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

Abstract

Biological contamination is one of the main bottlenecks in the production of microalgae, reducing quality and productivity, sometimes leading to complete loss of the cultures. This work evaluated the presence of bacterial contaminants in N. oleoabundans cultures through HTS and 16S analysis and their susceptibility to 6 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. mL− 1, with a reduction in bacterial counts of most isolates by 79% − 99%. The use of selected terpenes can be a pathway towards eco-friendly contamination control in microalgae cultures.