MOLECULAR AND BIOCHEMICAL CHARACTERIZATION OF SALT TOLERANT ENDOPHYTIC BACTERIA ISOLATED FROM WILD MALVACEAE FAMILY PLANTS
Loading...
Files
Date
2015-09
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Key words: salt tolerant endophytic bacteria, PGPB, 16s rRNA amplification,
GFP, WGS.
The importance of plant growth promoting rhizobacteria in growth
promotion and their ability to elicit ‘induced systemic tolerance’ against abiotic
stresses has been well documented. In this study, out of a seventy two bacterial
isolated from the tissues of four Malvaceae family plant grown under saline
environment collected from Kutch, Gujarat, through screening seventeen were
selected to be highly salt-tolerant up to 12.5% NaCl and identified and
characterized them using morphological, biochemical and molecular traits.
All seventeen isolates were able to reduced nitrate and none were positive
for phenylalanine deaminase. Fifteen isolates gave positive result for urease activity
while twele isolates produce H2S gas and dextrose sugar. Eleven isolates gave
positive results for arginine, ornithrine, glucose, fructose and galactose test. Five
isolates were positive for proline test. Ten isolates were able to fermate lactose,
arabinose, sucrose and maltose sugar. The nine isolates were positive for xylose,
while eight isolates were for sorbitol and cellobiose. The six isolates gave a positive
outcome for citrate utilization and fermentation of raffinose and inositol sugar,
where five isolates gave positive results for lysine and proline utilization and also
maltose sugar. The four showed positive for phosphate solubilization, while eleven
were able to produce siderophore. Ten isolates positive for protease activity and all
were positive for ACC deaminase production in which AIK35 gave highly ACC
deaminase activity which is directly affected to salt tolerance.
All 17 isolates able to produced IAA and EPS. The promising isolates
AIK35 and WC68 showed IAA production were 7.51 and 66.73 μgml-1 at 12.5%
NaCl concentration and also gave highly IAA in normal broth. Where AIK35,
AIB49, AIB52 and WC68 showed EPS production were 129.67, 180.76, 164.36 and
90.15 μgml-1 at 12.5% NaCl concentration. The isolates AIK35, AIB49, AIB52 and
WC68 showed good antagonism towards growth of Fusarium oxysporum and
Rhizoctonia Solani. Based on 16s rRNA analysis isolates, AIK35, AIB49, AIB52
and WC68 were identified as a Providencia rettgeri strain NCTC 11801,
Microvirga zambiensis strain WSM3693, Providencia vermicola strain OP1 and
Alcaligenes faecalis strain NBRC 13111, respectively.
In vivo tests, the bacterial combination Providencia vermicola strain OP1,
Alcaligenes faecalis strain NBRC 13111 and Providencia rettgeri strain NCTC
11801 were applied as an aqueous suspension to the rhizosphere was found most
effective in enhancing growth of the cotton plant in soil having 2.5 EC NaCl
concentration as compare to normal soil (0.4EC) after three month of plant
emergence followed by Microvirga zambiensis strain WSM3693, Providencia
vermicola strain OP1 and Alcaligenes faecalis strain NBRC 13111combination.
The four efficient isolates AIK35, AIB49, AIB52 and WC68 were
successfully GFP-tagged with pGLO plasmid. Bacteria were successfully colonized
all parts (roots, stem and leaves) of cotton plant observed by fluorescent
microscopic. The screened best isolate AIK35 was Gram negative cocco bacilli
observed by scanning electron microscope. Based on screened best isolate
Providencia rettgeri MR4 (AIK35) having genome size 3.2 Mb pusing whole
genome sequencing.
The present research support salt tolerant endophytic activity towards cotton
growth. The performance of this bacterium under saline conditions will be of great
importance in the current agricultural scenario.
Description
Keywords
bacteria, planting, tolerance, biological development, food preservation, vegetative propagation, productivity, growth promoters, enzymes, genomesMOLECULAR AND BIOCHEMICAL