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Red grapes often suffer from postharvest diseases like blue mold and black mold caused by Penicillium expansum and Aspergillus niger. Biological control using beneficial yeasts and bacteria is an effective method to manage these diseases. Rhodotorula sp. and Bacillus sp. are effective microorganisms for the control of postharvest diseases of red grapes. This study combined two yeast strains (Rhodotorula graminis and Rhodotorula babjevae) and two bacterial strains (Bacillus licheniformis and Bacillus velezensis) to investigate their biological control effects on major postharvest diseases of red grapes and explore the underlying physiological mechanisms. Research showed that compound microorganism W3 outperformed the others; it reduced spore germination and germ tube growth of P. expansum and A. niger, while its volatiles further inhibited pathogen growth. Additionally, the treatment enhanced the antioxidant capacity of grapes and increased resistance to pathogens by boosting peroxidase activities, superoxide dismutase, catalase and ascorbate peroxidase, phenylalanine ammonolyase, and polyphenol oxidase. Furthermore, the combined treatment increased the activity and accumulation of antifungal compounds such as total phenols and flavonoids, thereby improving disease resistance and reducing decay. Therefore, composite microorganisms combining various antagonistic strains may offer a viable substitute for tackling postharvest diseases in red grapes.

Postharvest diseases, such as black spots caused by Alternaria alternata, have caused huge economic losses to the tomato industry and seriously restricted its development. In recent years, biological control has become a new method to control postharvest diseases of fruits and vegetables. Our research group screened W. anomalus, a yeast demonstrating a promising control effect on a postharvest black spot disease of tomatoes, and explored its physiological mechanism of prevention and control. Therefore, this study investigated the prevention and control effect of metabolites of W. anomalus on tomato black spot disease and the inhibition effect of main components on A. alternata. A GC-MS analysis found that isoamyl acetate was the main component of W. anomalus that played an inhibitory role. The results showed that isoamyl acetate could inhibit the growth of A. alternata and had a certain control effect on postharvest black spots in tomatoes. Our findings suggest that isoamyl acetate could be a promising alternative to fungicides for controlling postharvest black spots in tomatoes.

The ability to learn continuously is crucial for a robot to achieve a high level of intelligence and autonomy. In this paper, we consider continual reinforcement learning (RL) for quadruped robots, which includes the ability to continuously learn sub-sequential tasks (plasticity) and maintain performance on previous tasks (stability). The policy obtained by the proposed method enables robots to learn multiple tasks sequentially, while overcoming both catastrophic forgetting and loss of plasticity. At the same time, it achieves the above goals with as little modification to the original RL learning process as possible. The proposed method uses the Piggyback algorithm to select protected parameters for each task, and reinitializes the unused parameters to increase plasticity. Meanwhile, we encourage the policy network exploring by encouraging the entropy of the soft network of the policy network. Our experiments show that traditional continual learning algorithms cannot perform well on robot locomotion problems, and our algorithm is more stable and less disruptive to the RL training progress. Several robot locomotion experiments validate the effectiveness of our method.

Mechanical stress induced by compression during preharvest and postharvest handling of fresh fruit is a major factor influencing the quality of fresh fruit. The degree of compression primarily governs the extent of quality deterioration. However, research on the damage mechanisms of mechanical compression in table grapes remains scarce. This investigation evaluated the impact of varying compression levels (0%, 20%, 40%, 60%, and 80%) on the postharvest quality attributes of table grapes. Changes in postharvest physical properties (overall appearance and color), structural properties (firmness, springiness, cohesiveness, and chewiness), physiological qualities (total soluble solids, titratable acidity, ascorbic acid, malonaldehyde content, and relative electrical conductivity), and cell microstructure of the berries was determined at 4 °C during 15 d of storage. Mechanical compression contributed to the deterioration of the quality of table grapes during storage, resulting in increased weight loss, decay rate, malonaldehyde content, and relative electrical conductivity; and decreased total soluble solids, titratable acidity, and ascorbic acid content. Furthermore, as compared to the control group, mechanical compression resulted in substantial yellowing and diminished textural qualities of grapes. In particular, compression treatment caused significant deformation of grape cell microstructure. In conclusion, mechanical compression stress significantly affects the physical and physiological properties of postharvest table grapes, as well as the internal cellular organization. As compression levels increase, the quality of table grapes progressively deteriorates, leading to a substantial reduction in storage life and commercial value. This study offers essential information for devising damage prevention strategies in preharvest and postharvest handling of table grapes.

