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Background Grapes are one of the highly valued non-climacteric fruits that can be consumed fresh or used to produce numerous food products and dietary supplements. Inadvertent fungal infections cause substantial economic and commodity loss in the grape industry. However, control measures have been developed and widely used to combat pathogenic fungal attacks in grapes, most of which are indiscriminate towards the pathogenic fungi. Precise interactions between various pathogenic fungi and grapes have not been fully explored. Scope and approach In the past decade, advanced molecular technics and ‘omics’ approaches have allowed progress to understand such interactions. Discoveries regarding pathogen entry, optimal conditions for pathogenesis, virulence factors, mycotoxin production, fungal genes involved in pathogenesis, quiescent and necrotrophic lifestyles of pathogenic fungi, and grape fruit's response towards the pathogen attack have been published. Key findings and conclusions This review paper summarizes the possible pathways of fungal pathogenesis in grapes and environmental factors influencing fungal infections. We emphasize the molecular aspects of fungal invasions and the transition between quiescent and necrotrophic lifestyles of grape fungal pathogens and the grape's immune response against pathogen attack and genes involved in the defence mechanism. We pinpoint the recent innovations in control strategies and prospective developments in the field. This review aims to reduce the knowledge gap between the fungal disease progression mechanisms and the development of various disease control strategies in grape production.

Sugars and organic acids are important factors associated with the postharvest quality of fruits and vegetables, but respiratory metabolism effects the metabolite contents. The objectives of this study were to explore the affects of Fusarium proliferatum infection on the postharvest quality and respiratory metabolism of green asparagus. It was found that F. proliferatum caused the soluble sugar concentration of asparagus to increase over the first 2 d of storage and then decrease again to become significantly lower than the control at 4 d. The titratable acidity (TA) of infected asparagus also increased from day 2 to day 6 and then decreased to become significantly lower than the control. Similarly, the key enzyme activities of the Embden-Meyerhof-Parnas (EMP) pathway, tricarboxylic acid (TCA) cycle, and pentose phosphate pathway (PPP) increased in pathogen-infected asparagus at the beginning of storage and then decreased to become lower than the control at the end. These findings demonstrate that F. proliferatum caused quality deterioration and an impairment of respiratory metabolism in postharvest asparagus. This research helps to clarify the relationships between pathogen infection, physiological metabolism, and asparagus quality and will provide valuable information for the control of postharvest diseases of asparagus.

Rhodotorula mucilaginosa is an antagonistic yeast for which our research team has recently reported interesting biocontrol activities against blue mould decay of apples and a strong ability to decr...

Biological control utilizing antagonistic yeasts is an effective method for controlling postharvest diseases. Long non-coding RNAs (lncRNAs) have been found to be involved in a variety of plant growth and development processes, including those associated with plant disease resistance. In the present study, the yeast antagonist, Wickerhamomyces anomalus, was found to strongly inhibit postharvest blue mold (Penicillium expansum) and gray mold (Botrytis cinerea) decay of kiwifruit. Additionally, lncRNA high-throughput sequencing and bioinformatic analysis was used to identify lncRNAs in W. anomalus-treated wounds in kiwifruit and predict their function based on putative target genes. Our results indicate that lncRNAs may be involved in increasing ethylene (ET), jasmonic acid (JA), abscisic acid (ABA), and auxin (IAA) levels, as well as activating signal transduction pathways that regulate the expression of several transcription factors (WRKY72, WRKY53, JUB1AP2). These transcription factors (TFs) then mediate the expression of downstream, defense-related genes (ZAR1, PAD4, CCR4, NPR4) and the synthesis of secondary metabolites, thus, potentially enhancing disease resistance. Notably, by stimulating the accumulation of antifungal compounds, such as phenols and lignin, disease resistance in kiwifruit was enhanced. Our study provides new information on the mechanism underlying the induction of disease resistance in kiwifruit by W. anomalus, as well as a new disease resistance strategy that can be used to enhance the defense response of fruit to pathogenic fungi.

Whitening cosmetics have a large market scale and broad development prospects, while whitening products of traditional Chinese medicine have always been a research hotspot. In this study, the whitening active extract of Platycodon grandiflorum (PGE) was isolated and purified for the first time, and the whitening activity mechanism and chemical composition of PGE were elucidated. A total of 45 components were identified via high-performance liquid chromatography-mass spectrometry (HPLC-MS) analysis, including arbutin, syringin, chlorogenic acid, platycoside E, platycodin D3, baicalin, platycodin D, and luteolin. The scavenging rates of PGE toward DPPH and ABTS free radicals were 98.03% and 84.30%, respectively. The inhibition rate of PGE toward tyrosinase was up to 97.71%. The PGE had significant anti-inflammatory effects on RAW264.7 macrophages stimulated by lipopolysaccharide (LPS) and had significant inhibition effects on tyrosinase and melanin generation of B16F10 cells stimulated by α-MSH. The results showed that the PGE achieved a synergistic whitening effect by inhibiting the activation of oxygen free radicals on tyrosinase, antioxidation, anti-inflammatory effect, enzyme activity, and melanin generation. As a whitening agent extracted from natural plants, PGE has great potential in the research and development of plant whitening cosmetics, which lays a foundation for the further development and utilization of Platycodon grandiflorum resources and also provides a theoretical basis for the development of green and organic whitening cosmetics.

The main postharvest pathogen of citrus fruit is Penicillium digitatum. The present study looked at the role of Rhodotorula mucilaginosa enhanced with 0.2 mM salicylic acid (SA) on pH, lignin content accumulation and growth dynamics as a resistance mechanism against P. digitatum in orange fruit. Our findings revealed that the increase in lignin content at 20 °C storage temperature resulted in the significant decrease (P ≤ 0.05) in the lesion diameter in fruit treated with R. mucilaginosa enhanced with or without 0.2 mM SA compared to the untreated fruit (control). In addition, the pH values of the fruit treated with R. mucilaginosa enhanced with or without 0.2 mM SA were 4.43 ± 0.07 and 4.15 ± 0.11, respectively, around the infection site compared to the untreated group. Moreover, the in vivo trial showed that the addition of 0.2 mM SA to the antagonist augmented its growth, and subdued substantially the hyphae and spore germination of P. digitatum in vitro. Also, lower levels of malondialdehyde (MDA) and hydrogen peroxide (H2O2) content were observed in fruit treated with the antagonist enhanced with or without 0.2 mM SA compared to the control. The results established that pH, lignin content accumulation and growth of the yeast played a significant role in the control of green mold decay of orange fruit.

