Agriculture Reference
In-Depth Information
Fig. 6.1
Crop-wise use of phosphorus and its distribution in different countries (Source: CRU,
Fertecon, IFA (Potash Corp. 2013)
6.3 Actinomycetes: An Ideal Candidate for Sustainable
Crop Production
Actinomycetes are a ubiquitous, saprophytic, and heterogeneous group of micro-
organisms belonging to an extensive and diverse group of Gram-positive, aerobic,
mycelial bacteria that have DNA with high %G+ C content (51-73 %) with the
exception of freshwater actinobacteria which has low GC content (Takisawa
et al.
1993
; Ghai et al.
2012
). Actinomycetes inhabit both the rhizoplane and
rhizosphere (Solans and Vobis
2003
; Frioni
2006
) and are known to play some
important ecological roles in soil nutrient cycling (Elliot and Lynch
1995
),
probiotics (Lievin et al.
2000
), bioremediation (Amoroso et al.
2013
), nitrogen
fixation, and deterioration and decomposition of plant and animal residues and also
provide many bioactive compounds such as vitamins, enzymes, and antibiotics
(de Boer et al.
2005
; Busti et al.
2006
; Prapagdee et al.
2008
; Genilloud et al.
2011
).
Apart from their beneficial impact, actinomycetes also cause some harmful effects
such as they cause diseases and spoil different useful materials (Waksman
1950
).
Other properties which make them an ideal candidate for developing inoculants are
as follows: (1) their high genetic and metabolic versatility, (2) they can easily be
genetically engineered (Pogell et al.
1991
), (3) high growth rate and relatively faster
colonization efficiency (Hsu and Lockwood
1975
), and (4) ability to tolerate high
salt concentration (Vassilev et al.
2012
). Despite possessing such qualities, actino-
mycetes in general have been less explored organisms in agricultural technology,
among variously distributed soil microflora (Qin et al.
2011
).
