Kemampuan bakteri endofit Micrococcus endophyticus G053 dalam memproduksi IAA-like compound dan meningkatkan pertumbuhan tanaman

Abstract

Endophytic bacteria are able to act as PGPB (plant growth-promoting bacteria) by producing hormones or increasing availability nutrients for plants. This study aimed to test the ability of endophytic bacterium Micrococcus endophyticus G053 to produce IAA-like compound, fix free nitrogen, and its ability to increase potato plantlet and tobacco plant growth. The ability of M. endophyticus G053 to produce IAA-like compound in TSB 50% and TSB 100% was tested using Salkowski reagent, whereas its ability to fix free nitrogen was tested by growing it in LGI agar. Potency of M. endophyticus G053 to increase plants growth was tested in vitro using potato plantlets and in planta using tobacco plants. The results showed that M. endophyticus G053 was able to produce IAAlike compound in both media and to fix free nitrogen. The highest production of IAA-like compound was at 6th day of incubation in TSB 50% (64.35 ppm) and at 8th day of incubation in TSB 100% (69.10 ppm). Potato plantlets inoculated with M. endophyticus G053 was able to increase plantlet height and its number of shoot. M. endophyticus G053 inoculated in tobacco plants rhizosphere was also able to increase shoot length, root length, and dry weight of tobacco plants. The ability of M. endophyticus G053 to increase potato plantlets and tobacco plants growth was due to their ability to produce IAA-like compound and to fix free nitrogen.