Longitudinal-torsional composite ultrasonic vibration has been widely used in grinding. This paper aims to solve the problem that the resonance frequency deviates greatly from the theoretical design frequency and the vibration mode is poor when the horn is matched with a larger tool head. This paper presents how the longitudinal-torsional composite ultrasonic conical transition horn was designed and optimized by the transfer matrix theory and finite element simulation. For this purpose, the spiral groove parameters were optimized and selected by finite element simulation. Then, the modal analysis and transient dynamic analysis of the horn with grinding wheel were carried out to verify the correctness of the theoretical calculation. The impedance analysis and amplitude test of the horn with grinding wheel were carried out. The test results were in very good agreement with the theoretical and simulation results. Finally, the grinding experiment was carried out. The surface roughness of the workpiece in longitudinal-torsional ultrasonic vibration grinding was obviously reduced compared to that of ordinary grinding. All these obtained results demonstrate that the designed longitudinal-torsional composite ultrasonic horn has very good operational performance for practical applications.

The genus Acorus, a perennial monocotyledonous-class herb and part of the Acoraceae family, is widely distributed in the temperate and subtropical zones of the Northern and Southern Hemispheres. Acorus is rich in biological activities and can be used to treat various diseases of the nervous system, cardiovascular system, and digestive system, including Alzheimer’s disease, depression, epilepsy, hyperlipidemia, and indigestion. Recently, it has been widely used to improve eutrophic water and control heavy-metal-polluted water. Thus far, only three species of Acorus have been reported in terms of chemical components and pharmacological activities. Previously published reviews have not further distinguished or comprehensively expounded the chemical components and pharmacological activities of Acorus plants. By carrying out a literature search, we collected documents closely related to Acorus published from 1956 to 2022. We then performed a comprehensive and systematic review of the genus Acorus from different perspectives, including botanical aspects, ethnic applications, phytochemistry aspects, and pharmacological aspects. Our aim was to provide a basis for further research and the development of new concepts.

β-1,3-glucanase plays an important role in the biodegradation, reconstruction, and development of β-1,3-glucan. An endo-β-1,3-glucanase which was encoded by PeBgl1 was expressed, purified and characterized from Penicillium expansum for the first time. The PeBgl1 gene was amplified and transformed into the competent cells of E. coli Rosetta strain with the help of the pET-30a cloning vector. The recombinant protein PeBgl1 was expressed successfully at the induction conditions of 0.8 mmol/L IPTG at 16 °C for 16 h and then was purified by nickel ion affinity chromatography. The optimum reaction temperature of PeBgl1 was 55 °C and it had maximal activity at pH 6.0 according to the enzymatic analysis. Na2HPO4-NaH2PO4 buffer (pH 6.0) and NaCl have inhibitory and enhancing effects on the enzyme activities, respectively. SDS, TritonX-100 and some metal ions (Mg2+, Ca2+, Ba2+, Cu2+, and Zn2+) have an inhibitory effect on the enzyme activity. The results showed that PeBgl1 protein has good enzyme activity at 50–60 °C and at pH 5.0–9.0, and it is not a metal dependent enzyme, which makes it robust for storage and transportation, ultimately holding great promise in green biotechnology and biorefining.

A bulb tubular pump unit is a horizontal tubular pump unit composed of a water pump and bulb with an electric motor installed. Electric motors, transmission equipment, and bearings are usually placed in the bulb. The bulb is located in the flow channel and has a relatively narrow space. Therefore, the shape of the bulb has a significant influence on the flow pattern and pump efficiency in the flow channel. In this study, the CFX 19.2 software was employed to optimize the bulb hydraulically according to its geometry and parameters. The research results indicate that the flow pattern at the tail of the elliptical bulb was better, the hydraulic loss at the bulb section was small, and the device efficiency was higher than that at the tail, which was round. The streamlined support had small flow resistance, minimal hydraulic loss, and a high pump unit head and efficiency. Nine schemes were selected, and the geometrical characteristics and parameters of the bulb were determined as follows: the shape of the tail of the bulb was oval, the bulb ratio was 0.96, and the shape of the support parts was streamlined. The results hold important reference significance to improve efficiency and broaden the operating conditions of bulb tubular pump devices.

