Because of their negative effects on the environment, humans, and other organisms, chemical pesticides have been prohibited in many countries. Alternative microbial management is easy-to-implement, effective, and safe for humans and the environment. Fungus-based biopesticide products like kojic acid could commercialize as effective alternative chemical pesticides. Aspergillus oryzae ASU44 (OL314732) was isolated from hollyhock rhizosphere and identified using 18S rRNA gene sequencing. The strain showed high ability of kojic acid production especially after optimizing the production using 41-run Box-Behnken statistical design. Maximum kojic acid production was 46.53 g/l (predicted values 46.62 g/l) obtained in run number (23) using Glucose (150, g/l), Yeast extract (5 g/l), KH2PO4 (3 g/l), MgSO4.7H2O (0.5 g/l) and pH (3). The design was effective to applied with coefficient (R2) 0.988, 0.986 (adjusted R2 0.975, 0.972) for kojic acid (g/l) and dry fungal mass formation (g/l). The pathogenicity of the fungus and their kojic acid in addition to standard synthetic kojic acid was investigated to the cotton aphid, Aphis gossypii Glover (Homoptera: Aphididae). All treatments had a considerable impact on aphid mortality. The mortality rate was relative to the duration of exposure and the quantities of bio-pesticides agents. However, data revealed that as concentrations increased, the lethal time values decreased . Aspergillus oryzae ASU44 and its extract containing kojic acid were found effective against A. gossypii. As a result, this research suggests that these agents could be effective in aphid cotton management.
The current research demonstrates the biotechnological economization of accumulated and inefficiently used agro-industrial orange peel wastes to generate amylase, endoglucanase, exoglucanase, pectinase, and xylanase, industrially essential enzymes with growing demands in enzyme markets, from three Cladosporium isolates. In submerged fermentation (SmF) at 10°C, the isolate AUMC 10865 produced the highest level of amylase (4164 IU/gram dry substrate). Endoglucanase, exoglucanase and xylanase had development peaks (923 IU/gds, 2280 IU/gds, and 1646 IU/gds, respectively in case of Cladosporium sp. AUMC 11366. Pectinase produced the most (7840 IU/gds) in the strain AUMC 11340. At 30°C, the strain AUMC 11340 secretes the most amylase (4120 IU/gds), endoglucanase (2700 IU/gds) and xylanase (3220 IU/gds). Exoglucanase development reached the peak (8750 IU/gds) in the isolate AUMC 10865. The overall production (5570 IU/gds) was instead enhanced by pectinase in the AUMC 11366 isolate. In solid-state fermentation (SSF) at 10°C, the isolate AUMC 10865 outperformed the other two isolates producing 640.0 IU/gds amylase, 763.3 IU/gds endoglucanase, 771.0 IU/gds exoglucanase, 1273.23 IU/ gds pectinase and 1062.0 IU/gds xylanase, while the isolate AUMC 11366 produced the least amount of 399.7 IU/gds, 410.0 IU/gds, 413.3 IU/gds, 558.7 IU/gds, and 548.0 IU/gds, respectively. At 30°C, the isolate AUMC 11340 was superiorly producing higher levels of amylase (973.3 IU/gds), endoglucanase (746.0 IU/gds), exoglucanase (1052.0 IU/gds), pectinase (1685.3 IU/gds) and xylanase (1340.0 IU/gds), whereas isolate AUMC 10865 generated the least amounts of amylase (556.7 IU/gds) and exoglucanase (452.7 IU/gfs), and the isolate AUMC 11366 produced the least endoglucanase (256.3 IU/gds), pectinase (857.7 IU/gfs) and xylanase (436.3 IU/gds) amounts.
