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Showing 6 results for Aspergillus Niger

Ahmad Hasanpour Fattahi, Hojatollah Jafaryan, Alireza Khosravi, Hosna Gholipour Kanani,
Volume 3, Issue 1 (6-2014)
Abstract

The probiotic effects of Saccharomyces cerevisiae and Aspergillus niger on the feeding efficiency, body composition, ammonia excretion, blood serum enzymes and the intestinal microbiota of juvenile beluga, Huso huso was investigated. The fish (31.8±2.81g) were randomly allocated into 12 oval tanks at a density of 30 individuals per tank with three replicates for each treatment,. The fish were fed either a basal diet (as control) or the diet supplemented with S. cerevisiae and A. niger (2×106, 4×106 and 6×106 cells g-1) for 8 weeks. The results indicated that the probiotic supplemented diet at 6×106 (cells g-1) significantly improved FCR and other nutritional indicators compared to the control treatment (p<0.05). Significant improvements (p<0.05) were also observed in ammonia excretion and blood serum enzymes between treatments. Total viable fungus and Lactobacillus spp. count were significantly improved in treatment compared to control (p<0.05). These results indicated that S. cerevisiae and A. niger improved feeding performance and blood serum enzymes of beluga.

Volume 7, Issue 3 (11-2016)
Abstract

Chitin and chitosan are two very important biopolymer products that have so many usages in the high cost industries. Chitin Converts into chitosan via de-acetylation of chitin. It occurs by alkaline melting method in the absence of oxygen. Chemical structure change, severe environmental pollution and De-polymerization are of the major problems in producing high quality chitosan. In this study for conversion of chitin into chitosan fungus Aspergillus niger strains (ATHUM-10864), the generator of de-acetylases enzymes were used instead of chemicals. Chitosan quality was determined via elemental analysis infrared spectroscopy, X-ray tomography, molecular weight determination and estimation of crystallinity percent, color and molecular structure.The results showed 80±5% efficiency in the conversion of chitin into chitosan or de-acetylation degree of chitin. The gained chitosan contained of 44.4 % carbon, 8.9 % nitrogen, 2.7 % hydrogen and 39.5 % oxygen. The physical characteristics were as 94.5% Crystallinity and pale brown color. The chemical structure of per unit of chitosan was obtained as C6H12NO4. The results showed that replacing biological methods instead of chemicals was possible to access well quality products. It also eliminates the use of chemical materials such as concentrate sodium hydroxide that is damaging the environment.

Volume 7, Issue 3 (11-2023)
Abstract

Research subject: Aspergillus niger stands as a versatile filamentous fungus renowned for its industrial significance in producing various organic acids, notably citric acid and oxalic acid. Low sugar concentration as substrate leads to the production of oxalic acid, therefore, this article delves into the intricate metabolic machinery orchestrating the synthesis of these acids within A. niger, shedding light on the pivotal role of culture media composition and metabolic activity.
Research approach: Through a comprehensive review of A. niger metabolism, this study elucidates the pathways involved in the biosynthesis of citric acid and oxalic acid, unraveling the intricate interplay of enzymatic cascades and regulatory mechanisms governing their production. Furthermore, it explores the impact of small molecules on metabolic flux through regulatory media, offering insights into strategies for controlling metabolic flux in order to eliminate oxalic acid production and amplify the citric acid production considering low sugar content of 30 g/l.
Main results: After careful review of previous researches, key reactions and genes was found and introduced for future researches in order to control the A. niger products. Examination of small molecule as a regulator in culture media not only elucidated the importance of culture media composition but also employing them helped us to redirect flux from oxalate toward citrate. NH4, Leucine, Cysteine, NaF, Glutathione, and Metformin were all found to be effective in the elimination of oxalic acid. In this regard, employing them leads to the production of 1868, 1530, 2093, 2250, 787, and 675 mg/L oxalic acid in comparison to the control culture media in which 5560 mg/L oxalic was produced. In addition, elimination of oxalic acid in some cases leads to the production of more acids like the culture containing NH4, Cysteine and Metformin.

