The Concurrent Application of Phosphogypsum and Modified Biochar as Soil Amendments Influence Sandy Soil Quality and Wheat Productivity.

Sandy soil covers a significant portion of Egypt's total land area, representing a crucial agricultural resource for future food security and economic growth. This research adopts the hypothesis of maximizing the utilization of secondary products for soil improvement to reduce ecosystem pollution. The study focuses on assessing the impact of combining phosphogypsum and modified biochar as environmentally friendly soil amendments on loamy sand soil quality parameters such as soil organic carbon, cation exchange capacity, nutrient levels, and wheat yield. The treatments were T1: the recommended NPK fertilizer (control); T2: 2.5 kg phosphogypsum m-2 soil; T3: 2.5 kg rice straw biochar m-2 soil; T4: 2.5 kg cotton stalk biochar m-2 soil; T5: 2.5 kg rice-straw-modified biochar m-2 soil; T6: 2.5 kg cotton-stalk-modified biochar m-2 soil; and T7 to T10: mixed phosphogypsum and biochar treatments. The results revealed that the combined use of phosphogypsum and modified cotton stalk biochar (T10) significantly enhanced soil organic carbon (SOC) by 73.66% and 99.46% in both seasons, the soil available N both seasons by 130.12 and 161.45%, the available P by 89.49% and 102.02%, and the available K by 39.84 and 70.45% when compared to the control treatment. Additionally, this treatment led to the highest grain yield of wheat (2.72 and 2.92 Mg ha-1), along with a significant increase in straw yield (52.69% and 59.32%) compared to the control treatment. Overall, the findings suggest that the combined use of phosphogypsum and modified biochar, particularly cotton-stalk biochar, holds promise for improving loamy sand-soil quality and wheat productivity.

The Synergistic Impact of Arbuscular Mycorrhizal Fungi and Compost Tea to Enhance Bacterial Community and Improve Crop Productivity under Saline-Sodic Condition.

Soil salinity has a negative impact on the biochemical properties of soil and on plant growth, particularly in arid and semi-arid regions. Using arbuscular mycorrhizal fungi (Glomus versiform) and foliar spray from compost tea as alleviating treatments, this study aimed to investigate the effects of alleviating salt stress on the growth and development of maize and wheat grown on a saline-sodic soil during the period of 2022/2023. Six treatments were used in the completely randomized factorial design experiment. The treatments included Arbuscular mycorrhizal fungus (AMF0, AMF1) and varied concentrations of compost tea (CT0, CT50, and CT100). AMF colonization, the bacterial community and endosphere in the rhizosphere, respiration rate, growth parameters, and the productivity were all evaluated. The application of AMF and CT, either separately or in combination, effectively mitigated the detrimental effects caused by soil salinity. The combination of AMF and CT proved to be highly efficient in improving the infection rate of AMF, the bacterial community in the rhizosphere and endosphere, growth parameters, and grain yield of maize and wheat. Therefore, it can be proposed that the inoculation of mycorrhizal fungi with compost tea in saline soils is an important strategy for enhancing salt tolerance in maize and wheat plants through improving microbial activity, the infection rate of AMF, and overall maize and wheat productivity.

Assessing Listeria monocytogenes growth kinetics in rice pudding at different storage temperatures.

Rice pudding is a popular artisanal dairy dessert highly consumed in the main rice-producing countries, including Egypt. This study aimed to evaluate and model the growth of Listeria monocytogenes in rice pudding dessert stored at different temperatures (4-25 °C) over its shelf-life. Lab-scale rice pudding samples were prepared following a traditional Egyptian recipe and inoculated with a three-strain cocktail of L. monocytogenes (ca. 3 × 102 cfu/g). Inoculated rice pudding samples (pH = 6.67 ± 0.06 and aw = 0.99 ± 0.002) were stored at different isothermal conditions (4, 8, 12, 18, and 25 °C) and microbiologically analysed for up to 30 days for pathogen quantification by plate count methodology. Global regression analysis was used to fit the Baranyi model coupled with the Ratkowsky model to growth data, relating L. monocytogenes concentrations (N, log cfu/g) with storage temperature (°C) and times (d). Model validation was performed using published independent data. L. monocytogenes growth potential increased by increasing storage temperature. The estimated Ratkowsky model parameters were b = 0.0819 ± 0.0017 log cfu/d·°C and Tmin = -3.28 ± 0.20 °C. The indices RMSE = 0.39 and R2adj = 0.97 indicated a good agreement between the experimental data and the model predictions. The estimated maximum growth rate (µmax) values ranged between 0.355 and 5.363 log cfu/d from 4 to 25 °C. The model was successfully validated using published L. monocytogenes Scott A and California strains growth data in rice pudding samples stored at 5, 12 and 22 °C, as evidenced by the assessed statistical indices. The predictive model developed and validated in this study will aid in decision-making regarding the microbiological safety of rice pudding dessert with respect to L. monocytogenes growth, considering a wide range of storage temperatures.

Antifungal and antitoxin effects of propolis and its nanoemulsion formulation against Aspergillus flavus isolated from human sputum and milk powder samples.

