Production of Insect Toxin Beauvericin from Entomopathogenic Fungi Cordyceps militaris by Heterologous Expression of Global Regulator

Abstract

Cordyceps militaris is one of entomopathogenic fungi species that is well known to be a traditional medicine in China for decades. Although the pharmaceutical and/or toxic properties of C. militaris has attracted attention as a promising resource for finding bioactive compounds, only a few substances including cordycepin have been reported so far. In the previous report heterologous expression of LaeA, a global regulator for secondary metabolites production in fungi, has been succeeded in C. militaris. The LaeA-engineered transformants are proved to produce new and/or elevated production of secondary metabolites, as detected by HPLC analysis. In order to further characterize the secondary metabolites that were being significantly produced by LaeA transformant, HPLC profiling and structure elucidation by proton NMR were conducted in two target compounds, designated as compound 1 and compound 2. Compound 1 possessed the highly similar characters to insect toxin beauvericin in UV spectrum, molecular weight, and retention time in HPLC analysis. Proton NMR analysis revealed that compound 1 had the same proton signals as beauvericin.

Morphological study, production and cryopreservation of blastospores of entomopathogenic fungi

“…from other fungal genera. This corresponds to a statement from Samson et al [9] who stated that blastospores may be used to classify a genus of entomopathogenic fungi in the same manner as other vegetative propagules or other structures.…”

“…Entomopathogenic fungi have also been signified as a valuable source of secondary bioactive metabolites. Several bioactive compounds have been isolated from Cordyceps spp., for instance, antimalarial cordypyridones A-D from C. nipponica [6,7], bioxanthracenes from C. pseudomilitaris [7], antimalarial red naphthoquinones from C. unilateralis [8], and beauvericin-like compound from C. militaris [9].…”

The abundance of canopy arthropods in South Sumatra (Indonesia) freshwater swamp main and ratooned rice applied with bioinsecticides and synthetic insecticide

“…C. militaris is not found to attack the insect pests of rice. It can produce beauvericin, a toxin for insect pests (Rachmawati et al 2018). While abamectin is an insecticide with broad-spectrum activity (Ananiev et al 2002) and often used by farmers in Indonesia to control a brown planthopper (BPH), Nilaparvata lugens but the abamectin reduced the parasitism level and the number of BPH parasitoid (Anagrus nilaparvatae) progeny emerged (Sasmito et al 2017).…”

Mejoramiento en la producción de beauvericina en cultivo sólido para su uso como agente antimicrobiano

“…Los procesos de purificación aprovechan las características fisicoquímicas de la BEA y utilizan solventes no polares donde sea soluble para su extracción, estos solventes polares se mezclan con la biomasa de los cultivos, posteriormente se separan los restos sólidos del solvente, los metabolitos extraídos con el solvente se someten a una purificación previa generalmente por extracción en fase sólida (EFS) usando una columna de sílica, C8 o C18 con el fin de separar los componentes polares previamente obtenidos de acuerdo a su grado de polaridad. Generalmente esta prepurificación se complemente con la purificación final HPLC preparativo, posterior a esto se necesita un análisis de identificación como espectroscopia de masas o resonancia magnética (Jiang et al, 2013;Logrieco et al, 2002;Meca et al, 2010;Rachmawati et al, 2018;Yiping et al, 2007).…”

“…Se realizó una prepurificación utilizando un cartucho C18 (Sep-Pak C18 1g Cartridge ® ), para ello el cartucho fue activado haciéndole pasar 3 mL de metanol grado HPLC al 100% y posteriormente 3mL de buffer PBS (phosphate buffered saline) 0.01M (1X, pH = 7.4). Una vez activado se le hicieron pasar los 20 mL de metanol con los metabolitos secundarios extraídos, previamente mezclados con 40 mL de buffer PBS 0.01M (1X, pH = 7.4) (razón 2:1), después se realizó un lavado con 10 mL de agua desionizada, finalmente los metabolitos fueron elucidados con 6 mL de metanol grado HPLC al 100%, antes de inyectar al cromatógrafo se filtró con un filtro Acrodisk ® de 0.22 μm (modificado de Logrieco et al, 2002;Rachmawati et al, 2018).…”