fungal growth
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Plant Disease ◽  
2022 ◽  
Author(s):  
Kecheng Xu ◽  
Ruiqi Zhang ◽  
Xue Li ◽  
Jinglong Zhang ◽  
Hang Zhao ◽  
...  

Eucalyptus species are widely planted in the tropics and subtropics, and eucalyptus is among the most important cash crop in Southern China. One of the most important diseases on eucalyptus is Ceratocystis wilt, caused by the fungus Ceratocystis fimbriata Ellis & Halst., and the genus name Chalaropsis has been proposed for anamorphs of Ceratocystis species (de Beer et al. 2014). During April 2018, severely infected Eucalyptus robusta trees were observed in Kunming, Yunnan Province, China. Symptomatic trees initially exhibited yellowing and wilting of foliage on individual branches, then spread to the whole canopy, sometimes followed by death of the whole tree. Reddish-brown to dark-brown discoloration in the woody xylem of affected trees, sometimes a grayish white layer of fungal growth may be seen. The disease was observed on 16% of trees surveyed. The base of trunks with typical symptoms were collected, then the discolored xylem tissues were surface disinfected with 75% ethanol for 30 s and 0.1% mercuric chloride (HgCl2) solution for 2 min, rinsed three times with sterile distilled water, plated onto potato dextrose agar (PDA) medium, and incubated at 25°C. After 6 days, a fungus was consistently observed growing from the tissue. Three isolates were obtained. In culture, colonies reaching 54mm diam within 15 days, mycelium initially white, then becoming celadon. Endoconidia unicellular, smooth, cylindrical, straight, biguttulate, 11.21 - 32.26 × 4.12 - 5.25 μm. Phialides produced on short, septate, aerial hyphae, lageniform and chain of phialoconidia (3.62 - 5.89 × 31.39 - 65.76 μm) were also observed. Chlamydospores (11.45 - 14.26 × 10.06 - 12.22 μm) were single, dark, thick-walled. Morphological characteristics of the fungus were consistent with the description of Chalaropsis thielavioides (Paulin-Mahady et al. 2002). The two of three isolates were used for molecular identification and genomic DNA was extracted from isolates (EKY2-2-1, EKY2-2-2) using the chelex-100 method (Xu et al. 2020). The ITS region of rDNA was sequenced using the procedures of Thorpe et al. (2005). Analysis of ITS sequence data (GenBank accessions MW242701, MW242702) showed that the isolates were 99% - 100% homologous to isolates of C. thielavioides from Hevea rubber, Monstera deliciosa L. and ants in China and Rosa sp. in Australia (GenBank accessions KT963172, KJ511482, KT963173 and KX954598) by BLAST analysis. Neighbor-joining (NJ) phylogenetic analysis were performed using MEGA 6.06 based on ITS sequences (Fig 1), the evolutionary distances were computed using the Maximum Composite Likelihood method. Analyses showed that both isolates (EKY2-2-1, EKY2-2-2) located on the same clade with all C. thielavioides, and clustered with the C. thielavioides strains with high bootstrap support (97% - 100%). Therefore, the fungus was identified as C. thielavioides based on morphology and molecular evidences. Pathogenicity of C. thielavioides was tested by inoculation of six one-year-old pot grown Eucalyptus citriodora seedlings. The sterilized soil of six seedlings was inoculated by drenching with 20 ml spore suspension (2.0 × 106 spores / ml). Control plants were inoculated with 20 ml of sterile distilled water. The seedlings were kept in a controlled greenhouse at 25°C and watered weekly. After one month incubation, all the isolates produced wilt symptoms, whereas control trees showed no symptoms. The original fungus was successfully re-isolated from inoculated trees and identified as C. thielavioides according to the methods described above, and no fungal growth was observed in the controls, thus satisfying Koch's postulates. Although wilt and canker caused by Ceratocystis fimbriata on eucalyptus have been previously reported in Brazil, Uruguay, Uganda, China and Pakistan (Ferreira et al. 1999; Li et al. 2014; Alam et al. 2017), eucalyptus wilt caused by C. thielavioides has not been reported anywhere. Also, wilt of rubber tree and postharvest rot on carrot caused by C. thielavioides have been reported (Li et al. 2021; Xu et al. 2020). To our knowledge, this is the first report of eucalyptus wilt caused by C. thielavioides in China.


