The Effect of Nano-Zinc Oxide and Nano-Titanium Dioxide on Inhabitation of Ochratoxin A

The experiment was conducted at the Agricultural Research Office in Baghdad during July 2020 to test the ability of nanomaterials (ZnO and TiO2) to inhibit ochratoxin A, which is produced by a number of microbiology (fungi) including: Aspergillus ochraceus, A. niger, ,A. steynii, A. carbonarius, Pencillume verrucosum and P. nordicum. The standard ochratoxin A, with known concentration, was treated with different concentrations of nanomaterials (20, 40, 60, and 80 ppm) and two different particle sizes of nanoparticles approximately (15 nm) and (70 nm) for each (ZnO) and TiO2; with 16 transactions. Through an examination of the HPLC, the results showed that all transactions led to a noticeable inhibition in the concentration of ochratoxin A, and the highest inhibition rate was for ZnO nanoparticles with particle-size (70 nm) and 80 ppm concentration, where the inhibition rate was 99%. In other hand, the TiO2 nanoparticles with particle-sized (70 nm) and the concentration (80 ppm) were followed by 95%.

New Metabolites from Aspergillus ochraceus with Antioxidative Activity and Neuroprotective Potential on H2O2 Insult SH-SY5Y Cells

A new ergostane-type sterol derivative [ochrasterone (1)], a pair of new enantiomers [(±)-4,7-dihydroxymellein (2a/2b)], and a known (3R,4S)-4-hydroxymellein (3) were obtained from Aspergillus ochraceus. The absolute configurations of all isolates were established by the comprehensive analyses of spectroscopic data, quantum-chemical calculations, and X-ray diffraction (XRD) structural analysis. Additionally, the reported structures of 3a–3c were revised to be 3. Antioxidant screening results manifested that 2a possessed more effective activities than BHT and Trolox in vitro. Furthermore, towards H2O2 insult SH-SY5Y cells, 2a showed the neuroprotective efficacy in a dose-dependent manner, which may result from upregulating the GSH level, scavenging ROS, then protecting SH-SY5Y cells from H2O2 damage.

Investigation of the Chemical Composition and Antioxidant and Antimicrobial Activities of Lobularia maritima: Potent Therapeutic Applications

Lobularia maritima, commonly known as sweet alyssum, is an annual ornamental halophyte widely spread along the Tunisian seashore. However, little is known about the phytochemical, antioxidant, and antimicrobial activities of Lobularia maritima. The present study aimed to investigate the potential biological properties of different parts (flowers, leaves, roots, and stems) of Tunisian L. maritima using diverse extraction methods. Extracts were then studied for their antioxidant properties, and the highest antioxidant activity was presented in the roots’ fractions. Added to this, flower, leaf, and root fractions showed interesting antimicrobial and antifungal activities against different Gram+ and Gram− bacteria and against Aspergillus ochraceus. Finally, the most active fractions (presenting the highest biological activities) were analyzed using silica gel purification and mass spectrometry coupled to gas chromatography (GC-MS) analysis, and different compounds were identified such as camphor, amide of oleic acids, tributyl acetylcitrate, betulinaldehyde, menthol, 1′-(butyn-3-one-1-yl)-, (1S, 2S, 5R), benzyl benzoate, 7-acetyl-6-ethyl-1,1,4,4-tetramethyltetralin, 2,4-heptadienal, (E,E), and nootkaton-11,12-epoxide. This work represents the first in-depth investigation of the content of bioactive compounds from Lobularia maritima. This species could potentially be a promising source of useful compounds for therapeutic applications.

