Resumen
- Bioproducts based on chlamydospore of nematophagous fungi had been proposed as a biological alternative to control free-living nematodes. Traditionally, these resistance structures are produced through solid fermentation causing high cost during production because the space required and energy used to maintain operation parameters as temperature and relative humidity. For this reason, liquid fermentation could be a feasible alternative. In this work, different liquid media were evaluated to produce chlamydospores of two Colombian strains of nematophagous fungi, Duddingtonia flagrans and Arthrobotrys musiformis. A suspension of chlamydospores was obtained from Petri dishes with Wheat Flour Agar (WFA) incubated at 25±0.5 oC for 7 days and used as an inoculum. For the evaluation, three liquid media were used: MYPG, JP and Wheat Flour with and without 0.05 %w/v agar as a widely reported chlamydospores production inductor. Liquid fermentations were performed on Erlenmeyer flasks completely aerated at 25±0.5 oC and 200 rpm. At 7 and 14 days, chlamydospores concentration was computed. The results of this evaluation showed that no chlamydospores production was observed after 7 days of fermentation on any of the liquid media. Nevertheless, chlamydospores could be determined at 14 days for both fungi. For A. musiformis, the only liquid medium with a significance chlamydospores concentration was Wheat Flour with a value of 2.8x105 chlam/mL and a specific chlamydospores rate (SCR) of 0.10 d-1. In the case of D. flagrans, the maximum chlamydospores concentration was 5.9x105 chlam/mL in Wheat Flour medium supplemented with Agar and an SCR of 0.13 d-1. In conclusion, A. musiformis and D. flagrans can produce chlamydospores on a liquid fermentation system, however, a big effort has to be done to design the adequate production media to increase the productivity of the process.