List of Articles Paenibacillus

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  1 - Synthesis, Optimization and Modeling of Curdlan Gum Production from Paenibacillus polymyxaUsing Response Surface Methodology (RSM)
  S.M. Rafigh M. Vossoughi A. Vaziri A.A. Safekordi M. Ardjomand
  Introduction: Curdlan gum is a bacterial polysaccharidic biopolymer that is the result of β-(1→3)-D-glycosidic linkages. Due to its ability to curdle and the water-holding capacity, curdlan has applications in the manufacture of food products such as jelly, no More

  Introduction: Curdlan gum is a bacterial polysaccharidic biopolymer that is the result of β-(1→3)-D-glycosidic linkages. Due to its ability to curdle and the water-holding capacity, curdlan has applications in the manufacture of food products such as jelly, noodles, edible fibers. Curdlan is biodegradable, nontoxic and it has applications in the pharmaceutical industry because of its potent biological activities. For the first time, the present study is concerned with the synthesis, characterization, optimization of cultural conditions and modeling of curdlan production from Paenibacillus polymyxa using RSM. Materials and Methods: After preparation of the microorganism and the medium, Plackett–Burman design with 12 experimental runs was used to screen the effective factors through 11 variables of batch culture medium for curdlan production. Central composite design with 20 experimental runs was used for optimization of the effective variables. In addition, four characterization methods such as FT-IR, C-NMR, XRD and DSC were employed. Results: The result of the experiments showed that three nutritional factors (glucose, yeast extract and triton x-100) had the predominant effect on curdlan production. The maximum production of curdlan was 4.75 g/l from the optimum condition consisting of glucose (100 g/l), yeast extract (3 g/l) and triton x-100(2.5 g/l). In addition, the average molecular weight of curdlan was determined at 170 kDa by GPC. Conclusion: The results from this study have demonstrated that Paenibacillus polymyxa PTCC 1020 with more specific growth rate (µ) than previous studies is capable to produce curdlan gum and also the production of the synthetic curdlan was confirmed using qualitative methods of identification.   Manuscript profile
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  2 - Screening of indigenous potassium-solubilizing bacterial strains and evaluation of their ability in solubilisation of absorbable potassium
  Jafar Dorjdor Sajjad Yazdansetad Mohammad Hosein Arzanesh Hatef Ajoudanifar
  Background & Objectives: Approximately 98% of total potassium in soil is in unavailable mineral forms for plants. Potassium-solubilizing bacteria are able to dissolve potassium bearing silicate minerals and release available form of potassium to the plants. The pres More

  Background & Objectives: Approximately 98% of total potassium in soil is in unavailable mineral forms for plants. Potassium-solubilizing bacteria are able to dissolve potassium bearing silicate minerals and release available form of potassium to the plants. The present study was intended to isolate potassium-solubilizing bacteria from rhizosphere soil of crop plants and to evaluate the ability of isolates in solubilisation of absorbable potassium. Material & Methods: Potassium-solubilizing bacteria were isolated from the rhizosphere of different crop plants. The isolates were grown on optimized Aleksandrov agar and were assayed based on the diameter of zone of potassium solubilization. The selected isolates were identified using macroscopic, microscopic, biochemical, and molecular methods. The Flame photometry was used to quantify potassium released by isolates in Aleksandrov broth and soil. Results: Totally, 5 out of 30 isolates with ability to release potassium showed high activity in potassium solubilisation. The biochemical and molecular studies indicated that these isolates belonged to the genera Bacillus, Paenibacillus, and Pseudomonas. The flame photometry results showed that the amount of potassium released by the isolates ranged from 950 to 1250 mg/l in broth media and 525 to 550 mg/kg in soil. Conclusion: The potassium-solubilizing bacteria were isolated and identified from rhizosphere samples and identified. These isolates showed high ability for solubilisation of silicate minerals and release of absorbable potassium and therefore they can be used in biofertilizers to enhance the availability of potassium in the soils and to improve the growth and yield of crop plants. Manuscript profile