Patulin contamination not only is a menace to human health but also causes serious environmental problems worldwide due to the synthetic fungicides that are used to control it. This study focused on investigating the patulin degradation mechanism in Pichia caribbica at the molecular level. According to the results, P. caribbica (2 × 106 cells/mL) was able to degrade patulin from 20 μg/mL to an undetectable level in 72 h. The RNA-seq data showed patulin-induced oxidative stress and responses in P. caribbica. The deletion of PcCRG1 led to a significant decrease in patulin degradation by P. caribbica, whereas the overexpression of PcCRG1 accelerated the degradation of patulin. The study identified that PcCRG1 protein had the ability to degrade patulin in vitro. Overall, we demonstrated that the patulin degradation process in P. caribbica was more than one way; PcCRG1 was an S-adenosylmethionine-dependent methyltransferase and played an important role in the patulin degradation process in P. caribbica.

The effectiveness of Rhodotorula mucilaginosa in combination with salicylic acid (SA) was explored for the control of green mold decay of oranges and the mechanisms involved. The results of the study showed that treatments with the diverse concentrations of SA was remarkable in reducing the disease incidence of oranges and that SA at a concentration of 0.2 mM reduced the decay of oranges from 93.06% to 61.12%. At an incubation temperature of 20 °C and RH of 95% the disease incidence and lesion diameter in fruit treated with R. mucilaginosa enhanced with or without SA were significantly reduced compared to that of the control (P

Penicillium digitatum is a mesophilic fungus belonging to the genus, Penicillium and a producer of citrinin. This mycotoxin is a secondary metabolite and its existence has been reported in several agricultural products. In this study, the effect of Rhodotorula mucilaginosa on the production of citrinin by P. digitatum and the degradation of citrinin in vitro was investigated. The effect of R. mucilaginosa was dependent on the type of media, yeast concentration, pH, and temperature. R. mucilaginosa degraded citrinin produced by P. digitatum and the toxin with a degradation rate of 91.67% and 91.61%, respectively compared to the control. The degradation of citrinin by R. mucilaginosa was significant in nutrient yeast dextrose broth compared to potato dextrose broth where it was fairly stable throughout the test period. The yeast concentration that showed better efficacy was 1 × 108 cells/mL with a degradation rate of 93.10% at 48 h. Numerically, degradation was highest at 28 °C with a pH 4.0 being the most favorable for citrinin degradation by R. mucilaginosa.

Citrinin (CIT) contamination has been reported in agricultural foods and is known to be nephrotoxic to human and animals. In the present study, the proteomes and transcriptomes of C. podzolicus Y3 treated with or without 10 μg/mL CIT were compared by two-dimensional electrophoresis (2-DE) and RNA sequencing, respectively. The proteomics results showed that there were 23 differentially expressed proteins (DEPs), 8 DEPs were up-regulated and 15 DEPs were significantly down-regulated. Transcriptomic analysis showed that 1208 genes were differentially expressed, 551 (43.05%) DEGs were up regulated and 657 (56.95%) were down-regulated. These results showed that the CIT treatment caused DNA damage, oxidative stress and cell apoptosis in C. podzolicus Y3. CIT treatment also activated the defense response (DNA repair and drug resistance biological process, antioxidative activity and TCA cycle) as well as drug metabolism (synthesize the CIT-degrading enzymes) in yeast cells to respond to CIT stress and degrade CIT.

Talaromyces rugulosus O1 is an ochratoxin A (OTA)-producing pathogen from grapes. The mechanisms involved in the infection of postharvest grapes by T. rugulosus O1 are not yet clear. In this study, the infection of grapes by T. rugulosus O1 and OTA production in grapes were investigated, and the role of cell wall degrading enzymes of T. rugulosus O1 and OTA in the infection of grapes by T. rugulosus O1 was explored. The results indicated that T. rugulosus O1 showed significant infection effect on grapes at 20 °C, and accumulated OTA in the wound of grapes in the infection progress. In comparison with the control, the activities of polygalacturonase (PG), pectin methylgalacturonase (PMG), exo-1,4-β-glucanase (C1) and β-glucosidase (β-G) secreted by T. rugulosus O1 in grapes were all increased in the infection process. Furthermore, the pectinase (PG and PMG) activities were higher than cellulase (C1 and β-G) activities. The expression levels of genes encoding PG and β-G in T. rugulosus O1 infecting grapes increased as the time prolong. Inoculation of T. rugulosus O1 in combination with addition of OTA in the wound of grapes resulted in higher decay incidence and lesion diameter of treated grapes compared with the treatment with T. rugulosus O1 or OTA alone. This indicated that OTA can promote the infection of grapes by T. rugulosus O1. This study provides useful information about the role of cell wall degrading enzymes and OTA in the infection of grapes by T. rugulosus O1.

BACKGROUND In the process of biological control, the antagonistic yeasts contend with various stresses that negatively influence yeasts' biocontrol efficiency. In the current study, we investigated the effect of trehalose supplementation on the biocontrol efficiency and oxidative stress tolerance of Sporidiobolus pararoseus Y16. RESULTS S. pararoseus Y16, an antagonistic yeast cultured in trehalose supplemented medium, exhibited better biocontrol efficiency against Penicillium expansum and Aspergillus tubingensis in table grapes. Trehalose-treated S. pararoseus Y16 cells showed good proliferation efficiency and oxidative stress tolerance than untreated cells. Increased β-1,3-glucanase, catalase, superoxide dismutase activity, and low protein carbonylation were observed in trehalose-amended S. pararoseus Y16 upon H2 O2 exposure. The RNA sequencing results indicated that trehalose significantly altered the transcriptome of S. pararoseus Y16. The GO, KEGG, and COG annotations revealed that the differentially regulated genes corresponded to the various biological process of the yeast. CONCLUSION Our findings suggested that trehalose use could enhance the biocontrol efficiency and oxidative stress tolerance of S. pararoseus Y16. Trehalose supplementation altered the transcriptome of S. pararoseus Y16, particularly the genes that correspond to amino acid metabolism, nucleotide metabolism, and protein modification. Thereby the oxidative stress tolerance and biological control efficiency of S. pararoseus Y16 was enhanced by trehalose. © 2021 Society of Chemical Industry.

