Isolation and in vitro Screening of Plant Growth Promoting Rhizospheric Bacteria from Corn (Zea mays var. indentata)

Many farmers use organic fertilizers to preserve the environment, but unfortunately, it's not as effective as chemical fertilizers. In recent years, the discovery of plant growth-promoting rhizobacteria (PGPR) has gained some attraction. PGPR have abilities to promote plant growth efficiently, including corn plants. Corn (Zea mays L.) is a staple food needed in large quantities. Our results show that some bacteria may have the potential to become PGPR for corn. Corn plant samples were obtained from maize plantations in Bunulrejo district, Blimbing, Malang (Republic of Indonesia). The potential of bacterial isolates obtained from the rhizosphere and endophyte area of corn as PGPR was determined based on several in vitro screening results, including the siderophore production test, indole-3-acetic acid (IAA) phytohormone production test, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase production test, and phosphate dissolution test. Five isolates contained the best potential to become PGPR, namely E6.2, E3.1, E4.2, R4.2, and R2.1. Later, E6.2 and E3.1 were known to be able to fix nitrogen and produce siderophores, IAA and ACC deaminase. Based on the sequencing results, the R2.1 isolate was considered Bordetella muralis, the E3.1 isolate was identified as Cellulosimicrobium cellulans, while the R4.2, E4.2, and E6.2 isolates belonged to Serratia nematodiphila. These isolates could be used as potential inoculants for biofertilizers for better agricultural practice.