Filamentous microalgae from genus Tribonema are promising sustainable sources of omega-7 palmitoleic acid, but their ability to accumulate this compound varies among species and depends on the initial nitrogen concentration (INC) supply. In this study, the palmitoleic acid accumulation capacities of five Tribonema species were examined under three different INCs to select the alga species with the highest production. Results showed that a high INC was associated with increased palmitoleic acid accumulation but led to decreased biomass concentration in all tested species. In particular, T. minus grown at 18 mmol L?1 INC had the highest pal- mitoleic acid content (20.72％ of dry weight) and productivity (90.88 mg L?1 d?1). The combination of alkali metal freezing precipitation (AMFP) and urea complexation successfully isolated and enriched palmitoleic acid from T. minus and obtained a purity of 80.11％ and a yield of 7.39 g (100 g)?1 of algal powder. The compound was identified as (9Z)-hexadecenoic acid (C16:1 ω-7). Antibacterial activity evaluation for the highly concentrated palmitoleic acid (10 mg mL?1) against Streptococcus agalactiae revealed the formation of a 12.10 mm-diameter inhibition zone and the minimum inhibitory concentration of 31.25 μg mL?1, indicating that palmitoleic acid is an effective antibacterial agent. This study is the first to report that palmitoleic acid derived from T. minus can antagonize S. agalactiae, which further broadens the potential application of Tribonema biomass in green aquaculture.

WANG Feifei;GUO Yuhao;CAO Yan;ZHANG Chengwu

School of Modern Industry for Selenium Science and Engineering,Wuhan Polytechnic University,Wuhan 430023,China;School of Food Science and Pharmaceutical Engineering,Nanjing Normal University,Nanjing 210023,China;Engineering Research Center of Tropical and Subtropical Aquatic Ecological Engineering,Ministry of Education,Guangzhou 510632,China;Department of Ecology and Research Center for Hydrobiology,Jinan University,Guangzhou 510632,China

中国海洋大学学报（自然科学英文版）

[1]WANG Feifei;GUO Yuhao;CAO Yan;ZHANG Chengwu-.In vitro Antibacterial Activity of Palmitoleic Acid Isolated from Filamentous Microalga Tribonema minus Against Fish Pathogen Streptococcus agalactiae)[J].中国海洋大学学报（自然科学英文版）,2022(06):1615-1621

Palmitoleic,Filamentous,Microalga,Tribonema,palmitoleic,INCs,mitoleic,AMFP,hexadecenoic

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