Exploration and Identification of Potential Soil Microorganisms from The Pepper Rhizosphere

Pepper is one of the plantation products with high economic value. Cultivation businesses are generally carried
out independently by the community using conventional methods. The limited availability of subsidized fertilizers is one
of the obstacles faced by farmers, while the price of non-subsidized fertilizers is quite high. This is certainly a burden for
farmers considering pepper is a type of plant that requires large amounts of nutrients. The utilization of soil
microorganism services as biofertilizers is an alternative to replace the use of inorganic fertilizers. The purpose of this
study was to identify the types of beneficial soil microbes in the roots of pepper plants, especially non-symbiotic nitrogen
fixing bacteria and phosphate solubilizing bacteria, as well as phosphate solubilizing fungi. The isolation of bacteria was
carried out by the spread method on agar media, while the isolation of fungi was carried out by the pour method. The
density of microorganisms was calculated by the Total Plate Count (TPC) method. Total soil microorganisms were quite
low, i.e., 8.8 x 10⁵ - 3.1 x 10⁷ colonies/gram of soil. Bacterial characterization was carried out by observing the
macroscopic morphology of the colonies, Gram staining and endospores, and catalase and motility tests. Fungal
characterization was carried out by observing macroscopic and microscopic morphology, which included hyphae, spore�producing, and spore-forming. Exploration of potential soil microorganisms carried out on pepper rhizosphere resulted in
3 groups of potential microorganisms, namely nitrogen-fixing bacteria, phosphate solubilizing bacteria and phosphate
solubilizing fungi. The types of nitrogen-fixing bacteria obtained were from the genera Rhizobium, Bradyrhizobium,
Acetobacter, Azotobacter, Azospirillum, and Clostridium. Phosphate solubilizing bacteria obtained were Azotobacter,
Bacillus, Pseudomonas, and Thiobacillus. In contrast, the types of phosphate solubilizing fungi that have been isolated
are Penicillum, Aspergillus, and Trichoderma. All isolates have the potential to be used as biofertilizers, but further tests
are needed to determine which isolates have the best ability to provide optimal effects on plants