Affiner votre recherche
Résultats 121-130 de 1,443
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 [-]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 [-]Partial Gap-Filling of the Nile Tilapia (Oreochromis niloticus) Draft Genome
2023
Hala Zoghly | Mohamed Rashed | Mahmoud Magdy
Nile tilapia is a freshwater fish of African origin, with productive and economic characteristics affecting global fish markets. The Oreochromis niloticus reference genome has a diploid set of 22 linkage groups (LGs) in addition to ungrouped sequences. A total of 42,622 genes have been identified, but 550 genomic gaps may include more. Our study focused on some of these genomic gaps, where appropriate primers were designed and then multiplied through the polymerase chain reaction (PCR) technique. From local samples, DNA was extracted and amplified with the new primers. Successful amplicons were sequenced and annotated using available bioinformatics tools. Five assessed sequences were annotated, of which three were newly predicted in O. niloticus, as mucin 1-like, and KLR genes, and SATB region. The other two sequences belonged to grid2 and trpm7 which were previously predicted. Although individual attempts to identify genomic gaps are not feasible in filling the large lack of information on the Nile tilapia genome, a good number and valuable new information has been reached. However, the following plan showed many technical problems, more time, effort and cost that could be avoided by suggesting the application of another technique, such as whole-genome sequencing, mapping, and assembly.
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.
Afficher plus [+] Moins [-]Effect of Pruning Levels on Yield and Fruit Quality of Melody (Blagratwo) Seedless Table Grape Cultivar
2023
Ali Ali | Nazmy Abdle Hamid | Amin shaddad | Mohamed Nasser
Three years old uniform vines for cv. "Melody syn. Blagratwo" seedless table grape were selected, and three levels of bud load were trimmed, namely 60, 72, and 78 buds/ vine. The findings revealed that vegetative growth traits, characteristics of yield and bunch quality were significantly affected by all different pruning levels of cane length in both seasons of this study. Highest bud load vines (78 buds/vine) produced the greatest yield and cluster number but had a negative effect on the percentage of bud behavior, shoot thickness, shoot length, weight of annual pruning (Kg/vine), cluster and berry quality parameters. In contrast, lowest vine bud load (78 buds/vine) had a better bud behavior, vegetative growth traits, cluster characteristics and berry characteristics but both bunch numbers and yield were reduced. In addition, vines pruned with bud load of 72 buds per vine significantly showed the best outcomes, since it successfully struck a balance be-tween features of vegetative growth, yield, cluster and berry physical and quality attributes in both seasons.
Afficher plus [+] Moins [-]Phylogenetic Evolution of Egyptian Goat Breeds “Capra Hircus” Based on Mitochondrial DNA D-Loop Sequence
2023
Eslam Bherey | Heba Hassan | Adel Ellbadawy | Mahmoud El_Maghraby | Mona Moghazee
The population genetic and molecular evidence of the Arabian goat breed's phylogenetic standing (Capra hircus) is misunderstood, and little is known about genetic diversity in this species. Despite their importance in producing meat and milk, as well as their capacity to endure difficult conditions with little access to food and water, goats are the most common animal in Arab countries. We investigated the phylogenetic history and demographics of domestic goats by sequencing a hypervariable segment of the mtDNA reference region for Baladi, Demuscous, and Zaraibi breeds, as well as sequences retrieved from 16 Arab countries. Three significantly divergent lineages associated with Africa and the Middle East were identified through phylogenetic analysis of the investigated strains of Egyptian goats' mtDNA D-loop region. All Egyptian goats were allocated to lineage A, which is made up of 445 different haplotypes, including Egyptian and Arabian goats. Diversity in haplotypes and in nucleotides for each Arabian goat population was calculated separately and estimated to be 0.99835 and 0.02576, respectively. Finally, we suggest that all goat lineages descend from a single clan. The ancient world's migration and travel may have influenced goat diversity, implying that goats had multiple matrilineal forebears
