Bio-enzymes have shown broad application prospects in controlling mycotoxins due to their strong specificity, fast reaction rate and mild reaction conditions. However, the number of enzymes isolated, ...purified and characterized to degrade patulin (PAT) is limited. We expressed an aldo-keto reductase (MgAKR) from Meyerozyma guilliermondii in Escherichia coli. The results demonstrated that the purified MgAKR could convert PAT into ascladiol in vitro with NADPH serving as a coenzyme. Adding 300 μg/mL MgAKR resulted in an 88 % reduction of PAT in fresh pear juice without affecting its quality in the biodegradation process. The site-directed mutagenesis suggested that the interaction between MgAKR and PAT occurred through the active sites of Lys242 and Leu240. This study serves as a valuable theoretical reference for the development of enzymes aimed at detoxifying PAT in fruit and their derivatives.
This research aimed to isolate lactic acid bacteria (LAB) from apple surface and to reveal their potential to inhibit the growth of Penicillium expansum. Besides, their ability to detoxify fruit ...juices contaminated with mycotoxin patulin, produced by this fungi, was also studied. The isolation was performed on a typical MRS medium under ambient conditions. The molecular identification of the strains was done by sequencing the 16S rRNA genes. Antifungal activities of the isolated strains have been evaluated using dual agar plate assay protocol. A total of 11 LAB isolates was obtained from apples. These isolates showed phenotypic traits consistent with the genera of LAB. They have been identified as Leuconostoc mesenteroides subsp. mesenteroides and Weissella paramesenteroides. Among them, the strain LB7 showed exciting inhibitory activities in vitro against P. expansum. LB7 also successfully detoxified homemade and commercial fruit juices contaminated with patulin. Further research will bring the application prospects of these LABs in food biocontrol and biopreservation strategies.
•Leuconostoc mesenteroides subsp. mesenteroides isolates from apple surfaces exhibited antifungal activities•L. mesenteroides subsp. mesenteroides LB7 inhibited in vitro the mycelial growth of P. expansum•L. mesenteroides subsp. mesenteroides LB7 reduced patulin in commercial fruit juices
Patulin (PAT) is a mycotoxin that can contaminate many foods and especially fruits and fruit‐based products. Therefore, accurate and effective testing is necessary to enable producers to comply with ...regulations and promote food safety. Traditional approaches involving the use of chemical compounds or physical treatments in food have provided practical methods that have been used to date. However, growing concerns about environmental and health problems associated with these approaches call for new alternatives. In contrast, recent advances in biotechnology have revolutionized the understanding of living organisms and brought more effective biological tools. This review, therefore, focuses on the study of biotechnology approaches for the detection, control, and mitigation of PAT in food. Future aspects of biotechnology development to overcome the food safety problem posed by PAT were also examined. We find that biotechnology advances offer novel, more effective, and environmental friendly approaches for the control and elimination of PAT in food compared to traditional methods. Biosensors represent the future of PAT detection and use biological tools such as aptamer, enzyme, and antibody. PAT prevention strategies include microbial biocontrol, the use of antifungal biomolecules, and the use of microorganisms in combination with antifungal molecules. PAT detoxification aims at the breakdown and removal of PAT in food by using enzymes, microorganisms, and various adsorbent biopolymers. Finally, biotechnology advances will be dependent on the understanding of fundamental biology of living organisms regarding PAT synthesis and resistance mechanisms.
One of the most significant challenges associated with postharvest apple deterioration is the blue mold caused by Penicillium expansum, which leads to considerable economic losses to apple production ...industries. Apple fruits are susceptible to mold infection owing to their high nutrient and water content, and current physical control methods can delay but cannot completely inhibit P. expansum growth. Biological control methods present promising alternatives; however, they are not always cost effective and have application restrictions. P. expansum infection not only enhances disease pathogenicity, but also inhibits the expression of host-related defense genes. The implementation of new ways to investigate and control P. expansum are expected with the advent of omics technology. Advances in these techniques, together with molecular biology approaches such as targeted gene deletion and whole genome sequencing, will lead to a better understanding of the P. expansum infectious machinery. Here, we review the progress of research on the blue mold disease caused by P. expansum in apples, including physiological and molecular infection mechanisms, as well as various methods to control this common plant pathogen.
Ochratoxin A (OTA) is a major mycotoxin contaminant of cereals and grapes. Our previous study proved the ability of Cryptococcus podzolicus Y3 to degrade OTA. The main aim of the present study was to ...investigate the OTA degradation mechanism by C. podzolicus Y3 using Next-generation sequencing. The results that showed 427 and 100 genes were up- and down-regulated after OTA exposure, respectively. Gene Ontology analysis indicated that genes related to yeast growth, reproduction, and activity were differentially regulated under OTA stress. The results of Kyoto Encyclopedia of Genes and Genomes enrichment showed that OTA stress enhanced energy metabolism, repair DNA and RNA, ribosome biogenesis and peroxisome biogenesis in C. podzolicus Y3. In contrast, OTA treatment inhibited glycosylation modification and degradation of endoplasmic reticulum-related proteins, MAPK signal transduction. Gene function analysis revealed that a biodegradable enzyme, carboxypeptidase A4, possibly catalyzed the amide bonds of OTA. Other essential genes of C. podzolicus Y3 that responded to OTA stress encoded cytochrome P450, zinc finger proteins and heat shock protein 70. However, glutathione S-transferase was not involved in the detoxification of OTA. This study unveiled the possible OTA degradation and response mechanisms of C. podzolicus Y3 at the transcriptional level.
