Shedding Light on Microbial Predator–Prey Population Dynamics Using a Quantitative Bioluminescence Assay
- 618 Downloads
This study assessed the dynamics of predation by Bdellovibrio bacteriovorus HD 100. Predation tests with two different bioluminescent strains of Escherichia coli, one expressing a heat-labile bacterial luciferase and the other a heat-stable form, showed near identical losses from both, indicating that protein expression and stability are not responsible for the “shutting-off” of the prey bioluminescence (BL). Furthermore, it was found that the loss in the prey BL was not proportional with the predator-to-prey ratio (PPR), with significantly greater losses seen as this value was increased. This suggests that other factors also play a role in lowering the prey BL. The loss in BL, however, was very consistent within nine independent experiments to the point that we were able to reliably estimate the predator numbers within only 1 h when present at a PPR of 6 or higher, Using a fluorescent prey, we found that premature lysis of the prey occurs at a significant level and was more prominent as the PPR ratio increased. Based upon the supernatant fluorescent signal, even a relatively low PPR of 10–20 led to approximately 5 % of the prey population being prematurely lysed within 1 h, while a PPR of 90 led to nearly 15 % lysis. Consequently, we developed a modified Lotka–Volterra predator–prey model that accounted for this lysis and is able to reliably estimate the prey and bdelloplast populations for a wide range of PPRs.
KeywordsPrey Population Cyan Fluorescent Protein Prey Concentration Luciferase Protein Prey Cell
This work was supported by the Creativity and Innovation Project as funded by the Ulsan National Institute of Science and Technology (UNIST) (Grant #1.120051.01) and by the National Research Foundation of Korea through the Ministry of Education, Science and Technology (Grant 2011–0000886).
- 1.Davidov Y, Jurkevitch E (2004) Diversity and evolution of Bdellovibrio-and-like organisms (BALOs), reclassification of Bacteriovorax starrii as Peredibacter starrii gen. nov., comb. nov., and description of the Bacteriovorax–Peredibacter clade as Bacteriovoracaceae fam. nov. Int J Syst Evol Microbiol 54(Pt 5):1439–1452. doi: 10.1099/ijs.0.02978-0 CrossRefPubMedGoogle Scholar
- 2.Baer ML, Ravel J, Chun J, Hill RT, Williams HN (2000) A proposal for the reclassification of Bdellovibrio stolpii and Bdellovibrio starrii into a new genus, Bacteriovorax gen. nov. as Bacteriovorax stolpii comb. nov. and Bacteriovorax starrii comb. nov., respectively. Int J Syst Evol Microbiol 50(Pt 1):219–224CrossRefPubMedGoogle Scholar
- 9.Paver SF, Hayek KR, Gano KA, Fagen JR, Brown CT, Davis-Richardson AG, Crabb DB, Rosario-Passapera R, Giongo A, Triplett EW, Kent AD (2013) Interactions between specific phytoplankton and bacteria affect lake bacterial community succession. Environ Microbiol. doi: 10.1111/1462-2920.12131 PubMedGoogle Scholar
- 10.Van Essche M, Sliepen I, Loozen G, Van Eldere J, Quirynen M, Davidov Y, Jurkevitch E, Boon N, Teughels W (2009) Development and performance of a quantitative PCR for the enumeration of Bdellovibrionaceae. Environ Microbiol Rep 1(4):228–233. doi: 10.1111/j.1758-2229.2009.00034.x CrossRefPubMedGoogle Scholar
- 12.Iebba V, Santangelo F, Totino V, Nicoletti M, Gagliardi A, De Biase RV, Cucchiara S, Nencioni L, Conte MP, Schippa S (2013) Higher prevalence and abundance of Bdellovibrio bacteriovorus in the human gut of healthy subjects. PloS One 8(4):e61608. doi: 10.1371/journal.pone.0061608 PubMedCentralCrossRefPubMedGoogle Scholar
- 18.Atterbury RJ, Hobley L, Till R, Lambert C, Capeness MJ, Lerner TR, Fenton AK, Barrow P, Sockett RE (2011) Effects of orally administered Bdellovibrio bacteriovorus on the well-being and Salmonella colonization of young chicks. Appl Environ Microbiol 77(16):5794–5803. doi: 10.1128/Aem.00426-11 PubMedCentralCrossRefPubMedGoogle Scholar
- 20.Rendulic S, Jagtap P, Rosinus A, Eppinger M, Baar C, Lanz C, Keller H, Lambert C, Evans KJ, Goesmann A, Meyer F, Sockett RE, Schuster SC (2004) A predator unmasked: life cycle of Bdellovibrio bacteriovorus from a genomic perspective. Science 303(5658):689–692. doi: 10.1126/science.1093027 CrossRefPubMedGoogle Scholar
- 22.Lerner TR, Lovering AL, Bui NK, Uchida K, Aizawa S, Vollmer W, Sockett RE (2012) Specialized peptidoglycan hydrolases sculpt the intra-bacterial niche of predatory Bdellovibrio and increase population fitness. PLoS Pathog 8(2):e1002524. doi: 10.1371/journal.ppat.1002524 PubMedCentralCrossRefPubMedGoogle Scholar
- 36.Mitchell RJ, Hong HN, Gu MB (2006) Induction of kanamycin resistance gene of plasmid pUCD615 by benzoic acid and phenols. J Microbiol Biotech 16(7):1125–1131Google Scholar
- 38.Mitchell RJ, Ahn JM, Gu MB (2005) Comparison of Photorhabdus luminescens and Vibrio fischeri lux fusions to study gene expression patterns. J Microbiol Biotech 15(1):48–54Google Scholar
- 44.Fenton AK, Kanna M, Woods RD, Aizawa SI, Sockett RE (2010) Shadowing the actions of a predator: backlit fluorescent microscopy reveals synchronous nonbinary septation of predatory Bdellovibrio inside prey and exit through discrete bdelloplast pores. J Bacteriol 192(24):6329–6335. doi: 10.1128/JB.00914-10 PubMedCentralCrossRefPubMedGoogle Scholar