Antimicrobial and Antioxidant Activity of Endophyte Bacteria Associated with Curcuma longa Rhizome

Abstract

Most cases of bacterial resistance towards antibiotics, encourage various efforts to gain new sources of antibiotics. Endophyte bacteria is a microorganism has important role as the producer of bioactive compounds. Endophyte bacteria from Curcuma longa with antimicrobial and antioxidant activities have not been studied yet. Curcuma longa has been utilized as the main ingredients of traditional herbal medicines ( jamu ). The objective of this research was to investigate the antimicrobial and antioxidant activity of endophyte bacteria associated with Curcuma longa rhizome. Based on morphological characteristics of bacterial colonies, eight endophyte bacteria was isolated from Curcuma longa rhizome. Screening of endophyte isolate has antimicrobial activity was done using agar well diffusion method. The culture supernatant of each endophyte isolate was dropped on agar well against pathogenic bacteria Salmonella enterica ser. Typhi, Staphylococcus aureus and yeast Candida albicans . Three endophyte isolates K 3 , K 2 and M 1b showed antimicrobial activity against pathogenic bacteria and yeast. Isolate K 3 showed strong antimicrobial activity against C. albicans and S. aureus , however, isolate K 2 and isolate M 1b showed antimicrobial activity against S almonella enterica ser. Typhi and S. aureus , respectively. Those endophyte bacteria also had antioxidant activity shown by scavenging ability toward DPPH radical with consecutive percentage of isolate K 3 (72.3 %), K 2 (51.3 %) and M 1b (64.6 %). Isolate K 3 showed the highest antimicrobial and antioxidant activity. Based on biochemical characteristics using Microbact 24E kit, isolate K 3 was identified as Paenibacilus alvei and isolate K 2 as Enterobacter agglomerans . Keywords: antimicrobial, antioxidant, Curcuma longa ’s rhizome, endophyte bacteria.