Strains Of Aspergillus Flavus Research Articles

Non-aflatoxigenic kojic acid-producing Aspergillus flavus NJC04 reduces the symptoms of Sclerotinia sclerotiorum in soybean

Although non-aflatoxigenic Aspergillus flavus strains have been thoroughly used to reduce aflatoxin contaminations in maize and nuts, the biocontrol potential of these strains for the management of fungal pathogens remains almost unexplored. This study aimed to evaluate the biocontrol mechanisms and efficacy of A. flavus NJC04, which was previously isolated from kiwifruit, for the control of soybean pathogen Sclerotinia sclerotiorum. Non-aflatoxigenic NJC04 was shown to contain important deletions in the aflatoxin and cyclopiazonic acid biosyntheses. Interestingly, this strain inhibited mycelial growth and sclerotia formation of soybean pathogen Sclerotinia sclerotiorum. NJC04 showed various antifungal mechanisms against S. sclerotiorum, including competition for space and nutrients, and the production of antifungal kojic acid, which was detected at 87 ± 4 mg/L in the culture medium. NJC04 colonized soybean plants during long periods and did not cause necrotic lesions. Preventive application of 1 × 107 and 1 × 108 NJC04 spores/mL reduced Sclerotinia rot symptoms by 83.2 % and 100 %, respectively. Collectively, the biocontrol efficacy of non-aflatoxigenic NJC04 for the control of S. sclerotiorum was examined for the first time revealing new insights into the mechanisms used by A. flavus strains to compete with plant fungal pathogens.

Comparative Analysis of Compost Quality Produced from Fungal Consortia and Rice Straw by Varying C/N Ratio and its Effect on Germination of Vigna radiata

Composting is considered to be one of the best methods for handling organic waste. It is a natural process and takes months to give quality mature compost. Characteristics of initial wastes and process conditions are the compost maturity deciding factors. Some biological inoculants, e.g., bacteria and fungi, can reduce the compost time and improve its quality. This research is based on the hypothesis that using fungus consortia on rice straw will boost the activities of microbes and, as a result, the rate of composting. The hypothesis was tested by preparing compost using rice straw residue with and without the applications of fungal consortia. Fungal consortia of Aspergillus flavus, Aspergillus fumigatus, and Aspergillus terreus cellulose-degrading strains along with Pusa-1121 rice variety were used for the study. Different C/N ratios were achieved by varying rice straw, green leaves, poultry droppings, and fungal inoculant proportions. During various stages of composting, changes in total nitrogen, organic carbon, C/N ratios, and other parameters were calculated. The germination index of Mung beans (Vigna radiata) was used to measure the quality of the completed compost extract. Statistical analysis with the help of a two-tailed independent t-test at the confidence level of 95% was applied to determine the statistical difference between the treatments and control. It has been found that the Seed Germination index of treatment C/N 30 was 91.5% and that of C/N 26 was 79.1% which were significantly (p<0.01) different from the 54% GI of control.

Preparation and characterization of a novel nanoemulsion consisting of chitosan and Cinnamomum tamala essential oil and its effect on shelf-life lengthening of stored millets

This study aimed to improve the stability of Cinnamomum tamala essential oil (CTEO) via encapsulating into chitosan nanoemulsion (CsNe) through an ionic-gelation technique and explore its food preservative efficacy against aflatoxigenic strain of Aspergillus flavus (AFLHPSi-1, isolated from stored millet), aflatoxin B1 (AFB1) contamination, and lipid peroxidation, causing qualitative deterioration of stored millets. The CTEO was characterized through gas chromatography–mass spectrometry (GC–MS) analysis that confirmed the presence of linalool as a major component occupying approximately 82.64% of the total oil. The synthesized nanoparticles were characterized through scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) analysis. The encapsulation efficiency (EE) and loading capacity (LC) of CTEO-CsNe were found to be 97.71% and 3.33%, respectively. In vitro release study showed a biphasic release pattern: with an initial burst release followed by a controlled release of CTEO. During investigation of efficacy, the CTEO-CsNe caused complete inhibition of A. flavus growth, and AFB1 biosynthesis at 1.0 and 0.8 μL/mL, respectively. The CTEO-CsNe exhibited its antifungal mode of action by altering fungal plasma membrane integrity (ergosterol inhibition) and permeability (leakage of important cellular constituents), and antiaflatoxigenic mode of action by inhibiting cellular methylglyoxal biosynthesis. CTEO-CsNe showed high free radical scavenging capacity (IC50 = 5.08 and 2.56 μL/mL) against DPPH•+ and ABTS•+ radicals, respectively. In addition, CTEO-CsNe presented remarkable preservative efficacy, inhibiting AFB1 and lipid peroxidation in model food system (Setaria italica) without altering their organoleptic properties. Based on overall results, CTEO-CsNe can be recommended as a novel shelf-life enhancer of stored millet samples.

