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The priming of defence responses in pathogen‐challenged model plants undergoes a preparation phase and an expression phase for defence function. However, the priming response in postharvest fruits has not been elucidated. Here, we found that 50 mM β‐aminobutyric acid (BABA) treatment could induce two distinct pathways linked with TGA1‐related systemic acquired resistance (SAR), resulting in the alleviation of Rhizopus rot in postharvest peach fruit. The first priming phase was elicited by BABA alone, leading to the enhanced transcription of redox‐regulated genes and posttranslational modification of PpTGA1. The second phase was activated by an H2O2 burst via up‐regulation of PpRBOH genes and stimulation of the MAPK cascade on pathogen invasion, resulting in a robust defence. In the MAPK cascade, PpMAPKK5 was identified as a shortcut interacting protein of PpTGA1 and increased the DNA binding activity of PpTGA1 for the activation of salicylic acid (SA)‐responsive PR genes. The overexpression of PpMAPKK5 in Arabidopsis caused the constitutive transcription of SA‐dependent PR genes and as a result conferred resistance against the fungus Rhizopus stolonifer. Hence, we suggest that the BABA‐induced priming defence in peaches is activated by redox homeostasis with an elicitor‐induced reductive signalling and a pathogen‐stimulated H2O2 burst, which is accompanied by the possible phosphorylation of PpTGA1 by PpMAPKK5 for signal amplification., BABA elicitation regulates the redox homeostasis and shortcut interaction of TGA1 and MAPKK5 for a SAR‐related priming defence in postharvest peaches.

Silver nanoparticles (AgNPs) can be produced through an easy and safe process called green synthesis and have been considered an efficient antimicrobial agent. The antimicrobial effect of silver nanoparticles green synthesized with E. tirucalli (aveloz) can be a promising technique for preserving stored strawberries. The objective of this work was to perform a green synthesis of AgNPs with aveloz extract (Av) and evaluate its effect on the physiology and preservation of stored strawberries. Silver nitrate was reduced with Av to produce Av-AgNPs. The Av-AgNPs were characterized by Scanning Electron Microscope, Energy Dispersive X-ray Spectrometry, and laser diffraction. The in vitro antifungal activity of Av-AgNPs was evaluated against Botrytis cinerea and Rhizopus stolonifer. Strawberries were treated with Av-AgNPs and stored (5 °C) for 12 days. Respiratory rate, decay, fresh mass loss, firmness, total phenolics and antioxidant activity of the strawberries were evaluated. According to the results, Av-AgNPs synthesis was performed, and it presented sizes between 40 and 90 nm. Av-AgNPs inhibited B. cinerea but was less effective for R. stolonifer. Total phenolic compounds, antioxidant activity, fresh mass loss and firmness of strawberries were not influenced by Av-AgNPs. Treated strawberries had a lower respiratory rate than the control and showed no symptoms of microbiological deterioration until 9 days of storage, while in the control the deterioration symptoms started after 3 days. This study showed that the green synthesis of AgNPs with Av produced nanoparticles smaller than 100 nm, and that they were effective against strawberries decay during storage, indicating to be a promising protection technique against decay.

A new series of thiazolo[4,5-d]pyrimidine-5-thione derivatives having indole and phenyl moieties were synthesized. Their structures were established by spectral and elemental analyses. All newly synthesized thiazolo[4,5-d]pyrimidine-5-thione derivatives were subjected to antifungal testing against Rhizopus stolonifer and Aspergillus terreus. One of the tested compounds was found to be more active against Aspergillus terreus than Rhizopus stolonifer, and the other compounds were inactive against the same fungal strains.

About 45% of the world’s fruit and vegetables are wasted, resulting in postharvest losses and contributing to economic losses ranging from $10 billion to $100 billion worldwide. Soft rot disease caused by Rhizopus stolonifer leads to postharvest storage losses of sweet potatoes. Nanoscience stands as a new tool in our arsenal against these mounting challenges that will restrict efforts to achieve and maintain global food security. In this study, three nanomaterials (NMs) namely C60, CuO, and TiO2 were evaluated for their potential application in the restriction of Rhizopus soft rot disease in two cultivars of sweet potato (Y25, J26). CuO NM exhibited a better antifungal effect than C60 and TiO2 NMs. The contents of three important hormones, indolepropionic acid (IPA), gibberellic acid 3 (GA-3), and indole-3-acetic acid (IAA) in the infected J26 sweet potato treated with 50 mg/L CuO NM were significantly higher than those of the control by 14.5%, 10.8%, and 24.1%. CuO and C60 NMs promoted antioxidants in both cultivars of sweet potato. Overall, CuO NM at 50 mg/L exhibited the best antifungal properties, followed by TiO2 NM and C60 NM, and these results were further confirmed through scanning electron microscope (SEM) analysis. The use of CuO NMs as an antifungal agent in the prevention of Rhizopus stolonifer infections in sweet potatoes could greatly reduce postharvest storage and delivery losses.

Hull rot disease of almond (Prunus dulcis), caused by the fungus Rhizopus stolonifer, is prevalent in well maintained orchards where trees are provided plenty of water and nitrogen to increase the growth and yield. The predominantly grown variety Nonpareil is considered very susceptible to hull rot, while the pollinator variety Carmel is more resistant. Reduced nitrogen rates and restricted irrigation scheduling decreased the incidence and severity of hull rot in Californian orchards. As a part of our research, the hull composition of Australian almond fruits of Nonpareil and Carmel varieties, grown under two levels of irrigation (high and low) and two levels of nitrogen (high and low), were analysed using 1H NMR-based metabolomics. Both Nonpareil and Carmel hulls contained sugars such as glucose, sucrose, fructose and xylose, and amino acids, particularly asparagine. Variety was the major factor with Nonpareil hulls significantly higher in sugars and asparagine than Carmel. Within varieties, nitrogen influenced the relative concentrations of glucose, sucrose and asparagine. In Nonpareil, high nitrogen high water (the control) had relatively high glucose and asparagine content. High nitrogen low water increased the sucrose component, low nitrogen high water increased the glucose component and low nitrogen low water increased the sucrose and asparagine components. In Carmel, however, high nitrogen low water and low nitrogen high water increased sucrose and asparagine, and low nitrogen low water increased sucrose and glucose. Hull rot symptoms are caused by fumaric acid production by R. stolonifer growing within the hull. These changes in the hull composition under different nitrogen and water scenarios have the potential to affect the growth of R. stolonifer and its metabolite production in hull rot disease.

