Association of Vampirovibrio chlorellavorus with decline and death of Chlorella sorokiniana in outdoor reactors
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The outdoor ARID raceway was established for optimizing the cultivation of microalgae for biofuel production. During the summers of 2014 and 2015, discoloration was observed in cultures of Chlorella sorokiniana (DOE1412), which shifted from a vibrant green color to yellow, followed by cell clumping, decline in density, and rapid death, resulting in 40–60% reduced biomass production. Total DNA was purified from the raceway samples and subjected to polymerase chain reaction (PCR) amplification using degenerate primers that amplify the 16S rRNA gene of eubacteria. BLASTn analysis of the cloned amplicon sequences revealed the presence of the Gram-negative, predatory bacterium, Vampirovibrio chlorellavorus. Scanning electron microscopic examination showed an abundance of coccoid cells, 0.3–0.6 μm in diameter, some of which were attached to C. sorokiniana cells. PCR amplification indicated the presence of V. chlorellavorus in raceway vessels, water lines, connective tubing, and in early, scaled-up DOE1412 cultures used to inoculate the raceway. Based on PCR detection, the decontamination of the equipment and water line with “Wal-Clean” more effectively eliminated V. chlorellavorus and delayed the onset of attack, compared to the chlorine disinfectant, trichloromelamine (TCM). Total DNA was isolated from soil samples collected monthly from the nearby Rillito River during 2014–2015 and subjected to PCR amplification using primers designed to amplify the 16S rRNA and 18S rRNA gene of V. chlorellavorus and C. sorokiniana, respectively. Results indicated that V. chlorellavorus and Chlorella spp. were present in most of the riverbed samples nearly year round, suggesting a possible naturally occurring reservoir of the predatory bacterium.
KeywordsChlorophyta Cyanobacteria DOE1412 Molecular detection Polymerase chain reaction
The authors thank Dr. Juergen Polle at the City University of New York, Brooklyn for providing the DOE1412 culture. We also thank the UA-ARID reactor cultivation and biology team members who provided outstanding support and enabled this research to be carried out.
This project was funded by the USDOE Office of Biomass Program, DE-EE0003046, as part of the National Alliance for Advanced Biofuels and Bioproducts or NAABB consortium, and recently, by the DOE RAFT Project DE-EE0006269.
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Conflict of interest
The authors declare that they have no conflict of interest.
- Das KC, Paul SS, Sahoo L, Baruah KK, Subudhi PK, Ltu K, Rajkhowa C (2014) Bacterial diversity in the rumen of mithun (Bos frontalis) fed on mixed tree leaves and rice straw based diet. Afr J Microbiol Res 8(13):8Google Scholar
- Doyle JJ, Doyle JL (1987) A rapid DNA isolation procedure for small quantities of fresh leaf tissue. Phytochem Bull 19:11–15Google Scholar
- Ganuza E, Sellers CE, Bennett BW, Lyons EM, Carney LT (2016) A novel treatment protects Chlorella at commercial scale from the predatory bacterium Vampirovibrio chlorellavorus. Front Microbiol 7:848Google Scholar
- Gromov BV, Mamkaeva KA (1972) Electron microscopic study of parasitism by Bdellovibrio chlorellavorus bacteria on cells of the green alga Chlorella vulgaris. Tsitologiia 14:256–260Google Scholar
- Gromov BV, Mamkaeva KA (1980) New genus of bacteria, Vampirovibrio, parasitizing chlorella and previously assigned to the genus Bdellovibrio. Mikrobiologiia 49:165–167Google Scholar
- Gromov BV, Pljusch AV, Mamkaeva KA (1999) Cultures of Rhizophydium spp. (Chytridiales)—parasites of chlorococcalean algae. Arch Hydrobiol Suppl Algol Stud 130:115–123Google Scholar
- Guglielmini J, de la Cruz F, Rocha EP (2013) Evolution of conjugation and type IV secretion systems. Mol Biol Evol 30:315–331Google Scholar
- Holzinger A, Karsten U (2013) Desiccation stress and tolerance in green algae: consequences for ultrastructure, physiological and molecular mechanisms. Front Plant Sci 4:327Google Scholar
- Ibelings BW, De Bruin A, Kagami M, Rijkeboer M, Brehm M, van Donk E (2004) Host parasite interactions between freshwater phytoplankton and chytrid fungi (Chytridiomycota). J Phycol 40:437–453Google Scholar
- Li X (2015) Effect of temperature and salt on laboratory growth of Vampirovibrio chlorellavorus and killing of a cultivated Chlorella host. University of Arizona, ThesisGoogle Scholar
- Sheehan J, Dunahay T, Benemann J, Roessler P (1998) A look back at the U.S. Department of Energy’s aquatic species program—biodiesel from algae. National Renewable Energy Laboratory, Golden, Colorado. Report NREL/TP-580-24190, pp 1-328Google Scholar
- Soo RM, Woodcroft BJ, Parks DH, Tyson GW, Hugenholtz P (2015) Back from the dead; the curious tale of the predatory cyanobacterium Vampirovibrio chlorellavorus. PeerJ 3:e968Google Scholar
- Tadayon S, Geological S, Pima C (1995) Quality of surface water and ground water in the proposed artificial-recharge project area, Rillito Creek Basin, Tucson, Arizona, 1994. Water-Resources Investigations Report 95–4270, U.S. Geological Survey, Tucson, ArizonaGoogle Scholar
- Wigmosta MS, Coleman AM, Skaggs RJ, Huesemann MH, Lane LJ (2011) National microalgae biofuel production potential and resource demand. Water Resour Res 47:WH00H04Google Scholar