Isolation and selection of endophytic bacteria with nitrogen fixing ability from Houttuynia cordata Thunb.

Abstract

    Houttuynia cordata Thunb. is a popular vegetable in the daily meals of Vietnamese families. In addition, H. cordata is also one of the medicinal plants that has long been used in traditional medicine to treat digestive diseases, rashes, blocked milk ducts, etc. The objective is to isolate and identify the endophytic bacterial strains in H. cordata that have high nitrogen-fixing ability. Results have shown that eleven bacterial strains were isolated from H. cordata root collected from Chau Thanh district, Tien Giang province on Nutrient agar (NA) medium and were confirmed as endophytic bacteria, using specific primers of endophytic bacteria. Of the 11 isolated strains, only 6 strains had the ability to fix nitrogen. Among them, strain R03 with the highest synthesized nitrogen content of 10.67 mg/L. This strain was identified as 99.93% similar to Bacillus flexus strain MP-9.