Production of Conidia by the Fungus Metarhizium anisopliae Using Solid-State Fermentation

Abstract

This chapter describes the production of conidia by Metarhizium anisopliae using solid-state fermentation. Before production of conidia, procedures for strains conservation, reactivation, and propagation are essential in order to provide genetic stability of the strains. The strain is conserved in freeze-dried vials and then reactivated through insect inoculation. Rice is used as a substrate for the conidia production in two different bioreactors: plastic bags and tubular bioreactor. The CO2 production in the tubular bioreactors is measured with a respirometer; this system allows calculating indirect growth parameters as lag time (tlag) (25-35 h), maximum rate of CO2 production (rCO2 max) (0.5-0.7 mg/gdm h), specific rate of CO2 production (μ) (0.10-0.15 1/h), and final CO2 production (CO2) (100-120 mg/gdm). Conidial yield per gram of dry substrate (gdm) should be above 1 × 10(9) conidia/gdm after 10 days of incubation. Germination and viability of conidia obtained after 10 days of incubation should be above 80 % and 75 %, respectively. Bioassays using of Tenebrio molitor as a host insect should yield a final mortality above 80 %.

Solid-state fermentation technology and innovation for the production of agricultural and animal feed bioproducts

“…Most Trichoderma species grow in the range of 25-30 ºC [79]. Incubation temperature for Beauveria and Metarhizium usually also varies between 25 and 30 ºC [95][96][97][98]. For the three of them, initial moisture content may vary from 40 to 70%, depending on the substrate used and its capacity to absorb water, and typical production cycles vary between 7 and 15 days [78,84,[94][95][96][97]; however, some processes may take more time.…”

Forced Aeration Influence on the Production of Spores by Trichoderma strains

“…Therefore, the production of spores from BCA's is a core point to gain ground to the chemical pesticides. Several reports have been published on the topic of spore production from different BCA's, such as Loera-Corral et al [6] evaluating Metarhizium anisopliae, Lopez-Perez et al [8] with Beauveria bassiana or de la Abstract The main purpose of the present study was to evaluate the effect of an initial aeration rate on the sporulation of six Trichoderma strains under solid state fermentation conditions and to evaluate the behavior of the lytic enzymes involved in the process at laboratory scale. A mixture of sugarcane bagasse, wheat bran, chitin, potato flour and olive oil were used as a substrate.…”

“…The main challenge faced by BCA products is its low availability and distribution due to the limited production of fungal biomass [5]. The fungal spore is the most resistant propagule that tolerates the critical environmental conditions presented in the field crops [6,7]. Therefore, the production of spores from BCA's is a core point to gain ground to the chemical pesticides.…”

The Effect of Aeration for 6-Pentyl-alpha-pyrone, Conidia and Lytic Enzymes Production by Trichoderma asperellum Strains Grown in Solid-State Fermentation

“…Several reports have been published on the topic of conidia production under SSF to evaluate the effect of water stress on sporulation. Indeed, fungal conidia is a resistant propagule, able to tolerate critical environmental conditions and having a long self-life [5,15]. On the present study, the application of forced aeration through a solid-state fermentation using three Trichoderma asperellum strains is evaluated to produce 6-PP, conidia and essential enzymes.…”