Isolation of L-Asparaginase-Producing Actinomycetes from Soil in Qom: Characterization and Anticancer Activity of L-Asparaginase Against MCF-7 Breast Cancer Cells

Actinomycetes play an important role in the pharmaceutical and biotechnology industries due to their ability to produce secondary metabolites. Among the most important enzymes they produce is L-asparaginase, a key drug used to treat blood cancer such as acute lymphoblastic leukemia. However, its production is costly and resource-intensive, highlighting the need for the identification of new sources and optimization of its production. The present study aimed to isolate and identify L-asparaginase-producing actinomycetes collected from soil samples in Qom City, Qom, Iran, optimize the conditions for enzyme production, and assess its anticancer effects on the MCF-7 Breast Cancer (BC) cell line in vitro.

In this laboratory study, soil samples were collected from various locations in Qom. Specific culture methods were used to isolate L-asparaginase-producing actinomycetes. The production conditions of the enzyme were optimized with respect to temperature, pH, and carbon and nitrogen sources. The effect of L-asparaginase on the MCF-7 cell line was tested for anticancer activity by the MTT method.

Among the 65 isolated colonies, three colonies showed the ability to produce L-asparaginase, and the superior strain with higher activity, Streptomyces flavoviridis, was identified. The specific activity of the enzyme increased to 415.25 mg protein/unit after purification, and the analysis by SDS-PAGE indicated a 30 kDa protein band. The enzyme extracted inhibited the growth of MCF-7 BC cells in a dose- and time-dependent manner, with IC₅₀ of 25.46 and 16.54 µg/mL at 24 and 48 h, respectively.

The findings showed that actinomycetes are suitable sources for producing L-asparaginase with anticancer effects.

The strains identified in this study could be a suitable solution for the industrial production of this enzyme with lower cost and greater effectiveness.