Filipendula palmata (Pall.) Maxim. remains unexplored and underutilized resources with a high potential to improve human health. In this study, a new ursane-type triterpenoid, namely, 2α, 3β-dihydroxyurs-12-en-28-aldehyde (compound 10), and other 23 known compounds were isolated. 5 triterpenoids (compounds 6, 8, and 10–12), 11 flavonoids (compounds 13–15 and 17–24), 6 phenolic compounds (compounds 1, 2, 4, 5, 9, and 16), 2 sterols (compounds 3 and 7) were isolated from the aqueous solution extract of the aerial parts of F. palmata. The structures of all compounds were elucidated by the use of extensive spectroscopic methods such as infrared spectroscopy (IR), high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), 1H-NMR, and 13C-NMR. The solvent extractions of ethyl acetate fraction were evaluated for antioxidant activities using DPPH (2, 2-diphenyl-1-picrylhydrazyl) and ABTS+ (2, 2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)) methods. The anti-inflammatory effects of the compounds were evaluated in lipopolysaccharide- (LPS-) stimulated RAW 264.7 macrophages. The extract cytotoxicity on the cancer cell lines MCF-7, HeLa, 4T1, and A549 was determined by MTT assay. As a result, compounds 10, 11, and 12 exhibited better antioxidant activity compared to the other compounds. Compounds 8–24 had different inhibitory effects on the release of NO, TNF-α, and IL-6 in LPS-stimulated RAW 264.7 cells. The new compound has shown a significant inhibiting effect on cancer cells, and the cell inhibition rate increased in a dose-dependent manner. Further research to elucidate the chemical compositions and pharmacological effects of F. palmata is of major importance towards the development and foundation of clinical application of the species.

Increasing patulin contamination in fruits and fruit-derived products has become a major challenge for the food industry. Biological methods of patulin control have an important role to play owing to their safety and efficiency. In this study, we used the yeast Pichia caribbica to degrade patulin effectively. The intermediate degradation products of patulin by P. caribbica were identified as (E)- and (Z)-ascladiol using high performance liquid chromatography and liquid chromatography-tandem mass spectroscopy. Only (E)-ascladiol was detected in the products of patulin degradation by intracellular enzymes. Toxic analyses on Escherichia coli Top10 cells, Arabidopsis thaliana, and human esophageal epithelial cells (Het-1a) showed that the intermediate degradation product ascladiol and the final degradation products were significantly less toxic and almost non-toxic compared to patulin (p 0.05) compared to patulin. Analysis of the characteristics and toxicity of the degradation products of patulin by P. caribbica demonstrate that ascladiol is less toxic and the final degradation products are not poisonous, therefore patulin detoxification strategies using P. caribbica are good approaches to limit the patulin risks.

Biological control of mycotoxin in cereals, fruits and vegetables have emerged as a promising method. In a previous study, Yarrowia lipolytica Y‐2 isolated by our research team showed biocontrol effect on the post‐harvest decay of grapes and ochratoxin A (OTA) elimination in polytoma medium. The aim of this study was to elucidate the possible mechanisms of OTA elimination by Y. lipolytica Y‐2. The results indicated that OTA elimination by Y. lipolytica Y‐2 was attributed to the degradation action of intracellular enzymes but not extracellular enzymes. A degradation product was identified as ochratoxin alpha (OTα) by liquid chromatography‐tandem mass spectrometry. The intracellular enzymes precipitated with 65% saturation of ammonium sulphate degrade OTA the most quickly and 97.2% OTA was degraded within 4 h. Analysis of this fraction showed that two proteins of carboxypeptidase were expressed in Y. lipolytica Y‐2 but not in Y. lipolytica Polh without the ability to degrade OTA. The results of the protein identification combined with product identification indicated that OTA was degraded to OTα by Y. lipolytica Y‐2 through the hydrolysis activity of carboxypeptidases. Additionally, many proteins of Y. lipolytica Y‐2 involved in stress response and reactive O₂ species elimination also played essential role in OTA degradation.

Patulin (PAT) mainly produced by Penicillium expansum is a very problematic mycotoxin, and its presence is often reported in different foods and food products. The prevention of these products from initial contamination and/or degradation is therefore of foremost importance in protecting consumer health. In this report, Pichia caribbica (1 × 108 cells mL−1) antagonistic yeasts incorporated with bamboo leaf flavonoid (0.01% w/v) were assessed for PAT degradation capabilities in in-vitro and in-vivo. Also the effects of treatments on wound lesion diameter, lignification and pH level were investigated. Clearly, the combined biocontrol agent (P. caribbica and bamboo leaf flavonoid) had the ability to degrade PAT in vitro with undetected level at 96 h of incubation in NYDB media. In apple fruits, PAT accumulation was significantly lower at 20 d (at 20 °C) of storage. Wound lignification was significantly enhanced from 0.31 to 0.27 after 15 d of storage, whereas pH was modified (>4.0) in host; which might lead to an increase in PAT breakdown. P. caribbica combined with bamboo leaf flavonoid could be a promising biocontrol agent for PAT degradation processes in apple fruits.

It has been reported that Yarrowia lipolytica can effectively control blue mold and green mold decay of mandarins (Citrus reticulata), and also the possible physiological mechanisms underlying this efficacy were studied in our previously research. However, the related molecular mechanisms were not clearly. In this study, the molecular mechanisms of disease-resistance in mandarins induced by Y. lipolytica were investigated. It was found that, after the treatment of Y. lipolytica, the related resistance enzyme activities of β-1,3-glucanase, superoxide dismutase, and ascorbate peroxidase in mandarins were enhanced, while the malondialdehyde content was decreased. Interestingly, based on the transcriptome analysis, it was found that Y. lipolytica can induce the up-regulation of genes related to the synthesis of resistant substances; key genes in the pathway of plant-pathogen interaction; genes related to scavenging reactive oxygen species; genes related to jasmonic acid, salicylic acid and ethylene signal transduction pathway in mandarins. Furthermore, Y. lipolytica down-regulated the expression levels of genes encoding cell wall degrading enzymes. Definitively, this unravelling of the molecular mechanisms of Y. lipolytica will contribute to consolidate its potential to serve as an effective biocontrol agent against post-harvest diseases of mandarins.

Patulin is a well-known mycotoxin widely found in rotten fruits, produced by a series of toxigenic fungi, particularly Penicillium expansum. Patulin is hazardous to human and animal health. Meyerozyma guilliermondii is an antagonistic yeast that has been found to have biocontrol properties against blue mold disease in pears. But, it is not clear whether M. guilliermondii can degrade patulin. The present study aimed to investigate M. guilliermondii to degrade patulin and the possible mechanisms involved. The results showed that neither uptake of patulin by cells nor adsorption by cell wall components were involved in patulin elimination by M. guilliermondii. Extracellular metabolites also do not degrade patulin. The addition of cycloheximide to the M. guilliermondii cells decreased the capacity of patulin degradation. Enzymes induced by patulin had a more substantial degradation effect on patulin, which indicated that the patulin-degradation ability of M. guilliermondii was inducible. Our results confirmed that M. guilliermondii could degrade patulin. The intracellular enzymes of M. guilliermondii, particularly a short-chain dehydrogenase (SDR), carried out the degradation process. The degradation ability of M. guilliermondii towards patulin would be a novel approach for the elimination of patulin contamination.

