*2.6. Microbiological Assays*

All prototypes were subjected to a microbiological control to evaluate the potential presence of *Enterobacteriaceae*. All prototypes were free of microbial contaminant such as coliforms, *Salmonella* and *Shigella*.

#### **3. Materials and Methods**

#### *3.1. Strains and Culture Conditions of Cyanobacteria*

Diazotrophic cyanobacteria *Nostoc* sp. Llayta (LLC-10) and *Nostoc* sp. Caquena (CAQ-15), were isolated from wetlands at the XV Region in northern Chile. The strains were cultured in an Arnon liquid medium [62] without additions of combined nitrogen at 30 ◦C under continuous white fluorescent light irradiation (180 μE m<sup>−</sup><sup>2</sup> s<sup>−</sup>1) and continuous aeration with air enriched with 1% (v/v) CO2. Cultures were harvested by centrifugation (10 min; 6000 rpm, rotor Sorvall SS-34) at the exponential phase of growth (15 days). The liquid cultures rendered approximately 1.0 g of wet weight per 160 mL of culture.