Volume 12, Issue 4 (12-2024)
Abstract

Aims: In this study, we evaluated the performance of direct microbial fuel cells using citric acid wastewater as a substrate under different concentrations of MLSS 1000 mg.L-1 and 3000 mg.L-1. 
Materials & Methods: Aspergillus niger yeast was used as a microorganism over 4 days and nights of this experiment. A Nafion membrane was used for proton transfer, and graphite plates were used for electron transfer. COD removal efficiency, maximum open circuit voltage, power, and current density were evaluated. 
Findings: The general trend of energy production and removal efficiency showed that energy production increased with increasing MLSS. The maximum of these variables was recorded for MLSS of 3000 mg.L-1, achieving a removal efficiency of 93%, an open circuit voltage of 500 mV, and power and current density of 24345 µW.m-2 and 444 mA.m-2, respectively. 
Conclusion: Our results showed that the designed MFC suits wastewater treatment and energy recovery.


Volume 16, Issue 95 (12-2019)
Abstract

This research was carried out to study the antifungal effect of aqueous extract and powder of Pistacia atlantica at 0, 0.5, 1, 2.5 and 5% on the growth of Aspergillus flavus and Aspergillus niger. Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) of the baneh extract and powder was certified against Aspergillus niger and Aspergillus flavus in concentrations of 0.5, 0.4, 0.3, 0.2, 0.1 and 0.05 g /ml were determined by Serial Dilution technique. After preparing lactic cheese samples, a 10 mm piece was placed inside the plate and 3 μl Aspergillus flavus and Aspergillus niger was added to its center. Plates were incubated at 26 ° C for 3 weeks and the zone diameter of mold growth was measured. The results showed that by increasing the storage period, the growth zone diameter of Aspergillus flavus and Aspergillus niger in all of treatments increased. The treatments had a greater effect on the control of Aspergillus flavus mold growth than that of Aspergillus niger in lactic cheese. In mold and yeast counting, the highest count was observed for control treatment and the lowest increase was related to treatment containing 5% extract of Pistacia atlantica. The experimental treatments also significantly affected the sensory properties of the cheese samples. The highest taste scores were for samples containing 0.5 and 1% Pistacia atlantica extract. The samples containing more levels of extract (2.5 and 5 %) were less scored in terms of flavor and taste than those containing powder of Pistacia atlantica. From the findings of this study, it can be concluded that extracts and powder of Pistacia atlantica have an appropriate antifungal activity against Aspergillus niger and Aspergillus flavus, Therefore, they can be used in medical pharmacology, food industries and health affairs as drugs and anti-fungal elements.

Volume 17, Issue 108 (1-2021)
Abstract

At present, increasing public awareness of the health and nutritional properties of agricultural products and their products, as well as the effects of chemical toxins and synthetic preservatives, doubles the demand for fresh and chemical-free food preservatives. Froriepia subpinnata is a member of the family Umbelliferae. This plant is native central and northern parts of Iran. Disk diffusion agar, well diffusion agar, minimum inhibitory concentration (broth microdilution and agar dilution) and minimum fungicidal concentration were used to evaluated the antifungal effect of Froriepia subpinnata essential oil. The results showed that Froriepia subpinnata essential oil was well able to prevent the growth of fungal strains that cause black and gray spoilage in vitro. The results showed that the inhibition zone diameter (disc diffusion method) for the fungal strains of Aspergillus niger and Botrytis cinerea was 15.50 and 13.30 mm, respectively. The results of the antifungal effect in the well agar method showed a much greater inhibition zone diameter than the disc diffusion method. The minimum fungicidal concentration for Aspergillus niger and Botrytis cinerea was 64 and 256 mg/mL, respectively. The minimum fungicidal concentration of Froriepia subpinnata essential oil was higher for Aspergillus niger and Botrytis cinerea strains than the minimum inhibitory concentration.

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