Th. Nielsen et al., Structure, production characteristics and fungal antagonism of tensin - a new antifungal cyclic lipopeptide from Pseudomonas fluorescens strain 96.578, J APPL MICR, 89(6), 2000, pp. 992-1001
Aim: To study the antagonistic activity by Pseudomonas fluorescens strain 9
6.578 on the plant pathogenic fungus Rhizoctonia solani.
Methods and Results: Strain 96.578 produced a new cyclic lipopeptide, tensi
n. High tensin production per cell was detected in liquid media with glucos
e, mannitol or glutamate as growth substrate while fructose, sucrose and as
paragine supported low production. Tensin production was nearly constant in
media with different initial C levels, while low initial N contents reduce
d production. When applied to sugar beet seeds, strain 96.578 produced tens
in during seed germination. When challenged with strain 96.578 or purified
tensin, Rhizoctonia solani reduced radial mycelium extension but increased
branching and rosette formation.
Conclusion: The antagonistic activity of strain 96.578 towards Rhizoctonia
solani was caused by tensin.
Significance and Impact of the Study: When coated onto sugar beet seeds, te
nsin production by strain 96.578 could be of significant importance for inh
ibition of mycelial growth and seed infection by Rhizoctonia solani.