Microorganisms are capable of producing a wide variety of biopolymers. Homopolymer peptides, which are made up of only a single type of amino acid, are far less ubiquitous. The only two amino-acid homopolymers known to occur in nature are presented in this volume. Poly-epsilon-L-lysine is a polycationic peptide and exhibits antimicrobial activity against a wide spectrum of microorganisms. It is both safe and biodegradable and is therefore used as a food preservative in several countries. In addition, there has been great interest in medical and other applications of poly-lysine and its derivatives. In contrast, poly-gamma-glutamic acid is an unusual anionic polypeptide. It is also water soluble, biodegradable, edible, non-toxic and non-immunogenic and can be chemically modified to introduce various drugs. These features are very useful for pharmaceutical and biomedical applications. Poly-glutamic acid is also a highly attractive as food ingredient.
Microbiology Monographs Volume 15 Series Editor: Alexander Steinbu¨chel Mu¨nster, Germany Microbiology Monographs Volumes published in the series Inclusions in Prokaryotes Volume Editor: Jessup M. Shively Vol. 1, 2006 Complex Intracellular Structures in Prokaryotes Volume Editor: Jessup M. Shively Vol. 2, 2006 Magnetoreception and Magnetosomes in Bacteria Volume Editor: Dirk Schu¨ler Vol. 3, 2007 Predatory Prokaryotes – Biology, Ecology and Evolution Volume Editor: Edouard Jurkevitch Vol. 4, 2007 Amino Acid Biosynthesis – Pathways, Regulation and Metabolic Engineering Volume Editor: Volker F. Wendisch Vol. 5, 2007 Molecular Microbiology of Heavy Metals Volume Editors: Dietrich H. Nies and Simon Silver Vol. 6, 2007 Microbial Linear Plasmids Volume Editors: Friedhelm Meinhardt and Roland Klassen Vol. 7, 2007 Prokaryotic Symbionts in Plants Volume Editor: Katharina Pawlowski Vol. 8, 2009 Hydrogenosomes and Mitosomes: Mitochondria of Anaerobic Eukaryotes Volume Editor: Jan Tachezy Vol. 9, 2008 Uncultivated Microorganisms Volume Editor: Slava S. Epstein Vol. 10, 2009 Microbial Megaplasmids Volume Editor: Edward Schwartz Vol. 11, 2009 Endosymbionts in Paramecium Volume Editor: Masahiro Fujishima Vol. 12, 2009 Alginates: Biology and Applications Volume Editor: Bernd H. A. Rehm Vol. 13, 2009 Plastics from Bacteria: Natural Functions and Applications Volume Editor: Guo-Qiang Chen Vol. 14, 2010 Amino-Acid Homopolymers Occurring in Nature Volume Editor: Yoshimitsu Hamano Vol. 15, 2010 Yoshimitsu Hamano Editor Amino-Acid Homopolymers Occurring in Nature Editor Yoshimitsu Hamano, Ph.D. Department of Bioscience Fukui Prefectural University 4-1-1 Matsuoka-Kenjojima, Eiheiji-cho Fukui 910-1195 Japan
[email protected] Series Editor Professor Dr. Alexander Steinbu¨chel Institut fu¨r Molekulare Mikrobiologie und Biotechnology Westfa¨lische Wilhelms-Universita¨t Corrensstr. 3 48149 Mu¨nster Germany
[email protected] ISSN 1862-5576 e-ISSN 1862-5584 ISBN 978-3-642-12452-5 e-ISBN 978-3-642-12453-2 DOI 10.1007/978-3-642-12453-2 Springer Heidelberg Dordrecht London New York Library of Congress Control Number: 2010930857 # Springer-Verlag Berlin Heidelberg 2010 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of S