Metals, sulfur content, and biochemical composition of macrocolonies of Nostoc sp. in different geographical locations in Ecuador

Nostoc sp. is a cyanobacterium identified in several localities of Ecuador, and it exhibits significant potential in the pharmaceutical, food, and environmental sectors, which urges the exploration of its possible applications in the country. Macrocolonies of Nostoc sp. were collected at different seasons, and the content of metals, sulfur, and biochemical composition was analyzed according to altitude and geographic position. The results showed that the average carbohydrate content corresponds to 30.34% dry biomass, 27.38% ash, 25.33% protein, 7.66% crude fiber, and 0.71% fat. Regarding the content of metals and elements, it was found that Aluminum presented the highest value of 2049.23 mg/kg, followed by 1786.74 mg/kg, 1364.08 mg/kg, and 443.12 mg/kg of Fe, Mg, and S, respectively, and with the lowest for Cu, Ni, Pb, and Cd of 7.34 mg/kg, 5.62 mg/kg, 3.99 mg/kg and 0.74 mg/kg; respectively; with the following descending order: Al>Fe>Mg>S>Cu>Ni>Pb>Cd at all sites sampled and regardless of altitude and period of rain or drought. Consequently, its potential to adsorb these elements from the environment is preliminarily demonstrated, showing that it could be used in applications for bioremediation of contaminated soils and waters or be an essential bioindicator of environmental pollution.