Isolation and Identification of Indole-3-Acetic Acid Producing Bacteria and Phosphate Solubilizing Bacteria from Bio-fermented Water

Abstract

Bio-fermented water has been widely used in agricultural applications such as bio-fertilizer and รนBio-fermented water has been used in agricultural application such as fertilizer and animal feed additives. However, the formulations and fermentation process, which is driven by natural microorganisms, influence the quality of bio-fermented water. Therefore, the objectives of this research was to isolate plant growth promoting bacteria by producing indole-3-acetic acid (IAA) and solubilizing phosphate and identify them at the molecular level. The inoculum was prepared from soybean powder supplemented with 2% yeast extract (w/w). Fermentation broth composted of 10 g of Peptone, 5 g of corn powder, 2.5 g of beef extract, 1.5 g of fish powder, 3 g of yeast extract, 2 g of coconut palm sugar, 1 g of salt, 1 g of rice bran, 1 g of pig blood in 1 L of water. Fermentation was stopped when the pH of fermentation broth reached to 2-3. Out of 29 isolates, the results revealed that 8 isolates of bacteria that produce IAA were found (27.5%). The bacteria were identified as Lactobacillus casei NV2203 Lacticaseibacillus rhamnosus NV2207 Bacillus cereus NV2210 Bacillus cereus NV2211 Lacticaseibacillus rhamnosus NV2214 Bacillus sp. NV2226 Terribacillus sp. NV2230 and Terribacillus saccharophilus NV2233. For phosphate solubilizing activity, 2 isolates consisting of Lactobacillus casei NV2203 and Bacillus subtilis NV2206 were found. These bacteria can be added to bio-fermentation water as an inoculum to improve and control quality.