Abstract. Oyster mushrooms (Pleurotus spp.) can bioconvert lignocellulosic residues due to the secretion of extracellular enzymes. The production of hydrolytic and oxidative enzymes by five Pleurotus spp. (P. ostreatus, P. columbinus, P. pulmonarius, P. sajor-caju, and P. floridanus), developed in the solid and liquid state of fermentation using three agro-wastes (rice straw, sugarcane bagasse, and cotton waste), as substrate was evaluated in this work. The total nitrogen and potassium percentage were the highest in the case of rice straw, (0.96% and 0.60%). Also, the biological efficiency (BE), from these results, was the highest in the case of P. sajor-caju and P. columbinus recorded 64.4% on rice straw. It was observed that the submerged liquid fermentation (SmF) was suitable for the growth of all Pleurotus species. Also, the high value of enzymatic activity was determined through this study was, higher in the submerged liquid fermentation SmF, than those produced during solid-state culture (SSF). Among proteolytic enzymes, protease produced by the five Pleurotus spp. presenting the highest enzymatic activity (23.80 U/mL) on SmF and (22.56 U/mg) on SSF. Considering the oxidative enzymes, laccase produced, the highest value (1.99 U/mL) of laccase activity of filtrate was estimated from P. ostreatus cultivated on sugarcane bagasse of SmF. Low enzyme level (0.39 U/mg) was manganese peroxidase, obtained from P. floridanus cultivated on the cotton waste of SSF. The enzymatic levels of α-amylase, β-amylase, cellulose, cellobiohydrolase, laccase, and lignin peroxidase were from 2.9-0.50 U/mL.

Abstract. Oyster mushrooms (Pleurotus spp.) can bioconvert lignocellulosic residues due to the secretion of extracellular enzymes. The production of hydrolytic and oxidative enzymes by five Pleurotus spp. (P. ostreatus, P. columbinus, P. pulmonarius, P. sajor-caju, and P. floridanus), developed in the solid and liquid state of fermentation using three agro-wastes (rice straw, sugarcane bagasse, and cotton waste), as substrate was evaluated in this work. The total nitrogen and potassium percentage were the highest in the case of rice straw, (0.96% and 0.60%). Also, the biological efficiency (BE), from these results, was the highest in the case of P. sajor-caju and P. columbinus recorded 64.4% on rice straw. It was observed that the submerged liquid fermentation (SmF) was suitable for the growth of all Pleurotus species. Also, the high value of enzymatic activity was determined through this study was, higher in the submerged liquid fermentation SmF, than those produced during solid-state culture (SSF). Among proteolytic enzymes, protease produced by the five Pleurotus spp. presenting the highest enzymatic activity (23.80 U/mL) on SmF and (22.56 U/mg) on SSF. Considering the oxidative enzymes, laccase produced, the highest value (1.99 U/mL) of laccase activity of filtrate was estimated from P. ostreatus cultivated on sugarcane bagasse of SmF. Low enzyme level (0.39 U/mg) was manganese peroxidase, obtained from P. floridanus cultivated on the cotton waste of SSF. The enzymatic levels of α-amylase, β-amylase, cellulose, cellobiohydrolase, laccase, and lignin peroxidase were from 2.9-0.50 U/mL.

The utilization of appropriate preparations of plant growth-promoting fungi (PGPF) is one of the most promising trends for inducing plant resistance against a pathogen. However, not much is known about their mechanisms. Herein, the goal of this study was to present more information on this matter. The isolated rhizosphere fungi Aspergillus falvus, Aspergillus niger, Penicillium citrinum, Penicillium chrysogenum, and Trichoderma koningiopsis were tested for plant growth promotion traits. In Triticum aestivum L., root colonizing PGPF stimulated induced systemic resistance (ISR) against wilt disease by Rhizoctonia solani R43, resulting in a restriction of symptoms and disease development. This study demonstrates that the PGPF strains activated the pathogenesis-related gene (PR-1, 2), plant defensive chitinase (Chit-1) and β-1, 3-glucanase (Glu-2) genes and increased the plant-specific defensive proteins against Rhizoctonia solani pathogen. Their ability for ISR stimulation in T. aestivum L. was investigated in comparison to benzothiadiazole (BTH) as a chemical inducer. PGPF treatments showed overexpression of the defensive genes and consequently fewer disease symptoms compared to the chemical inducer BTH and control. Physical damage of lesions by fungal pathogen was less severe in leaves treated with PGPF strains compared to control plants. The observation of smaller lesion widths in the leaves pre-treated with the PGPF strains may be due to induced expression of protein genes, which is described as ISR. Quantitative real-time PCR (qRT-PCR) investigation showed that PR-1.2, Chi-1, and, Glu-2 genes were remarkably activated in PGPF-treated wheat plants.

