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Kiwi is one of the best natural sources of vitamin C and has wide applications. During October–November 2021, small brown spots were examined on the Kiwi leaves. The diseased leaf samples were collected and placed on potato dextrose agar nutrient media for diagnosis. Morphological, anatomical, and molecular studies revealed this disease-causing agent to be Rhizopus oryzae. Molecular characterizations of the isolated pathogen were performed by using actin translation elongation factor (EF-1α) and ribosomal deoxyribose nucleotide inter transcribed sequence (rDNA ITS ITS1/ITS4) and elongation factors (EFl-F/EFl-R) primers. A BLAST study of the resultant ITS1/ITS4 sequence showed > 99% resemblance with R. oryzae (MT603964.1), while the EF-1α sequence revealed 100% similarity with translation elongation factor-1α gene of R. oryzae (MK510718.1). The obtained ITS1/ITS4 sequence was submitted to NCBI (MW603842.1). Koch's postulates established the pathogenicity of isolated R. oryzae and proved it to be the brown spot pathogen of Kiwi. For the environmentally-friendly management of Kiwi leaf spot, maize biochar-Zinc Oxide (MB-ZnO) nanocomposite was used. The prepared nanocomposite was characterized by Fourier transform infrared (FTIR) spectroscopy, thermo gravitational analysis (TGA), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) analysis. After successful preparation, MB-ZnO was assessed for its possible antifungal potential against R. oryzae. MB-ZnO displayed substantial growth inhibition, and the highest growth inhibition (79%) was observed at a 19 mg/mL dose rate of nanoparticles. These excellent findings propose that Ball-milled synthesis is a fast, economical, and environmentally friendly method for nanocomposite in the near future. The nanocomposite is used as a nominal substitute for chemical fungicides. [ABSTRACT FROM AUTHOR]

In this study, initially 11 different bacterial strains were tested for the degradation capabilities against Basic Orange 2 dye. In initial screening with 78.90% degradation activity, Escherichia coli emerged as the most promising strain to degrade the selected dye, and was then employed in subsequent experiments. For further enhancing the degradation capability of selected bacteria, the effects of various physicochemical parameters were also evaluated. Among the tested parameters, 20 ppm dye concentration, 1666 mg/L glucose concentration, a temperature of 40 °C, 666 mg/L sodium chloride concentration, pH 7, 1000 mg/L urea concentration, a 3-day incubation period and the use of sodium benzoate as a redox mediator (666 mg/L) were found to be ideal conditions to get the highest decolorization/degradation activities. Finally, all the mentioned parameters were combined in a single set of experiments, and the decolorization capacity of the bacteria was enhanced to 89.88%. The effect of pH, dye concentration, incubation time and temperature were found to be responsible for the optimum degradation of dye (p < 0.05), as predicted from the ANOVA (analysis of variance) of the response surface methodology. The metabolites were collected after completion of the process and characterized through Fourier transform irradiation (FTIR) and gas chromatography mass spectrometry (GC-MS). From the data obtained, a proposed mechanism was deduced where it was assumed that the azo bond of the dye was broken by the azoreductase enzyme of the bacteria, resulting in the formation of aniline and 3, 4-diaminobezeminium chloride. The aniline was then further converted to benzene by deamination by the action of the bacterial deaminase enzyme. The benzene ring, after subsequent methylation, was transformed into o-xylene, while 3, 4-diaminobezeminium chloride was converted to p-xylene by enzymatic action. These findings suggest that Escherichia coli is a capable strain to be used in the bioremediation of textile effluents containing azo dyes. However, the selected bacterial strain may need to be further investigated for other dyes as well. [ABSTRACT FROM AUTHOR]

Background: early blight disease caused by Alternaria solani is one of the most destructive diseases of the tomato, reducing tomato production globally. Methods: four fungal isolates were collected from four tomato cultivars and identified through morphological characterization and polymerase chain reaction (PCR) amplification of the internal transcript spacer (ITS) region. Plectranthus neochilus and Parthenocissus quinquefolia methanol extracts and the bioagents Trichoderma viride and Pseudomonas fluorescens were used as antifungal agents in vitro and in vivo and compared with chlorothalonil, a reference chemical fungicide. HPLC analysis of the plant extracts was used to identify the main flavonoid compounds, namely, rutin and myricetin. Results: molecular characterization showed that the fungal isolates belonged to A. solani. The results of in vitro antifungal activity studies revealed that chlorothalonil, at a concentration of 2500 mg/L, showed the highest inhibition percentage of fungal growth (IPFG) against A. solani (84.4%), followed by the bioagents T. viride and P. fluorescens, with IPFG values of 72.9% and 67.9%, respectively. Moderate to weak activity was found against A. solani when P. neochilus and P. quinquefolia extracts were applied at a concentration of 2500 mg/L, with an IPFG value of 54% for both extracts. The results of in vivo spray application showed that T. viride and chlorothalonil, as well as P. fluorescens, significantly reduced the disease index of early blight, and followed by the P. neochilus and P. quinquefolia extracts. By HPLC, the flavonoid compounds rutin and myricetin were identified in P. neochilus (leaf) with amounts of 2429.60 and 75.92 mg/100 g of extract, and in P. quinquefolia (fruit), with amounts of 1891.60 and 241.06 mg/100 g of extract, respectively. Conclusions: the results of the bioactivity of plant extracts and the bioagents indicate a vital role as antifungal activity against A. solani. [ABSTRACT FROM AUTHOR]