A growing body of evidence demonstrates the potential of various microbes to enhance plant productivity in cropping systems although their successful field application may be impaired by several biotic and abiotic constraints. In the present work, we aimed at developing multifunctional synthetic microbial consortia to be used in combination with suitable bioactive compounds for improving crop yield and quality. Plant growth-promoting microorganisms (PGPMs) with different functional attributes were identified by a bottom-up approach. A comprehensive literature survey on PGPMs associated with maize, wheat, potato and tomato, and on commercial formulations, was conducted by examining peer-reviewed scientific publications and results from relevant European projects. Metagenome fragment recruitments on genomes of potential PGPMs represented in databases were also performed to help identify plant growth-promoting (PGP) strains. Following evidence of their ability to coexist, isolated PGPMs were synthetically assembled into three different microbial consortia. Additionally, the effects of bioactive compounds on the growth of individually PGPMs were tested in starvation conditions. The different combination products based on microbial and non-microbial biostimulants (BS) appear worth considering for greenhouse and open field trials to select those potentially adoptable in sustainable agriculture.

Objectives The aim of this work was to set up a DNA-based method for detecting aflatoxigenic fungi Aspergillus flavus and Aspergillus parasiticus on whole maize kernels using species-specific primers. Methods In the experiments, two aflatoxigenic strains, A. flavus NRRL 3357 and A. parasiticus NRRL 2999, were used. Further, Aspergillus niger 7096, OTA producer strain, and other strains of Aspergillus spp., Penicillium spp. and Fusarium spp. isolated from maize kernels were analyzed. Twelve commercial maize hybrids employed in the food and feed industries, not inoculated and inoculated with the different fungi, at different water activities, were used in the polymerase chain reaction-based assay. Three primer pairs were used for amplifying fragments of Afl P (omt 1), Afl M (ver 1), Afl R, genes present in the aflatoxin biosynthesis cluster. Results DNA amplification was achieved only with DNA from fungal strains of A. parasiticus and A. flavus and from maize kernels inoculated with A. flavus or A. parasiticus. Amplification was never observed with DNA of the other fungal species. Amplification was evident in maize starting from 12 h of incubation after inoculation, when mycelium is not yet visible by stereomicroscope analysis. Conclusion The results indicate that these highly specific and sensitive polymerase chain reaction-based methods are able to discriminate maize kernels infected with A. flavus or A. parasiticus from uninfected ones. This polymerase chain reaction method could be a real, effective alternative to traditional diagnostic methods for the early detection of aflatoxigenic fungi in food commodities

The strengthening effect of a mild temperature treatment on the antimicrobial efficacy of essential oils has been widely reported, often leading to an underestimation or a misinterpretation of the product’s microbial status. In the present study, both a traditional culture-based method and Flow Cytometry (FCM) were applied to monitor the individual or combined effect of Origanum vulgare essential oil (OEO) and mild heat treatment on the culturability and viability of Escherichia coli in a conventional culture medium and in a fruit juice challenge test. The results obtained in the culture medium showed bacterial inactivation with an increasing treatment temperature (55 °C, 60 °C, 65 °C), highlighting an overestimation of the dead population using the culture-based method; in fact, when the FCM method was applied, the prevalence of injured bacterial cells in a viable but non-culturable (VBNC) state was observed. When commercial fruit juice with a pH of 3.8 and buffered at pH 7.0 was inoculated with E. coli ATCC 25922, a bactericidal action of OEO and a higher efficiency of the mild heat at 65 °C for 5′ combined with OEO were found. Overall, the combination of mild heat and OEO treatment represents a promising antimicrobial alternative to improve the safety of fruit juice.

To address the challenges of persistent plastic pollution and food waste reduction, sustainable active packaging systems derived from renewable biopolymers represent alternative to non-renewable petroleum-based fossil plastics. In this context, an active, soil-biodegradable bio-packaging film was engineered via solvent casting from a synergistic binary blend of food grade carob seed flour (E410) and kappa-carrageenan (E407) plasticized with glycerol and functionalized with an aqueous extract from red pomegranate peel, a byproduct of pomegranate processing. The extract, recovered from this agricultural byproduct through ultrasound-assisted water extraction, exhibited rich phenolic, flavonoid, and anthocyanin contents together with strong radical scavenging capacity and broad-spectrum antibacterial activity against foodborne pathogens. When incorporated into the biopolymeric polysaccharide network, these bioactive constituents significantly enhanced tensile strength while maintaining high film flexibility and a hydrophobic surface character. The natural polyphenols were physically integrated into the matrix without disrupting the hydrocolloid framework. The functionalized films demonstrated antibacterial activity against Gram-positive and Gram-negative bacterial strains, good water vapor and gas barrier performance, and complete biodegradation in agricultural soil. Overall, this fully bio-based material demonstrates the technological potential of valorizing agro-industrial byproducts into high-performance active packaging capable of extending the shelf life of perishable food while aligning with circular bioeconomy frameworks.