In this study, the activitiesof defense-related enzymes andthose involved in reactive oxygen species (ROS) and their corresponding genes coding for PPO , APX , CHI , PAL and CAT in response to Hanseniaspora uvarum and Hanseniaspora uvarum harvested from NYDB supplemented with 2% w/v trehalose in nutrient yeast dextrose broth (NYDB) were investigated. Conventional methods and qRT-PCR were used to perform defense-related enzyme activities and relative genes expression respectively. The results indicated that H. uvarum enhanced with 2% w/v trehalose demonstrated biocontrol efficacy against Aspergillus tubingensis in grapes.Furthermore, it was noticed that H. uvarum supplemented with 2% w/v trehalose in NYDB had a significantly effect on the induction of defense-related genes expression andenzyme activities compared to the control, 2% w/v trehalose and H. uvarum after storage at 20 °C for 72 h. CAT relative gene expression level in grapes treated with H. uvarum supplemented with 2% w/v trehalose was the highest with 23-fold increase compared to the control. These results suggested that H. uvarum pretreated with trehalose up-regulatedthe defense-relatedgenes expression and enzyme activitiesin the grapes. These findings indicated that, the application of H. uvarum harvested from NYDB supplemented with 2% w/v trehalose enhanced the defense-related mechanism of grapes against A. tubingensis .

The purpose of this research was to investigate the mechanisms involved in improving oxidative tolerance of Pichia caribbica by using ascorbic acid (VC). VC is noted for its ability to enhance oxidative tolerance. Therefore, this study investigated the effects of VC on the cellular oxidative damage as well as antioxidative enzymes activities of P. caribbica under oxidative stress. The results indicated that oxidative damage occurred in P. caribbica especially under the non-VC treatment condition. The application of VC significantly reduced the oxidative damage. On the other hand, system scavenging the excess reactive oxidative species such as antioxidative enzymes and substances was initiated when exposed to the H 2 O 2 . Moreover, VC enhanced the efficacy of antioxidative enzymes (ascorbic peroxidase, peroxidase, polyphenol oxidase) and antioxidative substances (glutathione and trehalose). Thus, VC improved the oxidative tolerance of P. caribbica , which could lead to an enhancement of biocontrol activity of P. caribbica .

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.

The glycoprotein from Schisandra chinensis was obtained with alkali extraction and acid precipitation, purified with DEAE Sepharose Fast Flow and Superdex G-75 column. The molecular composition structure and antifatigue activities of glycoprotein were studied. SCGP’s molecular weight was approximately 10 KDa, and it consisted of a carbohydrate component (52.94%) and protein component (47.06%). SCGP comprised mannose, galactoside, rhamnose, glucose, galactose, xylose, arabinose, and fucose, its molar ratio was 2.14 : 1.43 : 1.59 : 8.17 : 8.99 : 3.18 : 18.51 : 1, and it contained 16 kinds of amino acids. SCGP could obviously extend the swimming time in mice by increasing LDH, SOD level, GSH-Px activity, and liver glycogen and decreasing the contents of BUN and MDA. The antioxidant activity of SCGP is a potential mechanism of its antifatigue effect. In vitro antioxidant test showed that SCGP scavenged DPPH and OH radicals in a dose-dependent manner (IC50 was 0.91 mg/ml and 0.72 mg/ml).

Grapes are high nutritional and economic fruit but extremely vulnerable to fungus infections during postharvest storage. Our previous study found that the fungi, Talaromyces rugulosus O1 secretes ochratoxin A (OTA), which inflicts consumer health and economic value. This study found that T. rugulosus O1 has strong pathogenicity and spore germination to produce germ tubes to help it infect grapes. To better understand the molecular interaction between T. rugulosus O1 and grape, RNA sequencing (RNA-seq) was performed, and 5037 genes were identified as differentially expressed genes (DEGs) in grapes after T. rugulosus O1 infection. RNA-seq analysis revealed that T. rugulosus O1 infection, induced complex defense reactions in grapes, including an influx of Ca2+, oxidative burst, changes in GSH, plant hormone signal transduction, transcription factor regulation, overexpression of protein kinases, and biosynthesis of plant secondary metabolites. Our study found that the activity of the resistance enzymes in grapes was increased after T. rugulosus O1 infection, which is consistent with the RNA-seq results. Moreover, the accumulation of some antifungal compounds, including flavonoids, phenols, and lignin in grapes, increased grapes' antifungal ability.

Our previous study showed that the biocontrol efficacy of Rhodotorula mucilaginosa against postharvest diseases of strawberries can be significantly enhanced by chitosan. Proteome analysis of R. mucilaginosa induced by chitosan has preliminarily explored the molecular mechanisms involved in the enhanced antagonistic efficacy of R. mucilaginosa induced by chitosan. In this study, transcriptome analysis of R. mucilaginosa cultured with and without chitosan was performed, and the activities of CAT, PPO, POD, and SOD were also investigated to further explore the involved mechanisms. The results indicated that the activities of these antioxidant enzymes in R. mucilaginosa were all significantly increased by 0.5 g/100 mL chitosan. Especially, POD activity was about 1.5 - fold higher than the control. Transcriptome and bioinformatic analysis revealed that significant number of genes involved in growth and reproduction, adhesion, energy production, oxidative stress response and other stress response were all induced by chitosan, which resulted in the enhanced antagonistic efficacy of R. mucilaginosa. These results provide a reference for the future study on controlling postharvest disease of fruit and vegetables by antagonist yeast and provide a theoretical basis for the practical application of antagonist yeast.