The sulfur-containing salts, classified as food additives, sodium metabisulfite (SMBS), potassium metabisulfite (PMBS), aluminum sulfate (AlS), and aluminum potassium sulfate (AlPS), were evaluated for their activity against Monilinia fructicola, Rhizopus stolonifer, and Geotrichum candidum, the most economically important fungal pathogens causing postharvest disease of stone fruit. In in vitro tests with potato dextrose agar (PDA) Petri dishes amended with different concentrations of the salts (0, 10, 20, 30, 50, and 100 mM), SMBS and PMBS at all concentrations, AlS above 20 mM, and AlPS above 30 mM, completely inhibited the mycelial growth of the three fungi after incubation at 25 °C for up to 10 days. In in vivo primary screenings with artificially inoculated nectarines, aqueous solutions of the four salts reduced the incidence and severity of brown rot (BR) at concentrations of 10 and 50 mM, whereas only AlS and AlPS reduced Rhizopus rot (RR), and none of the salts was effective against sour rot (SR). Solutions at 100 mM were phytotoxic and injured the fruit peel. In small-scale trials, 1 min dip treatments at 20 °C in SMBS or PMBS at 10 mM significantly reduced the incidence and severity of BR after incubation at 20 °C for up to 8 days. Conversely, dips in AlS and AlPS reduced neither BR nor RR. Results highlight the potential of SMBS and PMBS as new nonpolluting tools for the integrated control of BR, but not RR and SR, on stone fruit.

During the postharvest stage of the strawberry, considerable losses can be caused mainly by the attack of phytopathogenic fungi. An alternative to the use of fungicides is the essential oil (EO) incorporated in the packaging in order to control these microorganisms. This study developed active paper with 2.5, 5, 7 and 10% of the cinnamaldehyde EO and evaluated its antifungal properties against Rhizopus stolonifer and Botrytis cinerea. Subsequently, strawberries were placed in “nests” made with the active paper produced with 5% OE, stored at refrigeration temperature (8 °C) and evaluated for its microbiological and physicochemical parameters at the times of 0, 3, 6, 9 and 12 days. The physicochemical analyzes of the fruit showed difference (p > 0.05) between the treatments for the firmness and fruit color. The reduction in the growth of filamentous fungi, yeasts and aerobic mesophiles was verified in the microbiological results of strawberries wrapped in the active paper. It is concluded that the use of the active paper incorporated with EO in strawberries composes an alternative in the substitution of agrochemicals, with potential application in other fruits.

This study investigated the effect of LED illumination on the inactivation of Rhizopus stolonifer and Botrytis cinerea on strawberries and physicochemical properties of the strawberries. Twelve days of illumination resulted in an antifungal effect of 3.4 and 1.9 log CFU/g on R. stolonifer and B. cinerea respectively. The illumination caused no significant effect (P ≥ 0.05) on the mass, color and texture of strawberries. Furthermore, total phenolic content, trolox equivalent antioxidant capacity and anthocyanin content of the illuminated strawberries significantly increased (P 0.05). Vitamin C content of illuminated strawberries was only significantly different (P 0.05) from the control starting from Day 9. These results show that 405 nm LED illumination can potentially complement temperature and humidity control in preventing mold spoilage and preserving physicochemical quality of strawberries during refrigerated storage.

Objective: This study produced a fungal chitosan membrane extracted from Rhizopus stolonifer, as well as its modification using dielectric barrier discharge plasma (DBD), aiming to improve the physicochemical characteristics of the membrane, optimizing its use in the medical research field. Method: The obtained chitosan was physically and chemically characterized (Molecular Weight, Fourier Transform Infrared, X-ray Diffraction), later were produced fungal chitosan membranes and DBD plasma was applied. The membranes were characterized before and after plasma application using the tests contact angle, swelling and atomic force microscopy (medium roughness) analyzes. Results: A fungal chitosan with a yield of 16.73 mg/g, and an apparent molecular weight of 4 kDa was obtained, being considered of low molecular weight and high degree of deacetylation (84%). It was possible to obtain the membrane and after application of DBD plasma, the contact angle dropped from 77.5° to 30.9°, making it more hydrophilic. Conclusion: Thus, the efficiency of the technique for increasing the hydrophilicity of the fungal chitosan membrane without the additive of chemical reagents during the process was confirmed and the membrane formed is a promising alternative can be used in different ways in the medical area. Objetivo: Este estudio produjo una membrana fúngica de quitosano extraída de Rhizopus stolonifer, así como su modificación mediante plasma de descarga de barrera dieléctrica (DBD), con el objetivo de mejorar las características físico-químicas de la membrana, optimizando su uso en el campo de la investigación médica. Método: El quitosano obtenido se caracterizó física y químicamente (Peso Molecular, Transformación de Fourier en infrarrojos, Difracción de Rayos X), posteriormente se produjeron membranas de quitosano fúngico y se aplicó plasma DBD. Las membranas se caracterizaron antes y después de la aplicación del plasma mediante ensayos de ángulo de contacto, hinchamiento y microscopía de fuerza atómica (rugosidad media). Resultados: Se obtuvo un quitosano fúngico con un rendimiento de 16,73 mg / gy un peso molecular aparente de 4 kDa, considerándose de bajo peso molecular y alto grado de desacetilación (84%). Se pudo obtener la membrana y luego de aplicar el plasma DBD, el ángulo de contacto bajó de 77.5 ° a 30.9 °, haciéndola más hidrofílica. Conclusión: Así, se confirmó la eficacia de la técnica para incrementar la hidrofilicidad de la membrana fúngica de quitosano sin la adición de reactivos químicos durante el proceso y la membrana formada es una alternativa prometedora que puede ser utilizada de diferentes formas en el campo médico. Objetivo: Este estudo produziu uma membrana fúngica de quitosana extraída de Rhizopus stolonifer, bem como sua modificação utilizando plasma de descarga de barreira dielétrica (DBD), visando melhorar as características físico-químicas da membrana, otimizando seu uso na área de pesquisa médica. Método: A quitosana obtida foi caracterizada física e quimicamente (Peso Molecular, Transformada de Fourier no Infravermelho, Difração de Raios X), posteriormente foram produzidas membranas de quitosana fúngica e aplicado plasma DBD. As membranas foram caracterizadas antes e após a aplicação do plasma por meio dos testes de ângulo de contato, intumescimento e microscopia de força atômica (rugosidade média). Resultados: Foi obtida uma quitosana fúngica com rendimento de 16,73 mg / g, e peso molecular aparente de 4 kDa, sendo considerada de baixo peso molecular e alto grau de desacetilação (84%). Foi possível obter a membrana e após a aplicação do plasma DBD, o ângulo de contato caiu de 77,5 ° para 30,9 °, tornando-o mais hidrofílico. Conclusão: Assim, foi confirmada a eficiência da técnica para aumentar a hidrofilicidade da membrana fúngica de quitosana sem o aditivo de reagentes químicos durante o processo e a membrana formada é uma alternativa promissora podendo ser utilizada de diferentes formas na área médica.

