title: Identification and topographical characterisation of microbial nanowires in Nostoc punctiforme.
abstract: Extracellular pili-like structures (PLS) produced by cyanobacteria have been poorly explored. We have done detailed topographical and electrical characterisation of PLS in Nostoc punctiforme PCC 73120 using transmission electron microscopy (TEM) and conductive atomic force microscopy (CAFM). TEM analysis showed that N. punctiforme produces two separate types of PLS differing in their length and diameter. The first type of PLS are 6-7.5 nm in diameter and 0.5-2 µm in length (short/thin PLS) while the second type of PLS are ~20-40 nm in diameter and more than 10 µm long (long/thick PLS). This is the first study to report long/thick PLS in N. punctiforme. Electrical characterisation of these two different PLS by CAFM showed that both are electrically conductive and can act as microbial nanowires. This is the first report to show two distinct PLS and also identifies microbial nanowires in N. punctiforme. This study paves the way for more detailed investigation of N. punctiforme nanowires and their potential role in cell physiology and symbiosis with plants.
authors.affiliation: TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon-Faridabad Road, Gurgaon, Haryana, 122 001, India.
authors.forename: Sandeep
authors.initials: S
authors.lastname: Sure
authors.affiliation: Centre for Cellular & Molecular Biology, Deakin University, 221 Burwood Highway, Burwood, Melbourne, VIC, 3125, Australia.
authors.forename: Angel A J
authors.initials: AA
authors.lastname: Torriero
authors.affiliation: TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon-Faridabad Road, Gurgaon, Haryana, 122 001, India.
authors.forename: Aditya
authors.initials: A
authors.lastname: Gaur
authors.affiliation: Institute for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Geelong, VIC, 3216, Australia.
authors.forename: Lu Hua
authors.initials: LH
authors.lastname: Li
authors.affiliation: Institute for Frontier Materials, Deakin University, Geelong Waurn Ponds Campus, Geelong, VIC, 3216, Australia.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.affiliation: TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon-Faridabad Road, Gurgaon, Haryana, 122 001, India.
authors.forename: Chandrakant
authors.initials: C
authors.lastname: Tripathi
authors.affiliation: TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon-Faridabad Road, Gurgaon, Haryana, 122 001, India.
authors.forename: Alok
authors.initials: A
authors.lastname: Adholeya
authors.affiliation: Centre for Cellular & Molecular Biology, Deakin University, 221 Burwood Highway, Burwood, Melbourne, VIC, 3125, Australia.
authors.forename: M Leigh
authors.initials: ML
authors.lastname: Ackland
authors.affiliation: TERI-Deakin Nanobiotechnology Centre, TERI Gram, The Energy and Resources Institute, Gual Pahari, Gurgaon-Faridabad Road, Gurgaon, Haryana, 122 001, India. mandira.kochar@teri.res.in.
authors.forename: Mandira
authors.identifier: http://orcid.org/0000-0002-8835-9629
authors.initials: M
authors.lastname: Kochar
mesh_terms: D053770:Nanowires / Q000648:ultrastructure*; D046937:Nostoc / Q000502:physiology / Q000648:ultrastructure*
keywords: Cyanobacteria; Microbial nanowires; Nostoc punctiforme; Pili-like structure