Occurrence and removal characteristics of phthalate esters from bottled drinking water using silver modified roasted date pits

BACKGROUND

This paper aims to investigate the occurrence and removal characteristics of phthalate esters from bottled drinking water using silver modified roasted date pits. Three adsorbents, namely roasted date pits (RODP), silver-modified roasted date pits (S-RODP), and activated carbon (AC) were used to investigate their adsorption characterizations in removing dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), di-2-ethylhexyl phthalate (DEHP), and di-n-octyl phthalate (DNOP) from the collected bottle water samples.

METHODS

The occurrences of the phthalate esters in the collected bottled water samples were carried out at different temperatures (30, 50, and 60 °C), and analyzed using gas chromatography-mass spectrometry analysis - selected ion monitoring. Batch adsorption isotherms were used to study and establish the efficiency of such adsorbents in removing phthalate esters, in which they describe the adsorbent-adsorbate interaction systems. Adsorption efficiency of the various adsorbents was investigated by using different adsorbent masses (0.05 g, 0.10 g, and 0.15 g) and temperature (30 °C, 50 °C, and 60 °C). Different physical and chemical characterizations were studied using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), Brunauer-Emmett-Teller (BET) surface area, pore radius, and pore volume.

RESULTS

The results indicated that the most abundant phthalate esters were DMP followed by DEP under 30 °C; however, DNOP was not detected in any of the tested water samples, except for one sample under 30 °C with a concentration of 0.031 μg/mL. The obtained results showed that phthalate esters leaching to the bottled drinking water were affected by storage temperature. The phthalate esters levels were increased with increasing the temperature to 60 °C. It was concluded that the ability of S-RODP for the adsorption of phthalate esters was better than the removal percentage obtained by AC and RODP. The removal percentage was increased from 90 to 99% by increasing the temperature from 30 to 50 °C and then decreased to 92.3% at 60 °C.

CONCLUSION

RODP was successfully used as an effective adsorbent for phthalate esters removal from drinking water. However, S-RODP has the highest removal abilities than other adsorbents due to the newly formed functional groups on its surface.

Isolation of the Endophytic Fungus Aspergillus terreus from a Halophyte (Tetraena qatarensis) and Assessment of Its Potential in Tomato Seedling Protection

Living in diverse environmentally harsh conditions, the plant exhibits a unique survival mechanism. As a result, the endophytes residing within the plant produce specific compounds that promote the plant's growth and defend it against pathogens. Plants and algae symbiotically harbor endophytes, i.e., microbes and microorganisms living within them. The objective of this study is to isolate endophytic fungi, specifically strains of Aspergillus terreus, from the leaves of the salt-tolerant plant Tetraena qatarensis and to explore the salt tolerance, antagonistic activity, and growth promotion properties. Strain C A. terreus (ON117337.1) was screened for salt tolerance and antagonistic effects. Regarding salt tolerance, the isolate demonstrated the ability to thrive in a concentration of up to 10% NaCl. A. terreus showed inhibitory activity against four fungal phytopathogens, namely Fusarium oxysporum, Alternaria alternata, Colletotrichum gloeosporioides, and Botrytis cinerea. The GC-MS investigation of the fungal (strain C Aspergillus terreus) extract showed the presence of about 66 compounds (secondary metabolites). Secondary metabolites (SMs) are produced, like Hexadecanoic acid, which aids in controlling phytopathogens. Also produced is lovastatin, which is used to treat hypercholesterolemia. Strain C, which showed salinity tolerance and the highest inhibitory activity, was further analyzed for its effect on tomato seed germination under pathogen stress from Fusarium oxysporum. The greenhouse experiment indicated that the fungi increased the length of tomato seedlings and the plant biomass. Therefore, the selected endophytes derived from Tetraena qatarensis were scrutinized for their potential as biocontrol agents, aiming to thwart fungal pathogens and stimulate plant growth. The in vitro and in vivo assessments of strain C (Aspergillus terreus) against Fusarium oxysporum in this investigation indicate the promising role of endophytes as effective biological control agents. Investigating novel bio-products offers a sustainable approach to agriculture, gradually reducing dependence on chemical fungicides.

Screening, Diversity, and Characterization of Fungal Endophytes Isolated From the Halophyte Limonium axillare and the Potential of Biocontrol Antagonists Against Fusarium oxysporum

Halophytes, plants that thrive in high-salinity environments, host unique microbial communities, including fungal endophytes, which contribute to plant growth and pathogen resistance. This study aimed to isolate, identify, and evaluate the antagonistic potential of fungal endophytes from the halophytic plant Limonium axillare, collected from both inland and coastal habitats. Fungal endophytes were isolated, identified via molecular techniques, and tested for antagonistic activity against phytopathogenic fungi using dual-culture assays. The results showed a diverse range of fungal endophytes, with Aspergillus and Cladosporium being the dominant genera. A total of 152 endophytic fungi were isolated from both locations, with 95 isolates coming from coastal plants and 57 from inland species. The isolates exhibited varying degrees of antagonistic activity against phytopathogens, highlighting their potential role in plant protection. Further research is needed to clarify these interactions' mechanisms and investigate their practical applications in agriculture. An endophytic isolate of Aspergillus terreus strain ((AL10) lim10qu) (ON210104.1) exhibited potent in vitro antifungal activity against Fusarium oxysporum, a pathogenic fungus affecting tomato plants. Greenhouse experiments demonstrated that the fungus significantly increased both the length of tomato seedlings and the overall plant biomass. Both laboratory-based (in vitro) and field-based (in vivo) evaluations of the strain ((AL10) lim10qu) (A. terreus) against F. oxysporum suggest the promising role of endophytes as effective biological control agents. Analysis using Gas Chromatography-Mass Spectrometry of the fungal extract detected around 100 compounds (secondary metabolites). In addition to gradually reducing the need for chemical fungicides, bio-products can also contribute to sustainable agriculture.