Known as black bread mold, R. stolonifer is a fungus commonly found in contaminated food products such as meat, preserved, and/or baked goods. Potassium sorbate is a common food preservative used t...

Different formulations based on nanoparticles of chitosan-plant extracts were evaluated to detect the infection process from the earliest stage of the fungus Rhizopus stolonifer on strawberry fruit during storage. Chitosan/polyvinyl alcohol (Ch/PVA) and chitosan/polyvinylpyrrolidone (Ch/PVP) films enriched with nanoparticles (NPs) of chitosan blended with plant extracts were prepared. They were placed inside a plastic package containing inoculated fruits and stored at 25 °C for 72 h. The thickness values of the films were in the range of 0.10 to 0.25 mm. All samples showed a maximum absorbance peak of about 300-320 nm; however, the Ch/PVP films enriched with NPs of chitosan and 10% of radish extract had an evident decrease in the optical absorbance as the fungal infection progressed. Additionally, as observed by scanning electron microscopy, the cross-section and surface morphology of films were not modified during storage, and the growth of R. stolonifer was evident after 48 h. Therefore, the Ch/PVP films enriched with chitosan NPs blended with 10% radish extract could be a reliable indicator of this fungus's growth.

The antifungal activity of a library of twenty-four aromatic methoximes was examined against five representative postharvest phytopathogenic fungi. The panel included Penicillium digitatum, Penicillium italicum, Rhizopus stolonifer, Botrytis cinerea and Monilinia fructicola, all of which cause relevant economic losses worldwide as a result of affecting harvested fruits. The minimum inhibitory concentrations and minimum fungicidal concentrations of each compound were defined and the main structure?activity relationships were determined. Although other congeners were more potent, drug likeliness considerations pointed to the methoxime derived from 2,4-dihydroxypropiophenone as the compound with the most suitable profile. The morphology of the colonies of the fungal strains treated with the methoxime was examined microscopically and the compound was also tested in freshly harvested peaches and oranges, exhibiting promising control profiles in both fruits, similar to those of the commercial agents Imazalil and Carbendazim. Fil: Cortés, Iván. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Di Liberto, Melina Gabriela. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Departamento de Química Orgánica. Área Farmacognosia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Kaufman, Teodoro Saul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina Fil: Derita, Marcos Gabriel. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Bracca, Andrea Beatriz Juana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentina

Standardized method of seed treatment is of prime importance in the production of groundnut. The study was to carry out control trial using bark extract (aqueous and ethanol) and oil (seed) of mahogany (Khaya senegalensis) on seven (7) isolated fungi from two groundnut genotypes (peruvian and valencia). The result shows that both mahogany bark and seed extracts are capable of inhibiting mycelial growth of all the isolates. There was no significant variation between the aqueous and ethanol bark extracts in-vitro, however the in-vivo test shows a significant difference between the aqueous and the ethanol bark extract in which the ethanol extract reduced growth of the pathogens more than the aqueous. For all the pathogens except Rhizopus stolonifer there was no growth between 50% to 100% concentration of the Khaya senegalensis oil in-vitro, however in-vivo control at 50% produced scanty to moderate growth for all the pathogens except Rhizopus stolonifer on…

Mono‐culture fermentation by Rhizopus stolonifer could promote the healthiness of immune systems and cholesterol levels. Hence, we examined the effect of diet from mono‐culture fermentation of Moringa oleifera seeds by R. stolonifer (MCF ‐MORS ) on hematological parameters and fundamental indicators of hypercholesterolemia in rat. The animals were divided into six groups (n = 6). Group 1 was placed on basal diet. Group II , III , IV and V were placed on a basal diets supplemented with 7.5%, 15%, 22.5% and 30%, respectively, of MCF ‐MORS . Group VI was placed on basal diet fed with unfermented M. oleifera seeds (UF ‐MOS ). The experiment lasted for eight weeks. The results revealed 7.5% MCF ‐MORS as better biological method to augment PCV , RBC and Hb count in animal model. Also, 7.5% and/or 15% MCF ‐MORS demonstrated highest levels in centrophils, neutrophils and eosinophils, whereas the levels of lymphocytes, basophils and monocytes showed no significant difference. Similarly, 7.5% and 15% MCF ‐MORS modulated LDL and HDL , respectively, better than UF ‐MOS ; but showing no difference in cholesterol level. MCF ‐MORS also maintained architectural integrity of villi and splenocytes better than UF ‐MOS . We therefore concluded that diet from MCF ‐MORS at 7.5% and 15% modulates HDL , LDL , cholesterol and immune system‐related disorders better than UF ‐MOS in rat model.

