caa a22 4500 605498946 CHVBK 20210128100548.0 cr unu---uuuuu 210128e20150301xx s 000 0 eng 10.1007/s00253-014-6225-2 doi (NATIONALLICENCE)springer-10.1007/s00253-014-6225-2 Production and quality of conidia by Metarhizium anisopliae var. lepidiotum [Elektronische Daten] critical oxygen level and period of mycelium competence [Nohemi Garcia-Ortiz, Saúl Tlecuitl-Beristain, Ernesto Favela-Torres, Octavio Loera] Mycoinsecticides application within Integral Pest Management requires high quantities of conidia, with the proper quality and resistance against environmental conditions. Metarhizium anisopliae var. lepidiotum conidia were produced in normal atmospheric conditions (21% O2) and different concentrations of oxygen pulses (16, 26, 30, and 40%); conidia obtained under hypoxic conditions showed significantly lower viability, hydrophobicity, and virulence against Tenebrio molitor larvae or mealworm, compared with those obtained under normal atmospheric conditions. Higher concentrations of oxygen (26 and 30%) improved conidial production. However, when a 30% oxygen concentration was applied, maximal conidial yields were obtained at earlier times (132h) relative to 26% oxygen pulses (156h); additionally, with 30% oxygen pulses, conidia thermotolerance was improved, maintaining viability, hydrophobicity, and virulence. Although conidial production was not affected when 40% oxygen pulses were applied, viability and virulence were diminished in those conidia. In order to find a critical time for mycelia competence to respond to these oxidant conditions, oxygen pulses were first applied either at 36, 48, 60, and 72h. A critical time of 60h was determined to be the best time for the M. anisopliae var. lepidiotum mycelia to respond to oxygen pulses in order to increase conidial production and also to maintain the quality features. Therefore, oxygen-enriched (30%) pulses starting at 60h are recommended for a high production without the impairment of quality of M. anisopliae var. lepidiotum conidia. Springer-Verlag Berlin Heidelberg, 2014 Mycoinsecticide nationallicence Mass production nationallicence Oxygen nationallicence Conidial quality nationallicence Virulence nationallicence Garcia-Ortiz Nohemi Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, 09340, Mexico, DF, Mexico aut Tlecuitl-Beristain Saúl Programa Educativo de Ingeniería en Biotecnología, Universidad Politécnica de Tlaxcala, 90180, Tlaxcala, Mexico aut Favela-Torres Ernesto Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, 09340, Mexico, DF, Mexico aut Loera Octavio Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, 09340, Mexico, DF, Mexico aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/6(2015-03-01), 2783-2791 0175-7598 99:6<2783 2015 99 253 https://doi.org/10.1007/s00253-014-6225-2 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-014-6225-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Garcia-Ortiz Nohemi Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, 09340, Mexico, DF, Mexico aut NATIONALLICENCE 700 1- Tlecuitl-Beristain Saúl Programa Educativo de Ingeniería en Biotecnología, Universidad Politécnica de Tlaxcala, 90180, Tlaxcala, Mexico aut NATIONALLICENCE 700 1- Favela-Torres Ernesto Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, 09340, Mexico, DF, Mexico aut NATIONALLICENCE 700 1- Loera Octavio Departamento de Biotecnología, Universidad Autónoma Metropolitana-Iztapalapa, 09340, Mexico, DF, Mexico aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/6(2015-03-01), 2783-2791 0175-7598 99:6<2783 2015 99 253