Fine Resolution Analysis of bacterial communities associated with Neochloris oleoabundans culture and insights into terpenes as contamination control agents

Abstract

Abstract Biological contamination is one of the main bottlenecks in microalgae production, reducing quality and productivity and sometimes leading to the complete loss of the cultures. Selecting terpenes can be a pathway toward eco-friendly contamination control in microalgae cultures. This work evaluated the presence of bacterial contaminants in N. oleoabundans cultures through HTS and 16S analysis and their susceptibility to six natural terpenes (α-pinene, β-pinene, limonene, trans-cinnamaldehyde, linalool, and eugenol). The principal phyla identified were Proteobacteria, Bacteroidetes, and Actinobacteria, and based on these data, 89 bacterial isolates of seven genera were obtained (36 Aureimonas sp., 27 Microbacterium sp., 5 Pseudomonas sp., 9 Bacillus sp., 14 Shinella sp., 1 Brevundimonas sp., and 1 Exiguobacterium sp.). The minimal inhibitory concentration of terpenes was 6.25 mg L-1, with a reduction in bacterial counts of most isolates by 79% - 99%.