Identification of epiphytic bacterial species from longevity spinach leaves

Gynura procumbens or longevity spinach plant is a type of medicinal plant that distributes widely in Southeast Asia including Malaysia. G. procumbens is commonly called as pokok Sambung Nyawa, Sabong Nyawa, Akar Sebiak, or Kecam Akar by Malaysians; and often consumed as ulam or salad. Thus, there might be several microorganisms particularly bacteria that still inhabiting the leaves. Intensive studies on the therapeutic potential of G. procumbens have indeed been carried out over time. However, studies focusing on the link between medicinal plants and bacteria that inhabit the plant specifically epiphytic bacteria on the leaf surface have yet to be fully appreciated. Besides, only one available study on the diversity of bacteria inhabiting the phyllosphere was available showing the lack of related studies. Thus, this study aimed to identify epiphytic bacteria of G. procumbens leaves based on morphology through Gram-staining and genetics using 16S ribosomal RNA gene sequencing; and to determine the possible contribution of the bacteria to the medicinal properties of G. procumbens by further readings. The findings from this research suggested the presence of five species of bacteria i.e. Bacillus subtilis, Bacillus amyloliquefaciens, Pantoea agglomerans, Sphingomonas melonis, and Burkholderia cepacia. From further readings, it is known that some of the bacterial species have the potentials towards medicinal applications. Also, it is hypothesised that the production of some secondary metabolites in the plant might be due to the presence of the bacteria.