poster ECFGversie2 gecorrigeerd.pub

Identification of micro-organisms fighting T. agrresivum
and other “Weed” fungi in mushroom compost
N. Jacobs(1), M. van Erp(1), W. Arts(2), T. Goosen, C.A.M.J.J. van den Hondel (3)and B. C. Lokman(1)
(1)
(2)
(3)
HAN BioCentre: P.O. Box 6960, 6503 GL Nijmegen, the Netherlands, [email protected]
CNC: P.O. Box 13, 6590 AA Gennep, the Netherlands
HiTeXacoat, Waterlelie 124, 2804 PZ Gouda
Introduction
The cultivation of mushrooms is susceptible to unwanted growth of fungi, like Trichoderma aggresivum and Penicillium. The growth of these fungi causes substantial decrease of yields to the growers or even destroy the harvest
completely. In this study we have identified micro-organisms present in compost that are able to inhibit growth of
fungi like T. aggresivum and Penicillium leaving the mycelial growth of the commercial mushroom Agaricus bisporus unaffected. Furthermore, we have shown that Pseudomonas strains derived from natural soil are very effective in inhibiting weed fungi.
Methods and Results
Method 1: Plate-inhibition assay: 4 different bacterial strains are inoculated at fixed distance from a “weed” fungus
on compostmedium agar plate. Growth inhibition was analyzed after 4 days incubation at 28°C (Fig. 1).
Used method
T. aggresivum
(control)
T. aggresivum
+ bacterial strains
Penicillium
(control)
Peniciilium
+ bacterial strains
A. bisporus
(control)
A. bisporus
+ bacterial strains
X
Fig 1. Plate-inhibition assay. X “weed” fungus; o different bacterial strains.
Bacteria inhibiting growth of fungus.
Method 2: Liquid-inhibition assay: Bacterial strains are cultivated together with different “weed” fungi in liquid compostmedium. Mixed cultures were incubated at 28°C and analyzed on fungal and bacterial growth on compostmedium
agar plates (Fig. 2).
Mixed cultures in
compostmedium
Purification
method
Penicill./37-A2-2
mixculture
Penicill./37-A1-5
mixculture
Penicill./37-BP-6
+ bacterial strains
T.aggresivum
(control)
T.aggr./37-A1-4
mixculture
Fig 2. Liquid-inhibition assay. Plates on which T. agresivum and Penicillium are inhibited in growth by bacterial strains are indicated
1 with
Final Results inhibition assays:
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Table 1. Final result inhibition assays. Y: Growth inhibition in both assays. Y: Growth inhibition in method 1. N: No growth inhibition in both assays.
N: No growth inhibition in method 1. Y/N: Inhibition difficult to determine.
Promising strains: growth inhibition of several “weed” fungi leaving
A. bisporus unaffected.
Conclusion
Future plans
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Five bacterial strains present in mushroom
compost and three Pseudomonas strains have
antifungal activity against T. aggresivum and
other “weed” fungi leaving A. bisporus unaffected.
•
Future research will be focused on the potential of
these bacterial strains as biocontrol agents in mushroom cultivation.
Highthroughput screening of more
strains/compounds on antifungal activity.
Acknowledgements
This research was financed by the Dutch government (Stichting Innovatie Alliantie: RAAK-Pro), Productschap Tuinbouw,
CNC grondstoffen, and HiTeXacoat.