In the current investigation, the potentiality of black Aspergillus species isolated from sugarcane bagasse to produce cellulolytic enzymes, and citric acid was evaluated. Furthermore, the cellulolytic activity and citric acid production by the active producers were assayed on a carboxy methylcellulose medium. The study was extended to improve citric acid production from sugarcane bagasse using mixed cultures of the highest endo-cellulases (CMCase) and citric acid-producing isolates. All the tested fungal isolates exhibited varying amounts of acid production on Czapek’s dextrose (Cz-Dox) solid medium containing CaCO3. The highest concentration of citric acid produced using a Cz-Dox liquid medium was 8.49 ±2 g/L as recorded by A. brasiliensis Am 27. This amount of citric acid is equivalent to 29.22% of initial sugar. A.niger Am 270 showed the highest endo-cellulases production (0.73±0.2 IU/mL) whereas A. niger Am 258 exhibited the highest citric acid yield (14.74%). These isolates were chosen for the maximization of citric acid production from sugarcane bagasse. The highest amount of citric acid from sugarcane bagasse medium by A. niger Am 258 was obtained after 10 days of incubation, recording 34 g/L citric acid and by increasing the incubation period, the obtained amount of citric acid decreased. Whereas the mixed cultures of Am 270 and Am 258 strains revealed a slight enhancement of citric acid production recording 35.1 g/L citric acid after 8 days of the total incubation period. So the presented results may provide a suitable strategy for citric acid production using sugarcane bagasse.
Comprehensive field, litho-, biostratigraphy, and paleoenvironmental studies of the upper Paleocene–lower Eocene (P–E) boundary interval in the Gabal El-Gir area were conducted. Two selected sections El-Gir-1 and El-Gir-2 were investigated. The prevailed paleoenvironmental conditions were discussed in the frame of the nannofossils, planktonic, and benthic foraminiferal assemblages. Benthic foraminifera assemblages indicate a remarkable turnover across the PETM. The extinction of Angulogavelinella avnimelechi at the base of the PETM represents a significant marker for the base of the benthic foraminifera extinction event at this site and other neritic sites in the Tethyan region. The dominance of calcareous planktonic excursion taxa at the base of the PETM indicates adaptation to extremely warm sea surface temperatures and low nutrient levels. Also, our data suggests that the biotic responses to environmental change in the early Eocene resembled those observed in the early Eocene hyperthermals at the Dababiya and El-Ballas sections. This could indicate that similar processes characterized the Egyptian sedimentary basin during the early Eocene. Stratigraphically, despite the limited distance between the studied sections, the Dababiya Quarry Member (DQM) in El-Gir-1 resemble those of the Global Stratotype Section and Point (GSSP) but reduced in thickness. While in El-Gir-2, the lower part of the DQM was missing. These findings could indicate that the DQM was deposited in a submarine channel. Three third-order depositional sequences were recognized covering the P–E interval. The reconstructed sea level curve shows the presence of eustatic similarities with the global sea level.
Bioethanol is one of the most employed liquid biofuels due to the easy adaptability of this fuel to existing engines and because this is a cleaner fuel with a higher-octane rating than gasoline. Among the widely used substrates for ethanol production is sugarcane molasses. Unsuitable storage of molasses results in deterioration of fermentable sugars consequently ethanol yield quality and efficiency. The present study aimed to shed light on the effect of the storage period on the efficiency of sugarcane molasses and its effect on ethanol fermentation efficiency in distillery factories. The results showed that the total fermentable and non-fermentable sugars involved in sugar cane molasses varied between samples that were collected according to the location source. Also, ethanol yield and fermentation efficiency were different in the fermented molasses media which contained the same concentration of fermentable sugars. About 2.6511.20% of fermentable sugars in molasses were lost when stored under different temperatures. The loss was increased with the increasing storage temperature. Most of the loss happened in the first two months, especially at high temperatures. The decrease in ethanol yield and fermentation efficiency was affected sharply in the molasses storage at high temperatures than the low ones. From this study, the suitable storage temperature must not exceed 40°С to maintain molasses quality and avoid molasses deterioration by heat in temperatures.
