Axenic mass culture of soil-borne nematodes using artificial egg yolk medium

ABSTRACT The amenability to axenic culture in vitro on solid medium including MacConkey, soybean casein, nutrient broth and egg yolk medium of Oscheius tipulae, Caenorhabditis elegans, Acrobeloides tricornis, Acrobeloides bodenheimeri and Teratorhabditis synpapillata were tested using Petri dishes. These nematodes were incapable of growing in MacConkey, soybean casein and nutrient broth, except for C. elegans which was able to multiply in soybean casein medium. While all nematodes used were successfully mass cultured using egg yolk medium at 25°C, results revealed that the highest yield of nematodes was observed with O. tipulae (TC2 and OC2), attaining 176 and 150 k nematodes per plate, respectively, after 10 days post-inoculation. In contrast, the lowest yield was recorded for T. synpapillata. The medium was optimised using different egg yolk concentrations (0, 5, 10, 20 and 40 g/L) and was tested for four nematode species O. tipulae, A. bodenheimeri, A. tricornis and T. synpapillata. The results showed that the egg yolk concentrations and the kinetic of nematode multiplication were positively correlated. Additionally, egg yolk liquid medium was applied to the mass culture of nematodes. Oscheius tipulae, A. bodenheimeri and A. tricornis were capable of reproduction in Petri dishes containing egg yolk liquid medium, at 25°C. Contrarily, T. synpapillata was unable to grow on the same liquid medium. The highest nematode yields of O. tipulae and A. bodenheimeri were attained 10,266 and 4110 nematodes in average, respectively, at 16 days post-inoculation. The maximum multiplication of A. tricornis was recorded at 20 days post-inoculation with 8430 nematodes.