The induction of biofilm formation has been explored as a means of harvesting microalgae for bioprocessing applications. Environmental stressors have been implicated in the induction of biofilm formation; however, it is unclear whether all stressors, or a select few, are responsible. This study aimed to investigate the effects of three stressors, nitrogen depletion, reduced or elongated day lengths, and increased culture turbulence on bio-film formation of Parachlorella kessleri . We also examined corresponding effects on growth and production of reactive oxygen species. Turbulence induced the greatest response in which a significant decrease in growth plus an increase in superoxide production and flocculation efficiency were seen for the 300-rpm treatment. For varying day lengths, stress response was not observed, however, a significant increase in EPS secretion was measured in both shorter and longer days. Nitrogen depletion induced a low-level stress response, in which superoxide production increased for the highest concentrations, while growth was not impacted. In contrast to previous studies on nitrogen depletion, a significant increase in EPS secretion was not observed. Results indicate that stress response varies according to type and magnitude. EPS production and thus biofilm formation are not linked to the stress indicators investigated. P. kessleri uses small quantities of EPS to contribute to cell stickiness, but not necessarily to the full formation of a biofilm; however, cell stickiness served as a mechanism for substrate adherence and cellular aggregation none the less.
Di Pippo, F.D., Ellwood, N.T.W., Guzzon, A., Bohn, A. and Congestri, R. (2014) Diversity and Biomass Accumulation in Cultured Phototrophic Biofilms. European Journal of Phycology, 49, 384-394. https://doi.org/10.1080/09670262.2014.948075
Schnurr, P.J. and Allen, D.G. (2015) Factors Affecting Algae Biofilm Growth and Lipid Production: A Review. Renewable & Sustainable Energy Reviews, 52, 418-429. https://doi.org/10.1016/j.rser.2015.07.090
Di Pippo, F.D., Bohn, A., Congestri, R., Philippis, R.D. and Albertano, P. (2009) Capsular Polysaccharides of Cultured Phototrophic Biofilms. Biofouling, 25, 495-504. https://doi.org/10.1080/08927010902914037
Sutherland, I.W. (2001) The Biofilm Matrix—An Immobilized But Dynamic Microbial Environment. Trends in Microbiology, 9, 222-227. https://doi.org/10.1016/S0966-842X(01)02012-1
Flemming, H.-C. and Wingender, J. (2010) The Biofilm Matrix. Nature Reviews Microbiology, 8, 623-633. https://doi.org/10.1038/nrmicro2415
Yang, Z., Liu, Y., Ge, J., Wang, W., Chen, Y. and Montagnes, D. (2010) Aggregate Formation and Polysaccharide Content of Chlorella pyrenoidosa Chick (Chlorophyta) in Response to Simulated Nutrient Stress. Bioresource Technology, 101, 8336-8341. https://doi.org/10.1016/j.biortech.2010.06.022
Rossi, F. and De Philippis, R. (2015) Role of Cyanobacterial Exopolysaccharides in Phototrophic Biofilms and in Complex Microbial Mats. Life, 5, 1218-1238. https://doi.org/10.3390/life5021218
Raposo, M.F., de Morais, R.M.S.C. and Bernardo de Morais, A.M.M. (2013) Bioactivity and Applications of Sulphated Polysaccharides from Marine Microalgae. Marine Drugs, 11, 233-252. https://doi.org/10.3390/md11010233
Di Pippo, F.D., Ellwood, N.T.W., Guzzon, A., Siliato, L., Micheletti, E., Philippis, R.D. and Albertano, P.B. (2012) Effect of Light and Temperature on Biomass, Photosynthesis and Capsular Polysaccharides in Cultured Phototrophic Biofilms. Journal of Applied Phycology, 24, 211-220. https://doi.org/10.1007/s10811-011-9669-0
del Hoyo, A., álvarez, R., Campo, D., Gasulla, E.M.F., Barreno, E. and Casano, L.M. (2011) Oxidative Stress Induces Distinct Physiological Responses in the Two Trebouxia Phycobionts of the Lichen Ramalina farinacea. Annals of Botany, 107, 109-118. https://doi.org/10.1093/aob/mcq206
Mallick, N. and Mohn, F.H. (2000) Reactive Oxygen Species: Response of Algal Cells. Journal of Plant Physiology, 157, 183-193. https://doi.org/10.1016/S0176-1617(00)80189-3
Cirulis, J.T., Scott, J.A. and Ross, G.M. (2013) Management of Oxidative Stress by Microalgae. Canadian Journal of Physiology and Pharmacology, 91, 15-21. https://doi.org/10.1139/cjpp-2012-0249
Rioboo, C., O’Connor, J.E., Prado, R., Herrero, C. and Cid, á. (2009) Cell Proliferation Alterations in Chlorella Cells under Stress Conditions. Aquatic Toxicology, 94, 229-237. https://doi.org/10.1016/j.aquatox.2009.07.009
Ito, T., Tanaka, M., Shinkawa, H., Nakada, T., Ano, Y., Kurano, N., Soga, T. and Tomita, M. (2013) Metabolic and Morphological Changes of an Oil Accumulating Trebouxiophycean Alga in Nitrogen-Deficient Conditions. Metabolomics, 9, 178-187. https://doi.org/10.1007/s11306-012-0463-z
Sekar, R., Nair, K.V.K., Rao, V.N.R. and Venugopalan, V.P. (2002) Nutrient Dynamics and Successional Changes in a Lentic Freshwater Biofilm. Freshwater Biology, 47, 1893-1907. https://doi.org/10.1046/j.1365-2427.2002.00936.x
Mishra, A. and Jha, B. (2009) Isolation and Characterization of Extracellular Polymeric Substances from Micro-Algae Dunaliellasalina under Salt Stress. Bioresource Technology, 100, 3382-3386. https://doi.org/10.1016/j.biortech.2009.02.006
Holzinger, A. and Karsten, U. (2013) Desiccation Stress and Tolerance in Green Algae: Consequences for Ultrastructure, Physiological and Molecular Mechanisms. Frontiers in Plant Science, 4, 327. https://doi.org/10.3389/fpls.2013.00327
Kiorboe, T., Andersen, K.P. and Dam, H.G. (1990) Coagulation Efficiency and Aggregate Formation in Marine Phytoplankton. Marine Biology, 107, 235-245. https://doi.org/10.1007/BF01319822
Cheng, Y.-S., Zheng, Y., Labavitch, J.M. and VanderGheynst, J.S. (2011) The Impact of Cell Wall Carbohydrate Composition on the Chitosan Flocculation of Chlorella. Process Biochemistry, 46, 1927-1933. https://doi.org/10.1016/j.procbio.2011.06.021
Philippis, R.D., Sili, C. and Vincenzini, M. (1996) Response of an Exopolysaccharide-Producing Heterocystous Cyanobacterium to Changes in Metabolic Carbon Flux. Journal of Applied Phycology, 8, 275-281. https://doi.org/10.1007/BF02178570
Gasljevic, K., Hall, K., Chapman, D. and Matthys, E.F. (2008) Drag-Reducing Polysaccharides from Marine Microalgae: Species Productivity and Drag Reduction Effectiveness. Journal of Applied Phycology, 20, 299-310. https://doi.org/10.1007/s10811-007-9250-z
Stal, L.J. (2010) Microphytobenthos as a Biogeomorphological Force in Intertidal Sediment Stabilization. Ecological Engineering, 36, 236-245. https://doi.org/10.1016/j.ecoleng.2008.12.032
Oliver, D.J. and Zelitch, I. (1977) Increasing Photosynthesis by Inhibiting Photorespiration with Glyoxylate. Science, 196, 1450-1451. https://doi.org/10.1126/science.867040
