Phosphate Bacteria Research Articles

Karakter dan Potensi Inokulum Bakteri Fosfat dalam Melepaskan Fosfor

Soil bacteria group which can release soil P-adsorbed is phosphate bacteria (PB). PB can release soil P-adsorbed through: 1) acidification, 2) chelating 3) ligand exchange 4) mineralization and 5) compete colloid sorption site. PB have a potential to release soil P-adsorbed. This study was aimed to determining the character and PB inoculant potential in soil P-adsorbed release. The results of BLASTn PB showed that isolate 1 was Pseudomonas trivialis , isolate 5 was Pseudomonas putida and isolate 9 was Pseudomonas fluorescens . Based on the growth curve on day 5 th (the end log. phase) population of Pseudomonas trivialis was 10 10 CFU/mL, Pseudomonas putida was 10 14 CFU/mL and Pseudomonas fluorescens was 10 17 CFU/mL. Storage inoculant PB population decrease 97-84 % and 80-65 % PB lowering capabilities.

N-Acyl Homoserine Lactones sebagai Signal Quorum Sensing untuk Meningkatkan Efektifitas Bakteri Fosfat

Phosphate bacteria (PB) are able to release P-adsorption by soil. PB effectiveness in releasing adsorption P controled by quorum sensing (QS) signal. PB produces a QS signal as N-acyl homoserine lactones (N-HSL). The aim of this study are to determine the type of N-HSL as QS signal of PB ( Pseudomonas trivialis, P. putida and P. fluorescens ) and find the source of N-HSL from root extracts of some plants (rice, corn, bamboo, banana and peanuts). Analysis of N-HSL using HPLC (Hitachi UV-VIS detector L-2420), L-2200 autosampler (20 mL), L-2130 pump and column C OOF-4250-CO/10 µm LaChrom Ultra 18 (2 µm) 100 A 150 x 4.60 mm 10 m KPOW 490065-1 (Phenomenex), temperature 60° C, flow rate of 0.9 mL/minute and a gradient of 30-100 % in 1.0 minutes. Standard N-HSL is C4-HSL, 6, 8, 10, 12 homoserine lactones (Sigma-Aldrich, Germany) was dissolved in acetonitrile (Merch, India) with a concentration of 50 mM. P-dissolved by PB determined by staining NVM and a spectrophotometer at a wavelength of 413 nm. PB population is determined by the OD ( optical density ) at a wavelength of 600 nm. PB populations on medium Pikovskaya influenced by PB isolates, the type of P sources and duration of incubation. N-HSL generated by PB highest is Butanoyl (C 4 ) homoserine lactones. PB isolates 9 and Ca-phosphate sources produce N-HSL most. Root extract of rice, corn, bamboo, bananas and peanuts can be a source of N-HSL. Soluble phosphorus from medium Pikovskaya influenced by the type of PB isolates and source of P.