Multi-omic approaches to investigate molecular mechanisms in peach post-harvest ripening

Peach post-harvest ripening is a complex developmental process controlled by a plethora of genetic and epigenetic factors. Specifically, it leads to protein, lipid and nucleic acid degradation, all resulting in cell death. Substantial research has been directed at investigating peach regulatory mechanisms underlying genomic, metabolomic and transcriptomic modifications occurring during this stage, and much progress has been made thanks to the advent of Next Generation Sequencing technologies. This review is focused on the latest multi-omics studies, with the aim of highlighting the most significant results and further investigating the regulation of the key genes involved in peach post-harvest processes and related physiology. By offering an exhaustive overview of peach omics profiles, it provides a comprehensive description of gene expression changes and their correlation with ripening stages, including some post-harvest treatments, as well as with volatile organic compound modifications. However, the present work highlights that, due to the complexity of the process, recent investigations do not elucidate all underlying molecular mechanisms, making further studies still necessary. For this reason, some key points for future research activities and innovative peach breeding programs are discussed, relying on trusted multi-omic approaches

Multi-omics approaches to study molecular mechanisms in Cannabis sativa

Cannabis (Cannabis sativa L.), also known as hemp, is one of the oldest cultivated crops, grown for both its use in textile and cordage production, and its unique chemical properties. However, due to the legislation regulating cannabis cultivation, it is not a well characterized crop, especially regarding molecular and genetic pathways. Only recently have regulations begun to ease enough to allow more widespread cannabis research, which, coupled with the availability of cannabis genome sequences, is fuelling the interest of the scientific community. In this review, we provide a summary of cannabis molecular resources focusing on the most recent and relevant genomics, transcriptomics and metabolomics approaches and investigations. Multi-omics methods are discussed, with this combined approach being a powerful tool to identify correlations between biological processes and metabolic pathways across diverse omics layers, and to better elucidate the relationships between cannabis sub-species. The correlations between genotypes and phenotypes, as well as novel metabolites with therapeutic potential are also explored in the context of cannabis breeding programs. However, further studies are needed to fully elucidate the complex metabolomic matrix of this crop. For this reason, some key points for future research activities are discussed, relying on multi-omics approaches

Molecular mechanisms underlying potential pathogen resistance in cannabis sativa

Cannabis (Cannabis sativa L.) is one of the earliest cultivated crops, valued for producing a broad spectrum of compounds used in medicinal products and being a source of food and fibre. Despite the availability of its genome sequences, few studies explore the molecular mechanisms involved in pathogen defense, and the underlying biological pathways are poorly defined in places. Here, we provide an overview of Cannabis defence responses against common pathogens, such as Golovinomyces spp., Fusarium spp., Botrytis cinerea and Pythium spp. For each of these pathogens, after a summary of their characteristics and symptoms, we explore studies identifying genes involved in Cannabis resistance mechanisms. Many studies focus on the potential involvement of disease-resistance genes, while others refer to other plants however whose results may be of use for Cannabis research. Omics investigations allowing the identification of candidate defence genes are highlighted, and genome editing approaches to generate resistant Cannabis species based on CRISPR/Cas9 technology are discussed. According to the emerging results, a potential defence model including both immune and defence mechanisms in Cannabis plant–pathogen interactions is finally proposed. To our knowledge, this is the first review of the molecular mechanisms underlying pathogen resistance in Cannabis

Bacterial community of Industrial raw Sausage Packaged in Modified Atmosphere throughout the Shelf Life

Ten lots of industrial raw sausages in modified atmosphere (CO2 30%, O2 70%), produced in the same plant over 7\u202fmonths, were analyzed at the day after production (S samples) and at the end of shelf life (E samples), after 12\u202fdays storage at 7\u202f\ub0C to simulate thermal abuse. Quality of the products was generally compromised by storage at 7\u202f\ub0C, with only 3 E samples without alterations. During the shelf life, the pH decreased for the accumulation of acetic and lactic acids. A few biogenic amines accumulated, remaining below acceptable limits. The profile of volatile compounds got enriched with alcohols, ketones, and acids (e.g. ethanol, 2,3-butanediol, 2,3-butandione, butanoic acid) originated by bacterial metabolism. Throughout the shelf life, aerobic bacteria increased from 4.7 log to 6.6\u202flog\u202fcfu/g, and lactic acid bacteria (LAB) from 3.7 to 8.1\u202flog\u202fcfu/g. Staphylococci, enterobacteria, and pseudomonads passed from 3.7, 3.0, and 1.7 to 5.5, 4.8, and 3.0\u202flog\u202fcfu/g, respectively. Dominant cultivable LAB, genotyped by RAPD-PCR, belonged to the species Lactobacillus curvatus/graminis and Lactobacillus sakei, with lower amounts of Leuconostoc carnosum and Leuconostoc mesenteroides. Brochothrix thermosphacta was the prevailing species among aerobic bacteria. The same biotypes ascribed to several different species where often found in E samples of diverse batches, suggesting a recurrent contamination from the plant of production. Profiling of 16S rRNA gene evidenced that microbiota of S samples clustered in two main groups where either Firmicutes or Bacteroidetes prevailed, albeit with taxa generally associated to the gastro-intestinal tract of mammals. The microbial diversity was lower in E samples than in S ones. Even though a common profile could not be identified, most E samples clustered together and were dominated by Firmicutes, with Lactobacillaceae and Listeriaceae as the most abundant families (mostly ascribed to Lactobacillus and Brochothrix, respectively). In a sole E sample Proteobacteria (especially Serratia) was the major phylum

