Screening and Characterization of L-Asparaginase producing endophytic fungi associated with certain medicinal plants of Lamiaceae

Abstract

Endophytic fungi residing in the host plants are well known for the production of industrially significant enzymes. This study deals with the isolation of fungal endophytes and the screening of extracellular enzymes from nine different plants of the family Lamiaceae with potent medicinal properties. Overall, 40 endophytic fungi (LCJ401 - LCJ440) were isolated from selected medicinal plants. The isolated endophytic fungi were evaluated for their capability to synthesize industrially important enzymes like amylase, protease, cellulase, laccase and L-Asparaginase in specific solid media. The results indicated that 45%, 37.5%, 35%, 32.5% and 52.5% of isolates could produce amylase, protease, cellulase, laccase and L-Asparaginase enzymes respectively. Based on the primary screening, the L-Asparaginase enzyme was more dominant and therefore the promising L-Asparaginase producing isolates were estimated by the nesselarization method. Of these, LCJ413, LCJ428, LCJ432 and LCJ438 were known to produce a high amount of L-Asparaginase. These isolates were subject to molecular analysis by 18S rRNA sequencing and MEGA software was used to construct a phylogenetic tree. The endophytic fungi identified were LCJ413 (Curvularia sp.), LCJ428 (Arxotrichum sp.), LCJ432 and LCJ438 (Fusarium sp.). Findings here revealed that fungal endophytes of Lamiaceae taxa have high L-Asparaginase-producing potency and can be exploited as a substitute reservoir for anticancer enzyme production.