Safety evaluation and comparative genomics analysis of the industrial strain Aspergillus flavus SU-16 used for huangjiu brewing

Huangjiu is a popular Chinese traditional alcoholic beverage, while its brewing processes have rarely been explored. We herein report the first gapless, near-finished genome assembly of the industrial strain Aspergillus flavus SU-16 for huangjiu brewing. This work provides insights and supports for the further industrial applications of A. flavus isolates by comprehensively studying of the safety and genomic variations of SU-16. We demonstrated that SU-16 is a non-aflatoxigenic A. flavus at both molecular and metabolic levels. Using of nanopore sequencing technology resulted in a complete genome sequence for all 8 A. flavus chromosomes, as well as the mitochondrion. Genome comparisons of SU-16 with reference strains identified the chromosomal rearrangements, revealed the adaption mechanism of SU-16 to huangjiu ecological niche, and found that SU-16 is a good repository for CAZymes and some bioactive secondary metabolites. The results will help to develop more scientific huangjiu fermentation processes, and explore metabolism pathways of desired or harmful components in huangjiu to improve its quality.

Influence of abiotic factors (water activity and temperature) on growth and aflatoxin production by Aspergillus flavus in a chickpea-based medium

The effect of water activity (aW; 0.87, 0.90, 0.92, 0.94, 0.96, 0.98 and 0.99), temperature (15, 25, and 30 °C), incubation time (5, 10, 14, and 21 days), and their interactions on mycelial growth and aflatoxin production in a chickpea-based medium by three Aspergillus flavus strains isolated from chickpea grains in Argentina was evaluated. Maximum growth rates were obtained at the highest aW (0.99) and 30 °C, with growth decreasing as the aW of the medium was reduced. Maximum levels of aflatoxins were produced at 0.99 aW and 25 °C after 5 days of incubation for two strains, and at 25 °C and 0.96 aW after 21 days of incubation for the third strain. The aflatoxin concentrations varied considerably depending on the aW and temperature interactions assayed. Two-dimensional profiles of aW by temperature interactions were developed from these data to identify areas where conditions indicate a significant risk from aflatoxin accumulation on chickpea. This study provides useful baseline data on conditions representing a high and a low risk for contamination of chickpea by aflatoxins which is of greater concern because this pulse is destined mainly for human consumption.

A Series of Novel Bioactive Cyclic Peptides: Synthesis by Head‐to‐Tail Cyclization Approach, Antimicrobial Activity and Molecular Docking Studies

AbstractA new series of cyclic antimicrobial peptides (AMPs) containing D/L‐α‐amino acids have been designed and characterized by spectroscopic techniques. Newly synthesized cyclic peptides were tested for antibacterial and antifungal activities in the hopes of discovering novel clues that may be used to create effective anti‐microbial medicine. Those cyclic AMPs demonstrated good antibacterial activity against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus and that was comparable to reference drug Imipenem, as well as good antifungal activity against microbial strains Aspergillus Flavus, Candida Albicans and Candida GlabarataI that was comparable to reference drug Miconazole. In continuous, molecular docking study of the targeted cyclic peptides revealed that they exhibited promising binding interaction networks with DNA gyrase and lanosterol‐14 alpha demethylase, which showed the correlation between biologic activity and docking score of the synthesized analogs.

Synergetic impacts of mesoporous α-Fe2O3 nanoparticles on the performance of alkali-activated slag against fire, gamma rays, and some microorganisms

This study describes the fabrication of green composite pastes with multifunctional properties that can be utilized in special applications. Low-cost mesoporous hematite nanoparticles (HNPs) were prepared using a sol-gel technique. Different doses of HNPs (0.25, 0.5, and 1%) were added to alkali-activated slag (AAS) using an aqueous solution of NaOH (5 wt % of slag) as an activator. All composite pastes, AAS and AAS-HNPs, were kept under high humidity at normal temperature for 90 days. After 28 days of curing, a group of specimens was fired at elevated temperatures in a range of 200–900 °C, and another group was exposed to 1000- 3000 KGy gamma radiation. The formed phases and morphological features of some selected composites were characterized using X-ray diffraction (XRD), thermal analyses (TGA/DTG), Fourier transformation infrared (FTIR), and scanning electron microscope with energy dispersive X-ray (SEM/EDX). The outcomes of the compressive strength test emphasized that AAS-0.25 HNPs composite paste has a superior thermal resistivity at all firing temperatures and the best impedance to radiation till 3000 KGy. Agar diffusion test (ASTM D4300-1) revealed that AAS containing 1% HNPs composite possessed an excellent antimicrobial activity with various microorganisms; two bacterial strains (Escherichia Coli ATCC 8739 and Staphylococcus aureus ATCC 6538) and two fungal strains (Aspergillus flavus and Mucor circinelloide).

Phytochemical, Antimicrobial and Cytotoxic Activities of Gaultheria Trichophylla Royle

Gaultheria trichophylla fruit is used by the indigenous people to treat asthma, headache, and as an appetizer in the alpine and sub-alpine regions of Western Himalaya. No studies exist on the antimicrobial significance of this species. The current study describes the phytochemical composition, in vitro cytotoxic, and antimicrobial effects of different extracts of Gaultheria trichophylla. In antimicrobial assay, four different bacterial strains (Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Staphylococcus aureus) as well as four fungal strains (Helminthosporium solani, Fusarium solani, Aspergillus flavus, and Aspergillus fumigates) were used. Qualitative phytochemical screening showed the existence of different active compounds. Quantitative phytochemical screening showed the existence of phenolic contents in the range from 3.27 ± 0.44 mg GE/g to 14.17 ± 088 mg GE/g, whereas flavonoids were from 8.08 ± 0.48 mg QE/g to 26.9 ± 0.23 mg QE/g. The elemental analysis quantified essential minerals of life importance such as Na (3.24 ± 0.05 µgg−1), Mg (1.93 ± 0.08 µgg−1), and Ca (1.83 ± 0.056 µgg−1), while none of the heavy metal levels were high from the permissible limit of WHO. Cytotoxic assay showed moderate activity in terms of LC50 of (50 μg/mL) for methanolic extracts. Antifungal assay of methanolic and other extracts against different tested fungal strains showed a zone of inhibitions from 29 ± 1.154% to 86.66 ± 0.09%. As an antibacterial, the MIC values were from 7.5 mg/mL to 15 mg/mL for the tested extracts. The observed biological potentials were at the expense of its phytochemical composition, however, further confirmation in animal models and responsible phytochemical isolations in pure form is needed.

Antibacterial activity of airborne fungal mediated nanoparticles in combination with Foeniculum vulgare essential oil

Introduction: A cost-effective and ecologically friendly method of generating silver nanoparticles (AgNPs) includes pathways that utilize a variety of biological sources to decrease metal ions. This study was designed to synthesize AgNPs using a fungus strain Aspergillus flavus and evaluate its antibacterial activities alone or in combination with Foeniculum vulgare (fennel) essential oil (EO). Methods: The antibacterial activity of different concentrations of biosynthesized AgNPs by Aspergillus flavus individually and in combination with fennel EO was investigated using disc diffusion methods and minimal inhibitory concentration (MIC). Bacterial species, including Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae, Shigella sp., Staphylococcus aureus, and Staphylococcus epidermidis were tested. Results: Formation of dark brown color, ultraviolet-visible (UV/Vis) spectroscopy, transmission electron microscope (TEM), and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) were used for the characterization of AgNPs. Obvious synergistic effects were observed between AgNPs and EO of fennel (F. vulgare) with all tested bacteria except S. aureus, through increases in fold area of inhibition (IFAs) within the range of 0.15 to 8.87. Although S. aureus had the most susceptibility toward both AgNPs and EO of fennel (24 and 17 mm, respectively), no synergistic activity was exhibited. The best synergistic capacity resulted from AgNPs and fennel EO was observed against S. epidermidis (8.87-fold in IFA). Conclusion: This study revealed that when biosynthesized AgNPs were mixed with the EO of F. vulgare, they became more bacteriostatic and might be developed to treat bacterial infections in the future.