Telomeric DNA acts as mitotic clock being gradually reduced at each cell division cycle, which will lead the cell to senescence and apoptosis. The G-rich sequences at telomeres can adopt G-quadruplex structures, which have been shown to directly inhibit the enzyme telomerase. The rational design of small-molecule ligands, with a particular focus on the structural features required for selectively binding to G-quadruplex structures, is significant and useful in biochemistry and clinical diagnosis. Here, a new small-molecule ligand Cp-1, a carbazole-quinolinum core bridged with a phenylboronic acid side chain, has been synthesized and characterized by NMR spectroscopy and mass spectrometry. The binding affinity and selectivity towards telomeric G-quadruplex DNA have been determined by fluorescence spectroscopy, UV/Vis titrations, CD spectroscopy and molecular docking study. These studies have shown that the ligand Cp-1 has higher binding affinity and selectivity towards telomeric G-quadruplex over duplex DNA. Binding mode analysis indicated Cp-1 interacted with G-quadruplex DNA mainly through end-stacking mode. Further, the ligand could enter live cells and localize in the cytoplasm as shown by confocal fluorescence microscopy.

Losses of harvested fruits and vegetables can be attributed to decaying fungi. These fungi are pathogenic and also a source of mycotoxins, which pose a health threat to humans and animals. As a result, national and international organizations have set detection levels for toxic secondary metabolites for harvested commodities and derived products. Citrinin (CIT) is a mycotoxin produced by fungi and is found in association with patulin, and ochratoxin A, which is nephrotoxic, hepatotoxic, immunosuppression, and carcinogenic. CIT has been recovered from fruit, grains, feedstuff, and biological fluids. Heart, kidney, liver, and reproductive system disorders can be a result of exposure to these mycotoxins. The review points out that, although CIT has health implications, its maximum levels have not been set and not been enforced by national and international organizations. The aim of this review is to look at its occurrence, risks implications, analytical techniques for its detection and quantification, production, biosynthesis, physiochemical properties, and control.

Ochratoxin A (OTA) has been found in a wide range of commodities and is highly toxic to both humans and animals. Therefore, a good understanding of the mechanisms of OTA production by fungi will contribute to the development of eco-friendly methods to mitigate this toxin. In this study, the results showed that Penicillium citrinum X9-4, which was isolated from infected grapes in our laboratory, produced the highest amount of OTA at pH 5 in culture media, and toxin production was restrained under an acidic environment (pH 3). Then, differentially expressed proteins of P. citrinum X9-4 cultured under these two conditions were analyzed by proteomic technology. Additionally, through the analysis of the transcriptome data of P. citrinum cultured at pH 3 and 5, the differentially expressed genes have been found to be involved in many metabolic pathways including amino acid transport and metabolism, transport and metabolism of carbohydrates, inorganic ion transport and metabolism, biosynthesis of secondary metabolites, and energy and supply metabolism, which are likely to be involved in the regulation of OTA biosynthesis. It was also revealed that the expression levels of some OTA synthesis-related enzymes, such as acetyltransferase, acyl coenzyme A oxidase, alcohol oxidase, cytochrome P450, acetyl xylan esterase, and turn ketol enzyme, and genes for the regulation of toxin synthesis pathways were reduced under acidic culture conditions.

The effect of phosphatidylcholine (soybean extract) on the biocontrol efficacy of the antagonistic yeast Hanseniaspora uvarum Y3 against green mold of oranges was investigated. The results showed that H. uvarum Y3 significantly inhibited green mold of oranges at different concentrations compared with the control. Besides, phosphatidylcholine was observed to enhanced the biocontrol efficacy of H. uvarum Y3. Among the different concentrations, phosphatidylcholine at 1.5% w/v combined with H. uvarum Y3 exhibited the best control effect, the green mold incidence of oranges was only 4.63%, while the incidence was 33.33% when treated with H. uvarum Y3. After 24 h incubation, phosphatidylcholine at the different concentrations did not significantly influence the population of H. uvarum Y3 in NYDB. However, it was found that, phosphatidylcholine (1.5% w/v) significantly improved the population dynamics of H. uvarum Y3 in orange wounds at 20 °C. The scanned electron microscope (SEM) results showed that H. uvarum Y3 combined with phosphatidylcholine (1.5% w/v) significantly inhibited the spore germination and mycelial growth of Penicillium digitatum in orange wounds. Moreover, H. uvarum Y3 in combination with 1.5% phosphatidylcholine treatment did not impair postharvest qualities of oranges. Conclusively, H. uvarum Y3 in combination with phosphatidylcholine offers a great potential as an alternative method against postharvest green mold of oranges.

Biological control using microbial antagonists is a promising alternative approach to synthetic fungicides. However, effective biological control requires enhancing the consistency and efficacy of the antagonists used to control postharvest diseases. This study investigated the effect of chitin on the biocontrol efficacy of Rhodotorula mucilaginosa against blue mold and Rhizopus decay of peaches and on the protein expression profiles of R. mucilaginosa. The antagonistic activity of R. mucilaginosa harvested from the nutrient yeast dextrose broth (NYDB) with 0.5% chitin added was significantly improved compared with culture in NYDB without chitin. The R. mucilaginosa population cultured in chitin-supplement NYDB and nutrient yeast chitin borth (NYCB) harvested from peach wounds was more than that of R. mucilaginosa cultured in NYDB without chitin throughout the storage period except at 1 d. The protein expression profiles findings revealed that there were several differentially expressed proteins of R. mucilaginosa in the 0.5% chitin-supplemented NYDB and NYCB compared with that of R. mucilaginosa in NYDB. Most of these were cellular proteomes relating to the primary metabolic reactions such as glycoside hydrolases, phosphoribosyl pyrophosphate, and NADH dehydrogenases. Some proteins were also related to signal transmission and stress response.

Background Ochratoxin A (OTA) remains a challenge in the face of continuous efforts to produce quality and wholesome wine and table grape berries to meet food safety standards. However, the use of chemicals to control postharvest diseases is a public concern with increasing consumer awareness of the dangers associated with the consumption of fungicide-treated commodities. Synthetic fungicides are well-known for their hazardous effects on human health and potential contamination to the environment. Moreover, pathogens are noted to have developed resistance to these chemicals because of their continuous use and abuse. Scope and approach This review focused on the efficacies, potentials and developmental trends of microbial antagonists in the control and biodegradation of OTA-producing fungi in grapes and wine. It outlined the steps and challenges in the development of bioproducts. It also recounted the successes and developments of biocontrol products to date. Key findings and conclusions OTA production in grapes is caused by the genera Aspergillus and Penicillium , with the species Aspergillus carbanarius as the dominant cause across the globe. The prevalence of OTA-producing fungi in grape vineyards are influenced by temperature, water activity (a w ), pH, relative humidity and type of cultivar. Biological control agents (BCAs) have proved successful to control and/or degrade OTA-producing fungi, among which antagonistic yeasts play the leading role. In addition, biocontrol products such as BioSave, Yieldplus, Serenade and Aspire have been developed. Preharvest application is acknowledged to be the best for grapes even a day before harvest because postharvest treatment affects the bloom of the grapes.

