Isolation, identification and characterization of the nematophagous fungus Arthrobotrys (Monacrosporium) sinense from China.

With the development of anthelmintic resistance of parastic nematodes, it is necessary to isolate and study nematophagous fungi to screen out the native isolates for their potential in the biocontrol of domestic animal nematodosis. This study aimed to isolate the Arthrobotrys sinense (Monacrosporium sinense) of nematophagous fungus, to characterize representative molecular isolates using scanning electron microscope (SEM), and to determine the effect of the temperature and pH values on radial growth of the isolate. Five isolates were isolated from 1532 samples of different types, and their occurrence frequencies were 0.32% of the total samples. They were identified as A. sinense by means of morphology and the sequence of the 5.8S, 18S, and 28S rDNA, as well as internal transcribed spacers 1 and 2. The isolate NBS003 could grow from 11°C to 35°C and had optimal growth at 30°C. The isolate could grow at pH 4 to 11, and its optimal value was obtained at pH 9. SEM results showed that 6 h after their addition, the second stage larvae (L2) and the third stage infective larvae (L3) of Haemonchus contortus were captured. L2 and L3 were penetrated by the fungus at 18 and 24 h post-capture, respectively. L2 and L3 were completely digested at 84 and 90 h post-capture, respectively. The NBS003 of the A. sinense should have a certain potential to be used for capturing the free-living stage of nematodes in sheep.