Characterization of strains of Aspergillus flavus and A. parasiticus isolated from groundnut (Arachis hypogea), rice (Oryza sativa) and maize (Zea mays) in Senegal

The contamination of certain food crop with aflatoxin poses a real public health problem for consumers and causes many market losses for exporters. Thus, several research works are oriented in the direction of developing methods to combat aflatoxinogenic fungus. This study aimed at identifying and characterizing strains of Aspergillus flavus and A. parasiticus on groundnut, maize and rice seeds grown or imported into Senegal. Four species (A. niger, A. tamarii, A. flavus and A. parasiticus) were isolated from the seeds with incidences ranging from 0 to 100% depending on the samples and their provenance. Six strains of A. flavus and 3 strains of A. parasiticus have been identified and characterized on CYA and G25N culture media. The characterization focused on the morphological characteristics (color and appearance, mycelial growth) of the colonies on the different culture media, and on some microscopic characteristics such as the density of sporulation (production of conidia) and the appearance of the conidiophore. Strains of A. flavus were more frequent on groundnuts and isolates with the same traits were also identified from rice and maize samples, hence the 3 strains of A. parasiticus were isolated.

Medium for the Production of Bacillus-Based Biocontrol Agent Effective against Aflatoxigenic Aspergillus flavus: Dual Approach for Modelling and Optimization.

One of the leading limiting factors for wider industrial production and commercialization of microbial biopesticides refers to the high costs of cultivation media. The selection of alternative sources of macronutrients crucial for the growth and metabolic activity of the producing microorganism is a necessary phase of the bioprocess development. Gaining a better understanding of the influence of the medium composition on the biotechnological production of biocontrol agents is enabled through bioprocess modelling and optimization. In the present study, after the selection of optimal carbon and nitrogen sources, two modelling approaches were applied to mathematically describe the behavior of the examined bioprocess—the production of biocontrol agents effective against aflatoxigenic Aspergillus flavus strains. The modelling was performed using four independent variables: cellulose, urea, ammonium sulfate and dipotassium phosphate, and the selected response was the inhibition-zone diameter. After the comparison of the results generated by the Response Surface Methodology (RSM) and the Artificial Neural Network (ANN) approach, the first model was chosen for the further optimization step due to the better fit of the experimental results. As the final investigation step, the optimal cultivation medium composition was defined (g/L): cellulose 5.0, ammonium sulfate 3.77, dipotassium phosphate 0.3, magnesium sulfate heptahydrate 0.3.

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The performance of twenty four 6-8 week old apparently healthy male and female weanling rabbits of mixed breed fed diets treated with aflatoxin, which contained 5% sweet orange (Citrus sinensis) fruit peel meal was evaluated in an 8 week feeding trial. Sweet orange peels were collected from orange sellers, sun-dried and milled. Fungal strain of Aspergillus flavus was cultured and inoculated into groundnut cake to produce aflatoxin using solid state fermentation method. Treated groundnut cake was incubated for seven days with incremental incubation temperature from 20-25 ºC The groundnut cake was autoclaved, milled and, aflatoxin extracted from 10 g sample of the milled cake with 50 ml chloroform, and its concentration quantified by Thin Layer Chromatography (TLC). Treated groundnut cake was included at 0, 50, 100 and 150 gram in grower rabbit diets to produce diets T1, T2, T3 and T4, having 0 ppb, 50 ppb, 100 ppb and 150 ppb aflatoxin, respectively. The rabbits were randomly allocated to four diets at the rate of six per diet, housed singly in rabbit hutches, fed and served water free choice. The result showed significant (P<0.05) negative effect  of diets on final live weight, weight gain, feed intake, feed conversion ratio, water consumption, protein intake and protein efficiency ratio as the dietary aflatoxin increased from 0 ppb to 150 ppb. Also, diets had significant (P<0.05) negative effect on dressed weight and carcass length and, kidney. Total aflatoxin residue varied significantly (P<0.05) from 0 μg/kg - 2.76μg/kg,  0 μg/kg - 1.94μg/kg and 0 μg/kg - 0.85μg/kg for liver, kidney and meat tissue, respectively as the dietary aflatoxin increased from 0 ppb to 150 ppb. Performance response of rabbits was affected negatively by aflatoxin, thereby showing the inability of 5% dietary inclusion of sweet orange (Citrus sinensis) peel meal to mitigate the adverse consequences of aflatoxin intake by rabbit. Key words: Growth responses, residual level, visceral organs, mitigate.

