بهینه‌سازی انحلال پتاسیم توسط باکتری Pseudomonas fluorescens با استفاده از طرح پلاکت-برمن و روش سطح پاسخ (RSM)

نوع مقاله : مقالات پژوهشی

نویسندگان

1 دانشجوی دکتری علوم خاک،دانشکده کشاورزی، دانشگاه ارومیه

2 استاد گروه علوم خاک، دانشکده کشاورزی، دانشگاه ارومیه

3 استادیار گروه علوم خاک، دانشکده کشاورزی، دانشگاه ارومیه

4 دانشیار گروه علوم خاک، دانشکده کشاورزی، دانشگاه ارومیه

چکیده

انحلال پتاسیم موجود در ساختار کانی­ها توسط ریزجانداران منجر به افزایش رشد و عملکرد گیاهان شده و علاوه بر صرفه­ی اقتصادی، دوستدار محیط زیست است، لذا شناسایی گونه­های کارا در انحلال پتاسیم و تعیین شرایط بهینه برای حداکثر فعالیت این گونه­ها از اهمیت بالایی برخوردار است. این پژوهش با هدف بررسی تأثیر سطوح مختلف متغیرهای منبع کربن، زمان انکوباسیون و pH بر میزان انحلال و آزادسازی پتاسیم از کانی­های فلدسپار و فلوگوپیت توسط باکتری Pseudomonas fluorescens انجام گرفت. برای این منظور در مرحله نخست بر مبنای طرح پلاکت– برمن، تعداد 12 آزمایش تعریف شد و تأثیر منابع مختلف کربن شامل گلوکز، ساکاروز و فروکتوز بر انحلال هر یک از کانی­های فلدسپار و فلوگوپیت بررسی شد. در ادامه بر اساس تحلیل نتایج مربوط به انحلال پتاسیم در مرحله اول، منبع کربن مهم و تأثیرگذار شناسایی و دامنه­های متفاوتی از متغیرهای pH (10-3)، زمان انکوباسیون (18-1 روز) و مقدار منبع کربن (12– 6/0 گرم در لیتر) در نظر گرفته شده و طرح مرکب مرکزی با 20 آزمایش و بر اساس مقادیر کدبندی شده متغیرهای مستقل طراحی گردید. نتایج نشان داد که مدل طرح مرکب مرکزی قابلیت مطلوبی (918/0– 944/0=R2 و 47/1– 82/0 =RMSE) در پیش­بینی مقدار آزادسازی پتاسیم از فلدسپار و فلوگوپیت دارد. تحلیل حساسیت مدل طرح مرکب مرکزی نشان داد که از بین سه متغیر مورد بررسی، pH بیشترین تأثیر را بر آزادسازی پتاسیم دارد. حداکثر غلظت پتاسیم محلول در حضور فلوگوپیت و فلدسپار به­ترتیب برابر با 16/121 و 96/82 میلی­گرم در لیتر، مربوط به 36/10 =pH، مقدار ساکاروز 5/6 گرم در لیتر و زمان10 روز بود. زمان­ انکوباسیون نیز بر آزادسازی پتاسیم تأثیر داشت. روند آزادسازی پتاسیم در مراحل اولیه انکوباسیون افزایشی، در مراحل میانی کاهشی و در ادامه افزایشی بود. بطور کلی بر اساس مدل طرح مرکب مرکزی، pHهای 36/10 و 34/10، و مقادیر 26/2 و 92/6 گرم در لیتر از ساکاروز و زمان­های 18 و 2 روز به­ترتیب به­عنوان شرایط بهینه برای دست‌یابی به بیشینه آزادسازی پتاسیم از فلدسپار و فلوگوپیت در محیط کشت پیش­بینی شدند.

کلیدواژه‌ها


عنوان مقاله [English]

Optimization of Potassium Dissolution by Pseudomonas fluorescens Using Placket-Burman Design and Response Surface Methodology

نویسندگان [English]

  • S. Ashrafi-Saeidlou 1
  • A. Samadi 2
  • MH. Rasouli-Sadaghiani 2
  • M. Barin 3
  • E. Sepehr 4
1 Department of Soil Science, Faculty of Agriculture, Urmia University, Urmia, Iran,
2 Department of Soil Science, Faculty of Agriculture, Urmia University, Urmia, Iran,
3 Department of Soil Science, Faculty of Agriculture, Urmia University, Urmia, Iran,
4 Department of Soil Science, Faculty of Agriculture, Urmia University, Urmia, Iran,
چکیده [English]