In order to obtain the optimal control point for single-cell lipid production with fatty acid profile similar to cocoa butter, this study explored the effects of carbon source, nitrogen source, temperature, sterculic acid methyl ester, cobalt on cell growth and lipid accumulation of Yarrowia lipolytica. Glycerol and ammonium tartrate-yeast extract were chosen as carbon source and nitrogen source for production of cocoa butter equivalent. Gradual increase in temperature (20-35°C) resulted in growth reduction, while increased in lipid content per Cell Dry Weight (CDW) (10.13 to 19.7%, w/w) and Saturated Fatty Acids (SFA). Our results suggests that the optimum conditions for Y. lipolytica to synthesize cocoa butter equivalent was 30°C with 0.6 mg L-1 of CoCl2.6H2O or 0.03 mL L-1 sterculic acid methyl ester in the medium with glycerol and ammonium tartrate-yeast extract as carbon source and nitrogen source.

The mycotoxin ochratoxin A (OTA) is a common contaminant of various plant-derived foods and feeds. However, methods for complete decontamination remain to be established. Recently, biological approaches for mycotoxin removal using various species of yeast have been explored. In the present study, we investigated the efficacy of OTA degradation by the yeast Yarrowia lipolytica under various conditions, altering yeast concentration, temperature, pH, and concentration of OTA in order to determine the optimal requirements of this species. At a yeast concentration of 108 cells/ml, the degradation rate was higher than that observed at any other concentration and, after 24 h, the OTA concentration was reduced to almost half of the initial level introduced to the culture. Further, Y. lipolytica cultured at 28 °C showed the highest level of OTA degradation. Similarly, the culture performed optimally at a pH of 4. The initial concentration of OTA also affected the ability of the yeast to degrade OTA, with the level of degradation being the highest when the initial OTA concentration was 0.1 μg/ml. Moreover, we also tested the toxicity of the OTA biodegradation products using HepG2 cells to determine the physiological applicability of this yeast species in the food industry and observed that these products were notably less toxic than non-degraded OTA. Y. lipolytica effectively reduced natural decay incidence of grapes, and had no negative effect to the storage quality of grape fruits. Taken together, these data suggest that Y. lipolytica could be a viable OTA contamination prevention/treatment option and additional research concerning its commercial use is warranted.

Rhodotorula mucilaginosa cultured in a medium amended with chitosan significantly enhances biological control efficacy against postharvest fungal diseases of strawberries. The molecular mechanisms underlying the enhanced disease resistance of strawberries, however, have not been explored. In this study, a transcriptomic and proteomic approach was used to analyze the induced resistance response in strawberry. Results revealed that several genes involved in JA/ET, ABA and GA signal transduction pathways, as well as downstream genes and protein, were up-regulated by R. mucilaginosa cultured in a medium amended with 0.5% (w/v) chitosan. Several genes and proteins related to the synthesis of resistance-related compounds and processes were also up-regulated, including genes related to ROS regulation, and genes involved in cell wall reinforcement. Collectively, results indicated that disease resistance in strawberry can be induced by R. mucilaginosa cultured with chitosan. A global view of gene expression and protein abundance in hosts treated with an antagonist provides a theoretical reference for understanding the enhancement of disease resistance of fruits by antagonistic yeast incubated with elicitors, information that will also help in obtaining regulatory approval for the commercial use of yeast as biocontrol agents.

The biocontrol efficacy of the yeast, Rhodotorula mucilaginosa against postharvest diseases of strawberries can be significantly enhanced by culturing the yeast in a medium containing chitosan. The molecular mechanisms involved in the enhanced biocontrol efficacy of R. mucilaginosa, however, have not been comprehensively explored. Results of the present study indicate that the biocontrol efficacy of the yeast against gray mold (Botrytis cinerea) of strawberry was greatest when the yeast was cultured in a medium containing 0.5% (w:v) chitosan for 24 h before use. Proteomic and bioinformatic analyses revealed that proteins involved in growth and reproduction, energy metabolism, antioxidant response, response to abiotic stress, and degradation of pathogen cell walls were all up-regulated by chitosan resulting in the enhanced antagonistic activity of R. mucilaginosa against B. cinerea. The decrease in ROS accumulation in R. mucilaginosa cultured in a medium containing chitosan was in agreement with the increased abundance of proteins related to antioxidant defense. Key differentially expressed proteins (DEPs) were identified and 12 randomly-selected DEPs were validated by parallel reaction monitoring. The present results provide a theoretical reference for further study of the molecular mechanisms involved in the improvement of biocontrol efficacy of antagonistic yeast by elicitor molecules and also provide a novel approach for improving biological control of postharvest diseases.

Polycyclic aromatic hydrocarbons (PAHs) are key air pollutants that may contribute to the risk of numerous diseases by inducing inflammation and oxidative stress. Individuals with metabolic disorders may be more susceptible to PAH-induced inflammation and oxidative stress. To test this hypothesis, we designed a panel study involving 60 patients with pre-type 2 diabetes (pre-T2D) and 60 reference participants, and conducted up to seven repeated clinical examinations. Urinary metabolites of PAHs (i.e., OH-PAHs), measured as indicators of total PAH exposure, showed significant associations with markers of respiratory and systemic inflammation, including exhaled nitric oxide, interleukin (IL)-6 in exhaled breath condensate, and blood IL-2 and IL-8 levels and leucocyte count. The most significant effect was on urinary malondiadehyde (MDA), a marker of lipid peroxidation; a onefold increase of OH-PAHs was associated with 9.2-46.0% elevation in MDA in pre-T2D participants and 9.8-31.2% increase in healthy references. Pre-T2D participants showed greater increase in MDA, suggesting that metabolic disorder enhanced the oxidative damage induced by PAH exposure. This study revealed the association between PAH exposure and markers of inflammation and oxidative stress, and the enhanced responses of pre-T2D patients suggested that individuals with metabolic disorders were more susceptible to the adverse health effects of PAH exposure.

Rhodotorula mucilaginosa, is an antagonistic yeast that has the ability to inhibit postharvest diseases of apples and effectively degrade patulin. The present study was designed to investigate the population dynamics of the yeast on the surface of apple fruit, the induction of defense response in apple, and the transcriptomic response of R. mucilaginosa to patulin. Results demonstrated that the population of R. mucilaginosa remained stable on the surface of apples kept at either 20 °C or 4 °C. Furthermore, R. mucilaginosa increased the activity of defense-related enzymes in apples, including chitinase and β-1,3-glucanase, which presumably enhanced the disease resistance of apples. The RNA-Seq analysis, identified 182 differentially expressed genes (DEGs), which included 104 that were up-regulated and 78 that were down-regulated genes. Further analysis indicated that the degradation of patulin by R. mucilaginosa was highly regulated, and identified the major stress tolerance-related DEGs and metabolic pathways involved in patulin degradation.

