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Environmentally friendly natural dyes have gained popularity recently because synthetic dyes have negative health effects. Through preliminary phytochemical screening, the work examined the dyeing potential of primary and secondary metabolites of Tunisian lichens. In most of the lichen extracts examined, significant tannins, proteins, carbohydrates, and steroids were present. The dyeing potential was determined by ammonia fermentation (AFM) and boiling water (BWM) methods on wool and fabric. The dyes degraded when exposed to light and heat. Alum, copper sulfate, and iron sulfate were used for the mordanting process. The studied lichen species generated a variety of hues using both techniques, including brown, caramel, purple, olive, green, and yellow. Both approaches revealed a wide variety of colors in all species. On both fabrics, the coloring patterns were depicted. Brighter colors were created by AFM than by BWM. But using BWM, Xanthoria parietinaproduced stunning purple dyes for textiles. Fabrics that have been mordanted had better sunshine colorfastness. The color shading was finest with an alum mordant. Using an Android application colorimeter, the dyed materials were assessed using CIE Lab* Chroma, Hue, and standard procedures following international standards. There is an alternative to traditional instruments in the form of this smartphone app. Most dyed textiles had very good to exceptional color fastness. In conclusion, phytochemical analysis of Tunisian lichens revealed their potential as suppliers of natural colors that are friendly to the environment.

Air pollution in urban areas is a major problem for human health and the environment. The aim of this study was to monitor air quality in the Tunis metropolitan area using the lichen Flavoparmelia caperataas a transplant bioindicator. Lichen samples were transplanted for 5 months at two polluted urban sites (INAT and FST) and one rural control site (Oued Zeen). Markers of oxidative stress (levels of malondialdehyde MDA), total proteins, PTEs content (Pb, Al, Fe, etc.), and chlorophyll pigments were analyzed. The results showed a significantly higher accumulation of PTEs, increased levels of MDA indicating greater oxidative stress, and a decrease in chlorophyll aand blevels in lichens transplanted to urban sites compared with rural sites. These results demonstrate the toxic impact of atmospheric pollution on the physiology of lichens in an urban environment. This study highlights the potential of F. caperataas an effective bioindicator for monitoring air quality. Monitoring the physiological responses of this self-limiting organism seems relevant for the biomonitoring of air pollution in Tunisia.

In this study, peanut shell-derived activated carbon, produced by orthophosphoric acid activation, was used as a material to adsorb methylene blue (MB). An optimization process was conducted to determine the optimal values for the adsorption parameters, including adsorbent dosage, temperature, pH, and contact duration. The outcomes of experiments were analyzed using four adsorption isotherms, while the pseudo-first and second-order models were deployed for assessing the kinetics. The adsorption of MB achieved equilibrium after 120 min, following the pseudo-second-order kinetic model. The Langmuir model accurately represented the sorption process and achieved a maximum amount adsorbed of 219.7 mg/g at 25 °C. The thermodynamic variables (ΔH0, ΔG0, and ΔS0) were calculated by investigating the impact of temperature, revealing that the adsorption was both exothermic and spontaneous. Carbon functionalization with Fe3+or Ca2+ions enhances the adsorption capacity and expedites the adsorption process, with equilibrium being achieved in 70 min and 50 min, respectively.

This study focused on the diversity of lichens present in selected regions of northern Tunisia and assessed their resistance to atmospheric pollution. Twenty-five species of lichen were identified, divided into 13 families and 17 different genera. The results show that the Cladoniaceaeand Parmeliaceaefamilies predominate. Foliose and complex lichens are the most abundant. The main objective of this study was to examine, via atomic absorption spectrometry, the bioaccumulation of heavy metals (lead, zinc, copper, and cadmium) in the lichens Cladonia rangiformis,Flavoparmelia caperata,Parmotrema perlatum, and Evernia prunastri, which were selected due to the presence of similar lichens at the sites. The results showed high accumulations of lead, copper, and zinc at all stations (Nefza, Babouche, Oued Zen) characterized by intense road traffic and/or industrial activity, while cadmium levels were low at all stations. Flavoparmelia caperataproved to be a species tolerant of metal stress, making it a promising candidate for air quality biomonitoring programs aimed at assessing air pollution (17.53 mg/g DW of Pb and 89.8 mg/g DW of Zn in Nefza, and 2.36 mg/g DW of Cd and 10.13 mg/g DW of Cu in Oued Zen). These results highlight the importance of lichens as biological indicators for assessing pollution, the need to carefully monitor heavy metal concentrations in urban environments, and to provide future projects with funding for their potential transplantation to polluted.