•527 genes were significantly regulated in C. podzolicus Y3 during OTA stress.•CPA4 was potentially contributed to OTA degradation in C. podzolicus Y3.•OTA stress induced metabolic pathways and genes contributed to stress response.•OTA limited signal transduction and protein modification in C. podzolicus Y3.
•M. guilliermondii alleviated black spot disease index of postharvest broccoli.•M. guilliermondii stimulated AsA-GSH and GPX cycles in broccoli to scavenge ROS.•M. guilliermondii raised antioxidant ...enzymes activities in broccoli to scavenge ROS.•M. guilliermondii lowed ROS accumulation and membrane lipid peroxidation in broccoli.
Black spot caused by Alternaria brassicicola is one of the most common fungal diseases of postharvest broccoli. The present study investigated the biocontrol efficacy of Meyerozyma guilliermondii against black spot of postharvest broccoli and the mechanisms involved in the enhanced disease resistance of broccoli based on its effects on reactive oxygen species (ROS) metabolism. Our investigation proved that M. guilliermondii could decrease the disease index of postharvest broccoli caused by A. brassicicola. This antagonistic yeast could potentially increase peroxidase, catalase and superoxide dismutase activities, and the activities of enzymes involved in ascorbate–glutathione cycle and glutathione peroxidase cycle, such as ascorbate peroxidase, glutathione peroxidase and glutathione reductase. Furthermore, the contents of non-enzymatic antioxidants, including ascorbic acid and glutathione, were enhanced by this yeast. Accordingly, the accumulation of ROS, including hydrogen peroxide (H2O2) and superoxide anion (O2–), was reduced by M. guilliermondii, as well as malondialdehyde amount which was one of the membrane lipid peroxides. Our results suggested that M. guilliermondii could improve the activities of ROS scavenging enzymatic system and the levels of antioxidant substances to scavenge excessive ROS, and then protect cells from oxidative damage, which enhanced the disease resistance of broccoli to pathogens. Overall, our study provides a new disease control strategy for postharvest broccoli by improving the ability of ROS scavenging to resist pathogens.
Fruit‐based diets are recognized for their benefits to human health. The safety of fruit is a global concern for scientists. Fruit microbiome represents the whole microorganisms that are associated ...with a fruit. These microbes are either found on the surfaces (epiphytes) or in the tissues of the fruit (endophytes). The recent knowledge gained from these microbial communities is considered relevant to the field of biological control in prevention of postharvest fruit pathology. In this study, the importance of the microbiome of certain fruits and how it holds promise for solving the problems inherent in biocontrol and postharvest crop protection are summarized. Research needs on the fruit microbiome are highlighted. Data from DNA sequencing and “meta‐omics” technologies very recently applied to the study of microbial communities of fruits in the postharvest context are also discussed. Various fruit parameters, management practices, and environmental conditions are the main determinants of the microbiome. Microbial communities can be classified according to their structure and function in fruit tissues. A critical mechanism of microbial biological control agents is to reshape and interact with the microbiome of the fruit. The ability to control the microbiome of any fruit is a great potential in postharvest management of fruits. Research on the fruit microbiome offers important opportunities to develop postharvest biocontrol strategies and products, as well as the health profile of the fruit.
•Cell wall polysaccharides of cassava roots are cellulose, galactan rich pectins and xyloglucans.•Retting deeply reduced galactose and galacturonic acid contents in cassava root cell walls.•Enzyme ...profiling and immuno-labelling revealed that 1,4 linked d-galactans are degraded during retting.•Endo-galactanase is likely a major enzymatic activity involved in the retting process.
Retting is an important step in traditional cassava processing that involves tissue softening of the roots to transform the cassava into flour and various food products. The tissue softening that occurs during retting was attributed to the degradation of cell wall pectins through the action of pectin-methylesterase and pectate-lyase that possibly originated from a microbial source or the cassava plant itself. Changes in cell wall composition were investigated during retting using chemical analysis, specific glycanase degradation and immuno-labelling of cell wall polysaccharides. Pectic 1,4-β-d-galactan was the main cell wall polysaccharide affected during the retting of cassava roots. This result suggested that better control of pectic galactan degradation and a better understanding of the degradation mechanism by endogenous endo-galactanase and/or exogenous microbial enzymes might contribute to improve the texture properties of cassava products.
Abstract Fungal infections of fresh fruits and vegetables (FFVs) can lead to safety problems, including consumer poisoning by mycotoxins. Various strategies exist to control fungal infections of ...FFVs, but their effectiveness and sustainability are limited. Recently, new concepts based on the microbiome and pathobiome have emerged and offer a more holistic perspective for advancing postharvest pathogen control techniques. Understanding the role of the microbiome in FFV infections is essential for developing sustainable control strategies. This review examines current and emerging approaches to postharvest pathology. It reviews what is known about the initiation and development of infections in FFVs. As a promising concept, the pathobiome offers new insights into the basic mechanisms of microbial infections in FFVs. The underlying mechanisms uncovered by the pathobiome are being used to develop more relevant global antifungal strategies. This review will also focus on new technologies developed to target the microbiome and members of the pathobiome to control infections in FFVs and improve safety by limiting mycotoxin contamination. Specifically, this review stresses emerging technologies related to FFVs that are relevant for modifying the interaction between FFVs and the microbiome and include the use of microbial consortia, the use of genomic technology to manipulate host and microbial community genes, and the use of databases, deep learning, and artificial intelligence to identify pathobiome markers. Other approaches include programming the behavior of FFVs using synthetic biology, modifying the microbiome using sRNA technology, phages, quorum sensing, and quorum quenching strategies. Rapid adoption and commercialization of these technologies are recommended to further improve the overall safety of FFVs.
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