Barros, M.P., Pinto, E., Sigaud-Kutner, T.C., Cardozo, K.H., et al. (2005) Rhythmicity and Oxidative/Nitrosative Stress in Algae. Biological Rhythm Research, 36, 67-82. https://doi.org/10.1080/09291010400028666
Hama, T., Matsunaga, K., Handa, N. and Takahashi, M. (1988) Day-Night Changes in Production of Carbohydrate and Protein by Natural Phytoplankton Population from Lake Biwa, Japan. Journal of Plankton Research, 10, 941-955. https://doi.org/10.1093/plankt/10.5.941
Seyfabadi, J., Ramezanpour, Z. and Khoeyi, Z.A. (2011) Protein, Fatty Acid, and Pigment Content of Chlorella vulgaris under Different Light Regimes. Journal of Applied Phycology, 23, 721-726. https://doi.org/10.1007/s10811-010-9569-8
Grobbelaar, J.U. (1994) Turbulence in Mass Algal Cultures and the Role of Light/Dark Fluctuations. Journal of Applied Phycology, 6, 331-335. https://doi.org/10.1007/BF02181947
Barbosa, M.J., Albrecht, M. and Wijffels, R.H. (2003) Hydrodynamic Stress and Lethal Events in Sparged Microalgae Cultures. Biotechnology and Bioengineering, 83, 112-120. https://doi.org/10.1002/bit.10657
Leupold, M., Hindersin, S., Gust, G., Kerner, M. and Hanelt, D. (2013) Influence of Mixing and Shear Stress on Chlorella vulgaris, Scenedesmus obliquus, and Chlamydomonas reinhardtii. Journal of Applied Phycology, 25, 485-495. https://doi.org/10.1007/s10811-012-9882-5
Mitsuhashi, S., Hosaka, K., Tomonaga, E., Muramatsu, H. and Tanishita, K. (1995) Effects of Shear Flow on Photosynthesis in a Dilute Suspension of Microalgae. Applied Microbiology and Biotechnology, 42, 744-749. https://doi.org/10.1007/BF00171956
Hondzo, M. and Lyn, D. (1999) Quantified Small-Scale Turbulence Inhibits the Growth of a Green Alga. Freshwater Biology, 41, 51-61. https://doi.org/10.1046/j.1365-2427.1999.00389.x
Rodríguez, J.J.G., Mirón, A.S., Camacho, F.G., García, M.C.C., Belarbi, E.H., Chisti, Y. and Grima, E.M. (2009) Causes of Shear Sensitivity of the Toxic Dinoflagellate Protoceratium reticulatum. Biotechnology Progress, 25, 792-800. https://doi.org/10.1002/btpr.161
Jenkinson, I.R. and Sun, J. (2014) Drag Increase and Drag Reduction Found in Phytoplankton and Bacterial Cultures in Laminar Flow: Are Cell Surfaces and EPS Producing Rheological Thickening and a Lotus-Leaf Effect? Deep-Sea Research Part II: Topical Studies in Oceanography, 101, 216-230. https://doi.org/10.1016/j.dsr2.2013.05.028
Scoma, A., Giannelli, L., Faraloni, C. and Torzillo, G. (2012) Outdoor H2 Production in a 50-L Tubular Photobioreactor by Means of a Sulfur-Deprived Culture of the Microalga Chlamydomonas reinhardtii. Journal of Biotechnology, 157, 620-627. https://doi.org/10.1016/j.jbiotec.2011.06.040
Oh, H.M., Lee, S., Park, M.H., Kim, H.S., Kim, H.C., Yoon, J.H., Kwon, G.S. and Yoon, B.D. (2001) Harvesting of Chlorella vulgaris Using a Bioflocculant from Paenibacillus sp. AM49. Biotechnology Letters, 23, 1229-1234. https://doi.org/10.1023/A:1010577319771
Hückelhoven, R., Fodor, J., Trujillo, M. and Kogel, K.-H. (2000) Barley Mla and Rar Mutants Compromised in the Hypersensitive Cell Death Response against Blumeria graminis f. sp. Hordei Are Modified in Their Ability to Accumulate Reactive Oxygen Intermediates at Sites of Fungal Invasion. Planta, 212, 16-24. https://doi.org/10.1007/s004250000385
Li, L., Zhao, J. and Tang, X. (2010) Ultraviolet Irradiation Induced Oxidative Stress and Response of Antioxidant System in an Intertidal Macroalgae Corallina officinalis. Journal of Environmental Sciences, 22, 716-722. https://doi.org/10.1016/S1001-0742(09)60168-6
