Saccharification of orange peel wastes with crude enzymes from new isolated Aspergillus japonicus PJ01

Simple one-step treatment for saccharification of mango peels using an optimized enzyme cocktail of Aspergillus niger ATCC 9642

Developing efficient microbiological methods to convert polysaccharide-rich materials into fermentable sugars, particularly monosaccharides, is vital for advancing the bioeconomy and producing renewable chemicals and energy sources. This study focused on optimizing the production conditions of an enzyme cocktail from Aspergillus niger ATCC 9642 using solid-state fermentation (SSF) and assessing its effectiveness in saccharifying mango peels through a simple, rapid, and efficient one-step process. A rotatable central composite design was employed to determine optimal conditions of moisture, time, and pH for enzyme production in SSF medium. The optimized enzyme cocktail exhibited cellulase activity (CMCase) at 6.28 U/g, filter paper activity (FPase) at 3.29 U/g, and pectinase activity at 117.02 U/g. These optimal activities were achieved with an SSF duration of 81 h, pH of 4.66, and a moisture content of 59%. The optimized enzyme cocktail effectively saccharified the mango peels without the need for chemical agents. The maximum saccharification yield reached approximately 81%, indicating efficient conversion of mango peels into sugars. The enzyme cocktail displayed consistent thermal stability within the tested temperature range of 30-60°C. Notably, the highest sugar release occurred within 36 h, with glucose, arabinose, galactose, and xylose being the primary monosaccharides released during saccharification. This study highlights the potential application of Aspergillus niger ATCC 9642 and SSF for enzymatic production, offering a simple and high-performance process for monosaccharide production. The optimized enzyme cocktail obtained through solid-state fermentation demonstrated efficient saccharification of mango peels, suggesting its suitability for industrial-scale applications.

Technological advances for improving fungal cellulase production from fruit wastes for bioenergy application: A review

Fruit wastes can be imperative to elevate economical biomass to biofuels production process at pilot scale. Because of the renewable features, huge availability, having low lignin content organic nature and low cost; these wastes can be of much interest for cellulase enzyme production. This review provides recent advances on the fungal cellulase production using fruit wastes as a potential substrate. Also, the availability of fruit wastes, generation and processing data and their potential applications for cellulase enzyme production have been discussed. Several aspects, including cellulase and its function, solid-state fermentation, process parameters, microbial source, and the application of enzyme in biofuels industries have also been discussed. Further, emphasis has been made on various bottlenecks and feasible approaches such as use of nanomaterials, co-culture, molecular techniques, genetic engineering, and cost economy analysis to develop a low-cost based comprehensive technology for viable production of cellulase and its application in biofuels production technology.

Green Synthesis of Silver Nanoparticles by Extracellular Extracts from Aspergillus japonicus PJ01

The present study focuses on the biological synthesis, characterization, and antibacterial activities of silver nanoparticles (AgNPs) using extracellular extracts of Aspergillus japonicus PJ01.The optimal conditions of the synthesis process were: 10 mL of extracellular extracts, 1 mL of AgNO3 (0.8 mol/L), 4 mL of NaOH solution (1.5 mol/L), 30 °C, and a reaction time of 1 min. The characterizations of AgNPs were tested by UV-visible spectrophotometry, zeta potential, scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric (TG) analyses. Fourier transform infrared spectroscopy (FTIR) analysis showed that Ag+ was reduced by the extracellular extracts, which consisted chiefly of soluble proteins and reducing sugars. In this work, AgNO3 concentration played an important role in the physicochemical properties and antibacterial properties of AgNPs. Under the AgNO3 concentration of 0.2 and 0.8 mol/L, the diameters of AgNPs were 3.8 ± 1.1 and 9.1 ± 2.9 nm, respectively. In addition, smaller-sized AgNPs showed higher antimicrobial properties, and the minimum inhibitory concentration (MIC) values against both E. coli and S. aureus were 0.32 mg/mL.

High value-added products from the orange juice industry waste

An underutilized residue called Citrus Pulp of Floater (CPF), which causes problems during the industrial process of manufacturing of orange juice, was explored for the production of high value-added products. Mixed, first (1G) and second generation (2G) ethanol, a clean and renewable biofuel, was obtained after an enzyme cocktail isolated from the Xanthomonas axonopodis pv. citri (Xac) was applied in hydrolysis of this biomass. Then, mono- and co-culture fermentations were performed using the yeast Saccharomyces cerevisiae and two Candida strains (Candida parapsilosis IFM 48375 and NRRL Y-12969), where the last two were isolated from the orange bagasse in natura. After the enzymatic hydrolysis step, sugars obtained were converted to ethanol achieving a yield of almost 100% after co-fermentation. Hesperidin, a flavonoid widely used for its antimicrobial and/or antioxidant activities, was also extracted from CPF by liquid-solid extraction and precipitation, with the yield of 1.2% and 92.6% pure. Finally, nanocellulose was produced through processes such as extraction, bleaching and nanonization with the yield of 1.4% and over 98% of purity. These products - ethanol, hesperidin and nanocellulose were obtained from three independent processes: (1) after an enzyme-based hydrolysis of CPF, liquid part was used for ethanol production, and solid was preserved; (2) hesperidin was isolated from a dry CPF, and solid residue was preserved; and (3) nanocellulose was obtained from the solid residues after processes cited in 1 and 2.