BACKGROUND AND AIM: Aspergillus flavus causes human and animal diseases through either inhalation of fungal spores or ingestion of mycotoxins as aflatoxins produced in human and animal feed as secondary metabolites. This study was aimed to detect the incidence of A. flavus and its aflatoxins in human sputum and milk powder samples and explore the efficacy of pure propolis (PP) and propolis nanoemulsion (PNE) as natural decontaminants against fungal growth and its released aflatoxins. MATERIALS AND METHODS: A. flavus was isolated by mycological culture and identified macroscopically and microscopically. Coconut agar medium and thin-layer chromatography (TLC) were used to qualitatively detect aflatoxins in the isolated strains. Toxins were extracted from toxigenic strains by the fast extraction technique. The quantitative detection of toxin types was explored by high-performance liquid chromatography (HPLC). PNE was prepared by a novel method using natural components and characterized by Fourier-transform infrared spectroscopy, Zetasizer, and transmission electron microscopy. The effects of PP and PNE on A. flavus growth and its toxin were determined by the well-diffusion method and HPLC. RESULTS: The mycological culture showed that 30.9% and 29.2% of sputum and milk powder samples were positive for A. flavus, respectively. TLC confirmed the production of 61.8% and 63.2% aflatoxin by the isolated strains in sputum and milk powder, respectively. PP and PNE showed antifungal activity on A. flavus growth with mean±standard error (SE) inhibition zones of 27.55±3.98 and 39.133±5.32 mm, respectively. HPLC revealed positive contamination of toxin extracts with AFB1, AFB2, and AFG2 at 0.57±0.026, 0.28±0.043, and 0.1±0.05 mg/L, respectively. After treatment with PP and PNE, a significant decrease in AFB1, AFB2, and AFG2 concentrations was observed. CONCLUSION: This study suggested using propolis and its nanoformulation as antifungal and antitoxins in human medicine and the food industry to increase the food safety level and stop food spoilage.

Investigation of the effect of chitosan and silver nanoparticles on the antibiotic resistance of Escherichia coliO157:H7 isolated from some milk products and diarrheal patients in Sohag city, Egypt.

BACKGROUND AND AIM: Antimicrobial-resistant Escherichia coli O157:H7 causes serious diseases in humans, especially when circulated in their food. This study was designed to detect the presence of E. coli O157:H7 using the fliC H7 gene in some milk products as kareish cheese, labena, and yoghurt sold in Sohag city, Egypt, and among diarrheal patients admitted to governmental hospitals in Sohag and also to highlight the risk factors associated with their infection. In addition, the antimicrobial resistance and the effect of chitosan nanoparticles (CNP) and silver nanoparticles (SNP) on E. coli O157:H7 isolates obtained from both milk products and patients were investigated. MATERIALS AND METHODS: Microbiological culture methods and polymerase chain reaction were used for detecting E. coli O157:H7 in 150 milk products and 150 stool samples. Resistance against some antimicrobials that were used in the treatment of animals and humans was investigated using the disk diffusion technique. CNP and SNP at two concentrations (30 and 60 µg/mL) and average sizes of 25.1 and 26.5 nm, respectively, were identified by transmission electron microscopy. Their effect on E. coli O157:H7 isolates was examined using the well diffusion method. Risk factors for infection were investigated using statistical analysis. RESULTS: There were 11.3% and 14.7% of milk products and stool samples positive for E. coli O157:H7, respectively. These isolates exhibited high antimicrobial resistance to ampicillin, tetracycline, and gentamycin. CNP and SNP demonstrated inhibitory effects on E. coli O157:H7 growth, which significantly increased at high concentrations (60 µg/mL), with mean inhibition zones of 31.941±3.749 and 30.681±3.871 mm for CNP in milk products and patient isolates, respectively. The respective values for SNP were 33.588±3.675 mm and 32.500±2.444 mm, indicating a higher bactericidal effect than that of CNP. Regarding risk factors for infection, both young and elderly subjects and those in contact with infected persons and/or having chronic diseases were infected. CONCLUSION: CNP and SNP are suitable for both medical and agricultural applications for disease control and enhancement of food quality.

Organochlorine and organophosphorus pesticide residues in raw buffalo milk from agroindustrial areas in Assiut, Egypt.

Raw buffalo milk samples from the agroindustrial zone in upper Egypt were analyzed for the presence of organochlorine and organophosphorus pesticides using gas chromatography-mass spectroscopy. Five organochlorine pesticides namely, alachlor, dieldrin, hexachlorobenzene, lindane and methoxychlor and three organophosphorus pesticides chlorpyrifos, malathion, and parathion-methyl were detected in the milk samples. In 44% of the samples, the concentrations of lindane and malathion residues exceeded tolerance levels set by the European Commission (EC) in 2008. In addition, the concentrations of chlorpyrifos, methoxychlor, and hexachlorobenzene residues exceeded the 2008 EC maximum residual limits (MRLs) by 33, 66, and 88% of the examined samples, respectively. However, the levels of alachlor, dieldrin, and parathion-methyl residues were below EC MRLs. The results of this study confirm the risks of pesticide residues exposure that threaten consumer health in Egypt. Thus, we recommend that pesticide residue monitoring programs be instituted in all the developing countries.