ASSESSMENT OF BIOACTIVE METABOLITES FROM THE ROOT ENDOPHYTE ISOLATED FROM CASUARINA JUNGHUHNIANA Miq.

Abstract

Objective: Casuarina junghuhniana Miq. is a well-known multipurpose tree belonging to family Casuarinaceae. This tree has the ability to sustain in different edaphic and extreme environmental conditions. The root extract of this tree is a rich source of potential secondary metabolites. Therefore, the main objective of this study is to isolate fungal root endophyte from this tree and to determine its bioactive compound which can be utilized in agriculture and pharmaceutical industries.Methods: C. junghuhniana Miq. root samples were collected from the State Forestry Research Institute, Neyveli (Vridhachalam Research Range, Cuddalore District). Isolation of fungal endophyte was carried out using potato dextrose agar medium. The qualitative and quantitative phytochemicals screening and enzyme assays were carried out using standard procedures. Antimicrobial assay was tested against different pathogens using well diffusion method. Further, the phytochemicals in the root extract were evaluated using Fourier transform infrared (FTIR), high performance liquid chromatography (HPLC), and gas chromatography-mass spectrometry (GC-MS) studies.Result: Among the isolated endophytes, the dominant isolate (CJN5) was identified as Aspergillus sp. which showed positive result in the production of industrially important enzymes, namely, cellulase, lipase, and amylase. The qualitative screening revealed the presence of various phytoconstituents. Total phenolic content of culture filtrate extract (CFE) (208.20±2 mg/g) was found higher than culture mycelium extract (CME) (165.5±3 mg/g). The total flavonoid content of CFE (25.95±2 mg/g) was also found higher than CME (3.59±2 mg/g) using respective standards. Antimicrobial activity showed maximum zone of inhibition against Pseudomonas aeruginosa (bacterial pathogen) (24±0.1 mm) and Fusarium oxysporum (fungal phytopathogen) (34±0.2 mm). FTIR analysis showed the presence of varied functional groups. HPLC study revealed the presence of gallic acid and salicylic acid. Several peaks were obtained in GC-MS analysis which indicates the presence of different secondary metabolites. Conclusion:Aspergillus sp, isolated from the root of C. junghuhniana Miq. is a promising source of bioactive compounds which can be utilized in agriculture and pharmaceutical industries.