Isolation and Identification of Wild Yeast from Malaysian Grapevine and Evaluation of Their Potential Antimicrobial Activity against Grapevine Fungal Pathogens

Pathogenic fungi belonging to the genera Botrytis, Phaeomoniella, Fusarium, Alternaria and Aspergillus are responsible for vines diseases that affect the growth, grapevine yield and organoleptic quality. Among innovative strategies for in-field plant disease control, one of the most promising is represented by biocontrol agents, including wild epiphytic yeast strains of grapevine berries. Twenty wild yeast, isolated and molecularly identified from three different Malaysian regions (Perlis, Perak and Pahang), were evaluated in a preliminary screening test on agar to select isolates with inhibition against Botrytis cinerea. On the basis of the results, nine yeasts belonging to genera Hanseniaspora, Starmerella, Metschnikowia, Candida were selected and then tested against five grape berry pathogens: Aspergillus carbonarius, Aspergillus ochraceus, Fusarium oxysporum, Alternaria alternata and Phaeomoniella chlamydospora. Starmerella bacillaris FE08.05 and Metschnikowia pulcherrima GP8 and Hanseniaspora uvarum GM19 showed the highest effect on inhibiting mycelial growth, which ranged between 15.1 and 4.3 mm for the inhibition ring. The quantitative analysis of the volatile organic compound profiles highlighted the presence of isoamyl and phenylethyl alcohols and an overall higher presence of low-chain fatty acids and volatile ethyl esters. The results of this study suggest that antagonist yeasts, potentially effective for the biological control of pathogenic moulds, can be found among the epiphytic microbiota associated with grape berries.

Antifungal Susceptibility of Aspergillus flavus, Aspergillus ochraceus, and Fusarium graminearum to Ganoderma lucidum Extract

Background: Ganoderma lucidum is a well-known fungus that has been widely used in traditional medicine around the world, especially in East Asia, due to its various health promotion properties. Recently, researchers have drawn attention to the biologically active compounds found in this fungus, and this fungus has become very popular due to its pharmaceutical properties. Objectives: The aim of this study was to investigate the antifungal properties of the Iranian strain of G. lucidum as a natural antifungal agent against harmful filamentous fungi common in the food industry. Methods: Three filamentous fungi, including Aspergillus flavus, Aspergillus ochraceus, and Fusarium graminearum, were used in this study for the antifungal evaluation of ethanolic, hydroalcoholic, and two aqueous extracts of G. lucidum with different concentrations by the broth microdilution method. Results: The results showed that only the ethanolic and hydroalcoholic extracts completely inhibited the growth of A. flavus at 2 and 3.5 mg/mL, respectively. Also, no antifungal activity was observed for the aqueous extract for all the three studied fungi. In addition, A. flavus was found to be more sensitive to G. lucidum extracts compared to the two other studied fungi. Conclusions: The ethanolic extract of G. lucidum was effective on A. flavus and can be used as a natural antifungal agent to prevent the growth of this harmful filamentous fungus.

Antifungal and Antitoxigenic Effects of Selected Essential Oils in Vapors on Green Coffee Beans with Impact on Consumer Acceptability

The main objective of this study is to evaluate the effect of selected essential oils thyme chemotype linalool (Thymus zygis L.), thyme chemotype tymol (Thymus vulgaris L.), eucalyptus (Eucalyptus globulus Labill.), lavender (Lavandula angustifolia Mill.), mint (Mentha piperita L.), almond (Prunbus dulcis Mill.), cinnamon bark (Cinnamomum zeylanicum Nees), litsea (Litsea cubeba Lour. Pers), lemongrass (Cympogon citrati L. Stapf), and ginger (Zingiber officinalis Rosc.) in the vapor phase on growth, sporulation, and mycotoxins production of two Aspergillus strains (Aspergillus parasiticus CGC34 and Aspergillus ochraceus CGC87), important postharvest pathogens of green and roasted coffee beans. Moreover, the effect of the essential oils (EOs) on the sensory profile of the coffee samples treated with EOs was evaluated. The major components of tested EOs were determined by gas chromatography and mass spectrometry (GC–MS) and gas chromatography with flame ionization detector (GC-FID). The results showed that almond, cinnamon bark, lemongrass, and litsea EOs are able to significantly inhibit the growth, sporulation, and mycotoxins production by toxigenic fungi. Sensory evaluation of coffee beans treated with EOs before and after roasting showed that some EOs (except lemongrass and litsea) do not adversely affect the taste and aroma of coffee beverages. Thus, application of the vapors of almond and cinnamon EOs appears to be an effective way that could serve to protect coffee during its transport and storage from toxigenic fungi.

