CGC Bibliography Paper 4929

Cuticular disruption and mortality of Caenorhabditis elegans exposed to culture filtrate of Byssochlamys nivea

Park JO, Hargreaves JR, Cole ALJ, Ghisalberti EL, Gams W, Sivasithamparam K

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Citation:

Nematology 3: 355-363 2001

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ARTICLE

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Abstract:

A strain of a Byssochlamys nivea, isolated from saline mud in Western Australia as a part of statewide survey of soil fungi for nematophagous activity, was evaluated for its effect on nematodes. Culture filtrate of the fungus grown on potato dextrose broth for 7 days caused structural changes in the cuticle, aggregation of individuals, and mortality of Caenorhabditis elegans. In addition, the culture filtrate completely inhibited hatching of C. elegans eggs. Exudates from agar colonies also caused cuticular disruption and mortality of C. elegans. The cuticular disruption observed, not reported in nematodes before, was initiated in the labial region and spread towards the posterior region of the nematode within 10 min of application. This reaction occurred only in live nematodes. Cuticular disruption and mortality caused by the culture filtrate varied according to growth conditions. The active compound(s) in the culture filtrate were thermostable (100 degreesC for 1 h); however freezing the culture filtrate (-20 degreesC for 2 days) eliminated the activities, as did dialysis (< 14 000 molecular weight). Cuticular disruption and mortality were also observed when the nematode was exposed to culture filtrates of two other strains of B. nivea supplied by CBS, The Netherlands. The culture filtrate also inhibited in vitro growth of the plant-pathogenic fungi Fusarium oxysporum, Gaeumannomyces graminis var. tritici, Phytophthora cinnamomi, Pythium irregulare and Rhizoctonia solani.