The proteomic and lysine acetylation (Kac) changes, accompanying degradation of patulin in Rhodotorula mucilaginosa were analyzed using tandem mass tagging and N6-acetyllysine affinity enrichment followed by LC-MS/MS. Proteomic results showed that expression level of short-chain reductase protein and glutathione S-transferase involved in detoxification was significantly up-regulated. In addition, the expression levels of zinc-binding oxidoreductase and quinone oxidoreductase that are involved in antioxidant process, ABC transport and MFS transport responsible for chemical transport were activated when treated with patulin. The quantitative real time PCR (qRT-PCR) result also indicated these genes expression levels were increased when treated with patulin. Kac changes accompanying degradation of patulin in R. mucilaginosa were also observed. Totally, 130 Kac sites in 103 proteins were differentially expressed under patulin stress. The differentially up expressed modified proteins were mainly involved in tricarboxylic acid cycle and nuclear acid biosynthesis. The differentially down expressed Kac proteins were mainly classified to ribosome, oxidative phosphorylation, protein synthesis and defense to stress process. Our results suggest that patulin exposure prompt R. mucilaginosa to produce a series of actions to resist or degrade patulin, including Kac. In addition, the Kac information in R. mucilaginosa and Kac in response to patulin stress was firstly revealed.

Biological control of postharvest diseases of fruit by antagonistic yeast has been considered to be an effective and promising strategy to reduce the postharvest loss of fruits. In this study, the biocontrol efficacy of Pichia membranefaciens against Rhizopus rot of peaches was investigated. Also, the study was aimed to explore the mechanisms involved in the induced disease resistance of peaches by investigating the activities of defense-related enzymes and transcriptome analysis. The results indicated that P. membranefaciens had significant biocontrol efficacy against Rhizopus rot of peaches. The activities of defense-related enzymes including PPO, POD, PAL and CAT were potentially induced by this yeast. The transcriptome analysis revealed that MAPK cascade signaling pathway and signal transduction pathways of ethylene (ET), jasmonate (JA) and salicylic acid (SA) were triggered in peaches by P. membranefaciens to regulate the transcription factors (TFs). Then, these TFs further mediated the expression of downstream defense-related genes including PR genes (PR1, CHI4 and major allergen Pru ar 1) and glutathione S-transferase (GST) genes (MKP11.22 and Atlg10370), the genes classified into plant-pathogen interaction pathways (CML48, MUK11.19 and ROBHA) and the genes involved in the synthesis of secondary metabolites (GGPS, PKS5, CHS1, CYP75B2, DFR, LDOX, PAL, PNC1 and ROMT) to enhance the disease resistance potential of peaches. Besides, the accumulation of some antifungal compounds including flavonoids and lignin was stimulated to enhance the antifungal ability of peaches. Consequently, the present study contributes to understand the mechanisms behind the induced disease resistance of peaches by antagonistic yeast, and would provide new disease control strategy by improving the defense responses of fruit against pathogens.

20-Hydroxy-3-oxolupan-28-oic acid (HOA), a lupane-type triterpene, was obtained from the leaves of Mahonia bealei, which is described in the Chinese Pharmacopeia as a remedy for inflammation and related diseases. The anti-inflammatory mechanisms of HOA, however, have not yet been fully elucidated. Therefore, the objective of this study was to characterize the molecular mechanisms of HOA in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. HOA suppressed the release of nitric oxide (NO), pro-inflammatory cytokine tumor necrosis factor &alpha, (TNF-&alpha, ), and interleukin 6 (IL-6) in LPS-stimulated RAW264.7 macrophages without affecting cell viability. Quantitative real-time reverse-transcription polymerase chain reaction (RT-qPCR) analysis indicated that HOA also suppressed the gene expression of inducible NO synthase (iNOS), TNF-&alpha, and IL-6. Further analyses demonstrated that HOA inhibited the phosphorylation of upstream signaling molecules, including p85, PDK1, Akt, I&kappa, B&alpha, ERK, and JNK, as well as the nuclear translocation of nuclear factor &kappa, B (NF-&kappa, B) p65. Interestingly, HOA had no effect on the LPS-induced nuclear translocation of activator protein 1 (AP-1). Taken together, these results suggest that HOA inhibits the production of cytokine by downregulating iNOS, TNF-&alpha, and IL-6 gene expression via the downregulation of phosphatidylinositol 3-kinase (PI3K)/Akt and mitogen-activated protein kinases (MAPKs), and the inhibition of NF-&kappa, B activation. Our findings indicate that HOA could potentially be used as an anti-inflammatory agent for medical use.

Background: Studies showed associations between air pollution exposure and the incidence of diabetes; however, the evidence on the underlying mechanism is limited. Insulin resistance (IR) has been ...

Patulin (PAT) is a mycotoxin produced by some Penicillium, Aspergillus, and Byssochlamys species. Rhodotorula mucilaginosa is able to degrade PAT in vivo as well as in vitro, up till date, the process and molecular mechanism(s) involved patulin degradation still remains unknown. Protein lysine crotonylation (Kcr) plays an important role in regulating chromatin dynamics, gene expression, and metabolic pathways in mammals and eukaryotes. Investigation of the Kcr changes accompanying degradation of patulin in R. mucilaginosa were observed to investigate the mechanisms of patulin inhibition. Tandem mass tag (TMT) labeling and Kcro affinity enrichment, followed by high-resolution LC-MS/MS analysis, were used to perform quantitative lysine crotonylome analysis on R. mucilaginosa. Consequently, 1691 lysine crotonylation sites in 629 protein groups were identified, among which we quantified 1457 sites in 562 proteins. Among the quantified proteins, 79 and 46 crotonylated proteins were up-regulated and down-regulated, respectively. The differentially up expressed modified proteins were mainly involved in tricarboxylic acid cycle and gluconeogenic pathway. The differentially down expressed Kcr proteins were mainly classified to ribosome and carbohydrate transport and metabolism. Bioinformatic analyses were performed to annotate the quantifiable lysine crotonylated targets. Moreover, interaction networks and high confidence domain architectures of crotonylated proteins were investigated with the aid of bioinformatic tools, and these results showed that there was an increase in the number of yeasts with crotonylated proteins. The results also provided information on the various roles of crotonylation, which are involved in PAT degradation.

