UHPLC-HRMS-Based Untargeted Lipidomics Reveal Mechanism of Antifungal Activity of Carvacrol against Aspergillus flavus

Aspergillus flavus is a common contaminant in grain, oil and their products. Its metabolite aflatoxin B1 (AFB1) has been proved to be highly carcinogenic. Therefore, it is of great importance to find possible antifungal substances to inhibit the growth and toxin production of Aspergillus flavus. Carvacrol (CV) was reported as a potent antifungal monoterpene derived from plants. In this paper, the antifungal effects and mechanism of CV on Aspergillus flavus were investigated. CV was shown good inhibition on the growth of Aspergillus flavus and the production of AFB1. CV used in concentrations ranging from 0, 50, 100 and 200 μg/mL inhibited the germination of spores, mycelia growth and AFB1 production dose-dependently. To explore the antifungal mechanism of CV on Aspergillus flavus, we also detected the ergosterol content of Aspergillus flavus mycelia, employed Scanning Electron Microscopy (SEM) to observe mycelia morphology and utilized Ultra-High-Performance Liquid Chromatography-High-Resolution Mass Spectrometry (UHPLC-HRMS) to explore the lipidome profiles of Aspergillus flavus. The results showed that the production of ergosterol of mycelia was reduced as the CV treatment concentration increased. SEM photographs demonstrated a rough surface and a reduction in the thickness of hyphae in Aspergillus flavus treated with CV (200 µg/mL). In positive ion mode, 21 lipids of Aspergillus flavus mycelium were downregulated, and 11 lipids were upregulated after treatment with 200-µg/mL CV. In negative ion mode, nine lipids of Aspergillus flavus mycelium were downregulated, and seven lipids upregulated after treatment with 200-µg/mL CV. In addition, the analysis of different lipid metabolic pathways between the control and 200-µg/mL CV-treated groups demonstrated that glycerophospholipid metabolism was the most enriched pathway related to CV treatment.

Pathogenicity of Cordyceps javanica (Hypocreales: Cordycipitaceae) to Diaphorina citri (Hemiptera: Liviidae) Adults, with Ultrastructural Observations on the Fungal Infection Process

Entomopathogenic fungi are proposed biological control agents against the Asian citrus psyllid (Diaphorina citri). We quantified the pathogenicity of Cordyceps javanica strain Apopka 97 strain (Cja Apopka 97) (blastospores and conidia) against D. citri using the spray technique. We also used light and scanning electron microscopy to observe the Cja Apopka 97, infection process against D. citri adults at different stages pre- and post-mortem. Our findings demonstrated that psyllid mortality in the blastospore treatment ranged from 8 to 25% within 24–48 h of exposure, compared to 0% in the conidial and control treatments. However, psyllid mortality rate had reached 100% by 7 days after exposure at a concentration of 107 spores/mL, under both fungal treatments compared to the controls (0%). SEM and light microscopy revealed several stages in in the Cja Apopka 97 infection process of D. citri, including spore adherence and germ tube formation within 24 h post-inoculation, penetration pegs and mycelia growth on wings after 72 h, rupturing of cuticle after 96 h and mycelial mass colonizing host body after 144 h. Our study findings provide basic information on the interaction of entomopathogenic fungi with D. citri which will assist in the understanding of the infection process and the potential roles of entomopathogenic fungi in its management.

Antifungal Efficacy of Allium Sativum and Zingiber Officinale on Fungi Isolated from Spoilt Bread

Zingiber officinale is a common condiment for various foods and beverages and a history of important traditional medicine herb for the treatment of stomach disorder. This study deals with the antifungal activity of Allium sativum and Zingiber officinale and their phytochemical composition. Ethanolic extracts of two spices (Allium sativum and Zingiber officinale) were tested for antifungal activities against Aspergillus sp, Penicillium sp and Fusarium sp using mycelia growth extension method, result showed varying degrees of antifungal activities against the test fungi. The two extracts showed similar pattern of antifungal activities on the test fungi withthe extract of Allium sativum being more effective with increased zones of inhibition with increased concentrations. Phytochemical screening revealed the presence of flavonoids, saponins, terpenoids and tannin for Allium sativum and flavonoids, glycosides, tannins and anthraquinone for Zingiber officinale. The significant growth of inhibitions of the test fungi by the plant extract suggest the possible use of these spices in controlling infections caused by these fungi and food spoilage.

APPLICATION OF FUNGICIDES AND PLANT EXTRACTS IN CONTROL OF FUSARIUM ROT OF TOMATO FRUITS

In the present study few Fungicides and Plant extracts were tested for the control of Fusarium rot of tomato fruits, among fungicides Carbendazim was found to be the most effective in inhibiting the mycelia growth of Fusarium solani. In the case of leaf extracts, the leaf extracts of Neem (Azadirachta indica) reduced effectively the incidence of Fusarium rot of tomato fruits.

