Isolates from pure culture of Rhizopus stolonifer were aseptically grown in potato dextrose broth to early exponential phase and centrifuged. The biological synthesis of Iron nanoparticles from the fungus was carried out using simple techniques. Filtrates obtained by simple methods were reacted with 1 M Ferric chloride solution. Characterization of the synthesized iron nanoparticles was monitored using Ultraviolet-visible spectrophotometer and Fourier transform infrared spectroscopy (FTIR). An increase in synthesis of the iron nanoparticles by over 200% occurred when culture of selected isolate was agitated. At 325 nm, peaks of absorbance (3.5) were read at pH 4.5 and 6, while maximum production of the iron nanoparticles was reached at 35 °C. Peaks of transmittance of biosynthesized iron nanoparticles from selected isolate as shown by the FTIR spectrum were located at 750, 1100, 1700, 2500 and 3750 cm−1, representing the CH, C-O, C=O, SH and OH groups respectively. The varying degree of transmittance and pH reported presents the selected R. stolonifer isolate as a biological entity for the synthesis of stable iron nanoparticles.
There is an increasing global search for commercially and environmentally clean synthesis of metallic nanoparticles from bioresources. However, there is insufficient reported information on the production of iron nanoparticles (FeNPs) from fungi such as Trichoderma species which has potentials for greater for yield of FeNPs as compared with bacterial sources. Filtrates obtained from biomass of pure cultures grown (72 h) in Potato Dextrose Broth were reacted with 1 M ferric chloride solution. A change in coloration monitored by ultraviolet-visible spectrophotometer (200-600 nm) as compared with control (ferric chloride solution) indicated a positive result. Nanoparticle synthesized in the reactive filtrate was characterized using utltraviolet-visible spectroscopy and Fourier transform infrared spectroscopy (FTIR). The effects of some physical parameters such as agitation, pH and temperature were monitored. The UV-vis spectrum revealed the peak of absorbance of synthesized nanoparticle by selected Trichoderma species at 275 nm. Optimum conditions for nanoparticle biosynthesis were observed at pH 4.5, 35 °C and when cells were agitated. Peaks of transmittance were observed at 950, 1800, 2250, 3000 and 3500 cm−1. These peaks represent the C-H, C=O, C=N, C=H and the OH functional groups respectively. The presence of the alkene, carboxyl and phenol groups suggests a capping of the NPs by the organism after redox reaction. The properties of extracellular iron nanoparticles synthesized by Trichoderma species from this study, presents the fungi as a bioresource for synthesis of stable NPs.
The potential of protoplast fusants of Wickerhamomyces anomalus and Galactomyces candidum isolates for ethanol production from cassava starch was evaluated. The protoplasts were obtained from 18 h yeast cells digested by zymolase and fused by polyethylene glycol (PEG). Regenerated recombinants were randomly selected and examined for desired marker traits: rate of fermentation of glucose, maltose and ethanol tolerance. Cassava starch hydrolysates were obtained by the amylolytic action of partially purified amylase extracts from Aspergillus species. Three of the selected fusants exhibited improvements in fermentation parameters over the parents. Enhanced ethanol tolerance of (25% v/v) as against 20% of the parents was exhibited by fusants R4 and R7. All isolates displayed higher ethanol productivity than CO 2 . The highest values of carbon dioxide productivity (4.79 L/L.h), volumetric ethanol productivity (11.54 g/L.h) and an ethanol mass concentration of 110.88 g/l were obtained from the fermentation by R1. Fusant R1 also had the highest fermentation efficiency (80%) and actual ethanol recovery (10.19%), as compared to other fusants and the parent yeast isolates. Parent isolates and selected fusants were characterized using molecular tools. The possibility of the occurrence of a genetic recombination in selected fusants as a result of protoplast fusion was observed. ARTICLE HISTORY
The recent increase in consumers’ preference for commercially sold bean flour necessitated the need to determine associated mycoflora and quantify the toxin production by the isolates, since several fungal genera have been associated with bean grains. Four fungal genera were isolated from fifteen beans flour samples sourced from various markets in Abeokuta by serial dilutions and pour plates methods on Potato Dextrose Agar (PDA) plates. Distinct colonies were transferred to Methyl Red Dessicated Coconut Agar (MRDCA) plates to identify toxin- producing isolates and High Performance Liquid Chromatography (HPLC) was used for aflatoxin quantification from the bean flour samples. The isolated fungal genera were, Aspergillus (60%), Fusarium (10%), Rhizopus (15%) and Mucor (5%). Nine of the fifteen samples were found positive for aflatoxigenic organisms and also produced aflatoxins that ranged from 0.006 to 0.151 ng/kg. The presence of toxin- producing organisms in the bean flour which is above the acceptable standard is a red flag that must be addressed vigorously if public health is a priority.
Optimization of Vegetable Sponge (Luffa aegyptiaca) (VS) -immobilization conditions of Aspergillus niger ATCC 1015 lipase on Solid State Fermentation (SSF) was carried out using Response Surface Methodology (RSM). Four independent variables (temperature, pH, enzyme loading and enzyme stability) were optimized using Central Composite Design of RSM for lipase production in a solid rice branphysic nut cake medium. The optimal immobilization conditions obtained were 45 °C, pH 7.0, 2.5% (w/v) enzyme loading and 32.5% (v/v) enzyme stability (using glutaraldehyde as crosslinking agent) resulted into lipase activity of 98.6 Ug -1 . The result demonstrates the potential application of vegetable sponge under SSF system in immobilizing lipase, thus contributed to efficiency of the use of this biomatrix as an immobilizing agent. The statistical tools employed predicted the optimal conditions for the production of the immobilized lipase thus revealing the full potential of the support.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.