Pérez-Guzmán D, Montesinos-Matías R, Arce-Cervantes O, Gómez-Quiroz L E, Loera O, Garza-López P M
División de Ingeniería Ambiental, Tecnológico de Estudios Superiores del Oriente del Estado de México, La Paz, Estado de México, Mexico.
Centro Nacional de Referencia de Control Biológico, Tecomán, Colima, Mexico.
J Appl Microbiol. 2016 Aug;121(2):453-60. doi: 10.1111/jam.13156. Epub 2016 Jun 9.
The aim of this study was to determine the relationship between reactive oxygen species (ROS) production and conidial infectivity in Beauveria bassiana.
Beauveria bassiana Bb 882.5 was cultured in solid-state culture (SSC) using rice under three oxygen conditions (21%, or pulses at 16 and 26%). Hydrophobicity was determined using exclusion phase assay. Bioassays with larvae or adults of Tenebrio molitor allowed the measurements of infectivity parameters. A fluorometric method was used for ROS quantification (superoxide and total peroxides). NADPH oxidase (NOX) activity was determined by specific inhibition. Conidial hydrophobicity decreased by O2 pulses. Mortality of larvae was only achieved with conidia harvested from cultures under 21% O2 ; whereas for adult insects, the infectivity parameters deteriorated in conidia obtained after pulses at 16 and 26% O2 . At day 7, ROS production increased after 16 and 26% O2 treatments. NOX activity induced ROS production at early stages of the culture.
Modification of atmospheric oxygen increases ROS production, reducing conidial quality and infectivity.
This is the first study in which conidial infectivity and ROS production in B. bassiana has been related, enhancing the knowledge of the effect of O2 pulses in B. bassiana.
本研究旨在确定球孢白僵菌中活性氧（ROS）产生与分生孢子感染力之间的关系。
球孢白僵菌Bb 882.5在三种氧气条件（21%，或16%和26%的脉冲）下，以大米为基质进行固态培养（SSC）。使用排阻相分析法测定疏水性。通过对黄粉虫幼虫或成虫进行生物测定来测量感染力参数。采用荧光法对ROS（超氧化物和总过氧化物）进行定量。通过特异性抑制来测定NADPH氧化酶（NOX）活性。氧气脉冲使分生孢子疏水性降低。仅用从21%氧气条件下培养物中收获的分生孢子可使幼虫死亡；而对于成虫，在16%和26%氧气脉冲后获得的分生孢子，其感染力参数变差。在第7天，16%和26%氧气处理后ROS产生增加。在培养早期，NOX活性诱导ROS产生。
大气氧气的改变会增加ROS产生，降低分生孢子质量和感染力。
这是第一项将球孢白僵菌的分生孢子感染力与ROS产生联系起来的研究，增进了对氧气脉冲对球孢白僵菌影响的认识。
