IJSRST1841333 | Received : 12 Feb 2018 | Accepted : 26 Feb 2018 | January-February-2018 [ (4) 2: 1479-1484 ]
© 2018 IJSRST | Volume 4 | Issue 2 | Print ISSN: 2395-6011 | Online ISSN: 2395-602X
Themed Section: Science and Technology
1479
Plant Growth Promoting Characteristics of Bacillus
Licheniformis DS3 Isolated from Agriculture Field Soil
D. Silpa, P. Brahmaji Rao, G. Kranthi Kumar, M. Raghu Ram*
Department of Botany & Microbiology, Acharya Nagarjuna University, Guntur, Andhra Pradesh , India
ABSTRACT
Plant growth promoting rhizobacteria (PGPR) are known to influence the plant growth by various direct or
indirect mechanisms. In search of efficient PGPR strains with multiple activities, a total of 10 bacterial isolates
belonging to Bacillus species isolated from different banana field soils, Tadepalli, Guntur district of Andhra
Pradesh, India. Out of ten only one strain Bacillus licheniformis DS3 showed potential activity of producing
IAA, Gibberellic acid production, Siderophore production and excretion of Ammonia. Bacillus licheniformis
DS3 showed the maximum IAA and Gibberellic acid productions are 142 µg/ml and 74.75 µg/ml respectively.
An orange halo appears around the Bacillus licheniformis DS3 on CAS agar media indicates the siderophore
production. The optimum conditions for IAA production in Bacillus licheniformis DS3 are 0.1 % L-tryptophan,
48 h of incubation, Glucose (1%) and Ammonium sulphate (0.5%) were used as carbon and nitrogen sources.
This strain has shown to exhibit multiple plant growth promoting characteristics. These plant growth
promoting abilities can make this isolate a potential PGPR candidate for its application in sustainable
agriculture.
Keywords : Ammonia, PGPR, IAA, Gibberellic acid (GA3), Siderophore
I. INTRODUCTION
Plant growth promoting Bacillus licheniformis (PGPB)
are beneficial bacteria which have the ability to
colonize the roots and either promotes plant growth
through direct or indirect mechanism or via biological
control of plant diseases (Kloepper and Schroth, 1978).
They are associated with many plant species and are
generally present in varied environments. Strains with
PGPB characteristics, belonging to genera Bacillus
licheniformis, have been reported (Hurek and
Reinhold-Hurek, 2003). Bacteria that colonize the
rhizosphere and plant roots, and enhance plant
growth by any mechanism are referred to as PGPR.
Plant growth promoters can exhibit a variety of
characteristics responsible for influencing plant
growth. The common traits include production of
plant growth regulators (like auxin, gibberellins, and
ethylene, siderophores, HCN and antibiotics (Arshad
et al., 1992).
Gibberellic acid (GA3) is an important member of the
gibberellins family and acts as a natural plant growth
hormone, controlling many development processes,
which is gaining great attention all over the world due
to its effective use in agriculture, nurseries, tissue
culture ( Shukla et al., 2005). Gibberellic acid
production was confirmed from B. pumilus and B.
licheniformis [Gutierrez- Manero, 2001].
More than 80% of the bacteria isolated from the
rhizosphere can produce (IAA) Indole Acetic Acid
(Khalid et al., 2004) as secondary metabolite by
obtaining tryptophan either through root exudates or
from the proteins released by the dead bacteria cells
(Patten and Glick, 1996). Indole-3-acetic acid (IAA), a
plant hormone compound, is a natural auxin produced
by plants, bacteria, fungi and a diverse group of
organisms. It is a metabolite derived from tryptophan
by many tryptophan dependant and tryptophan