Antimicrobial activity of chitosan film containing nanocomposite of Trachyspermum ammi (ajwain) seed oil loaded Halloysite nanotubes against foodborne pathogenic microorganisms

Ajwain seed oil (ASO) is a volatile organic compound possessing antimicrobial properties against a wide range of microorganisms. Halloysite nanotubes (Hal) are aluminosilicate natural clay minerals with about 200–2000 nm in length and diameters between 10-50 nm. The structure of Hal allows a sustained release of antimicrobial agents to microbial cells which can be beneficial in the food packaging field. In this work, we loaded ASO into Sodium hydroxide (NaOH) treated Hal and further incorporated it with chitosan to develop an innovative antimicrobial food packaging nanocomposite film. The developed nanocomposite films were characterized by UV–visible spectroscopy, Fourier transform infrared spectroscopy, Raman Spectroscopy, Differential scanning calorimetry, Field emission scanning electron microscopy and X-ray diffraction. The antimicrobial properties of the developed nanocomposites were studied against two bacterial strains (Escherichia coli and Bacillus mojavensis) and two fungus strains (Aspergillus niger and Aspergillus flavus) potential food spoilage microorganisms. The nanocomposite (ASO-NaOH-Hal) prevented the growth of Esherichia coli up to 99%, Bacillus mojavensis up to 95%, Aspergillus niger about 97%, and Aspergillus flavus about 97% at concentrations of 5 mg/ml, 7 mg/ml, 5 mg/ml and 5 mg/ml, respectively. And the chitosan film containing ASO-NaOH-Hal presented a clear zone of inhibition against the above-mentioned bacterial strains and inhibited the growth of fungus on the tomato's surfaces therefore, this nanocomposite film could find application in the food packaging field owing to its antimicrobial and antioxidant properties.

Light and scanning electron microscopic characterization of aflatoxins producing Aspergillus flavus in the maize crop.

Maize (Zea mays L.) is considered as one of the main cereals, used as a source of food, forage, and processed products. The loss of maize productivity is reported due to effect on roots, stalks, ears, and kernels mainly caused by many fungi. Among these fungal pathogens of maize, Aspergillus flavus (A. flavus) are the most prevalent that produces highly toxigenic aflatoxins that are highly carcinogenic to the consumers. The present study is confined to isolate and characterize the A. flavus from maize seeds for accurate identification that can be helpful for determination and management of aflatoxins in maize crop. Eighty stored seed samples of maize were collected from warehouses where seeds are stored for food and feeding purposes. For the isolation of A. flavus, Potato Dextrose Agar was used. Isolated fungi were identified macro and microscopically using light microscope and scanning electron microscope. A total of 212 Aspergillus isolates were identified based on macro-morphological and micro-morphological characteristics. The results showed that A. flavus colonies were granular, flat with yellow-green to deep yellow-green colony color having a white border and compact, spherical spore heads. Rapid rate of growth was observed maturing in about 3-5 days. In microscopic features, A. flavus have apically swollen conidiophores with various conidia bearing cells in long and dry chains. Spherical conidial heads were split into several columns ranging 300-400 μm in diameter. This will be helpful for farmers, researchers and traders in future for correct identification of sources of aflatoxins. RESEARCH HIGHLIGHTS: Maize seed samples were collected from Pothohar region of Pakistan. The fungi were isolated on PDA. Aspergillus flavus was identified macro-morphologically by observing growth rate, colony color and texture. Furthermore, these fungi were identified micro-morphologically by using light and scanning electron microscope. The 212 Aspergillus flavus strains were isolated and identified.

Short Communication: Identification of phytochemical constituents of Syzygium aromaticum L. using gas chromatography coupled with mass spectrometry and evaluation of antimicrobial activity

