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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.

Cooking of bambara groundnut is time and energy consuming. This research was therefore carried out to find a way of reducing the cooking time of bambara groundnut and at the same time reduce losses of nutrients. Green pawpaw slices, both fresh and dried were added to the raw bambara groundnut and cooked. The treated Bambara groundnut recorded the lowest cooking time (P

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.

Background: Biological control of fruit postharvest diseases by antagonistic microorganisms has been considered an effective alternative to chemical fungicides. The influence of microbial antagonists on fruit-associated microbiome will provide a new perspective for in-depth study of the antagonistic mechanism. In this study, the biocontrol efficacy of A. pullulans S-2 against postharvest diseases of tomatoes was investigated. Meanwhile, the fungal and bacterial microbiota on tomato surfaces were examined by high-throughput sequencing. Results: A. pullulans S-2 can significantly inhibit the decay rate, maintain fruit firmness and reduce weight loss of tomatoes. In addition, the treatment group can maintain higher titratable acid, ascorbic acid and lycopene than the control group. After using A. pullulans S-2, more dramatic changes were observed in fungal diversity than bacterial in the microbiota. Aureobasidium was significantly enriched in the treatment group, while Cladosporium, Mycosphaerella, Alternaria and Penicillium were deficient compared with the control group. Pantoea, Brevibacterium, Brachybacterium, Serratia, Glutamicibacter and Pseudomonas also had significant differences between the two groups.Conclusions: This study demonstrated that the application of A. pullulans S-2 resulted in alterations in the bacterial and fungal community and that could inhibit pathogens and decrease fruit disease incidence. It provides new insights into the dynamics of the tomato's surface microbiome after microbial antagonist treatment.

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.

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.

Pears are one of the most essential fruit worldwide, they are susceptible to Penicillium expansum infection during postharvest storage, which results in high economic losses. Due to the dearth of information involving the mechanisms of infection of P. expansum in pear fruit it is very important to clarify its pathogenicity. In this study, the fungus strain was isolated from rotten pears and identified as P. expansum, which has strong pathogenicity. The results from SEM revealed that P. expansum relies on the growth of spores or the secretion of filamentous materials to degrade the cell wall of infected pear tissues. In addition, it was found that tissues were completely damaged after 24 h of infection. The RNA-seq results of P. expansum in infected pear tissue suggested that total differentially expressed genes (DEGs) were grouped into 4 profiles due to an upward trend in their gene expression patterns using the STEM software. The DEGs of the 4 profiles were involved in extracellular enzyme activity, cellular response to reactive oxygen, glutathione metabolic species, and polysaccharide metabolic process particularly the plant cell wall degrading enzyme (CWDEs) synthesis pathway. In summary, this research provides a piece of new information with regards to the infection mechanisms of P. expansum on pears, which could be useful in understanding the phenomenon of pathogen -host -fruit interaction and the development of new measures for the control of fungal diseases.