To investigate the transcriptional regulation of cellobiose synthase (CBS) in Rhizopus stolonifer. Transcription factor XYR1 was identified as responsible for the activation of cbs. In comparison with wild-type R. stolonifer, the deletion of XYR1 resulted in transcriptional down-regulation of cbs by approximately 40%, while XYR1 over-expression increased cbs transcription up to 175%. The highest FPA activity (1.8 IU/ml) was obtained in the XYR1-overexpressing strain OExyr1 cultivated in a 2% (m/V) glucose media, corresponding to a 96% increase compared with that of the parent strain (0.92 IU/ml). Moreover, cellulase synthesis was inhibited after cbs-inactivation mutation in OExyr1. XYR1 directly activates the transcription of cbs to promote cellulase production in R. stolonifer utilizing glucose as a substrate.

Composite dressing composed of Rhizochitosan and Regenplex™ to promote wound healing were assessed. Rhizochitosan was fabricated by deacetylation of Rhizochitin, which obtained by simply depigmenting sporangium-free mycelial mattress produced from Rhizopus stolonifer F6. Physicochemical characterizations of Rhizochitosan demonstrated that it contained 13.5% chitosan with a water-absorption ability of 35-fold dry weight and exhibiting hydrogel nature after hydration. In a wound-healing study on SD rats with full-thickness injury, the composite dressing had a better healing effect than those for each individual components and control group and wound even healed as functional tissue instead of scar tissue. The underlying mechanism of the composite beneficial to wound remodeling is likely attributable to a more reduction level of matrix metalloproteinase (MMP)-9 expression in early stage and a higher MMP-2 expression level in a later stage of healing process. Conclusively, the composite dressing demonstrated to be highly beneficial to the healing of full-thickness injury wound.

A study was conducted on the requirement of lipids for growth and lipase production by Rhizopus stolonifer . Growth and lipase production were suppressed by incorporation of lipids, namely olive oil, butter oil, tributyrin, tricaproin and tripropionin, into the growth medium.

This study evaluated, at a meso-scale, the antifungal effect of 405 nm LED illumination against Botrytis cinerea and Rhizopus stolonifer on tomatoes, as well as its effect of on the physicochemical properties. Tomatoes were surface-inoculated with B. cinerea and R. stolonifer, and illuminated with 87 W/m2 for twelve days. Subsequently, the antifungal effect, defined as the difference in mold populations on the control and illuminated samples, was observed to be 1.9 log CFU/g for B. cinerea and 3.2 log CFU/g for R. stolonifer. In terms of physicochemical effects, beginning from day 9, the total phenolic content, TEAC and vitamin C content of illuminated samples was significantly higher (P > 0.05) by 24.6 %, 28.2 % and 16.5 %, respectively, compared to control, but a greater reduction in mass and lycopene content was also observed. Overall, these results suggest the potential of 405 nm LEDs for controlling mold growth on tomatoes during transportation and storage, retaining their physicochemical quality.

Biotransformation of the antifungal compound 16-oxocleroda-3,13(14)E-dien-15-oic acid (1) isolated from Polyalthia longifolia leaves was achieved by Rhizopus stolonifer in broth medium containing t...

(The Molds Caused the Spoilage of “Pendap” the Traditional Food of Bengkulu) ABSTRACT. Pendap is a traditional Bengkulu food prepared from fermentation of fish. The research was conducted to identify molds caused spoilage of pendap, and to select the species of molds which were able to use for other process in microbiology. The data in this study were laboratory analysis. Samples were collected weekly in a month from productions centre of Pendap and traditional markets, and analyzed microbiologically to determine and identify the molds which were contaminated. There were four specieses of molds found in pendap after three days storage in room condition, namely Rhizopus stolonifer, Mucor sp, Aspergillus terreus, and Penicillim sp. While two specieses which were not produce toxin and the other two were known as the molds which were produced mycotoxin.

The fungi Rhizopus stolonifer (Ehrenb.:Fr.) Vuill. (R. stolonifer (Ehrenb.:Fr.) Vuill.) and Botrytis cinerea Pers. Fr. (B. cinerea Pers. Fr.) are causal agents of important post-harvest diseases in strawberries. For their control, the essential oil (EO) extracted from the leaves of Eucalyptus staigeriana Muell. ex Bailey (E. staigeriana F. Muell. ex Bailey) and Eucalyptus urograndis W. Hill ex Maiden (E. urograndis W. Hill ex Maiden) can be a good alternative to the synthetic fungicides. Thus, the antifungal activity of the EOs from E. staigeriana F. Muell. ex Bailey and from E. urograndis W. Hill ex Maiden was evaluated in vitro on the fungi B. cinerea Pers. Fr. and R. stolonifer (Ehrenb.:Fr.) Vuill.. The effects on pathogen morphology and the in vivo antifungal activity of the EO that presented the highest activity in vitro, associated with carboxymethylcellulose (CMC), were also verified. The chemical composition of the essential oils evaluated was determined. The EO from E. staigeriana F. Muell. ex Bailey was the most efficient in the in vitro assays on the two fungi. This EO, whose major compound is limonene, caused dehydration and rupture of the fungal hyphae, suggesting its action is on the cell wall and membrane. The incorporation of this EO to CMC in the curative way reduced the severity of soft rot, caused by R. stolonifer (Ehrenb.:Fr.) Vuill.; nevertheless, it did not present an effect on the inhibition of B. cinerea Pers. Fr.. These results suggest that E. staigeriana F. Muell. ex Bailey EO, associated to CMC coating, can be an alternative to the use of synthetic fungicides for the control of R. stolonifer (Ehrenb.:Fr.) Vuill., mainly.

