PT  - JOURNAL ARTICLE
AU  - Jinny Wu Yang
AU  - Feng-Hsun Chang
AU  - Yi-Chun Yeh
AU  - An-Yi Tsai
AU  - Kuo-Ping Chiang
AU  - Fuh-Kwo Shiah
AU  - Gwo-Ching Gong
AU  - Chih-hao Hsieh
TI  - Trade-off between competition ability and invulnerability to predation in marine microbes; protist grazing versus viral lysis effects
AID  - 10.1101/2021.10.09.463787
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.10.09.463787
4099  - http://biorxiv.org/content/early/2021/10/09/2021.10.09.463787.short
4100  - http://biorxiv.org/content/early/2021/10/09/2021.10.09.463787.full
AB  - Trade-offs between competition ability and invulnerability to predation are important mechanisms explaining how predation promotes bacterial diversity. However, existence of these trade-offs has apparently not been investigated in natural marine bacterial communities. Here, we address this question with growth-based measurements for each marine bacterial taxon by conducting on-board dilution experiments to manipulate predation pressure and using high-throughput sequencing to assess the response of bacterial communities. We determined that bacterial taxa with a higher predation-free growth rate were accompanied with higher predation-caused mortality, supporting existence of competitiveness-invulnerability trade-off. This trade-off was stronger and more consistent under viral lysis than protist grazing. In addition, predation generally flattened out the rank-abundance distribution and increased the evenness and richness of the bacterial community. These findings supported the “Kill-the-Winner” hypothesis. All experiments supported a significant competitiveness-invulnerability trade-off, but there was substantial variation among bacterial communities in response to predation across experiments conducted in various sites and seasons. Therefore, we inferred that the Kill-the-Winner hypothesis is important but likely not the only deterministic mechanism explaining how predation shapes bacterial assemblages in natural marine systems.Competing Interest StatementThe authors have declared no competing interest.