2022 ◽  
Vol 8 (4) ◽  
pp. 248-253
Author(s):  
Aarti Sangray ◽  
Ajeet Pal Singh ◽  
Amar Pal Singh

To evaluate the activity of Ethanolic and Aqueous extracts of leaves of against three fungal strains i.e. MTCC3814, and Candida tropicalis MTCC9038 in-vitro.Phytochemical analysis of belonging to family brassicacaea was examined using Ethanolic and Aqueous extracts. Ethanolic and Aqueous extracts of leaves of were investigated individually for antifungal activity by Agar well diffusion method. Both the extracts were tested against selected fungal strains i.e. and to find the inhibitory activities of fungal growth at the dose level of 50 and 100 μg/ml.The phytochemical analysis of ethanolic and aqueous extracts confirmed the presence of phenolic compounds, glycosides, tannins, carbohydrates, proteins, amino acids, tannins, reducing suger, non-reducing suger and inorganic compounds such as calcium, magnesium, iron, carbonate & sulphates. Ethanolic extract of showed considerably high antifungal activities against selected microorganisms than aqueous extract.Although the active components were not isolated but antifungal active plant principles such as flavonoids, glycosides and tannins were observed in the extract. Ethanolic extract of possess effective antifungal properties for selected fungal strains i.e.


2022 ◽  
Author(s):  
Man In Lam ◽  
Kinga Vojnits ◽  
Michael Zhao ◽  
Sepideh Pakpour ◽  
Piers Macnaughton

Built environments play a key role in the transmission of infectious diseases. Ventilation rates, air temperature and humidity affect airborne transmission while cleaning protocols, material properties and light exposure can influence viability of pathogens on surfaces. We investigated how indoor daylight intensity and spectrum through electrochromic (EC) windows can impact the growth rate and viability of indoor pathogens on different surface materials (polyvinyl chloride (PVC) fabric, polystyrene (PS), and glass) compared to traditional blinds. Our results showed that tinted EC windows let in higher energy, shorter wavelength daylight than those with clear window and blind. The growth rates of pathogenic bacteria and fungi were significantly lower in spaces with EC windows compared to blinds: nearly 100% growth rate reduction was observed when EC windows were in their clear state followed by 41-100% reduction in bacterial growth rate and 26-42% reduction in fungal growth rate when EC windows were in their darkest tint. Moreover, bacterial viabilities were significantly lower on PVC fabric when they were exposed to indoor light at EC-tinted window. These findings are deemed fundamental to the design of healthy modern buildings, especially those that encompass sick and vulnerable individuals.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 606
Author(s):  
Abhishek Sadananda Madival ◽  
Deepak Doreswamy ◽  
Shripathi Adiga Handady ◽  
Krishna Raghava Hebbar ◽  
Shobha Karabylu Lakshminarayana

Managing rice crop stubble is one of the major challenges witnessed in the agricultural sector. This work attempts to investigate the physical, mechanical, and liquid absorption properties of rice straw (RS)-reinforced polymer composite for assessing its suitability to use as an ayurvedic treatment table. This material is expected to be an alternative for wooden-based ayurvedic treatment tables. The results showed that the addition of rice straw particles (RSp) up to 60% volume in epoxy reduced the density of the composite material by 46.20% and the hardness by 15.69%. The maximum tensile and flexural strength of the RSp composite was 17.53 MPa and 43.23 MPa, respectively. The scanning electron microscopy (SEM) analysis showed deposits of silica in the form of phytoliths in various size and shapes on the outer surface of RS. The study also revealed that the water absorption rate (WA) was less than 7.8% for the test samples with 45% volume of RSp. Interestingly the test samples showed greater resistance to the absorption of Kottakal Dhanvantaram Thailam (<2%). In addition, the developed samples showed resistance towards bacterial and fungal growth under the exposure of treatment oils and water.