Abstract. Benmakhlouf Z, Benserradj O, Kellab R. 2022. Short Communication: Identification of phytochemical constituents of Syzygium aromaticum L. using gas chromatography coupled with mass spectrometry and evaluation of antimicrobial activity. Biodiversitas 23: 2586-2593. Syzygium aromaticum L. is a traditional spice that has various pharmacological activities attributed to its content of bioactive molecules. The purpose of this work is to evaluate phytochemical constituents of S. aromaticum L. extract using gas chromatography coupled spectrometry mass (CG/MS). The number detected of phenolic compounds was 45, which the most abundant being eugenol (54.63%), followed by Phenol,2-metoxy-4-(2-propenyl)-, acetate (eugenol acetate) (21.57%) and caryophyllene (16.71%). In addition, the antimicrobial activity was screened by the paper disc diffusion method for three bacterial strains, (Pseudomonas aeruginosa ATCC 27853, Salmonella sp. and Staphylococcus aureus 6538) and by the direct contact method on three fungal strains (Aspergillus niger, Aspergillus flavus and Candida albicans). The results showed that extract presents an inhibitory activity with all the strains tested. Salmonella sp. is very sensitive (++) to the stock solution (100mg/ml), sensitive (+) to dilutions (50 and 25) mg/ml with inhibition diameters of (16, 12, 10) mm respectively. The other bacterial strains are sensitive (+) only to the stock solution. The results of our experiment confirm that fungi strains: A. niger, A. flavus and C. albicans show a remarkable antifungal activity at 100mg/ml. The result indicated that the extract obtained from dried buds of S. aromaticum could be considered an agent for antibacterial and antifungal in the pharmaceutical field.

Efficacy of sodium metabisulphite for control of Aspergillus flavus and aflatoxin B1 contamination in vitro and in chilli powder and whole red chillies

Chillies are an important spice in many regions of the world. During the production and processing phases, they are prone to infection by mycotoxigenic fungi, especially Aspergillus Section Flavi species and contamination with aflatoxins. There is significant interest in controlling aflatoxin B1 (AFB1) contamination in such spices to ensure they remain below the legislative limits for human consumption. This study initially examined the potential efficacy of sodium metabisulphite (NaMBS, up to 5000 mg/L) for the control of growth and AFB1 production by Aspergillus flavus strains in vitro on a chilli-based medium modified to 0.93–0.995 water activity, aw). Subsequent studies examined efficacy of NaMBS in stored naturally contaminated chilli powder and whole red chillies, or when inoculated with A. flavus at 0.70, 0.80, 0.90, 0.95 aw and 30 °C for 20 days. NaMBS was effective in vitro in controlling growth of the three strains of A. flavus at the different aw levels examined. No growth occurred with >500–1250 NaMBS mg/L. AFB1 was only produced at 0.98 aw with complete inhibition at ≥1250 mg/L of the preservative at 30 °C. The in vitro ED50, ED90 for NaMBS varied with aw conditions. In situ studies with chilli powder and whole red dry chillies (naturally contaminated or + conidial inoculum of A. flavus) showed that at 0.70 and 0.80 aw, NaMBS treatments of 1000 and 2000 mg/L resulted in AFB1 contamination levels below the legislative limits for spices. However, under wetter conditions at 0.90 and 0.95 aw, AFB1 contamination of stored chilli powder, −/+ A. flavus inoculum, were above the legislative limits, even with 2000 mg/L NaMBS and 20 days storage at 30 °C. Stored whole chillies inoculated with A. flavus resulted in a reduction of populations, especially at 2000 mg/L NaMBS. Control of AFB1 was achieved only with 2000 mg/L NaMBS treatment after 10 and 20 days storage. Studies with commercial laminated sheets containing immobilised NaMBS with slow release of SO2 properties significantly reduced fungal populations and effectively controlled AFB1 contamination of the stored and packaged whole red chillies.

Survival and growth of microscopic fungi derived from tropical regions under future heat waves in the Pannonian Biogeographical Region

Warming and heat waves are predicted by different climate models in the near future in the Pannonian Biogeographical Region (PBR). These climatic effects may have impact on the prevalence and distribution of certain fungal species of this area. In this study the effects of predicted climate scenarios were tested on fungi being endemic or unintentionally introduced by global trade from regions of warm temperate climate. Common fungal species were selected for the study and exposed to heat waves during 7 days according to two climate scenarios: one moderately (RCP 4.5, Tavg = 27 °C, Tmax = 35 °C, RH: 100%) and one strongly pessimistic (RCP 8.5, Tavg = 30 °C, Tmax = 40 °C, RH: 100%) that include predictions for the Central Hungarian Region for July 2050. According to our results, Aspergillus flavus, Aspergillus niger, Aspergillus tubingensis and Fusarium strains introduced from tropical regions tolerated heat waves, unlike Penicillium and Talaromyces spp. and endemic Cladosporium spp. which were unable to grow under the RCP 8.5 treatment. The effects of climate change on fungi raise new issues not only from economic and health perspectives, but also in relation with plant protection and environment. Our results suggest that heat waves driven by climate change promote the colonization and growth of the tested strains of non-native fungi more likely than that of the native ones.