Isolates from pure culture of Rhizopus stolonifer were aseptically grown in potato dextrose broth to early exponential phase and centrifuged. The biological synthesis of Iron nanoparticles from the fungus was carried out using simple techniques. Filtrates obtained by simple methods were reacted with 1 M Ferric chloride solution. Characterization of the synthesized iron nanoparticles was monitored using Ultraviolet-visible spectrophotometer and Fourier transform infrared spectroscopy (FTIR). An increase in synthesis of the iron nanoparticles by over 200% occurred when culture of selected isolate was agitated. At 325 nm, peaks of absorbance (3.5) were read at pH 4.5 and 6, while maximum production of the iron nanoparticles was reached at 35 °C. Peaks of transmittance of biosynthesized iron nanoparticles from selected isolate as shown by the FTIR spectrum were located at 750, 1100, 1700, 2500 and 3750 cm−1, representing the CH, C-O, C=O, SH and OH groups respectively. The varying degree of transmittance and pH reported presents the selected R. stolonifer isolate as a biological entity for the synthesis of stable iron nanoparticles.

The effect of β-aminobutyric acid (BABA) on Rhizopus rot produced by Rhizopus stolonifer in harvested peaches and the possible action modes were investigated. Treatment with 50 mmol L−1 of BABA resulted in significantly lower lesion diameter and disease incidence compared with the control. The activities of defense-related enzymes chitinase and β-1,3-glucanase were notably enhanced by this treatment. Meanwhile, BABA treatment also increased lignin accumulation and maintained higher energy status in peaches by enhancing activities of enzymes in the phenylpropanoid and energy metabolism pathways. Semiquantitative reverse transcription PCR results indicated that the transcription of four defense-related genes was substantially and rapidly enhanced only in that BABA-treated fruit upon inoculation with the pathogen. Thus, our results demonstrated that BABA was effective on controlling Rhizopus rot by inducing disease resistance, which includes the increase in gene transcription and activity of defense-related enzymes, the enhancement of cell wall strength, and the maintenance of high energy status in Prunus persica fruit. Moreover, the disease resistance induced by BABA was demonstrated through priming model rather than direct induction.

Strawberry has a limiting postharvest shelf life, especially because of soft rot. The antifungal activity of the essential oils (EOs) of Eucalyptus staigeriana, Lippia sidoides and Pimenta pseudocaryophyllus was tested in vitro against plant pathogen Rhizopus stolonifer. The chemical composition of the EO with the highest activity and its effects on pathogen morphology were verified. The in vivo antifungal activity of this EO associated with carboxymethylcellulose (CMC) coating, in preventive and curative applications, was also evaluated. L. sidoides EO presented the highest in vitro antifungal activity. The analysis of the chemical composition of this EO showed a prevalence of the compound thymol and the scanning and transmission electron microscopy showed that L. sidoides EO was able to cause damage to the cell wall and the intracellular components of the pathogen. Strawberries treated with L. sidoides EO associated with CMC presented a reduction in disease severity, especially when treated in a curative way.

Structural transformation of the sesquiterpene ester, ferutinin (1), by suspended fungal cultures of Aspergillus niger, Rhizopus stolonifer, and Fusarium lini, resulted in the formation of a metabolite. This metabolite was identified as ferutinin α-epoxide (2), by different spectroscopic techniques. Metabolite 2 showed a good antibacterial activity against Staphylococcus aureuscompared to ferutinin (1).

Microbial transformation of mestanolone (1) using the plant pathogenic fungus, Rhizopus stolonifer, resulted in the production of two known metabolites, identified as 11α-hydroxymestanolone (3) and 6α-hydroxymestanolone (4). Transformation of 17-methyl-1-testosterone (2) by R. stolonifer yielded two known metabolites, methandrostenolone (5) and 11α,17β- dihydroxy-androsta-1,4-diene-3-one (6). These transformations included α-hydroxylations at C-11 and C-6, dehydrogenation at C-4, androsta and a demethylation at C-17 positions. Structures of transformed products were determined using spectroscopic techniques.

The effect of chitosan was evaluated in three isolates of Rhizopus stolonifer from infected tomatoes that were harvested in different regions of the state of Morelos, Mexico. Changes in the membrane integrity of spores, modifications in pH media and the proteins released were analysed in each isolate against three different molecular weights of chitosan at three fixed concentrations. There was an observed decline in the integrity of spores in the presence of chitosan at all the concentrations evaluated. The protein released was different depending on the isolate, kind of chitosan and used concentration. There was a significant difference in the pH changes on the growth media for all the tested isolates. Chitosan of high molecular weight showed the best results to inhibit the infection caused by R. stolonifer on the tomato fruits. The severity of symptoms of soft rot was not related with the molecular weight of chitosan.

Microbial transformation of (20S)-20-hydroxymethylpregna-1,4-dien-3-one (1) by four filamentous fungi, Cunninghamella elegans, Macrophomina phaseolina, Rhizopus stolonifer, and Gibberella fujikuroi, afforded nine new, and two known metabolites 2–12. The structures of these metabolites were characterized through detailed spectroscopic analysis. These metabolites were obtained as a result of biohydroxylation of 1 at C-6β, -7β, -11α, -14α, -15β, -16β, and -17α positions, except metabolite 2 which contain an O-acetyl group at C-22. These fungal strains demonstrated to be efficient biocatalysts for 11α-hydroxylation. Compound 1, and its metabolites were evaluated for the first time for their cytotoxicity against the HeLa cancer cell lines, and some interesting results were obtained.

