Whatman cellulose filter paper grade 1

Halotolerance of the isolates were estimated by plotting growth curves at differing pH and salt concentrations. International Streptomyces Project media 2 (ISP 2) broths were prepared with three NaCl concentrations (5%, 10% & 20%) and three different pH values (5.0, 7.0 & 9.0). The pH tests were carried out in broths that had 10% NaCl and the halotolerance tests were done at in media at pH 7.0.
Spore suspensions (~10² viable spores) of the strain were inoculated into 9 tubes of each media and incubated in an orbital shaker at 28 °C at 120 rpm. For each strain, 3 tubes of every media were removed for analyses after 7, 14 and 21 days. Each tube represented a replicate (among triplicates) for each strain per condition. The broth was individually filtered through pre-weighed Whatman^® cellulose filter paper (Grade 1). The harvested biomass oven dried at 55 °C for 24 h. Total dry weights of each of the triplicates per condition for each strain were recorded and plotted against time to evaluate tolerance to pH and salt.

The extraction protocol as reported by Kehili and co-workers [15 (link)] was adopted as the conventional method for the extraction of lycopene and β-carotene from tomato pomace. About 5 g of the dried tomato pomace was mixed at 200 rpm in 100 mL of hexane solution overnight at room temperature. The extract was filtered using Whatman cellulose filter paper (Grade 1; pore size = 11 µm) and the collected solid waste was re-extracted twice using 100 mL of fresh hexane under the same conditions. The hexane extract was combined and evaporated using a rotary evaporator at 40 °C. The concentrated carotenoid was dissolved with 2 mL of THF prior to the analysis.