Coatings ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 85
Author(s):  
Kent Davis ◽  
Scott Leavengood ◽  
Jeffrey J. Morrell

Wood exposed in exterior applications degrades and changes color due to weathering and fungal growth. Wood coatings can reduce the effects of weathering by reducing the damaging effects of ultraviolet light, reducing water absorption, and slowing fungal growth on the surface. Coating performance depends on the blend of resins, oils, and pigments and varies considerably among different wood species and conditions. Specific information describing expected service for different wood species and exposure conditions is not commonly available; certain combinations may work well in one climate or on one timber species, but underperform elsewhere. This study compared the performance of three industrial wood coatings on two wood species for two temperate climates under natural weathering conditions. Most of the coatings/species combinations lost their protective properties within 12 to 15 months; however, fungal growth was more prevalent at the wetter site than at the drier site for several combinations. Film-forming coatings often peeled and cracked, while penetrating coatings weathered and changed color relatively uniformly during the study. While no coating was completely effective, the results illustrate the benefits of using coatings that promote the development of natural, uniform-patinaed wood surfaces. The findings also guide coating maintenance programs for mass timber structures exposed to natural weathering conditions.


2022 ◽  
Vol 8 ◽  
Author(s):  
Anjali D. Boyd ◽  
Nia S. Walker ◽  
Stephanie R. Valdez ◽  
Y. Stacy Zhang ◽  
Andrew H. Altieri ◽  
...  

In coastal wetlands and tropical reefs, snails can regulate foundation species by feeding on marsh grasses and hard corals. In many cases, their impacts are amplified because they facilitate microbial infection in grazer-induced wounds. Whether snails commonly graze live plants and facilitate microbial growth on plants in tropical seagrass systems is less explored. On a Belizean Caye, we examined patterns in snail-generated grazer scars on the abundant turtlegrass (Thalassia testudinum). Our initial survey showed the occurrence of snail-induced scarring on live turtlegrass blades was common, with 57% of live leaves scarred. Feeding trials demonstrated that two of five common snails (Tegula fasciata–smooth tegula and Smaragdia viridis–emerald nerite) grazed unepiphytized turtlegrass blades and that smooth tegula abundance had a positive relationship with scarring intensity. Subsequent surveys at three Caribbean sites (separated by &gt;150 km) also showed a high occurrence of snail-induced scars on turtlegrass blades. Finally, simulated herbivory experiments and field observations of a turtlegrass bed in Florida, United States suggests that herbivore damage could facilitate fungal growth in live seagrass tissue through mechanical opening of tissue. Combined, these findings reveal that snail grazing on live turtlegrass blades in the Caribbean can be common. Based on these results, we hypothesize that small grazers could be exerting top-down control over turtlegrass growth directly via grazing and/or indirectly by facilitating microbial infection in live seagrass tissue. Further studies are needed to determine the generality and relative importance of direct and indirect effects of gastropod grazing on turtlegrass health.


Foods ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 195
Author(s):  
Shanshan Zhao ◽  
Xiangmei Hao ◽  
Fengyuan Yang ◽  
Yuan Wang ◽  
Xiaomiao Fan ◽  
...  

Lactic acid bacteria (LAB) can produce many kinds of antifungal substances, which have been widely proven to have antifungal activity. In this study, 359 strains of LAB were screened for antifungal activity against Aspergillus niger (A. niger) using the 96-well microtiter plate method, and three showed strong activity. Of these, ZZUA493 showed a broad-spectrum antifungal ability against A. niger, Aspergillus oryzae, Trichoderma longibrachiatum, Aspergillus flavus and Fusarium graminearum. ZZUA493 was identified as Lactobacillus plantarum. Protease treatment, the removal of hydrogen peroxide with catalase and heat treatment had no effect on the antifungal activity of the cell-free supernatant (CFS) of ZZUA493; organic acids produced by ZZUA493 appeared to have an important role in fungal growth inhibition. The contents of lactic acid, acetic acid and phenyllactic acid in the CFS tended to be stable at 48 h, and amounted to 28.5, 15.5 and 0.075 mg/mL, respectively. In addition, adding ZZUA493, as an ingredient during their preparation, prolonged the shelf life of Chinese steamed buns. Overall, ZZUA493 appears to have good potential as a fungal inhibitor for food preservation.


2022 ◽  
Vol 8 (1) ◽  
pp. 72
Author(s):  
Ming-Hua Wu ◽  
Lu-Yao Huang ◽  
Li-Xiao Sun ◽  
Hui Qian ◽  
Yun-Yun Wei ◽  
...  

