Abstract
Mexican isolates ofPaecilomyces fumosoroseus (Wize) Brown & Smith virulent to nymphs and adults ofBemisia tabaci Gennadius (Homoptera: Aleyrodidae) were screened in terms of spore production in submerged culture. Effects of light, temperature stress and yeast extract on sporulation were studied. Cycles of 12 hours light/12 hours dark increased spore production as well as an incubation for 24 hours at 37°C prior to incubation at 30°C. In absence of organic nitrogen both fungal growth and sporulation were very low. Spore production in fermentors with a culture media of a C:N ratio of 25 was doubled as compared to a media with a C:N ratio of 11. Both conidia and blastospores were produced. Production of conidia directly from blastospores through microcyclic sporulation was observed. The proportion of conidia obtained under optimal conditions was 88.8%. Submerged culture ofP. fumosoroseus seemed advantageous compared to ricefilled plastic bags production method because of shorter fermentation times, higher spore yields and substantially higher volumetric spore productivity.
Results indicated that careful manipulation of nutritional and environmental conditions allowed for production of conidia during submerged growth ofP. fumosoroseus, microcyclic sporulation being induced under a set of environmental conditions including temperature stress and nutrients limitation.
Résumé
Des souches dePaecilomyces fumosoroseus, virulentes contre les adultes et les nymphes deBemisia tabaci (Homoptera : Aleyrodidae) ont été isolées au Mexique. Les recherches présentées ici concernent l’étude de la production de spores de ces isolats en culture immergée. Les résultats ont confirmé la faisabilité et l’intérêt de la fermentation en milieu liquide. En effet, tant la production de conidies que celle de blastospores a pu être obtenue, ainsi que la conidiogénèse à partir de blastospores. Par comparaison avec les techniques plus classiques de production de spores en sac de riz, les expériences menées ont permis de multiplier la production volumétrique de spores. Les effets de la lumière, de la température et de la concentration d’extrait de levures ont été étudiés. Les résultats obtenus montrent que des cycles de 12 heures de lumière suivies de 12 heures d’obscurité augmentent de manière significative la production de spores. De la même manière, une incubation durant 24 heures à 37 °C avant l’incubation à température optimale (30 °C) a un effet positif sur la production de spores. Les résultats montrent également que la concentration en azote organique a un effet majeur tant sur la sporulation que sur la croissance fongique. Ainsi, en l’absence d’azote organique, croissance et sporulation sont restées très faibles. De l’autre côté, une augmentation du rapport C/N de 11 à 25 a permis de doubler le nombre de spores produites, dont 88.8% étaient des conidies.
Les résultats obtenus montrent que la production de conidies en culture immergée deP.fumosoroseus est possible, par une manipulation adéquate des conditions nutritionnelles et de culture, le microcycle de sporulation pouvant être induit dans différentes conditions de culture. Les effets du stress de température et de la limitation des nutrients sont précisés
Similar content being viewed by others
References
Anderson, J. C. &Smith, J. E. - 1971. The production of conidiophores and conidia by newly germinated conidia ofAspergillus niger (microcycle conidiation). -Gen. Microbiol. 69, 185- 197.
Anderson, J. C. &Smith, J. E. - 1972. The effects of elevated temperatures on spore swelling and germination inAspergillus niger. -Can. J. Microbiol. 18, 289–297.
Fargues, J., Mania, N. K., Delmas, J. C. &Smiths, N. - 1992. Influence of temperature on the in vitro growth of entomopathogenic hyphomycetes. -Agronomie, 12, 557–564.
Fraikin, Y. G. &Rubin, B. L. -1979. Some physiological effects of near-ultraviolet light on microorganism. -Photochem. Photobiol., 29, 185–187.
Garza, G. E. & Arredondo, B. H. - 1993. Sensibilidad “in vitro” de adultos de mosquita blanca de las hortalizasBemisia tabaci (Homoptera:Aleyrodidae) aPaecilomyces spp. yVerticillium lecanii. -Abstracts XVI Congreso Nacional de Control Biológico, Monterrey, Nvo. León, México, 31–32.
Humphreys, A. M., Matewele, P., Cunliffe, B., Trincy, A. P. J. &Gillespie, A. T. -1989. Effects of water activity on morphology, growth and blastospore production ofMetarhizium anisopliae, Beauveria bassiana andPaecilomyces farinosus in batch and fed-batch culture. -Mycol. Res., 92, 257–264.
Humphreys, A. M., Matewele, P., Cunliffe, B. &Trinci, A. P. J. - 1990. Comparison of sporula- tion ofPaecilomyces farinosus andBeauveria bassiana in batch and fed-batch culture. -Mycol. Res., 94, 1046–1050.
Kumagai, T. - 1977. Mycochrome system and conidial development in certain fungi imperfect. -Photochem. Photobiol. 27, 371–379.
Medellin, M. A. & Garza, G. E. - 1993. Sensibilidad in vitro de estados ninfales de mosquita blancaBemisia tabaci (Homoptera: Aleyrodidae) a 12 aislamientos dePaecilomyces spp. -Abstracts XVI Congreso Nacional de Control Biológico, Monterrey, Nvo. León, México, 29–30.
Rombach, M. C. - 1989. Production ofBeauveria bassiana (Deuteromycotina: Hyphomycetes) sympoduloconidia in submerged culture. -Entomophaga, 34, 45–52.
Osborne, S. L. - 1990. Biological control of whiteflies and other pests with a fungal pathogen. -US Patent, 4, 942, 030.
Smith, J. E., Deans, G., Anderson, G. &Davis, B. - 1977. The nature of fungal sporulation. In:Meyrath J. &Bu’Lock J. D. (eds). Biotechnology and fungal differentiation. -Academic Press, Ilkley, 17–41.
Thomas, K. C., Khachatourians, G. &Ingledew W. M. - 1986. Production and properties ofBeauveria bassiana conidia cultivated in submerged culture. -Can. J. Microbiol., 33, 12–20.
Torres-Sánchez, E. & Cárdenas-Cota, H. - 1996.Paecilomyces fumosoroseus (Wize) Brown & Smith en el control microbiano de la mosquita blancaBemisia argentifolii Bellows & Perring (Homoptera: Aleyrodidae). -Abstracts XIX Congreso Nacional de Control Biológico, Culiacan,Sinaloa, México.
Vidal, C., Lawrence, A., Lacey & Fargues, J. - 1996. Intraspecific variability ofPaecilomyces fumosoroseus: vegetative growth as function of temperature. -Abstracts 4th Annual Progress Review of the 5-year National Research and Action Plan for Development of Management and Control Methodology for silverleaf whitefly, San Antonio, Texas, USA.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
de la Torre, M., Cárdenas-Cota, H.M. Production ofPaecilomyces Fumosoroseus conidia in submerged culture. Entomophaga 41, 443–453 (1996). https://doi.org/10.1007/BF02765796
Issue Date:
DOI: https://doi.org/10.1007/BF02765796