DuBois, M., Gilles, K.A., Hamilton, J.K., Rebers, P.A. and Smith, F. (1956) Colorimetric Method for Determination of Sugars and Related Substances. Analytical Chemistry, 28, 350-356. https://doi.org/10.1021/ac60111a017
Grossart, H.-P. and Simon, M. (1998) Significance of Limnetic Organic Aggregates (Lake Snow) for the Sinking Flux of Particulate Organic Matter in a Large Lake. Aquatic Microbial Ecology, 15, 115-125. https://doi.org/10.3354/ame015115
Arad, S., Lerental, Y. and Dubinsky, O. (1992) Effect of Nitrate and Sulfate Starvation on Polysaccharide Formation in Rhodella Reticulata. Bioresource Technology, 42, 141-148. https://doi.org/10.1016/0960-8524(92)90073-7
Bergman, B. (1980) Stimulation of Nitrogenase Activity and Photo-synthesis in Some Cyanobacteria by Glyoxylate. Physiologia Plantarum, 49, 398-404. https://doi.org/10.1111/j.1399-3054.1980.tb03324.x
Menon, K.R., Balan, R. and Suraishkumar, G.K. (2013) Stress Induced Lipid Production in Chlorella vulgaris: Relationship with Specific Intracellular Reactive Species Levels. Biotechnology and Bioengineering, 110, 1627-1636. https://doi.org/10.1002/bit.24835
Domozych, D.S., Kort, S., Benton, S. and Yu, T. (2005) The Extracellular Polymeric Substance of the Green Alga Penium margaritaceum and Its Role in Biofilm Formation. Biofilms, 2, 129-144. https://doi.org/10.1017/S147905050500181X
Litchman, E., Steiner, D. and Bossard, P. (2003) Photosynthetic and Growth Responses of Three Freshwater Algae to Phosphorus Limitation and Daylength. Freshwater Biology, 48, 2141-2148. https://doi.org/10.1046/j.1365-2427.2003.01157.x
Krzeminska, I., Pawlik-Skowronska, B., Trzcinska, M. and Tys, J. (2014) Influence of Photoperiods on the Growth Rate and Biomass Productivity of Green Microalgae. Bioprocess and Biosystems Engineering, 37, 735-741. https://doi.org/10.1007/s00449-013-1044-x
Hastings, J., Rusak, B. and Boulos, Z. (1991) Circadian Rhythms: The Physiology of Biological Timing. In: Neural Integr. Anim. Physiol., Wiley-Liss, Hoboken, 435-546.
Wolfstein, K. and Stal, L.J. (2002) Production of Extracellular Polymeric Substances (EPS) by Benthic Diatoms: Effect of Irradiance and Temperature. Marine Ecology Progress Series, 236, 13-22. https://doi.org/10.3354/meps236013
Hosaka, K., Hioki, T., Furuune, H. and Tanishita, K. (1995) Augmentation of Microalgae Growth Due to Hydrodynamic Activation. Energy Conversion and Management, 36, 725-728. https://doi.org/10.1016/0196-8904(95)00107-O
Thomas, W.H. and Gibson, C.H. (1990) Effects of Small-Scale Turbulence on Microalgae. Journal of Applied Phycology, 2, 71-77. https://doi.org/10.1007/BF02179771
Johnson, M.B. and Wen, Z. (2010) Development of an Attached Microalgal Growth System for Biofuel Production. Applied Microbiology and Biotechnology, 85, 525-534. https://doi.org/10.1007/s00253-009-2133-2
Dayananda, C., Sarada, R., Usha Rani, M., Shamala, T.R. and Ravishankar, G.A. (2007) Autotrophic Cultivation of Botryococcus braunii for the Production of Hydrocarbons and Exopolysaccharides in Various Media. Biomass Bioenergy, 31, 87-93. https://doi.org/10.1016/j.biombioe.2006.05.001
Córdoba-Castro, N.M., Montenegro-Jaramillo, A.M., Prieto, R.E. and González Marino, G.E. (2012) Analysis of the Effect of the Interactions among Three Processing Variables for the Production of Exopolysaccharides in the Microalgae Scenedesmus obliquus (UTEX 393). Vitae, 19, 60-69.