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Molecular Genetic Studies on Honeybees in Response to Some Environmental Stresses
2023
Rehab Mohamed | Naglaa Ebeed | Khalid Fahmy | Naima Alsenosy | Sawsan Abdelmegeed
The honeybee, Apis mellifera, is a widespread pollinator insect. Colony collapse disorder (CCD) has recently caused a significant decline in honeybee numbers worldwide. The beekeeping industry, agriculture, and world biodiversity are threatened by the honeybee population decline. We examined the mRNA levels of heat shock protein gene 60 (hsp60), acetylcholinesterase 1, and acetylcholinesterase 2, as biomolecular markers of the insect response to three separate forms of environmental stress, including high temperature, low temperature, and insecticide. The obtained results indicated increased levels of hsp60 and acetylcholinesterase 2 after the exposure of worker bees to temperatures of 17, 32, and 40°C for one hour, as well as exposure to a low dose of pesticide for 24 h ingestion of imidacloprid solution (2 ppm); meanwhile, acetylcholinesterase 1 showed remarkable expression decrease under heat and cold stresses but increased under pesticide treatment. The responses of honeybees to hsp60, acetylcholinesterase 1, and acetylcholinesterase 2 are diverse and very specific to various stimuli. According to this research, the distinct expression profiles of hsp60 and acetylcholinesterase 2 can serve as useful instruments for tracking honeybees' vulnerability to varied environmental effects. Due to its insufficient responsiveness, acetylcholinesterase 1 expression is not permitted for use as a biomarker.
Afficher plus [+] Moins [-]Harvesting Microalgae by Chitosan as Sustainable Biopolymer
2023
Ola Obyd | Ayman Abou Hadid | Shawky Selim | Tarek El-Arabi
This study aimed to use the organic polymer, chitosan, as a flocculant for harvesting microalgae Chlorella. sp. Various polymer concentrations were tested. Within three min, 50 mg/L of chitosan showed the highest efficiency (98.9±0.5%), at pH 6.3, while the lowest efficiency (86.7±0.5%) was observed at pH 7.5. Harvesting efficiency in this study was chitosan concentration dependent. The present study showed that chitosan can be a promising and sustainable solution as an organic source and environmentally friendly flocculant. Additionally, it has excellent harvest productivity and requires minimum effort for quick outcomes.
Afficher plus [+] Moins [-]Increasing of Amylopectin in Tetraploid Potato Desiree Cultivar (Solanum tuberosum L.) Via CRISPR/Cas9
2023
Nermin Ali | Mohamed Abdel-Salam | aiman hanfy | Haytham Abd-Elhalim | Nouh Ahmed | Emad Metry
Potato tuber starch characteristic is influenced by the ratio of amylose to amylopectin, which is affected by the granule-bound starch synthase (GBSS) gene. GBSS gene expression was decreased in the leaves of the Desiree potato variety utilizing genome editing using CRISPR-Cas9. Constructs encoding Cas9 gene and sgRNAs targeting GBSS gene were inserted into plant leaves using Agrobacterium-mediated transformation delivery. The results obtained lines with mutations in GBSS genes accounting for 21% of regenerated shoots. The identification of mutations within one base pair of the used guide sequence provided further evidence of the considerable similarity between the target region around the protospacer adjacent motif (PAM) position and the used guide sequence. Transforming DNA into potato leaves produced mutants that lacked the Cas9 gene. Using microscopic inspection of iodine-stained starch granules, the increase of amylopectin in the starch granules of editing potato tubers was evaluated.
Afficher plus [+] Moins [-]Isolation and Characterization of Probiotics from Various Food Products as Potential Human Food Additives
2023
Fekria Mohamed Ali | Enas Hassan | Ahmed Abdelhafez | Basma Abd-Elhalim
In this study, human-safe lactic acid microorganisms (LAM) were isolated from food samples to be used as potential additives for human food. Samples from various food sources (artisanal cheeses, fermented chickpeas, fermented rice, natural yogurt, pickles, and raw milk) were used to inoculate de Man, Rogosa, and Sharpe (MRS) and malt agar plates, which were incubated at 30°C for 48 h or 37°C for 72 h to isolate lactic acid bacteria and yeast, respectively. Out of 120 isolates (85 bacteria and 35 yeast), 75 isolates showed γ-hemolytic activity and were considered “Generally Recognized As Safe” (GRAS) isolates. After testing their growth rate under the gastrointestinal tract (GIT) conditions, including acidic pH and specific bile salt concentrations, we selected 30 isolates. Then, we evaluated the fermentative abilities of these 30 isolates on nine types of carbohydrates, their total acidity, and their antagonistic activity against five human pathogens. Based on the results of these tests, four isolates were selected for identification using the Biolog program and 16S rRNA sequencing for bacteria and 18S rRNA sequencing for yeast and found to be Bacillus bingmayongesis (FJAT-13831), Lacticaseibacillus paracasei (R094), Pediococcus pentosaceus (DSM 20336), and one yeast isolate as Saccharomyces cerevisiae (SaCe1 26S).
