title: Inquisition of Microcystis aeruginosa and Synechocystis nanowires: characterization and modelling.
abstract: Identification of extracellular conductive pilus-like structures (PLS) i.e. microbial nanowires has spurred great interest among scientists due to their potential applications in the fields of biogeochemistry, bioelectronics, bioremediation etc. Using conductive atomic force microscopy, we identified microbial nanowires in Microcystis aeruginosa PCC 7806 which is an aerobic, photosynthetic microorganism. We also confirmed the earlier finding that Synechocystis sp. PCC 6803 produces microbial nanowires. In contrast to the use of highly instrumented continuous flow reactors for Synechocystis reported earlier, we identified simple and optimum culture conditions which allow increased production of nanowires in both test cyanobacteria. Production of these nanowires in Synechocystis and Microcystis were found to be sensitive to the availability of carbon source and light intensity. These structures seem to be proteinaceous in nature and their diameter was found to be 4.5-7 and 8.5-11 nm in Synechocystis and M. aeruginosa, respectively. Characterization of Synechocystis nanowires by transmission electron microscopy and biochemical techniques confirmed that they are type IV pili (TFP) while nanowires in M. aeruginosa were found to be similar to an unnamed protein (GenBank : CAO90693.1). Modelling studies of the Synechocystis TFP subunit i.e. PilA1 indicated that strategically placed aromatic amino acids may be involved in electron transfer through these nanowires. This study identifies PLS from Microcystis which can act as nanowires and supports the earlier hypothesis that microbial nanowires are widespread in nature and play diverse roles.
authors: TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon Faridabad Road, Gurgaon, 122 001, Haryana, India.
authors: Sandeep
authors: S
authors: Sure
authors: Centre for Cellular and Molecular Biology, Deakin University, 221 Burwood Highway, Burwood, Melbourne, VIC, 3125, Australia.
authors: Angel A J
authors: AA
authors: Torriero
authors: TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon Faridabad Road, Gurgaon, 122 001, Haryana, India.
authors: Aditya
authors: A
authors: Gaur
authors: Institute for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Geelong, VIC, 3216, Australia.
authors: Lu Hua
authors: LH
authors: Li
authors: Institute for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Geelong, VIC, 3216, Australia.
authors: Ying
authors: Y
authors: Chen
authors: TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon Faridabad Road, Gurgaon, 122 001, Haryana, India.
authors: Chandrakant
authors: C
authors: Tripathi
authors: TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon Faridabad Road, Gurgaon, 122 001, Haryana, India.
authors: Alok
authors: A
authors: Adholeya
authors: Centre for Cellular and Molecular Biology, Deakin University, 221 Burwood Highway, Burwood, Melbourne, VIC, 3125, Australia.
authors: M Leigh
authors: ML
authors: Ackland
authors: TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon Faridabad Road, Gurgaon, 122 001, Haryana, India. mandira.kochar@teri.res.in.
authors: Mandira
authors: http://orcid.org/0000-0002-8835-9629
authors: M
authors: Kochar
mesh_terms: D019295:Computational Biology / Q000379:methods; D036781:Fimbriae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D010861:Fimbriae, Bacterial / Q000502:physiology / Q000648:ultrastructure; D046931:Microcystis / Q000502:physiology / Q000648:ultrastructure; D018625:Microscopy, Atomic Force; D008958:Models, Molecular; D053770:Nanowires; D011487:Protein Conformation; D046939:Synechocystis / Q000502:physiology / Q000648:ultrastructure
chemical_list: D036781:Fimbriae Proteins
keywords: Conductive AFM; Microbial nanowires; Microcystis aeruginosa; Pilus-like structures; Synechocystis