Cooked ham microbiota packed in modified atmosphere

15 cooked ham (CH) unflawed samples were analyzed at the beginning and at the end of the shelf-life, while 7 flawed ones were processed only at the date of shipment. Cultivable bacteria on MRS were clusterized through RAPD-PCR Each biotype was identified through amplification of 16S sequences. The microbiota was further characterized by metataxonomic analysis

Biotecnologie dei microrganismi: uno sguardo alle tecniche microbiche applicate agli alimenti

Nutrition represents one of the widest and oldest microbial biotechnologies application fields. The spontaneous transformation of raw materials by microorganisms generally found in the environment, with preservation purposes, came even before cooking food. Even today a lot of common food products are preserved, produced or enhanced through the direct action of microorganisms. Microbial biotechnologies can be used in different ways, improving the potential application of food fermentation processes with preservation aims. The selection of starters is maybe the most significant example. In this article, after a brief view of such biotechnologies and the most relevant microorganisms used in this field, we'll focus on the most commonly used bacterial identification methods. Such techniques are also able to analyze the dynamic processes in which food microbiota is involved. Therefore, the focus is on the most perishable food products

Molecular Investigations of Peach Post-Harvest Ripening Processes and VOC Biosynthesis Pathways: A Review Focused on Integrated Genomic, Transcriptomic, and Metabolomic Approaches

Peach (Prunus persica L.) represents a very important model plant given its small and publicly accessible genome, the availability of homozygous doubled haploids, and its taxonomic similarity to other popular stone fruits. Albeit it is an economically important crop with a great production potential, the consumption of peach is still considered low in comparison with that of other fresh fruits, such as apple and banana. A way to increase it could be to improve its quality and aroma, which tend to be affected during the often-prolonged storage and transport periods. Recently, substantial research efforts have been directed towards the characterisation of the regulatory mechanisms underlying the hormonal, transcriptomic, and metabolomic changes happening during peach fruit post-harvest ripening. Biosynthesis pathways of volatile organic compounds related to changes in aroma have also been investigated. Due to advances in next-generation sequencing, new insights into the molecular functions of peach genes have been gained. Studies have mapped out the molecular bases of peach fruit post-harvest ripening using a multi-omics approach, combining genomic, transcriptomic, and metabolomic methods. This review aims to discuss the most relevant recent research results in this area in order to provide a useful starting point for researchers in the field and future perspectives for improving peach quality

Evolution of sliced cooked ham microbiota packaged in modified atmosphere

Microorganisms colonize cooked ham (CH) packaged in modified atmosphere with a preferential growth of psychrotrophic lactic acid bacteria (LAB). Depending on the strains, the overwhelming colonization can result in a premature spoilage, characterized by pH decrease, gas and slime production, discoloration, and off-flavors formation. The LABs of 15 CH samples coming from different manufacturers were analyzed both at the beginning (T0) and at the end (Tf) of the shelf-life. Randomly selected colonies were subjected to RAPD-PCR clustering, and each biotype was taxonomically characterized through 16S rRNA gene partial sequencing. The evolution of sensorial properties was monitored by evaluation of the samples at T0 and Tf. Seven other CH samples were similarly processed when identified as flawed and withdrawn from the market before the sell-by date. The samples at the end of the shelf life and the spoiled ones shared a similar cultivable microbiota, dominated by Lactobacillus sakei, L. curvatus, and Leuconostoc carnosum. Less recurrent species were Weissella viridescens, Leuconostoc mesenteroides, Enterococcus faecalis, and Enterococcus pseudoavium. The microbiota of the flawed and unflawed (T0 and Tf) samples was further characterized by meta-taxonomic analysis. Initial population was generally represented by consortia of bacteria belonging to the order of Lactobacillales (Lactobacillus, Carnobacterium, Leuconostoc, Enterococcus, Vagococcus, Weissella, Streptococcus), Acinetobacter spp. and other Moraxellaceae, Pseudomonas spp., Bacillus, Prevotella, Weissella, Brochotrix, Vibrio rumoiensis, and Vellionella dispar. Samples that evolved into a spoiled product and samples that were delivered as flawed were often characterized by a dominant population of Lactobacillales. Among the flawed CH samples, overwhelming colonization of Brochothrix or Vibrio rumoiensis was detected

MICROBIOTA OF FRESH CURED PORK SAUSAGE OVER THE SHELF-LIFE

Italian style fresh sausage is a traditional pork food, commonly consumed after cooking. It is a perishable product that over the time can be colonized by spoilage bacteria that render the product inacceptable because of undesirable modifications of sensorial properties, such as appearance, texture, odor, and flavor. Indeed, being fresh meat a matrix with high water activity, slightly acidic pH, and high level of nutrients including glucose, lactic acid, nitrogenous compounds, and amino acids, it allows growth and proliferation of several bacteria. Temperatures and MAP (Modified Atmosphere Packaging) are the most important extrinsic factors affecting growth of microorganism. Generally fresh sausages are conserved refrigerated in MAP to maintain the red colour of the meat. The refrigeration of raw meat slows down growth of bacteria, allowing selection and blooming of psychrotrophic aerobic and aerotolerant species