Afficher plus [+] Moins [-]Morphological and Molecular Identification of Penicillium digitatum Causing Green Mould of Citrus Fruits in Egypt
2023
Abdalrahman Desouki | Labiba Ahmed Reda | Mohamed Rashed | Shehata Shehata
Nine Penicillium digitatum isolates were isolated from citrus fruits and tested for their pathogenicity on Navel orange fruit (Citrus sinensis L.). In this regard, the isolates exhibited three different levels of virulence. The isolates were identified morphologically using malt extract agar (MEA) and Czapek yeast extract agar (CYA) for colony characteristics, and MEA for microscopic features. Each one of the isolates has the unique features of P. digitatum, especially the largest conidia (6.1-11.9 µm long X 3.2-8 µm width), and phialides (10.1-21.4 µm long X 4-5.1 µm width). In addition, the isolates were identified on a molecular basis using ITS1 and ITS4 primers to confirm morphological identification. Phylogenetic analysis revealed that there was high variance among the isolates, and there were different relations between some of our isolates and other P. digitatum registered strains originating from different countries all over the world. The sequences were submitted to respective GenBank nucleotide databases with accession No. OR198852, OR198853, OR198854, OR198855, OR198856, OR198857, OR198858, OR198859 and OR198860. We also isolated a new P. digitatum (OB15: OR198859) strain with high virulence and rapid sporulation
Afficher plus [+] Moins [-]Effect of Total Mixed Rations Versus Traditional Feeding of Concentrate and Roughage Rations on Dairy Cattle Performance in Sudan
2023
Mahgoub Elhag | Bedria Mohammed | Mohmed Sayed | Mohmed Abdulla | Mayser Abdulla | Yassin Abakar
Dairy cattle in Sudan are traditionally fed on separate concentrate and roughage diets. Because of the high cost of forages, feeding strategies should be attempted to reduce feeding costs. A traditional dairy ration (As-fed), composed of 49% sorghum grains (SG), 29.4% groundnut seed cake (GSC), 19.6% wheat bran (WB), 1% limestone (LS) and 1% salt (NaCl), was used as a control. The test ration was a total mixed ration (TMR) composed of 40% SG, 23% groundnut seed hulls (GSH), 20% GSC, 15% WB, 1% LS and 1 % NaCl. The control traditional ration was fed at 10 Kg/cow/day together with 7 Kg sorghum chaff. Two levels of TMR were used with alfalfa hay (AH); (17 Kg TMR + 1 Kg AH/cow/day and 15 Kg TMR + 2 Kg AH. Three cross-bred dairy cows (European x Local) were used with the feeding regimes in a 3x3 Latin square design. Cows consumed similar amounts of DM, CP and ME and produced similar quantities of milk (P > 0.05). TMR had no effects (P > 0.05) on the composition of milk. The cost for TMR was decreased by 19%.TMR was thus effective in reducing feeding costs without affecting milk production and composition.
Afficher plus [+] Moins [-]Impact of Maltodextrin and Inulin on Synbiotic Fermented Milk Production
2022
Reda Mohamed El-Komaily | Osama Elbatawy | Ihab Aumara
The influence of maltodextrin or inulin added as a prebiotic on the survival of various strains of probiotics in synbiotic fermented milk along cold storage was investigated. Synbiotic fermented milk was prepared using several probiotic strains (Lb. helveticus and Lb. acidophilus) and 2% maltodextrin or inulin and compared with traditional yoghurt starters (Lb. delbrueckii subsp. bulgaricus and Str. thermophilus). Synbiotic fermented milk samples were stocked at 4°C then the chemical, microbiological and sensory characteristics were estimated. Starter culture strains showed no significant effect on dry matter and ash contents in various synbiotic fermented milk samples during storage. However, starter culture type, fortification by maltodextrin or inulin, and storage period significantly influenced the acidity, total and soluble nitrogen contents (SN\TN), acetaldehyde, diacetyl contents and viscosity in various synbiotic fermented milk samples. In addition, fortification of maltodextrin or inulin significantly influenced the survival of yoghurt starter culture strains, Lb. helveticus and Lb. acidophilus strains. The counts of probiotic strains used in all treatments of synbiotic fermented milk survived well and were above the recommended minimum levels (106CFU/ mL) during a storage period.
Afficher plus [+] Moins [-]