AbstractThe present study aims to study the chemical composition of the essential oils from needles of three pine species: Pinus halepensisMill., P. pinasterAiton. and P. pineaL., and the evaluation of their in vitroanti-radical and antibacterial properties. GC-MS analysis showed that the essential oils were characterized by the abundance of monoterpene hydrocarbons (61.55-86.72 %). α-pinene, β-pinene, α-terpinolene, α-fenchene, and β-caryophyllene were the most plentiful components in P. halepensis.Limonene, α-pinene, and β-caryophyllene were particularly abundant in P. pineaand P. pinasteressential oils. The strongest DPPH-radical scavenging activity (IC50= 73.03 μg/mL) was observed for the limonene-rich essential oils of P. pinea. The three essential oils were effective against the Gram+ bacteria Bacillus subtilisand Listeria monocytogenesand the Gram- bacteria Salmonella entericaand Escherichia coli. These results suggest that P. halepensis, P. pinaster, and P. pineacould constitute a consolidated source of natural bioactive ingredients with anti-radical and antimicrobial properties.

AbstractThe composition and antioxidant activity of the essential oil of Carya illinoinensiswere evaluated in this research. The yield of essential oils from three varieties was found to vary from 0.024 to 0.03%. GC-MS analysis of the essential oils resulted in the identification of seventy-four compounds representing over 99.97% of the leaf oil. The three essential oils had different chemotypes. The major components identified were camphor (0.0-44.03% of total essential oil), l-fenchone (0.0-28.85%), cis-carvone oxide (0.0-23.64%), β-elemene (0.0-17.66%), cis-z-α-bisabolene epoxide (0.0-16.76%), aromadendrane (0.0-13.31%), camphene (0.0-11.54%), β-eudesmene (0.0-9.41%) and caryophyllen oxide (0.47-8.98%). The antioxidant activity was tested using 2,2-diphenyl-1 picrylhydrazyl (DPPH). The essential oil showed a weak antioxidant activity. This is the first report on the composition and the antioxidant activity of the essential oil of Carya illinoinensisgrown in Tunisia.

AbstractReaumuria vermiculatais a gypso—halophytic plant belonging to the Tamaricaceae family. The physiological response of this species, expressed by the weight growth, nutritional response and osmotic adjustment, has been studied. Different NaCl concentrations varying from 0 to 700 mM were tested. We demonstrated that Reaumuria vermiculatais a halophyte with growth none significantly affected by 100 and 300 mM salinity concentration. In fact, the total biomass of cultivated plants at 100 and 300 mM represents 78.5 and 70.5% of the control, respectively. Mineral analysis showed a Na+accumulation gradient from the roots toward the aerial organs. Indicative of an osmotic strategy for transporting salt compartmentalizing it in vacuoles. Furthermore the proline content regularly increased at medium salinity. Varying from 60 μM.g−1dry weight in the control aerial organs up to 220 μM.g−1dry weight at 700 mM NaCl.

AbstractThe study of NaCl effects on wheat and triticale showed an increase in root biomass from the lowest dose (50 mM) in the two cereals and maintenance of shoot growth even at the highest concentration (200 mM). However, triticale shoot growth was decreased by 25% at 200 mM NaCl. Wheat absorbed and exported more Na+ ions to its shoots than triticale. The latter accumulated the majority of the absorbed sodium within its roots. In addition, triticale seems to be more selective towards K+ions since it limited Na+uptake and transport to shoots and ensured better K+nutrition. The measurements of root respiration intensity in seedlings grown under saline (100 mM NaCl) and non saline (0 mM NaCl) conditions showed that in salt—treated wheat plants, respiration displayed no change, whereas in those of triticale, it was enhanced by 27% as compared to the control. This stimulation could be related to K/Na selectivity.