Studies on the molecular mechanism of antagonistic yeasts to control apple postharvest diseases are not comprehensive enough. Our preliminary investigations screened the biocontrol effect of Hannaella sinensis, an antagonistic yeast, and discovered its control efficacy on apple blue mold decay. However, the molecular mechanism of H. sinensis-induced resistance in apple has not been studied. In this study, proteins from apple treated with H. sinensis and sterile saline were analyzed using TMT proteomics technology. It was found that H. sinensis treatment induced the expressions of apple resistance-related proteins. Among the proteins in H. sinensis-induced apple, proteins related to plant defense mechanisms, such as reactive oxygen species scavenging, improvement of plant resistance and synthesis of resistant substances, improvement of plant disease resistance, the degradation of the pathogen cell wall, cell signaling, antibacterial activity, transport of defense-related substances, and protein processing, were differentially regulated. The results of this study revealed the underlying molecular mechanisms of H. sinensis-induced apple resistance at the protein level; the results also provided a theoretical basis for the commercial application of H. sinensis.

Patulin (PAT), mainly produced by Penicillium expansum, is a potential threat to health. In recent years, PAT removal using antagonistic yeasts has become a hot research topic. Meyerozyma guilliermondii, isolated by our group, produced antagonistic effects against the postharvest diseases of pears and could degrade PAT in vivo or in vitro. However, the molecular responses of M. guilliermondii over PAT exposure and its detoxification enzymes are not apparent. In this study, transcriptomics is used to unveil the molecular responses of M. guilliermondii on PAT exposure and the enzymes involved in PAT degradation. The functional enrichment of differentially expressed genes indicated that the molecular response mainly includes the up-regulated expression of genes related to resistance and drug-resistance, intracellular transport, growth and reproduction, transcription, DNA damage repair, antioxidant stress to avoid cell damage, and PAT detoxification genes such as short-chain dehydrogenase/reductases. This study elucidates the possible molecular responses and PAT detoxification mechanism of M. guilliermondii, which could be helpful to further accelerate the commercial application of antagonistic yeast toward mycotoxin decontamination.

Blue mold, caused by Penicillium expansum, is the most destructive fungal disease of apples and causes great losses during the post-harvest storage of the fruit. Although some apple cultivars are resistant to P. expansum, there has been little information on the molecular mechanism of resistance. In this study, differential proteomic analysis was performed on apple samples infected and uninfected with P. expansum. Parallel reaction monitoring (PRM) technology was used to target and verify the expression of candidate proteins. The label-free technique identified 343 differentially expressed proteins, which were mainly associated with defense responses, metal ion binding, stress responses, and oxidative phosphorylation. The differential expression of enzymes related to reactive oxygen species (ROS) synthesis and scavenging, the activation of defense-related metabolic pathways, and the further production of pathogenesis-related proteins (PR proteins) during P. expansum infection in apples, and direct resistance to pathogen invasion were determined. This study reveals the mechanisms of apple response at the proteomic level with 9 h of P. expansum infection.

Transcription factors play a key role in Penicillium expansum infection process. Although the crucial characteristics of some transcription factors of pathogenic fungi have been found, many transcription factors involved in P. expansum infections have not been explored and studied. This study aimed to screen the transcription factors of P. expansum involved in postharvest pear infections by ATAC-seq analysis and to analyze the differentially expressed peak-related genes by GO enrichment and KEGG pathway analysis. Our results found the up-regulation of differentially expressed peak-related genes involved in the MAPK signaling pathway, pentose phosphate pathway, starch and sucrose metabolism, and pentose and glucuronate interconversions. Our study especially confirmed the differential regulation of transcription factors MCM1, Ste12 and gene WSC in the MAPK signaling pathway and PG1, RPE1 in the pentose and glucuronate interconversions pathway. These transcription factors and related genes might play an essential role in pear fruit infection by P. expansum. RT-qPCR validation of twelve expressed peak-related genes in P. expansum showed that the expression levels of these twelve genes were compatible with the ATAC-Seq. Our findings might shed some light on the regulatory molecular networks consisting of transcription factors that engaged in P. expansum invasion and infection of pear fruits.