This present study tested the extent to which 2% w/v trehalose enhanced the proteins expression profile of Hanseniaspora uvarum Y3. Furthermore, it explored the relative gene expression of stilbene synthase (StSy), one of the vital defense-related genes found in the skin of grapes. The proteomics profile revealed that 29 proteins were differentially expressed out of which 26 were significantly up-regulated and 3 were download-regulated. The pathogenesis related (PR) and other protein spots were visible at 97.4 kDa and 14.4 kDa. Peroxiredoxin TSA1 and superoxide dismutase were the main proteins involved in defense response and both proteins were significantly up-regulated. The carbohydrate and energy metabolism proteins were also significantly up-regulated. The results revealed that the treatments were associated with substantial increase in peroxidase activity compared to the control. StSy relative gene expression level was observed to increase by 2.5-fold in grapes treated with the pre-enhanced H. uvarum compared to the control.

Phytic acid integrated with Pichia caribbica or as separate treatments for the control of wound infections, spoilage of intact apple fruits and enzymatic activities were investigated. The combined treatment of P. caribbica and phytic acid (0.2% v/v) showed significant improvement in the control of Penicillium expansum infections on apples than either yeast or phytic acid alone. Disease incidence and lesion diameter in treated fruits were significantly lower than the control fruits after 10 days of storage (20 °C, RH 95%). P. caribbica treated with or without phytic acid significantly reduced the natural decay incidence, weight loss, browning index, while maintained the firmness, total phenolic compound, total soluble solids (TSS) and titratable acidity (TA) of the apples. Similarly, the combination of yeast and phytic acid led to increases of peroxidase (POD), polyphenoloxidase (PPO), catalase (CAT) and low malondialdehyde (MDA) activities. Therefore, phytic acid could be used as a potential elicitor against blue mold decay caused by P. expansum .

Octenyl succinic anhydride modified inulin (In-OSA) was synthesized via chemical modification of inulin with octenyl succinic anhydride (OSA). The esterification of inulin with OSA was confirmed by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and degree of substitution (DS) calculation. Antibacterial activity of In-OSA against Staphylococcus aureus and Escherichia coli was investigated by minimum inhibitory concentration (MIC) and inhibition rate determination. The results showed that inhibition rates against both E.coli and S. aureus increased with the increase of the In-OSA concentration. And the MICs against E. coli and S. aureus were 1% and 0.5% (w/v), respectively. The antibacterial mechanism was analyzed with the results of the proteins and nucleic acids leakage, SEM and negative staining transmission electron microscopy (TEM). Both the leakages of proteins and nucleic acids increased with the increase of the In-OSA concentration. The leakage occurred mainly in the early stage which indicated that cell membrane and wall were destroyed by In-OSA quickly. The images of SEM and negative staining TEM suggested that the cell membranes and cell walls of S. aureus were damaged more severely and even destroyed completely; but only pores appeared on the surface of E. coli.

The occurrence of patulin in fresh apples and apple products is a great burden from health, safety and economic perspectives. Attempts to prevent patulin accumulation in fruits might lead to the excessive use of fungicides. Therefore, guaranteeing the safety of apple foods is crucial for the international apple industry. Recently, literature revealed that application of antagonistic yeasts and other BCAs have been able to disrupt the process of fungal infection and patulin production in apples. Although, over the years the effect of interaction between BCAs and fungi on patulin production has been reported, the exact mechanism(s) of their action remain unclear. Here, the review focused on toxicology and occurrence of PAT; research advances made over the past few years on the interaction between antagonistic yeast, fruits and patulin-producing fungi; the prevalence of patulin in apple fruits and products and the implications of synthetic-fungicide applications. In addition, attention was focused on the mechanism(s) and the enhancement of the biocontrol efficacy of antagonistic for patulin control.

Citrinin (CIT) is a toxic secondary metabolite produced by fungi belonging to the Penicillium, Aspergillus, and Monascus spp. This toxin has been detected in many agricultural products. In this study, a strain Y3 with the ability to eliminate CIT was screened and identified as Cryptococcus podzolicus, based on the sequence analysis of the internal transcribed spacer region. Neither uptake of CIT by cells nor adsorption by cell wall was involved in CIT elimination by Cryptococcus podzolicus Y3. The extracellular metabolites of Cryptococcus podzolicus Y3 stimulated by CIT or not showed no degradation for CIT. It indicated that CIT elimination was attributed to the degradation of intracellular enzyme(s). The degradation of CIT by C. podzolicus Y3 was dependent on the type of media, yeast concentration, temperature, pH, and initial concentration of CIT. Most of the CIT was degraded by C. podzolicus Y3 in NYDB medium at 42 h but not in PDB medium. The degradation rate of CIT was the highest (94%) when the concentration of C. podzolicus Y3 was 1 × 10⁸ cells/ml. The quantity of CIT degradation was highest at 28°C, and there was no degradation observed at 35°C. The study also showed that acidic condition (pH 4.0) was the most favorable for CIT degradation by C. podzolicus Y3. The degradation rate of CIT increased to 98% as the concentration of CIT was increased to 20 μg/ml. The toxicity of CIT degradation product(s) toward HEK293 was much lower than that of CIT.

The proteomic and lysine acetylation (Kac) changes, accompanying degradation of patulin in Rhodotorula mucilaginosa were analyzed using tandem mass tagging and N6-acetyllysine affinity enrichment followed by LC-MS/MS. Proteomic results showed that expression level of short-chain reductase protein and glutathione S-transferase involved in detoxification was significantly up-regulated. In addition, the expression levels of zinc-binding oxidoreductase and quinone oxidoreductase that are involved in antioxidant process, ABC transport and MFS transport responsible for chemical transport were activated when treated with patulin. The quantitative real time PCR (qRT-PCR) result also indicated these genes expression levels were increased when treated with patulin. Kac changes accompanying degradation of patulin in R. mucilaginosa were also observed. Totally, 130 Kac sites in 103 proteins were differentially expressed under patulin stress. The differentially up expressed modified proteins were mainly involved in tricarboxylic acid cycle and nuclear acid biosynthesis. The differentially down expressed Kac proteins were mainly classified to ribosome, oxidative phosphorylation, protein synthesis and defense to stress process. Our results suggest that patulin exposure prompt R. mucilaginosa to produce a series of actions to resist or degrade patulin, including Kac. In addition, the Kac information in R. mucilaginosa and Kac in response to patulin stress was firstly revealed.