Afficher plus [+] Moins [-]The Potential Efficiency of Lactobacillus farraginis Isolated from Ruminants with a View to be Used as Animal Probiotics
2023
Mona Zayed | Dalia Abd El-Fattah | Rateb Abbas | N. El-Bordeny | Sherif Edris
Probiotics refer to microorganisms that exhibit a beneficial effect on the animals’ health through intestinal microbial balance. This investigation intends to identify and define the probiotic characteristics of Lactobacillus strains isolated from the digestive systems of ruminants. Bacterial strains were isolated purified and characterized based on morphological and biochemical characteristics. The isolates were identified using the 16S rRNA gene partial sequencing method. Most of the strains exhibited a decrease in the growth by increasing the concentration of the bile salt, NaCl, increasing the temperature over 37oC, and moving toward neutrality and alkalinity of the media. Strain Lactobacillus farraginis MD_A11 revealed the lowest decrease in the growth percentage when subjected to different bile salt concentrations of 5.96, 6.61, 6.85, 7.40, 7.53, and 7.64%, NaCl% concentrations of 1.40, 5.62, 6.48, 7.36, 7.39, 7.41, 7.42, 7.28, and 13.76%, raising the temperature over 37oC being 4.19 & 3.945%, different pH levels as compared to control, and it recorded the lowest medium pH after the third day being 4.20 with titrable acidity of 0.32%. Strain Lactobacillus farraginis MD_A11 could be recommended as a probiotic feed additive for ruminants to improve their growth performance and productivity.
Afficher plus [+] Moins [-]Effect of Foliar Spraying with Pink Pigmented Facultative Methylotrophic Bacteria on the Growth and Productivity of Strawberry
2023
shadia Ismail | Fafy Mohammed
Pink-pigmented facultative methylotrophic bacteria (PPFM) isolated from cotton leaves was identified based on phenotypic and genotypic characteristics as Methylobacterium rodiotolerance. Two field experiments were conducted to investigate the effects of PPFM, methanol (10 and 30%) and a combination of bacteria and methanol on the growth, fruit quality, and yield of two strawberry cultivars (Florida and Festival). The main differences between the two cultivars are greater foliage fresh weight and early yield in cv. Florida while Festival cv. had a higher total yield per plant and greater anthocyanins and ascorbic acid contents. The greatest vegetative growth, dry matter percentage, potassium content, and carbohydrate content besides the earliest yield per plant were observed following spraying with PPFM or PPFM mixed with 10% methanol. Spraying with PPFM resulted in the highest total yield per plant, highest yield per feddan, and fruit quality. Spraying cv. Florida with PPFM resulted in the best early yield while spraying cv. Festival with PPFM resulted in the highest total yield and fruit quality. Spraying with PPFM appears to be the most efficient treatment for enhancing the total yield of Festival cv. by an average of 23.02 and 24.06 tons per feddan in the first and second seasons, respectively.
Afficher plus [+] Moins [-]Molecular Identification of Some Rhizobium and Serratia Isolates as Potential Producers of Indole-3-Acetic Acid
2023
Shaimaa Sello | Ashraf Abdel Razik | Samir Ibrahim | Sawsan Elateek
In order to reduce the use of chemical fertilizers, the use of biological inoculants has been increased. Beneficial microorganisms are used to increase crop yields by stimulating plant growth through the production of phytohormones. In the present study, Indole Acetic Acid (IAA) production was analyzed in 18 bacterial isolates with Plant Growth-Promoting (PGP) capabilities; 15 of these isolates were Rhizobium, and three were Serratia. All isolates have been characterized morphologically and biochemically, and their IAA production in the presence of tryptophan, a precursor for IAA biosynthesis, has been evaluated. IAA production was detected using the Salkowski reagent with CT-2200 spectrophotometer at 530 nm. The levels of IAA production varied between the different isolates. The top two IAA producers were selected for genetic identification using 16SrRNA primers (27F and 1492R). One of the Rhizobium isolates (NRC-R2) shared 95% sequence similarity with Rhizobium sp., according to a Blastn search in GenBank and Rhizobium leguminosarum, whereas the Serratia isolate (Ain Shams Center for Genetic Engineering and Biotechnology (ACGEB)-S2 was 99.5% similar to Serratia sp. Accordingly, these two isolates could serve as biological sources for IAA.