Zearalenone (ZEN) is produced by Fusarium spp. and is widely found in moldy wheat, corn, and other grains. ZEN has a strong toxicity and causes reproductive and immune disorders and estrogenic syndrome in animals and humans. Biodegradation has been demonstrated as an efficient way to control the hazardous effect of ZEN. A promising way to apply biodegradation in feed is to introduce anaerobic ZEN-degrading microorganisms, which can function during the digestion process in animal intestines. The aim of this study was to isolate anaerobic ZEN-degrading bacteria from anaerobic environments. A strain named F39 was isolated from animal intestinal contents and had a ZEN-degradation rate of 87.35% in 48 h to form trace amount of α- and β-zearalenol. Based on the morphological and physiological properties and phylogenetic analysis of 16S rRNA and rpoB gene sequences, F39 was identified as Clostridium sporogenes. The optimum temperature for the growth of F39 was 37 °C, the optimum pH was 7.0, and the most suitable carbon source was beef extract, while the optimal conditions for the degradation of ZEN were as follows: 35 °C, pH 7.0, and GAM medium. ZEN was degraded by F39 with a high efficiency in the concentration range of 1–15 mg/L. The bioactive factors responsible for ZEN degradation were mainly distributed intracellularly. F39 can degrade most of the ZEN present, but a small amount is broken down into two secondary metabolites, α- and β-zearalenol, and the toxicity of the degradation products is reduced. With an efficiency of 49%, F39 can more effectively degrade ZEN in wheat-based feedstuffs than in other feedstuff, and the degradation efficiency was pH related. To the best of our knowledge, this is the first report of Clostridium sporogenes F39’s ability to maintain the biodegradation potentials.

Gray mold decay is a widespread postharvest disease in tomato that results from infection by the pathogen Botrytis cinerea, leading to huge economic losses. The objective of this study was to select the most effective antagonistic yeast to control tomato gray mold from six potential biocontrol agents and to investigate the possible control mechanism. The results showed that the yeast Wickerhamomyces anomalus was the most effective in inhibiting B. cinerea among the six strains both in vivo and in vitro on tomato, with a colony diameter of 11 mm, a decay diameter of 20 mm, and the lowest decay incidence (53%)—values significantly smaller and lower than the values recorded for the control group and the other yeasts. The efficacy of the control depended on the increase in yeast concentration, and the decay incidence and lesion diameter were reduced to 31%, 28% and 7 mm, 6 mm, respectively, when treated with 1 × 108 and 1 × 109 cells/mL W. anomalus. In addition, W. anomalus was able to rapidly colonize and stably multiply in tomato, occupying the space to control pathogen infection. W. anomalus was also able to motivate the defense mechanism of tomato with stimulation of defense-related enzymes PPO, POD, APX, and SOD and promotion of the content of total phenols and flavonoid compounds. All these results suggest that W. anomalus exhibited exceptional ability to control gray mold in tomato.

Transcriptome analysis (TA) was conducted to characterize the transcriptome changes in postharvest disease-related genes of table grapes following treatment with Pichia anomala induced with chitosan (1% w/v). In the current study, the difference in the gene expression of table grapes after treatment with P. anomala induced with chitosan and that of a control group was compared 72 h post-inoculation. The study revealed that postharvest treatment of table grapes with P. anomala induced with chitosan could up-regulate genes that have a pivotal role in the fruit’s disease defense. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) results also confirmed that GO terms and the KEGG pathways, which have pivotal roles in plant disease resistance, were significantly enriched. The up-regulated genes of the treatment group have a unique function in the fruit’s disease resistance compared to the control group. Generally, most genes in the plant–pathogen interaction pathway; the plant Mitogen-activated protein kinase (MAPK) signaling pathway; the plant hormone signal transduction pathway; the pathway of glutathione metabolism; the pathway of phenylalanine, tyrosine, and tryptophan biosynthesis; and the pathway of flavonoid biosynthesis were all up-regulated. These up-regulations help the fruit to synthesize disease-resistant substances, regulate the reactive oxygen species (ROS), enhance the fruit cell wall, and enrich hormone signal transduction during the pathogen’s attack. This study is useful to overcome the lags in applying transcriptomics technology in postharvest pathology, and will provide insight towards developing other alternative methods to using bio-pesticides to control postharvest diseases of perishables.