The study investigated the in-vitro antifungal activities of sodium bicarbonate (NaHCO 3 ) and leaf extracts of Vernonia amydgalina (bitter leaf) and A zadirachta indica (neem) on fungal species isolated from two cowpea cultivars; IFE BROWN and Drum (a local cultivar). Concentrations of 1.95 mg/ml and 1.43 mg/ml were used for A. indica while 1.45 mg/ml and 1.15 mg/ml were used for V. amydgalina . Sodium bicarbonate was evaluated on all the isolates at 2.0 mg/ml and 3.0 mg/ml. The inhibitory effects of these antifungal agents were compared with benlate (a synthetic fungicide) on Potato Dextrose Agar. Benlate totally inhibited all the fungal isolates. Candida species isolated from the two cowpea cultivars were greatly inhibited by the antifungal agents while Trichoderma species isolated from IFE BROWN was the least inhibited. The inhibitory effects of NaHCO 3 and A. indica on Candida spp. were not significantly different and values ranged from 74.5% to 84%. The two concentrations of A. indica had better inhibitory effect on Pythium spp . than NaHCO 3 . Vernonia amydgalina at 1.45 mg/ml inhibited A. niger and Candida spp. by 83.75% and 87.5% respectively while NaHCO 3 at 2.0 mg/ml inhibited Rhizopus stolonifer isolated from Drum by 75%. The study concludes that the two plant extracts and sodium bicarbonate had broad spectrum activities on fungal species and are therefore recommended as alternatives to toxic and synthetic fungicides. Keywords: Cowpea, eco-friendly, fungicide, inhibition

As part of an effort to discover bioactive natural products from marine sources, we investigated the bioactive secondary metabolites from two marine isolates of the fungi, Trichoderma viride and Rhizopus stolonifer. Three cyclopentenones, myrothenones A (1) and B (2) and trichodenone A (3), were isolated from T. viride and two cyclopentenones, 2-bromomyrothenone B (4) and botrytinone (5), were isolated from R. stolonifer. The molecular structures and absolute stereochemistries of the cyclopentenones were determined from chemical and physicochemical evidence, including quantum chemistry calculations, X-ray analysis, and the circular dichroism (CD) exciton chirality method. Myrothenone A (1) displays tyrosinase inhibitory activity, with an IC 50 value of 6.6 μM, and is therefore more active than the positive control, kojic acid.

Introduction. La conservation prolongee des pommes les expose a differentes affections qui peuvent etre d’origine physiologique, souvent liees au froid, ou d’origine parasitaire, pour l’essentiel des maladies fongiques. Materiel et methodes. Le controle des especes fongiques responsables de la pourriture des pommes en conservation (Rhizopus stolonifer, Penicillium expansum, Aspergillus niger, Aspergillus fumigatus, Alternaria alternata, Cladosporium herbarum, Fusarium oxysporum, Saccharomyces cerevisiae, Monilia fructigina, Cryptosporiopsis malicorticis, Spilocaea pomi et Trichothecium roseum) par quatre sels de calcium : hydroxyde de calcium (Ca (OH) 2), chlorure de calcium (CaCl 2), nitrate de calcium (Ca(NO3) 2) et carbonate de calcium (CaCO 3). Resultats et discussion. In vitro, le nitrate de calcium et le carbonate de calcium ont peu d’effet sur les trois stades de vie des champignons, ainsi que le chlorure de calcium qui est moyennement efficace sur la croissance mycelienne, la germination conidienne et la sporulation de tous les champignons etudies. In vivo et a froid, la plupart des sels de calcium testes s’averent efficaces sur le developpement de la pourriture des pommes causee par le complexe fongique. Ces resultats justifient l’utilisation de ces sels de calcium comme moyen de lutte non polluant contre les maladies d’origine fongiques des pommes en conservation.

Dichloromethane, ethyl acetate, methanol, and aqueous extracts obtained from 16 Spanish medicinal plants were screened for their antioxidant and antifungal activities. The radical scavenging capaci...

Effect of seed treatment on seedling health of chili (BARI Morich 1) was studied at Bangladesh Agricultural University (BAU), Mymensingh, Bangladesh. BAU Bio-fungicide (3% of seed weight), chitosan (1% solution), thiovit (0.3% of seed weight), compressed moist heat (54oC for 15 minutes), neem leaf extract (1 : 1 w/v), garlic clove extract (1:3 w/v), ginger extract (1:2 w/v) and allamonda leaf extract (1:1 w/v) were employed as seed treating agents. The treated seeds were placed on moistened blotter paper. Data were recorded on percent germination, production of percent healthy seedling and seedling vigour of chili. The results of seed health testing showed that, five different seed borne fungi viz. Colletotrichum capsici, Curvularia lunata, Rhizopus stolonifer, Aspergillus flavus and Fusarium moniliforme were found to be associated with the tested chili seed samples. Among these fungi, Curvularia lunata was the most prevalent one which was followed by Rhizopus stolonifer, Colletotrichum capsici, Fusarium moniliforme and Aspergillus flavus . All the seed treating agents were found to be effective compared to control in controlling seed borne fungi for the blotter method. The highest percentage of germination (93.33%) was recorded when the seeds of BARI Morich 1 were treated with BAU Bio-fungicide, whereas the lowest percentage of germination (61.33%) was recorded in case of untreated seeds. The highest percentage of healthy seedling (95.33%) was recorded when the seeds were treated with BAU Bio-fungicide and allamonda leaf extracts, whereas the lowest percentage of healthy seedling (59.00%) was recorded in case of untreated seeds. The highest vigour index (681.59) was recorded when the seeds were treated with neem leaf extracts, whereas the lowest vigour index (214.66) was recorded in case of untreated seeds. DOI: http://dx.doi.org/10.3329/jesnr.v7i1.22167 J. Environ. Sci. & Natural Resources, 7(1): 177-181 2014

The diterpene ent-18,19-dihydroxytrachylobane was biotransformed for the first time by Rhizopus stolonifer, and yielded the new ent-11β,18,19-trihydroxytrachylobane derivative besides the new ent-kaur-11-ene diterpenes ent-16α,18,19-trihydroxykaur-11-ene and ent-18,19-dihydroxy-16α-methoxykaur-11-ene. Their structures were determined by spectrometric methods.

