, followed by conversion into alanine [ 56 ].…”

Microbiome Research as an Effective Driver of Success Stories in Agrifood Systems – A Selection of Case Studies

“…Autochthonous microbiome display an extensive pool of genes with adapted metabolic functions, which can be potentially used as starter culture to prevent the loss of typicity and guarantee quality and safety. Ferrocino et al, 2018;Franciosa et al, 2021 The microbiota of home-made and industrial kefir produced in Greece.…”

“…The meat microbiome has an important role in the conversion of the components of meat into several metabolites, with a consequential major impact on physical and organoleptic properties, and the quality and safety of the final products ( Cobo-Díaz et al, 2021 ; Franciosa et al, 2021 ). The initial microbiota is influenced by several factors such as the season, slaughter procedure, transport conditions, manufacturing equipment, factory environment and operators ( Franciosa et al, 2021 ). Re-contamination is often a stochastic process throughout the slaughter line, which is complex to monitor ( Mann et al, 2016 ).…”

“…Case study 8 ( Table 1 ) relates to fermented sausages, where a multi-omics approach was used to reveal the importance of the autochthonous microbiome in precision meat fermentation ( Ferrocino et al, 2018 ; Franciosa et al, 2021 ). The use of meta-omics approaches, coupling DNA sequencing with metabolomics, was used to connect sensorial quality of the final products with the metagenomic repertoire of sausages obtained both without starters or using with a commercial starter culture (a mixture of Lactilactobacillus sakei and Staphylococcus xylosus strains; Ferrocino et al, 2018 ).…”

The Application of Artificial Intelligence Technology in the Asset Management of Start-Ups in the Context of Deep Learning

“…The asset structure needs to be scientifically arranged on the basis of considering the development strategy of the company. A reasonable asset structure can promote the stable operation of the company according to the business strategy and reduce the comprehensive capital cost rate and financial risk of the company [ 16 ]. (5) Liquidity is a feature that measures the ability of an asset to obtain cash.…”