The utilization of appropriate preparations of plant growth-promoting fungi (PGPF) is one of the most promising trends for inducing plant resistance against a pathogen. However, not much is known about their mechanisms. Herein, the goal of this study was to present more information on this matter. The isolated rhizosphere fungi Aspergillus falvus, Aspergillus niger, Penicillium citrinum, Penicillium chrysogenum, and Trichoderma koningiopsis were tested for plant growth promotion traits. In Triticum aestivum L., root colonizing PGPF stimulated induced systemic resistance (ISR) against wilt disease by Rhizoctonia solani R43, resulting in a restriction of symptoms and disease development. This study demonstrates that the PGPF strains activated the pathogenesis-related gene (PR-1, 2), plant defensive chitinase (Chit-1) and β-1, 3-glucanase (Glu-2) genes and increased the plant-specific defensive proteins against Rhizoctonia solani pathogen. Their ability for ISR stimulation in T. aestivum L. was investigated in comparison to benzothiadiazole (BTH) as a chemical inducer. PGPF treatments showed overexpression of the defensive genes and consequently fewer disease symptoms compared to the chemical inducer BTH and control. Physical damage of lesions by fungal pathogen was less severe in leaves treated with PGPF strains compared to control plants. The observation of smaller lesion widths in the leaves pre-treated with the PGPF strains may be due to induced expression of protein genes, which is described as ISR. Quantitative real-time PCR (qRT-PCR) investigation showed that PR-1.2, Chi-1, and, Glu-2 genes were remarkably activated in PGPF-treated wheat plants.

Rosemary essential oil was evaluated for antifungal potentiality against six major ginseng pathogens: Sclerotinia sclerotiorum, Sclerotinia nivalis, Cylindrocarpon destructans, Alternaria panax, Botrytis cinerea, and Fusarium oxysporum. The in vitro fungicidal effects of two commonly used fungicides, namely mancozeb and fenhexamid, and the volatile organic compounds (VOCs) of Trichoderma koningiopsis T-403 on the mycelial growth were investigated. The results showed that rosemary essential oil is active against all of the pathogenic strains of ginseng root rot, whereas rosemary oil displayed high ability to inhibit the Sclerotinia spp. growth. The highest sensitivity was S. nivalis, with complete inhibition of growth at 0.1% v/v of rosemary oil, followed by Alternaria panax, which exhibited 100% inhibition at 0.3% v/v of the oil. Minimum inhibitory concentrations (MICs) of rosemary oil ranged from 0.1 % to 0.5 % (v/v). Chemical analysis using GC-MS showed the presence of thirty-two constituents within rosemary oil from R. officinals L. Camphore type is the most frequent sesquiterpene in rosemary oil composition. Mancozeb and fenhexamid showed their highest inhibition effect (45% and 30%, respectively) against A. panax. T. koningiopsis T-403 showed its highest inhibition effect (84%) against C. destructans isolate. This study may expedite the application of antifungal natural substances from rosemary and Trichoderma in the prevention and control of phytopathogenic strains in ginseng root infections

Electricity can be directly biogenerated by bacteria in a microbial fuel cell (MFC) using many different biodegradable wastes as substrate. When cellulose is used as a substrate, the cellulolytic and electrogenic activities require a microbial consortium for energy generation. In this study, cellulose-degrading bacteria were isolated from an MFC using CMC (carboxymethylcellulose) agar medium and their cellulolytic activity was assessed. Cellulolytic bacteria isolated from the MFC were characterized and identified based on their phenotypic characteristics and analysis of their 16S rRNA genes sequence. Of thirty-two isolates, only ten cellulolytic bacterial strains were successfully isolated from the MFC reactor under aerobic conditions. The bacterial isolates had a cellulolytic index between 3.63 to 8.96 U mL-1. The bacterial strain SAM3a demonstrated high identity (99% via 16S-rRNA sequencing) to Staphylococcus saprophyticus which showed the highest CMCase activity (8.96) 0.34U mL-1). Enterobacter cancerogenus JCT-55 showed the next highest CMCase activity (8.34 ± 0.56 U mL-1); S. epidermidis BAB-2554 showed the lowest CMCase activity (3.63) 0.05 U mL-1). In the MFC, the genus Staphylococcus was found to be the most dominant group of cellulose-degrading bacteria which used rice straw as a carbon source. In this study, Escherichia coli, S. saprophyticus, Enterobacter cancerogenus, S. epidermidis, S. hominis, Bacillus subtilis, L. murinus, S. haemolyticus, S. epidermidis, and S. epidermidis were found to possess cellulolytic activity.

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The current simulations treat impacts of the thermal radiation on some natural convective process and entropy generation along a vertical surface impeded in a non-Darcy porous medium. Various convective practicabilities are due to various thermal boundary conditions, namely, isothermal surface with horizontal leading edge C1, uniform surface with horizontal leading edge C2, an adiabatic surface with a concentrated heat source along the horizontal leading edge C3 and a plane plume rising from a horizontal thermal source C4. Beside the boundary conditions, these convection modes are characteristic with a power index n such that n=0 refers to C1, n=0.2 refers to C2 and n=-0.6 refers to C3 and C4. The worked mixture is Cu-water nanofluid. The dependent variables are expanded in terms of small parameters γ(x) and λ(x), those are function in the permeability parameter. Numerical imitations are …

In this paper, numerical investigations for magnetohydrodynamic natural convection from two heating systems inside fined triangular enclosures filled with an isotropic porous medium using the nanofluids are performed. The two heating modes are represented by two cases, namely, case 1 a triangular enclosure with a heated part at the left wall and including a cold fin at the bottom wall and case 2 in which a cold part at the left wall and a heated fin located at the bottom wall. The copper is considered as nanoparticles and the Darcy model is applied to the porous medium. The triangular physical model is transformed to a rectangular computational model using suitable grid transformations and then the finite-volume method is applied to solve the resulting system. The key parameters in this study are the height, width and locations of the fin, different lengths and locations of the active part, nanoparticles volume …