The microbial transformation of leucosceptrine ( 1 ), the first member of class leucosesterterpenes, by Rhizopus stolonifer afforded two metabolites, 1α-hydroxyleucosceptrine ( 2 ), and 8α-hydroxyleucosceptrine ( 3 ).

Chlorine dioxide (ClO2) is an alternative to hypochlorites (NaOCl, Ca(OCl)2) for fruit and vegetable sanitization to reduce postharvest decays caused, among other fungi, by Botrytis cinerea, Penicillium expansum and Rhizopus stolonifer. Due to economical reasons and because of its explosiveness, the use of chlorine dioxide has been relatively limited. However, the development of stabilized commercial formulations has allowed to reintroduce it. In this study, the efficacy of a new stabilized chlorine dioxide formulation (Tecsa®Clor, Protecsa S.A., Santiago,Chile) to inhibit conidial germination of B. cinerea and P. expansum, and sporangiospore germination of R. stolonifer was demonstrated. The efficacy was dependent primarily on concentration and exposure time but it was also affected by pH. Conidia germination of B. cinerea was inhibited over 98% at concentrations higher than 75 or at 25 mg·mL-1 after 1 or 30 min of contact, respectively. Similarly, over 90% inhibition of conidial germination of P. expansum was achieved with 100 and 25 m·mL-1 after 1 and 30 min, respectively. Sporangiospores of R. stolonifer were inhibited by 90% at 100 mg·mL-1 for 30 min. The pH of the solution increased as chlorine dioxide concentration increased, and the biological activity decreased considerably at pH higher than 8, after 5 and 15 min of contact. No phytotoxic effects were obtained on pear cv. Packham’s Triumph even at 1000 mg·mL-1 after 20-day-exposure at 20 oC. Therefore the stabilized commercial formulation of chlorine dioxide is an alternative to chlorinate water to treat fruits by immersion in order to control B. cinerea, P. expansum and R. stolonifer during postharvest. For a complete control, concentrations higher than 75 mg·mL-1 should be used at pH between 7 and 8. El dioxido de cloro (ClO2) es una alternativa al uso de hipocloritos (NaOCl, Ca(OCl)2) util para la sanitizacion de la fruta en poscosecha y reducir el riesgo de pudriciones causadas entre otros por Botrytis cinerea, Penicillium expansum o Rhizopus stolonifer. Razones economicas y la explosividad de este gas al mantenerlo bajo presion han limitado su uso. Sin embargo, el desarrollo de formulaciones comerciales, estabilizadas, ha permitido reintroducir el dioxido de cloro con estos propositos. En este trabajo se demostro la eficacia de este compuesto, formulado y estabilizado (Tecsa®Clor, Protecsa S.A., Santiago,Chile), en el control de la germinacion de conidias de B. cinerea y P. expansum y esporangiosporas de R. stolonifer. Sin embargo, la efectividad de este producto dependio primeramente de la concentracion y del tiempo de exposicion, pero tambien tuvo importancia en la mortalidad de las esporas el pH de la solucion. Una concentracion de dioxido de cloro > 75 o 25 mg·mL-1 1 o 30 min de exposicion, respectivamente, inhibio en mas de 98% la germinacion de conidias de B. cinerea. En forma similar, se obtuvo sobre un 90% de inhibicion de la germinacion de conidias de P. expansum con 100 y 25 mg·mL-1 por 1 y 30 min, respectivamente. La germinacion de esporangiosporas de R. stolonifer se inhibio por sobre un 90% unicamente con 100 mg·mL-1 por 30 min. El pH de la solucion acuosa de dioxido de cloro aumento considerablemente con la concentracion, disminuyendo la efectividad con pH superior a 8, tanto luego de 5 como 15 min de exposicion. No hubo efectos fitotoxicos en peras cv. Packham’s Triumph aun expuestas a concentracion de 1000 mg·mL-1, luego de 20 dias a 20 oC. Por lo tanto, el dioxido de cloro formulado comercialmente es una alternativa para el control de B. cinerea, P. expansum y R. stolonifer en poscosecha. Sin embargo, se recomienda corregir la dosis en funcion de los patogenos predominantes y verificar el pH de la solucion de modo que esta permanezca entre 7 y 8.

Incubation of sclareol with Rhizopus stolonifer affords in high yield a mixture of triols with 18-hydroxy-sclareol as the main component.

Peracetic acid (PAA) treatment of stone fruits (sweet cherry, apricot, peache and nectarine) reduced the incidence of brown rot caused by Monilinia laxa and soft rot caused by Rhizopus stolonifer. The efficacy of the treatment depended on the length of time. Fruit, neither wounded nor inoculated and dipped for 1 min in a 125 mg L-1 PAA solution, showed a significant reduction of Monilinia rots with respect to control. Significant inhibition was also observed on fruit wounded and inoculated with R. stolonifer and treated for 1 min with 250 mg L-1 PAA solution. Preliminary experiments were also conducted to determine the effects of sodium bicarbonate (SBC) sodium propionate (Na-Pro) and potassium sorbate (K-Sorb), substances generally regarded as safe (GRAS) against pathogens. Phytotoxic effects appeared on fruit treated with SBC at the minimum effective concentration (3%). Only K-Sorb at 1.5% was able to significantly reduce Monilinia infections in sweet cherries (61.6%), apricots (78%) and nectarines (31.8%) with respect to control, without any visible damage on the skin. Similar results were obtained on apricot wounded and inoculated with three different concentrations (102, 103 and 104 conidia ml-1) of R. stolonifer. PAA and K-Sorb showed the same efficacy on apricots and nectarines against M. laxa. K-Sorb was less effective than PAA on nectarines and peaches inoculated with R. stolonifer. Fruit hydro-refrigeration significantly reduced the incidence of brown rot in Nero I and Van sweet cherries; disease control was improved by addition of PAA (125 mg L-1) in cold water. PAA efficacy on pre-existing infections can be very useful to control stone fruit diseases that can spread during shipping and marketing.

