BARBI BHUYAN*, PABANITA SENAPATI, SURAIYA AKHTAR, RAJA AHMED, RAFIUL AMIN LASKAR AND KUMANAND TAYUNG
Department of Botany, Gauhati University, Guwahati-781 014 (Assam), India
*(e-mail: barbibhuyan61@gmail.com; Mobile : 86382 73699, 97060 89634)
(Received: August 15, 2022; Received: October 2, 2022)
ABSTRACT
Finding new and effective antimicrobial metabolites has become more important as bacterial pathogens
have developed a major resistance to antibiotics. Several active metabolites and their antimicrobial
properties have been reported from endophytes isolated from medicinal plants. The goal of the current
study was to isolate endophytes from the leaves of Litsea chinensis and assess the antibacterial activity
of the crude metabolites produced by these endophytes. The endophytes were isolated from surface-
sterilized healthy leaves inoculated on different mycological media – Potato Dextrose Agar (PDA), Host
extract+Agar (HEA) and Water Agar (WA). A total of 27 endophytes were isolated from the three distinct
media with the highest colonization frequency in WA (50%) media followed by HEA (20%) and PDA (20%)
media. The highest fungal colonies were recovered from WA media, whereas more yeast colonies were
isolated from PDA and HEA media. The pure cultures of the isolated endophytes were cultured on
Potato Dextrose Broth (PDB) and five different isolates were obtained. The crude metabolites of only
one of the isolates (LCEA1) showed promising antimicrobial activity against all the test organisms. The
isolate LCEA1 was again tested for antimicrobial activity at 14 and 21 days of incubation, with the
maximum antibacterial activity reported at 21 days. However, the highest zone of inhibition (18 mm)
was observed against MTCC-737 (Staphylococcus aureus) followed by MTCC-736 (Bacillus subtilis) (12
mm) and MTCC-424 (Pseudomonas aeruginosa) (11 mm). The crude metabolites had a max value of 0.53,
indicating the presence of some bioactive metabolites responsible for antimicrobial activity.
Key words : Endophytic fungi, Litsea chinensis, antimicrobial activity, Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa