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conferenceseries
.com
Volume 9
Journal of Biotechnology & Biomaterials
ISSN: 2155-952X
JOINT EVENT
February 28-March 02, 2019 | Berlin, Germany
5
th
International Conference on
Enzymology and Protein Chemistry
&
22
nd
Global Congress on
Biotechnology
Biotechnology 2019
Enzymology 2019
February 28-March 02, 2019
&
Biocontrol efficacyof two
Bacillus
species against chilli pepperanthracnose causal agent
Colletotrichum
truncatum
H B P Sandani
1
, N P Ranathunge
1
, P L N Lakshman
1
, G Degrassi
2
and
W M W Weerakoon
3
1
University of Ruhuna, Sri Lanka
2
ICGEB Laboratory, Argentina
3
Field Crop Research Institute, Sri Lanka
A
pplicability of two
Bacillus
strains isolated from standard compost was assessed as a reliable alternative in the management
of the anthracnose in chilli pepper. Out of twenty promising antagonistic bacterial isolates, two were genotypically
characterized as
Bacillus
spp. based on 16S rRNA analysis. Selected two antagonistic
Bacillus
strains significantly suppressed
the mycelial growth and the spore germination of chilli pepper anthracnose causal agent
Colletotrichum truncatum
(p<0.05).
Malformation of the fungal hyphae was dominant in the area subjected to antagonism. One of the major antagonistic
mechanisms extended towards the anthracnose pathogen
C. truncatum
by these two
Bacillus
strains was detected as antibiosis
in the cellophane overlay technique. They produced antifungal peptides, lipopeptides and also minute amount of organic
solvent soluble molecules as antifungal compounds against
C. truncatum
. These antifungal compounds showed minimum
inhibitory concentrations of 3200 ppm and 2460 ppm on
C. truncatum
and also these metabolites are thermally stable up to
120ºCwhile they could retain the antifungal properties more than 10 weeks under cold conditions and up to eight weeks at room
temperature. One of the
Bacillus
strains produces a bacteriocin like small peptide inhibitory against
C. truncatum
. Induction of
latent host defense mechanisms is another antagonistic mechanism employed by this
Bacillus
sp. upon
C. truncatum
infection
in chilli pepper. The tested
Bacillus
sp. could enhance the expression of defense related PAL and PO enzymes in chilli pepper
plants upon
C. truncatum
infection. Also these antagonistic
Bacillus
strains promote chilli pepper plants’ growth through the
production of significant amounts of Indole Acetic Acid (IAA) which is a growth hormone as an indirect mechanism against
C. truncatum
. They also showed a prominent swimming and swarming ability indicating their high potentiality in colonizing
plant tissues paving the way for successful green house and field applications. These two strains effectively managed the seed
borne infection of
C. truncatum
resulting healthy chilli pepper seedlings with good vigor. Also they effectively managed the
fruit decay caused by
C. truncatum
at color breaking stage and green stage suggesting the suitability of
Bacillus
spp. as a
potential candidate to be used in the development of a biocontrol agent against chilli pepper anthracnose causal agent
C.
truncatum
.
6826psandani@gmail.comJ Biotechnol Biomater 2019, Volume 9
DOI: 10.4172/2155-952X-C2-116