Mass Treatment of Flooded Archival Materials by Gamma Radiation

This work describes mass recovery processes of flooded archival materials at industrial scale. The presence of fungi on paper represents a threat to the integrity of the document because they degrade cellulose, one of the main components of paper. Gamma radiation treatments are investigated as mass disinfection agents for their high penetrating power, speed of treatment, and absence of risk due to chemical residuals. We compared two different recovery processes: thermal drying followed by gamma irradiation and gamma irradiation followed by thermal drying. Both these processes were conducted simultaneously on naturally contaminated archival items and on paper specimens artificially contaminated with species test. Efficacy was assessed by culture method and ATP assay, right after the treatments and after four years of storage at room temperature. Coupling gamma irradiation with a drying step with dry heat at 55–60 °C reduces the fungal loads on natural items up to levels close to the detection limits, and the reduction is maintained after four years. On artificial specimens, spore germination is completely inhibited, mycelia growth is also highly affected, but the melanised test species appear to be more resistant. A synergistic effect between gamma irradiation, water content, and thermal drying is highlighted in this paper.

Bio Scaffolds

Abstract‘Bio Scaffolds’ explores a series of design tectonics that emerge from a co-creation between human, machine and natural intelligences. This research establishes an integral connection between form and materiality by enabling biological materials to become a co-creator within the design and fabrication process. In this research paper, we explore a hybrid between architectural aesthetics and biological agency by choreographing natural growth through form. ‘Bio Scaffolds’ explores a series of 3D printed biodegradable scaffolds that orchestrate both Mycelia growth and degradation through form. A robotic arm is introduced into the system that can respond to the organism’s natural behavior by injecting additional Mycelium culture into a series of sacrificial frameworks. Equipped with computer vision systems, feedback controls, scanning processes and a multi-functional end-effector, the machine tends to nature by reacting to its patterns of growth, moisture, and color variation. Using this cybernetic intelligence, developed between human, machine, and Mycelium, our intention is to generate unexpected structural and morphological forms that are represented via a series of 3D printed Mycelium enclosures. ‘Bio Scaffolds’ explores an interplay between biological and computational complexity through non anthropocentric micro habitats.

Agro-Waste Mediated Silica Nanoparticles and Their Application to Sustainable Agriculture

Sustainable managing of environment implies the utilization of green approaches in agronomy for growth and crop protection. Since crop production is determined by extensive application of pesticide to resist plant infection and fertilizers to increase fertility of soil, these processes result in ecological unit deterioration as well economic cost. The current research aims at assessment of the potential of nanofertilizers and fungicidal activity of Silica nanoparticles (SiNPs) which have synthesized from agro-waste (sugarcane bagasse and corn cob).SiNPs Nanoparticles display exceptional biological functions and might behave as novel antifungal agents. SiNPs were characterized via scanning electron microscopy (SEM), Fourier transmission infrared spectroscopy (FTIR), X-ray diffraction (XRD) and energy dispersive X-ray (EDX).The plant reaction to SiNPs treatments were observed in relation to germination, growth characteristics, protein, chlorophyll, antioxidant and antifungal activities. Germination rate was enhanced upto 95.5% with SiNPsconcentration and growth parameters were increased upto1000ugL-1. The physiological changes showed the increment in protein and chlorophyll content upto 14.8mg g-1 and 4.08 mg g-1, respectively. Other than this, maximum mycelia growth inhibition was reported for Fusarium oxysporum and Aspergillus niger as73.42% and 58.92%, respectively. SiNPs positive response on Eruca sativa plant might improve its productivity and act as a potential antifungal agent against pathogenic fungi.

Direct Ethanol Production from Xylan and Acorn Using the Starch-Fermenting Basidiomycete Fungus Phlebia acerina

During our search for ethanol-producing basidiomycete fungi for a wide range of substrates, we isolated Phlebia acerina, which is a white rot basidiomycete fungus. It favorably converted starch into ethanol with approximately 70% yield. Although the yield decreased as the starch concentration increased, growth and fermentation were observed even at 200 g/L of starch. P. acerina produced ethanol from glucose, galactose, mannose, xylose, cellobiose, and maltose with 93%, 91%, 86%, 72%, 92%, and 68% yields, respectively. Additionally, P. acerina, which secreted xylanase and xylosidase, was capable of assimilating xylan and directly converting it to ethanol with a yield of 63%. Furthermore, P. acerina produced ethanol directly from acorns, which are plant fruits containing starch and tannins, with a yield of 70%. Tannin delayed mycelia growth, thus prolonging ethanol production; however, this did not particularly affect the yield. These results were similar to those of fermentation in a medium with the same amounts of starch and tannin as the target crop acorn, thus suggesting that P. acerina could successfully produce environmentally friendly ethanol from starch-containing lignocellulosic biomass, unlike previously reported ethanol-producing basidiomycete fungi.

Effect of Relative Humidity on Mycelial Growth of Cercospora canescens

The relative humidity studies revealed that maximum mycelial of fungus was observed at 90 per cent relative humidity (89.00 mm), which was followed by 100 per cent (86.30 mm). The least mycelia growth was observed at 50 per cent (45.30 mm). A significant decrease in mycelium growth was observed at 80, 70 and 60 per cent (80.40 mm, 70.20 mm and 57.00 mm) humidity level, respectively. Each fungus has its relative humidity range for the growth.