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Nitrogen Cycle Bacteria in Agricultural Soils
Published in Vivek Kumar, Rhizomicrobiome Dynamics in Bioremediation, 2021
Guillermo Bravo, Paulina Vega-Celedón, Constanza Macaya, Ingrid-Nicole Vasconez, Michael Seeger
Tebuconazole (TBZ) is a widely used systemic fungicide (Youness et al. 2018). Its structure is (RS)-1-p-chlorophenyl-4,4-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)-pentan-3-ol (Fig. 2). The fungicidal activity of TBZ is based on its capability to target specifically the 14a-demethylase (CYP51), which is a regulatory enzyme of the ergosterol biosynthetic pathway. Ergosterol plays an essential role in fungal membrane formation, altering its structure and functions such as permeability and fluidity (Desmyttere et al. 2019).
Biological Indicators for Monitoring Soil Quality under Different Land Use Systems
Published in Amitava Rakshit, Manoj Parihar, Binoy Sarkar, Harikesh B. Singh, Leonardo Fernandes Fraceto, Bioremediation Science From Theory to Practice, 2021
Bisweswar Gorain, Srijita Paul
It is predominantly considered as the principal sterol secreted endogenously from fungi, actinomycetes, and some of the microalgae. The concentration of ergosterol is a critical indicator of fungal proliferation on organic compounds and its mineralization efficiency (Battilani et al. 1996). It was demonstrated that ergosterol content was not affected by heavy metals concentrations (Cu 80 ppm, Zn 50 ppm or Cd 10 ppm) and fungicides (Thiram 3 ppm or pentachlorophenol 1.5 ppm) even at concentrations that reduce the metabolic activity by 18% to 53% (pollutant stressed cultures), while Zineb, a fungicide at a concentration of (25 ppm), reduced the ergosterol content significantly. Similarly, a significant correlation was observed between fungal hyphae and ergosterol concentration in pastures and arable soils. It was also demonstrated through electron microscopy that a beneficial role of fungi in thixotropy (a physical process involving the orientation of the claymicelles) also exists in soil (Barajas et al. 2002, Molope et al. 1987). Puglisi et al. (2003) worked out the concentrations of cholesterol, sitosterol, and ergosterol in some agricultural soils (hazelnut irrigated with contaminated water and intensive horticulture) and reported that crop rotation does not affect the concentration of these sterols, but ergosterol hastened the metabolic activity in soils with industrial contamination In the Pacific region, Joergensen and Castillo (2001) found positive correlations between gCO2 and ergosterol to biomass C. They opined that the low soil microbial availability was attributed to the low soil organic matter and phosphorus leading to poor soil fertility and health in Nicaragua. The reduced fungal population caused P deficiency to crops probably due to the inability of plant roots to access immobile nutrients for plant growth.
Hydrogels and Their Applications in Targeted Drug Delivery
Published in Shaker A. Mousa, Raj Bawa, Gerald F. Audette, The Road from Nanomedicine to Precision Medicine, 2020
Radhika Narayanaswamy, Vladimir P. Torchilin
Ergosterol-liposome grafted silicone materials loaded with nystatin (an anti-fungal agent) resembled a fungal infection and triggered nystatin release through a competitive mechanism. In the absence of the ergosterol (important sterol in the cell membranes of fungi) in the medium, the drug release was very negligible [17–20].
Leaf litter decomposition in Guinean savannah streams
Published in Inland Waters, 2018
Nathalie Sia Doumbou Tenkiano, Eric Chauvet
Leaf content of ergosterol as a surrogate for mycelial biomass was determined as described in Gessner (2005a). Five of the 10 leaf disks per sample were stored in methanol/KOH in a cool place. Ergosterol extraction and saponification were achieved by heating the disks in methanol/KOH to 80 °C for 30 min before being cooled to 4 °C for 30 min. The extracts were purified using solid-phase extraction cartridges (Oasis HLB, 60 mg, 3 cc, Waters, Milford, MA, USA), and ergosterol was quantified by high-performance liquid chromatography (HPLC 360/442, Kontron, Eching, Germany). The HPLC system was equipped with a LiChroCART 250-4 LiChrospher 100 RP-18 (5 µm) column (Merck, Darmstadt, Germany) maintained at 33 °C, the mobile phase was 100% methanol with a flow rate of 1.4 mL min−1, and the detector wavelength was set at 282 nm.
Effective production of biologically active water-soluble β-1,3-glucan by a coupled system of Agrobacterium sp. and Trichoderma harzianum
Published in Preparative Biochemistry and Biotechnology, 2018
Ying Liang, Li Zhu, Minjie Gao, Jianrong Wu, Xiaobei Zhan
Because of its rapid turnover in dead cells, ergosterol is frequently used as a marker of living fungi biomass.[20] The extraction and measurement of ergosterol levels were performed based on the method described in Montgomery et al.[21]T. harzianum mycelia were first treated with 2 mL methanol and 0.5 mL of 2 M NaOH. After 15 min, the mixture was neutralized with 1 M HCl, treated with 2 mL methanol, vortexed and then extracted with pentane. The combined pentane extracts were passed through a 0.45 µm Acrodisc filter, and then evaporated and taken to dryness under a stream of N2 gas. The residue was then taken up with 200 mL methanol, and the ergosterol from the T. harzianum extracts was separated on a 30 × 5 mm Nova Pak C18 (WAT052834) reverse-phase column packed with ODS (4 mm) preceded by a Nova Pak C18 15220 guard column (Waters, Milford, MA, USA) and eluted with acetonitrile/methanol (98:2, v/v) at 2 mL min−1. Ergosterol was detected with a Waters 486 variable wavelength detector (Waters, Milford, MA, USA) set at 282 nm. The ergosterol content was determined by comparing the sample peak areas with those of ergosterol standards (Sigma-Aldrich, St Louis, MO, USA). The correlation between T. harzianum biomass and ergosterol content was y = 0.2548x − 0.07 (R2 = 0.9996), where y is T. harzianum biomass and x is the ergosterol content.
A review on the efficacy and medicinal applications of metal-based triazole derivatives
Published in Journal of Coordination Chemistry, 2020
Sajjad Hussain Sumrra, Umme Habiba, Wardha Zafar, Muhammad Imran, Zahid Hussain Chohan
Similarly, ergosterol is the component of fungal cell membranes that is responsible for maintaining structural stability, membrane fluidity, cell viability and act as permeability barrier. Triazole derived antifungal agents target the ergosterol biosynthetic pathway [35], effectively blocking the cytochrome P450 dependent sterol 14α-demethylase enzyme that is required for conversion of lanosterol to ergosterol. As a result, the reduction of ergosterol disturbs the integrity and systematic functions of fungal membranes, thus inhibiting fungal cell growth [36].