Fungal Contamination and Characterization of Aspergillus flavus on Poultry Feeds and their Ingredients in North Sumatera

Poultry feeds mainly consist of cereal grains and crops that are vulnerable to fungal infection. Improper handling of the feeds increases spoilage and contamination by aflatoxigenic fungi. The aim of this study was to determine fungal contamination including characterization of toxigenic and non-toxigenic Aspergillus flavus strains in poultry feed and its ingredients. We collected 200 composite samples of compound poultry feeds and their ingredients sold by retailers at traditional markets. The fungal population was enumerated using a dilution followed by the pour plate in dichloran 18% glycerol agar medium. All isolated A. flavus were identified by culture technique and molecular approach. Aflatoxin production was determined in 10% coconut agar medium with thin layer chromatography. Regulatory (aflR) and structural (nor-1, ver-1, omt-1) genes of A. flavus strains were isolated using four sets of primers (aflR, nor-1, ver-1, omt-1). We found that all feeds were infected by fungi. Aspergillus chevalieri was the most found in all feeds, particularl on chick starter. Of the 200 samples of compound and poultry feed ingredients, 57 isolates of A. flavus were examined and 16 of them (28%) were toxigenic, each strain producing aflatoxin B1 from <3.01 to 35.50 ppb. Among feeds, layer finisher, pellet starter and grain corn were the most infected by toxigenic A. flavus, respectively. The contamination occurred on feeds that contained corn as the main compound. Routine analysis of compound poultry feeds and their ingredients for aflatoxigenic fungi particularly A. flavus is compulsory

Molecular inclusion of Cymbopogon martinii essential oil with β-cyclodextrin as a strategy to stabilize and increase its bioactivity

An essential oil complex (EOP) of Cymbopogon martinii with β-cyclodextrin (β-CD) was evaluated as a strategy to stabilize the essential oil of Palmarosa and increase its bioactivity. The complexation methods used were co-precipitation and kneading, and, for comparison, physical mixing was carried out. To confirm the molecular inclusion, techniques were combined for the characterization of the inclusion complex, such as Fourier Transformer Raman Spectroscopy (FT-Raman), Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR), Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA), which suggested the formation of the EOP-β-CD complex with complexation efficiency through the co-precipitation and kneading methods of 77.68% and 47.74%, respectively. Stability of the free and complexed EOP in relation to major compounds (linalool, geraniol, geranyl acetate and caryophyllene) during 14 days of storage was analyzed through Headspace Gas Chromatography coupled with Mass Spectrometry. Geraniol showed stability over the period of evaluation and increased availability when complexed by the Co-precipitation and kneading complex. Furthermore, the antifungal and antitumor activity of the EOP-β-CD complex was evaluated, showing reduced mycelial growth against Aspergillus flavus and Fusarium verticillioides strains compared to the free EOP (percentage of inhibition to toxigenic fungi A. flavus EOP-KM: 29.41%; EOP-CP and EOP-PM: 24.37 and 14.28%, respectively, and, the free EOP with 11.76%). In addition, an interesting activity against tumor cells (HeLa and HT-29) was observed against the tested complexes, which emphasizes the importance of the biotechnological use of β-CD for the stability of natural compounds.

An imperical analysis of various extracts of Bacopa Monnieri towards antibacterial and antifungal activities

Bacopa monnieri was also known as “Brahmi.” Theses plant has been considered as medicinal plants in Ayurvedic systems for centuries. This present study was carried out to evaluate the antibacterial and antifungal properties of ethanolic, diethyl ether, ethyl acetate, and aqueous extracts of B. monnieri. Agar disc diffusion tests were carried out to determine the antimicrobial effects of ethanolic, diethyl ether, ethyl acetate and aqueous extracts of B. monnieri against Gram-positive (Staphylococcus aureus), Gram-negative (Escherichia coli) bacterial strains and antifungal strains (Aspergillus flavus, and Candida albicans). Among the various extracts, diethyl ether extracts of B. monnieri has an antibacterial potency against Staphylococcus aureus (gram positive), and ethyl acetate extract showed effects on E. coli (gram negative) at higher concentrations of 300 μg mL-1. The ethanolic extract has potent antifungal activity against the fungus (Aspergillus flavus, and Candida albicans) compared to diethyl ether and ethyl acetate-ether. Both extracts (diethyl ether and ethyl acetate) has a minimum antifungal effect while these extracts showed more inhibitory effects on tested bacteria.