The productivity of algal biofuels is dependent on two factors: 1) biochemical composition of biomass and 2) culture resilience. When algae are grown in open pond settings, biological contamination causes an estimated 30% algae crop loss. Therefore, new crop protection strategies are needed to produce reliable, high-yield algal biomass. Our project called Development of Integrated Screening, Cultivar Optimization, and Verification (DISCOVR) seeks to develop optimal cultivation strategies for algal strains whose cellular composition is suitable for biofuels and bioproducts. Our research is focused on studying the natural assemblage of a symbiotic bacterial communities (bacteriome) with algae and understanding how microbes can increase crop protection and culture stability. To understand how pathogen responses could inform algal pond productivities, we identified a highly virulent pathogen for Picochlorum celeri and Tetraselmis striata and tested bacterial isolates using a high throughput algae lawn assay that demonstrates microbial pathogenic, commensal, or probiotic responses. Leo2 bacteriophage treatments were utilized as a countermeasure to prevent complete killing of P.celeri. However, our results indicated that the phage treatment does not fully alleviate the pathogen killing. We also identified numerous bacterial species from healthy and crash ponds that provide evidence for designing countermeasures against pond crashes. Future experiments will test effectiveness of countermeasures at scale in open ponds to understand and demonstrate improved cultivation strategies for algal biofuel feedstocks.

Sandia National Laboratories is a multimission laboratory managed and operated by NTESS, for DOE-NNSA under contract DE-NA0003525.