L-asparaginase (ASNase) is a therapeutic enzyme used to treat acute lymphoblastic leukemia. Currently, the most widely used ASNases are originated from bacteria. However, owing to the adverse effects of bacterial ASNases, new resources for ASNase production should be explored. Fungal enzymes are considered efficient and compatible resources of natural products for diverse applications. In particular, fungal species belonging to the genus Trichoderma are well-known producers of several commercial enzymes including cellulase, chitinase, and xylanase. However, enzyme production by marine-derived Trichoderma spp. remains to be elucidated. While screening for extracellular ASNase-producing fungi from marine environments, we found four strains showing extracellular ASNase activity. Based on the morphological and phylogenetic analyses using sequences of translation elongation factor 1-alpha (tef1α), the Trichoderma isolates were identified as T. afroharzianum, T. asperellem, T. citrinoviride, and Trichoderma sp. 1. All four strains showed different ASNase activities depending on the carbon sources. T. asperellem MABIK FU00000795 showed the highest ASNase value with lactose as a carbon source. Based on our findings, we propose that marine-derived Trichoderma spp. are potential candidates for novel ASNase production.

Introduction
Materials and Methods
    1. Isolation and preparation of Trichoderma spp.cultures
    2. Morphological observation
    3. DNA extraction, sequencing, and phylogeneticanalysis
    4. Screening of L-asparaginase producing Trichodermaspp.
    5. Effects of carbon source on extracellular Lasparaginaseactivities
Results and Discussion
    1. Colony morphology and growth rate of Trichodermaspp. on various media
    2. Phylogenetic analysis
    3. Screening of L-asparaginase-producing Trichodermaspp.
    4. Effects of carbon sources on extracellular Lasparaginaseactivity
Conclusion

• Woon-Jong Yu(Department of Microbial Resources, National Marine Biodiversity Institute of Korea, Seocheon 33662, Korea)
• Dawoon Chung(Department of Microbial Resources, National Marine Biodiversity Institute of Korea, Seocheon 33662, Korea)
• Yong Min Kwon(Department of Microbial Resources, National Marine Biodiversity Institute of Korea, Seocheon 33662, Korea)
• Seung Sub Bae(Department of Microbial Resources, National Marine Biodiversity Institute of Korea, Seocheon 33662, Korea)
• Eun-Seo Cho(Department of Microbial Resources, National Marine Biodiversity Institute of Korea, Seocheon 33662, Korea)
• Hye Suck An(Marine BioIndustrial Research Division, National Marine Biodiversity Institute of Korea, Seocheon 33662, Korea)
• Grace Choi(Department of Microbial Resources, National Marine Biodiversity Institute of Korea, Seocheon 33662, Korea) Corresponding author