Evaluation of fungicidal activity of extracellular filtrates of cyanobacteria--possible role of hydrolytic enzymes.
A set of seventy axenised and unicyanobacterial isolates belonging to the genus Anabaena were evaluated for biocidal activity against a set of phytopathogenic fungi. Among them, 35 Anabaena strains showed zone of inhibition against one or more fungi. The extracellular filtrates from 4 and 8 weeks old cultures of these Anabaena strains were further evaluated in terms of hydrolytic enzymes, proteins and IAA employing standard methods. Significant differences were also observed among the strains in terms of their FPase, chitosanase and xylanase activity, while low and relatively similar values of CMCase, cellobiase and protease activity were recorded in the strains analyzed. IAA production was also observed in all the strains. Comparative evaluation of activity of hydrolytic enzymes and antifungal activity revealed that such enzymes may contribute to the fungicidal activity of the cyanobacterial strains, besides other bioactive compounds, including IAA, which are established promising traits for biocontrol agents. This study is a first time report on the production of hydrolytic enzymes by these oxygenic photosynthetic prokaryotes, which can be potential candidates for the development of biocontrol agent(s) against selected phytopathogenic fungi.
Division of Microbiology and Centre for Conservation & Utilization of Blue-Green Algae (CCUBGA), Indian Agricultural Research Institute (IARI), New Delhi, India. radhapr@gmail.com
Radha
R
Prasanna
Lata
L
Nain
Ravindramani
R
Tripathi
Vishal
V
Gupta
Vidhi
V
Chaudhary
Sheetal
S
Middha
Monica
M
Joshi
Radhika
R
Ancha
Brahma D
BD
Kaushik
D000528:Alternaria / Q000187:drug effects; D017033:Anabaena / Q000201:enzymology* / Q000302:isolation & purification; D001230:Aspergillus / Q000187:drug effects; D001426:Bacterial Proteins / Q000378:metabolism*; D002480:Cellulase / Q000378:metabolism; D043364:Endo-1,4-beta Xylanases / Q000378:metabolism; D005659:Fungicides, Industrial / Q000494:pharmacology*; D005670:Fusarium / Q000187:drug effects; D006026:Glycoside Hydrolases / Q000378:metabolism; D006868:Hydrolysis; D007210:Indoleacetic Acids / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism; D010935:Plant Diseases; D012988:Soil Microbiology; D001617:beta-Glucosidase / Q000378:metabolism
D001426:Bacterial Proteins; D005659:Fungicides, Industrial; D007210:Indoleacetic Acids; D006026:Glycoside Hydrolases; C019868:chitosanase; D001617:beta-Glucosidase; D002480:Cellulase; C019826:carboxymethylcellulase; D043364:Endo-1,4-beta Xylanases; D010447:Peptide Hydrolases