Fungal biotransformations of alpha-santonin (1) were conducted with Mucor plumbeus (ATCC 4740), Cunninghamella bainieri (ATCC 9244), Cunninghamella echinulata (ATCC 9245), Curvularia lunata (ATCC 12017) and Rhizopus stolonifer (ATCC 10404). Rhizopus stolonifer (ATCC 10404) metabolized compound 1 to afford 3,4-epoxy-alpha-santonin (2) and 4,5-dihydro-alpha-santonin (3) while Cunninghamella bainieri (ATCC 9244), Cunninghamella echinulata (ATCC 9245) and Mucor plumbeus (ATCC 4740) were capable of metabolizing compound 1 to give a reported metabolite, 1,2-dihydro-alpha-santonin (4). The structures of these transformed metabolites were established with the aid of extensive spectroscopic studies. These fungi regiospecifically reduced the carbon-carbon double bond in ring A of alpha-santonin.

Nuclease Rsn from Rhizopus stolonifer catalyzes the hydrolysis of ss- and dsDNA in a ratio of approximately 2:1. Time course of 3 ′ and 5 ′ terminal analysis of the hydrolytic products of ss- and dsDNA showed that nuclease Rsn does not show any strict base preference and cleaves DNA in a non-specific manner. Moreover, separation of the hydrolytic products of ss- and dsDNA in the presence of Mg 2+ , Mn 2+ or Co 2+ showed the predominance of tetra-, tri-, and dinucleotides followed by mononucleotides, suggesting an endo mode of action.

Of 49 microbial strains screened for their capabilities to transform ginsenoside Rb1, Rhizopus stolonifer and Curvularia lunata produced four key metabolites: 3-O-[β-d-glucopyranosyl-(1,2)-β-d-glucopyranosyl]- 20-O-[β-d-glucopyranosyl]-3β,12β, 20(S)-trihydroxydammar-24-ene (1), 3-O-[β-d-glucopyranosyl-(1,2)-β-d- glucopyranosyl]-20-O-[β-d-glucopyranosyl]-3β,12β, 20(S)-trihydroxydammar-24-ol (2), 3-O-[β-d-gluco- pyranosyl-(1,2)-β-d-glucopyranosyl]-3β, 12β, 20(S)-trihydroxydammar-24-ene (3), and 3-O-β-d-glucopyranosyl-3β, 12β, 20(S)-trihydroxydammar-24-ene (4), identified by TOF-MS, 1H- and 13C-NMR spectral data. Metabolites 1, 3 and 4 were from the incubation with R. stolonifer, and 1 and 2 from the incubation with C. lunata. Compound 2 was identified as a new compound.

Methyl ent-17-hydroxy-16beta-kauran-19-oate was fed to a 2-day-old culture of the fungus Rhizopus stolonifer, fermenting at room temperature (25 degrees C) in an orbital shaker (21). After 11 days, both broth and mycelia were extracted with ethyl acetate. Two novel compounds were isolated from this experiment: methyl ent-9alpha,17-dihydroxy-16beta-kauran-19-oate and methyl ent-7alpha,17-dihydroxy-16beta-kauran-19-oate. Their structures were fully confirmed by spectroscopic methods.

The synthesis of new pyrazolo[3,4-b]pyrazines and related heterocycles has been reported. The key intermediate 1,6-diphenyl-3-methyl-1H-pyrazolo[3,4-b]pyrazine-5-carbonitrile 2 was obtained in one pot synthesis from the reaction of 5-amino-3-methyl-4-nitroso-1-phenylpyrazole 1 with benzoylacetonitrile. Modest antifungal activity was shown for some of the prepared compounds.

Many yeasts, including yeast-like fungi, were selectively isolated from fruits and vegetables. In several assays performed on strawberries, table grape berries and kiwifruit, the yeast-like fungus Aureobasidium pullulans L47 and the yeasts Candida vanderwaltii L60 and C. oleophila L66 were the most effective antagonists of Botrytis cinerea and Rhizopus stolonifer . Isolates L47 and L66 were utilized in trials on strawberries grown under plastic tunnels. They were applied at flowering (full bloom and late petal fall) and at fruit maturity (just before or after harvest). Isolate L47 was the most effective against both B. cinerea and R. stolonifer . Both antagonists were more active when applied at the flowering stage, with isolate L47 more effective than vinclozolin. The antagonist population was consistently high on flowers and developing fruits, and on cold-stored strawberries. Isolates L47 and L66 showed a low sensitivity towards some fungicides in culture and were able to grow at temperatures between those of cold storage and 33 °C. Competition for nutrients seems to be the main mode of action.

Microbial transformation of clerodane lactone ( 1 ) by a plant pathogen fungus, Rhizopus stolonifer , resulted in the production of metabolites 3 and 4 . While incubation of clerodane methyl ester ( 2 ) by R. stolonifer yielded metabolites 5 – 8 . The structures of the transformed products were determined by the spectroscopic techniques and compounds 4 , 7 and 8 were found. The antibacterial activity of clerodane diterpenoids 1 and 2 and their metabolites 3 – 8 were also studied. The metabolites 3 – 7 showed moderate activities against both Gram-positive and Gram-negative organisms. While metabolite 8 showed a moderate activity against Gram-positive organisms and a good activity against Gram-negative organisms.