2.1. Sampling and site description

In January 2021, sediment and brine samples were collected from a solar saltern, North Sinai, Egypt (Fig. 1), located at 31^o02′26.5″N33^o21′19.6″E. This solar saltern is in the southern part of the Bardawil lagoon's and it is used for NaCl production from seawater described as Elrawda saltern. Brine samples were taken from 3 to 5 cm below the surface and placed in sterile Pyrex bottles with a capacity of 1000 ml. 500 g of sediment samples were taken from red, pink, or white precipitate and placed in sterile plastic bags before being transported to the lab under cooling condition at −4^oC. They were immediately frozen at − 80 °C upon arrival at Arish University for DNA extraction. Physicochemical characterization of sediments and brines as pH and Electrical Conductivity (EC) were measured in the field by using pH and conductivity probes V. tech, pH/conductivity and temperature meter, Taiwan. The concentration of ions like Ca²⁺, Mg²⁺, Cl ^2- was measured by atomic absorption spectrophotometer, Model Perkin Elmer 2380 Szép et al. (2017 and 2019). The salinity of brines and sediments were determined in the chemistry department, science faculty, Suez Canal University, according to procedures described by Trussell and Fischbach (1989).

Location map of El-Rawda solar saltern, North Sinai, Egypt.