Antimicrobial Activity of Bacteria Associated with Seaweeds against Plant Pathogens on Par with Bacteria Found in Seawater and Sediments.
Loading...
Date
2014-08
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Aim: We report antimicrobial activities of bacteria associated with 10 native and one
invasive species of seaweeds on par with bacteria found in the seawater and sediment.
Bacteria exhibiting antimicrobial activity were phylogenetically analysed using 16S rRNA
gene.
Place and Duration of Study: Samples of seaweeds, seawater and sediments collected
at 6 localities of south east coast of India between December 2009 and January 2010
during monsoon season.
Methodology: Culturable bacteria in seaweeds (epibiotics and endobiotics), seawater
and sediments were isolated through serial dilutions using 1.5% ZoBell marine agar
(HiMedia, India). Bacterial isolates producing antibiotics were identified by screening
against commercial antibiotics and they were subjected to morphological, Gram’s staining
and biochemical studies. Chemical property and stability of antimicrobial substances
obtained from the promising bacteria active against plant pathogens were studied.
Phylogenetic analysis of antibiotics-producing marine bacteria was made using 16S rRNA
gene sequencing technique. Results: A number of673 isolates obtained through the isolation process were found to be
the member of 27 bacterial genera, with species of Bacillus recording a maximum of
40.2%. Generally species of bacterial isolates in the association (seaweeds: epibiotics,
39.54% and endobiotics, 40.74%, seawater 8.61% and sediments 11.11%) produced
antibiotics and active against plant pathogens (Xanthomonas axonopodis pv. citri, X.
oryzaepv. oryzae and Ustilaginoidea virens) were associated with seaweeds (epibiotics
33.46% and endobiotics 43.11%) and sediments (23.43%). Extracellular components of
active bacteria are proteins and retaining bioactivity at pH 7.0, up to 40°C and antifungal
property up to 60°C. Extracts obtained from the active bacteria are nonpolar lipophilic
substances exhibited only antifungal activity.
Conclusion: Bacterial population were considerably higher in seaweeds as compared to
seawater and sediments, and at the same time higher bacterial population was recorded
in Gulf samples than the open coast samples. Most of the bacterial isolates associated
with seaweeds were found to produce antibiotics.
Description
Keywords
Seaweeds, bacteria, endobiotics, epibiotics, antimicrobial activity, plant pathogens
Citation
Suvega T, Arunkumar K. Antimicrobial Activity of Bacteria Associated with Seaweeds against Plant Pathogens on Par with Bacteria Found in Seawater and Sediments. British Microbiology Research Journal. 2014 Aug; 4(8): 841-855.