Magnaporthe oryzae is the causal agent of rice blast outbreaks. L-ascorbic acid (ASC) is a famous antioxidant found in nature. However, while ASC is rare or absent in fungi, a five-carbon analog, D-erythroascorbic acid (EASC), seems to appear to be a substitute for ASC. Although the antioxidant function of ASC has been widely described, the specific properties and physiological functions of EASC remain poorly understood. In this study, we identified a D-arabinono-1,4-lactone oxidase (ALO) domain-containing protein, MoAlo1, and found that MoAlo1 was localized to mitochondria. Disruption of MoALO1 (ΔMoalo1) exhibited defects in vegetative growth as well as conidiogenesis. The ΔMoalo1 mutant was found to be more sensitive to exogenous H2O2. Additionally, the pathogenicity of conidia in the ΔMoalo1 null mutant was reduced deeply in rice, and defective penetration of appressorium-like structures (ALS) formed by the hyphal tips was also observed in the ΔMoalo1 null mutant. When exogenous EASC was added to the conidial suspension, the defective pathogenicity of the ΔMoalo1 mutant was restored. Collectively, MoAlo1 is essential for growth, conidiogenesis, and pathogenicity in M. oryzae.


Insects ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 67
Author(s):  
Shivaji Hausrao Thube ◽  
Thava Prakasa Pandian ◽  
Anthara Bhavishya ◽  
Merin Babu ◽  
Arulappan Josephrajkumar ◽  
...  

Xylosandrus crassiusculus (Coleoptera: Curculionidae: Scolytinae) is reported causing damage to areca palm plantations (Areca catechu L.—Arecaceae) in Karnataka (India). In particular, X. crassiusculus has been observed attacking and successfully reproducing on areca nuts; besides the new host plant record, the data provided here represent the first documented case of spermatophagy for this xyleborine beetle. All infestation symptoms of this polyphagous pest were documented and illustrated. The identity of the scolytid, besides morphologically, was confirmed by its DNA barcoding. Eggs, larvae and pupae were found within the galleries of infested kernels. All galleries of the infested kernels were characterized by the presence of whitish to greyish fungal growth. The fungus was identified as Ambrosiella roeperi, a known symbiont of Xylosandrus crassiusculus. Incidence of this symbiotic insect-fungus complex in the economic part of arecanut, i.e., the kernel, is of serious concern. In a climate change scenario, this beetle with fungal symbionts may pose a serious threat to arecanut production in India and elsewhere.


Author(s):  
Xia Kang ◽  
Laszlo Csetenyi ◽  
Xiang Gao ◽  
Geoffrey Michael Gadd

Abstract Cerium has many modern applications such as in renewable energies and the biosynthesis of nanomaterials. In this research, natural struvite was solubilized by Aspergillus niger and the biomass-free struvite leachate was investigated for its ability to recover cerium. It was shown that struvite was completed solubilized following 2 weeks of fungal growth, which released inorganic phosphate (Pi) from the mineral by the production of oxalic acid. Scanning electron microscopy (SEM) showed that crystals with distinctive morphologies were formed in the natural struvite leachate after mixing with Ce3+. Energy-dispersive X-ray analysis (EDXA), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) confirmed the formation of cerium phosphate hydrate [Ce(PO4)·H2O] at lower Ce concentrations and a mixture of phosphate and cerium oxalate decahydrate [Ce2(C2O4)3·10H2O] at higher Ce concentrations. The formation of these biogenic Ce minerals leads to the removal of > 99% Ce from solution. Thermal decomposition experiments showed that the biogenic Ce phosphates could be transformed into a mixture of CePO4 and CeO2 (cerianite) after heat treatment at 1000 °C. These results provide a new perspective of the fungal biotransformation of soluble REE species using struvite leachate, and also indicate the potential of using the recovered REE as biomaterial precursors with possible applications in the biosynthesis of novel nanomaterials, elemental recycling and biorecovery. Key points • Cerium was recovered using a struvite leachate produced by A. niger. • Oxalic acid played a major role in struvite solubilization and Ce phosphate biorecovery. • Resulting nanoscale mineral products could serve as a precursor for Ce oxide synthesis.


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