Growth Characteristics of a Desmodesmus Species from the San Antonio Springs and Its Short-Term Impact on Soil Microbial Dynamics

A new <i>Desmodesmus</i> species was isolated from the largest of the San Antonio Springs, the Blue Hole, in San Antonio, Texas, and characterized for its potential applications in sustainable agriculture. The xenic isolate (<i>XB</i>) was established by enrichment and subcultured to produce the axenic isolate (<i>AxB</i>), which was identified based on morphological features and DNA profiling, confirming its close phylogenetic relationship with <i>Desmodesmus</i> spp. Growth characteristics, biomass composition, and pigment profiles were assessed for both the xenic and axenic isolates along with their growth in saline conditions and a range of seasonal Texas temperatures. Both <i>Desmodesmus XB</i> and <i>Desmodesmus AxB</i> exhibited optimal growth at 25 °C as well as robust growth at 37 °C and in weakly saline media (5 g/kg NaCl). Biomass analysis revealed levels of carbohydrates, proteins, lipids, chlorophylls, and carotenoids comparable to other desmids and pigment profiles supported the <i>Desmodesmus</i> classification. Soil studies demonstrated the persistence of <i>Desmodesmus XB</i> and influence on microbial activity, indicating the potential of this isolate for agricultural applications such as soil remediation.