TY - JOUR

T1 - Inhibition of Metarhizium anisopliae by the gut bacterial flora of the desert locust, Schistocerca gregaria: Evidence for an antifungal toxin

AU - Dillon, R. J.

AU - Charnley, A. K.

PY - 1986/5

Y1 - 1986/5

N2 - A study has been made on the effects of the gut of the desert locust, Schistocerca gregaria, on germination and viability of conidia of the entomopathogenic fungus Metarhizium anisopliae. Germination in the gut of conventional insects in vivo and in conventional gut fluid in vitro was poor. In addition gut-passage through conventional insects reduced viability by over 50%. Adverse pH or osmotic pressure, dietary chemicals, oxygen or nutrient deficiency, fungal cell-wall degrading enzymes, and competition for nutrients with the microflora could not account for the inhibitory properties of the locust gut. Fungitoxicity was, however, dependent on the presence of the gut bacterial flora. Since there was no apparent difference in gut or whole animal physiology between axenic and conventional (nonparasitized) locusts, the hypothesis was made that an antifungal toxin, produced by the gut bacterial flora, was responsible for the above observations. The results are discussed in the light of this possibility.

AB - A study has been made on the effects of the gut of the desert locust, Schistocerca gregaria, on germination and viability of conidia of the entomopathogenic fungus Metarhizium anisopliae. Germination in the gut of conventional insects in vivo and in conventional gut fluid in vitro was poor. In addition gut-passage through conventional insects reduced viability by over 50%. Adverse pH or osmotic pressure, dietary chemicals, oxygen or nutrient deficiency, fungal cell-wall degrading enzymes, and competition for nutrients with the microflora could not account for the inhibitory properties of the locust gut. Fungitoxicity was, however, dependent on the presence of the gut bacterial flora. Since there was no apparent difference in gut or whole animal physiology between axenic and conventional (nonparasitized) locusts, the hypothesis was made that an antifungal toxin, produced by the gut bacterial flora, was responsible for the above observations. The results are discussed in the light of this possibility.

KW - Schistocerca gregaria

KW - Metarhizium anisopliae

KW - gut flora

KW - bacteria

KW - toxin

U2 - 10.1016/0022-2011(86)90106-0

DO - 10.1016/0022-2011(86)90106-0

M3 - Journal article

VL - 47

SP - 350

EP - 360

JO - Journal of Invertebrate Pathology

JF - Journal of Invertebrate Pathology

SN - 0022-2011

IS - 3

ER -