Afficher plus [+] Moins [-]Predicting and Optimizing Tillage Draft Using Artificial Network Technique
2023
Yasmin Shehta | Nabil Awady | Abdel-Fadil Kabany | Mohammed Abd-Elwahed | Waleed Elhelew
Tillage as one of the agricultural practices consumes the largest amount of energy, which reflects on the total production cost. The artificial neural network (ANN) technique was utilized in the current study to opti-mize the performance of the tillage process. The ANN-modeled multilayer perceptron network with a backpropagation learning algorithm and momen-tum term was used by the PYTHON program. The ANN inputs were: the implement type, soil texture, moisture, bulk density, width, speed, and depth. The draught was the output (kN). Five layers composed the ANN model's optimal configuration (13-64-16-4-1). The linear and rectified linear units (ReLU) functions were utilized with hidden layers and the output layer, re-spectively. Momentum term and learning rate were 0.00003 and 0.9 respec-tively. The iteration number was 1000 epochs and stopped at 290 epochs. The coefficient of determination in the test datasets was high (0.92) while the difference between actual and predicted output was low (2.08). Bulk den-sity and depth were the main determinants of the draft. The evaluation of the developed model for chisel, moldboard, and disk plow gave satisfactory re-sults of 0.985, 0.924, and 0.917. In comparison to the ANNs, the regression model's correlation coefficient for predicting draught force was the lowest (0.373).
Afficher plus [+] Moins [-]Residue Assessment of Bifenazate, Spirodiclofen and Abamectin in Strawberry Fruits Under Field Conditions
2023
Eman Abdelmaksoud | Walaa Elsayed | Shoukry Elrefai | kadry mahmoud | Khaled Ramadan
The dissipation behavior of three pesticides, bifenazate, spirodiclofen and abamectin was studied in strawberry fruits using a modified QuEChERS extraction technique. The residues of the tested acaricides were determined under field conditions after 1 hour (zero days), 1, 3, 7, 14, and 21 days. The maximum residue limits (MRLs) were 2, 2, and 0.15 mg/kg for bifenazate, spirodiclofen and abamectin, respectively. The strawberry fruits could be used safely after 15 days from bifenazate spraying and after 3 days from spirodiclofen spraying. The concentration of abamectin after 21 days did not reach MRL. The half-life values (t1/2) of bifenazate, spirodiclofen, and abamectin in strawberry fruits were 0.99, 0.86, and 5.7 days, respectively.
Afficher plus [+] Moins [-]Stenotrophomonas rhizophila a Novel Plant-Associated Bacterium With Distinguished PGPRs Properties
2023
Asmaa Elhosieny | Mona Zayed | Shawky Selim | Ayman Yassen | Norhan Abdel Aziz
Stenotrophomonas sp. is a plant-associated rhizospheric bacteria. It can enhance plant productivity. It acts as a mineral dissolution and growth promoter for plants under salt-stress conditions. The selected isolates revealed the general morphological and biochemical characteristics of Stenotrophomonas sp. All the isolates exhibited the highest growth density after 15 hr. at 30oC, resistance to different levels of salinity, different pH levels, and different temperature degrees. Also, the isolates revealed their capabilities to solubilize phosphorus and potassium and to produce different phytohormones. The isolate X.M9 exhibited the highest growth performance in the form of 1.376,1.326,1.292,1.053 and 1.059 OD in most salts’ concentrations compared to all tested isolates respectively. In addition, it (X.M9) exhibited the highest resistance to low temperatures 10 and 15oC being 0.917 and 1.354 OD respectively. The isolate X.M9 recorded the highest IAA of 83.73 mg/100ml compared to all the tested isolates. The isolate X.M9 was identified using 16 SRNA sequencing and submitted to the GenBank database un-der accession number No: OP050187 as Stenotrophomonas rhizophila.
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