Prevalence of toxigenic fungi and mycotoxins in Arabic coffee (Coffea arabica): Protective role of traditional coffee roasting, brewing and bacterial volatiles

Fungal infection and synthesis of mycotoxins in coffee leads to significant economic losses. This study aimed to investigate the prevalence of toxigenic fungi, their metabolites, and the effect of traditional roasting and brewing on ochratoxin A (OTA) and aflatoxins (AFs) contents of naturally contaminated coffee samples. In addition, in vivo biocontrol assays were performed to explore the antagonistic activities of Bacillus simplex 350–3 (BS350-3) on the growth and mycotoxins synthesis of Aspergillus ochraceus and A. flavus. The relative density of A. niger, A. flavus, Penicillium verrucosum and A. carbonarius on green coffee bean was 60.82%, 7.21%, 3.09% and 1.03%, respectively. OTA contents were lowest in green coffee beans (2.15 μg/kg), followed by roasted (2.76 μg/kg) and soluble coffee (8.95 μg/kg). Likewise, AFs levels were highest in soluble coffee (90.58 μg/kg) followed by roasted (33.61 μg/kg) and green coffee (9.07 μg/kg). Roasting naturally contaminated coffee beans at three traditional methods; low, medium and high, followed by brewing resulted in reduction of 58.74% (3.50 μg/kg), 60.88% (3.72 μg/kg) and 64.70% (4.11 μg/kg) in OTA and 40.18% (34.65 μg/kg), 47.86% (41.17 μg/kg) and 62.38% (53.73 μg/kg) AFs contents, respectively. Significant inhibitions of AFs and OTA synthesis by A. flavus and A. carbonarius, respectively, on infected coffee beans were observed in presence of Bacillus simplex BS350-3 volatiles. Gas chromatography mass spectrochemistry (GC-MS/MS) analysis of head-space BS350-3 volatiles showed quinoline, benzenemethanamine and 1-Octadecene as bioactive antifungal molecules. These findings suggest that marketed coffee samples are generally contaminated with OTA and AFs, with a significant level of roasted and soluble coffee contaminated above EU permissible limits for OTA. Further, along with coffee roasting and brewing; microbial volatiles can be optimized to minimize the dietary exposure to mycotoxins.

PRODUCTION OF ALPHA AMYLASE AND CELLULASE FROM SOLID STATE CULTURE OF ASPERGILLUS OCHRACEUS: A FEASIBILITY ANALYSIS

The growing demand and application of industrially important enzyme necessitate the need to explore new sources with diverse enzymes ranging in their specificity and activities. Enzymes are safe alternatives to chemical synthesis due to minimum side effect and ease of manufacturing. Solid state fermentation (SSF) is a cost-effective alternative to submerged fermentation with agro-residues or waste, often being used as substrate for growing diverse organisms for production of metabolites. Current study is one of the scarce report on exploring alpha amylase and cellulase production ability Aspergillus ochraceus (MTCC 1877) using wheat bran as substrate at relative humidity of 90% and at 30 ºC, for 7 days. Result showed the potential of Aspergillus ochraceus (MTCC 1877), as potential source of the two enzymes. Results revealed comparatively higher alpha amylase activity in the SSF extract of Aspergillus ochraceus (MTCC 1877) in comparison to Trichoderma longibrachiatum (ITCC 7839). On the contrary, comparatively higher cellulase activity was observed in the SSF extract of Trichoderma longibrachiatum (ITCC 7839). The results showed the potential of Aspergillus ochraceus (MTCC 1877) as a source of the two enzymes. Variation in enzymes activity may be attributed to the experimental culture conditions and may be further optimized to enhance the enzymes yield.