Microbial

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1995) plus two reference strains, was evaluated by rneasuring their sur- vival rate in the rhizosphere ...... Fusarium and fluorescent Pseudomonas strains in rockwool, a substratum for soilless culture. .... Bi01 Fertil Soil 30:433-439. Maurhofer M ...
Ajit Varma Sudhir Chincholkar (Eds.)

Microbial Siderophores With 24 Figures

- Springer

PROF.DR. AJIT VARMA Director Amity Institute of Microbial Sciences and Vice Chairman (International) Amity Science Technology Foundation Amity University Uttar Pradesh Sector- 125 Noida 201303 India E-mail: [email protected] PROF.SUDHIRB. CHINCHOLKAR Director School of Life Sciences North Maharashtra University P.O. Box 80 Jalgaon 425 001 India E-mail: [email protected]

Library of Congress Control Number: 200792 1586

ISSN 1613-3382 ISBN-978-3-540-71159-9 Springer-Verlag Berlin Heidelberg New York ïhis work is subject to copyright. Al1 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, aind storage in data banks. Duplication of this publication or parts thereof is permitted only unldtrr the provisions of the German Copyright Law of September 9, 1965, in its current version, and permissions for use must always be obtained from Springer-Verlag. Violations are liable for prosecution under the German Copyright Law. Springer-Verlag is a part of Springer Science+Business Media springeronline.com O Springer-Verlag Berlin Heidelberg 2007

The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Editor: Dr. Dieter Czeschlik, Heidelberg, Germany Desk Editor: Dr. Jutta Lindenborn, Heidelberg, Germany Cover design: WMXDesign GmhH, Heidelberg, Germany Typesetting and production: LE-TEX Jelonek, Schmidt & Vockler GbR, Leipzig, Germany Printed on acid-free paper SPIN 11372882 3113100 YL 5 4 3 2 1 O -

Implication of Pyoverdines in the Interactions of Fluorescent Pseudomonads with Soil Microflora and Plant in the Rhizosphere Philippe Lemanceau, Agnès Robin, Sylvie Mazurier, Gérard Vansuyt

Introduction Soils are known to be oligotrophic environments wherea,s soil microflora is mostly heterotrophic in such way that microbial growth in so:ilis mainly 1imit.ed by the scarce sources of readily available organic compounds (Wardle 1992). Therefore, in soils, microflora is mostly in stasis (fungistnsis/bacteriostasis) (Lockwood 1977). In counterpart, plants are autotrophic organisms responsible for the primary production resulting from the photosynthesis. A significant part of photosynthetates are released from plant roots to the soil through a process called rhizodeposition. These products, i.e. the rhizodeposits, are made of exudates, lysates, mucilage, secretions and dead ce11 material, as well as gases including respiratory CO2 and ethylene. Depending on plairit species, age and environmental conditions, rhizodeposits can account for up I:O40% of net fix:ed carbon (Lynch and Whipps 1990). On average, 17%of net fixed carbon appears to be released by the roots (Nguyen 2003). ïhis significant release of organic compounds by plant roots in soil oligotrophic environments is then expected to affect strongly thle heterotrophic microflora located closely to the roots. Indeed, one century a,go, Hiltner (1904) observed an increased proliferation of heterotrophic bacteria in contact with the roots. ïhis author proposed to cal1 rhizosphere the volume of soil surrounding roots in which the microflora is influenced by these roots. Since then, further studies have shown that living roots modify the biological and physicochemical properties of rhizospheric soil determining the rhizosphere effect (Curl and Truelove 1986; Lemanceau and Heulin 1998; Lynch 1990; Rovira 1965). Rhizodeposition affects the soil microflora and especially leads to (i) an .increase of its density (Clark 1949; Rovira 1965),biomass (Barber and Lynch 1977) INRA-CMSE, UMR 1229 INRAIUniversitk de Bourgogne 'Microbiologie du Sol et de l'Environnement', 17 rue Sully, 21034 Dijon cedex, France, email: [email protected] Soil Biology, Volume 12 Microbial Siderophores A. Varma, S.B. Chincholkar (Eds.) O Springer-Verlag Berlin Heidelberg 2007

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Phi.lippe Lemanceau et al.

and activity (Soderberg and Baith 1998) and to (ii) variaiilons of the structure and diversity of their populations (Ede1 et al. 1997; Lemanceau et al. 1995; Mavingui et al. 1992). In the rhizosphere, trophic interactions and communications lead indeed to (i) selection of the most adapted microbial