Green mold disease, a common citrus post-harvest disease caused by Penicillium digitatum, has an unresolved initial infection mechanism. Understanding the infection mechanism leads to the development of potential controls and preventive measures against the disease. The present study aimed to delineate the infection mechanism by investigating spore germination, changes of organic molecules and enzyme activity, and differential expression of genes in the P. digitatum infection. P. digitatum spore germination was observed by a pathology section scanner and it was found that in vivo germination was 3 h behind the in vitro germination. In addition, cell wall degrading enzymes and soluble sugar and titratable acid content during the infection process measured dynamically. The level of pectinase reached its maximum of 6067 U/g before 48 hpi, while cellulase increased rapidly after 48 hpi. The soluble sugar and organic acid content increased considerably with the progression of the infection. The transcriptomic profile of P. digitatum before and after infection was analyzed by RNA-seq. The genes related to cell wall degrading enzymes were significantly up-regulated and annotated to participate in two major carbon source synthesis pathways. The study delineated the initial infection mechanism of P. digitatum which eventually opened the gate way for the development of new control strategies in the future.

Blue mold, caused by Penicillium expansum, is an important postharvest disease of apple, and can result in significant economic losses. The present study investigated the interaction between P. expansum and wounded apple fruit tissues during the early stages of the infection. Spores of P. expansum became activated one hour post-inoculation (hpi), exhibited swelling at 3 hpi, and the germ tubes were found entering into apple tissues at 6 hpi. RNA-seq was performed on samples of P. expansum and apple fruit tissue collected at 1, 3, and 6 hpi. The main differentially expressed genes (DEGs) that were identified in P. expansum were related to interaction, cell wall degradation enzymes, anti-oxidative stress, pH regulation, and effectors. Apple tissues responded to the presence of P. expansum by activating pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) at 1 hpi, then activated effector-triggered immunity (ETI) at 3 hpi. This research provides new information on the interaction between P. expansum and apple fruit tissue at an early stage of the infection process.

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 α (TNF-α), 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-α, and IL-6. Further analyses demonstrated that HOA inhibited the phosphorylation of upstream signaling molecules, including p85, PDK1, Akt, IκBα, ERK, and JNK, as well as the nuclear translocation of nuclear factor κB (NF-κB) 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-α, 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-κB activation. Our findings indicate that HOA could potentially be used as an anti-inflammatory agent for medical use.

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Ochratoxin A (OTA) contamination has been established as a world-wide problem. In this study, the strains with the ability of OTA production were screened by analyzing the green fluorescence of the isolates colonies from the grapes in Zhenjiang with 365 nm UV light and confirmed by HPLC with fluorescent detection (HPLC-FLD). The results showed that seven isolates acquired the characteristic of the fluorescence, of which only five showed the ability of OTA production as confirmed by HPLC-FLD analysis. The five OTA-producing strains were identified based on comparative sequence analysis of three conserved genes (ITS, BenA and RPB2) of the strains, and they are Talaromyces rugulosus (O1 and Q3), Penicillium commune (V5-1), Penicillium rubens (MQ-5) and Aspergillus aculeatus (MB1-1). There are two Penicillium species of the five OTA-producing strains and our study is the first to report that P. rubens, T. rugulosus and A. aculeatus can produce OTA. This work would contribute to comprehensively understanding the fungi with an OTA-producing ability in grapes before harvest and then take effective measures to prevent OTA production.

In this work, we examined the mechanisms involved in the degradation of patulin by Pichia caribbica. Our results indicate that cell-free filtrate of P. caribbica reduced patutlin content. The heat-killed cells could not degrade patulin. However, the live cells significantly reduced the concentration of the patulin. In furtherance to this, it was observed that patulin was not detected in the broken yeast cells and cell wall. The addition of cycloheximide to the P. caribbica cells decreased the capacity of degradation of patulin. Proteomics analyses revealed that patulin treatment resulted in an upregulated protein which was involved in metabolism and stress response processes. Our results suggested that the mechanism of degradation of patulin by P. caribbica was not absorption; the presence of patulin can induce P. caribbica to produce associated intracellular and extracellular enzymes, both of which have the ability to degrade patulin. The result provides a new possible method that used the enzymes produced by yeast to detoxify patulin in food and feed.