Introduction: Among the elements, potassium (K) is the third important macronutrient for plant nutrition that plays a significant role in plant growth and development. The development of intensively managed agriculture has led to the consumption of increasing amounts of K, low K supply has therefore become an important yield-limiting factor in agriculture. However, more than 98% of potassium in the soil exists in the form of silicate minerals such as illite and lattice K in K-feldspars which K cannot be directly absorbed by plants. Potassium and other minerals can be released when these minerals are weathered. Some microorganisms can play a role in releasing K from minerals. They solubilize K-bearing minerals through different mechanisms including chelation, acidolysis, pH reduction, exchange reaction, complexation, biofilm formation and secretion of organic acid and polysaccharides. Since the use of potassium solubilizing microorganisms (KSMs) as K-biofertilizers reduces the agrochemicals application and supports eco-friendly agriculture, so it is imperative to isolate the KSMs and optimize various growth parameters so as to improve their activity.
Materials and Methods: The present study was an attempt to model and evaluate the effects of pH, incubation time and different amounts of carbon source on K release by Pseudomonas fluorescens using Placket-Burman design and response surface methodology with a central composite design. At the first step, 12 experiments based on Placket-Burman design were carried out to screen and identify the effective carbon source in potassium release. According to the results of the first step, response surface methodology with the central composite design was employed to evaluate and model the effects of the coded independent variables including pH (3-10), incubation time (1-18 days) and carbon source (0.6-12 g L-1) on K release from feldspar and phlogopite. After the completion of each period, samples were centrifuged at 3000 rpm for 10 minutes and filtered using Whatman paper (No. 41). Potassium concentration of samples was measured by flame photometer. Used minerals in the experiment including feldspar and phlogopite were grounded and filtered through a 230 mesh sieve. In order to remove exchangeable K, the samples were saturated by calcium chloride solution (with a ratio of 2:1), after washing with HCl, samples were then dried at 105oC for 48 hours.
Results: Results showed that there was no difference between carbon sources, applied at the first step of the experiment, so each can be employed as alternatives to each other in the culture medium. The central composite design showed R2 of 0.944 and 0.918 with RMSE of 0.82 and 1.47 for predicting K release of feldspar and phlogopite, respectively, indicating high efficiency. Sensitivity analysis of the central composite design revealed that the pH is the most important factor in K release. The highest concentration of the K was observed at the highest levels of pH. Incubation time also had an impact on potassium release. In the early stages of the incubation time, the trend of potassium release was increasing, in middle stages, K amount decreased but it was accelerated over long times of incubation. The maximum potassium release in presence of phlogopite and feldspar was 121.16 and 96/82 mg L-1, respectively, which was observed at pH= 10.36, sucrose amount= 6.5 g L-1 during 10 days. Potassium amount in this treatment hence increased by 31.52% as compared to feldspar. According to central composite design, maximum potassium release of feldspar and phlogopite was obtained at pH= 10.36 and 10.34, sucrose concentrations of 2.26 and 6.92 g L1 at 18 and 2 days, respectively.
Conclusion: Our results showed that pH had a significant impact on K release by Pseudomonas fluorescens using response surface methodology. Overall, increasing incubation time along with high pH leads to the high amounts of K release from minerals. Different minerals released different content of potassium. Application of soil K-bearing minerals in combination with efficient potassium solubilizing bacterial strains as biofertilizers is required to replace chemical fertilizers and reduce the crop cultivation cost. Many bacterial strains have been found to solubilize minerals and improve plant growth under laboratory and greenhouse conditions, but their ability under field conditions remains unexplored. The capability of these bacteria, considering the soil and plant type, and environmental factors, should be thus evaluated under field conditions. 

کلیدواژه‌ها [English]

  • Aleksandrov medium
  • Central composite design
  • K-bearing minerals
  • Potassium solubilizing
1- Aleksandrov V.G., Blagodyr R.N., and Ilev I.P. 1967. Liberation of phosphoric acid from apatite by silicate bacteria. Mikrobiolohichnyĭ zhurnal 29: 111-114.
2- Archana D.S. 2007. Studies on potassium solubilizing bacteria. Doctoral dissertation, UAS, Dharwad.
3- Ashrafi-Saeidlou S., Rasouli-Sadaghiani M.H., Asadzadeh F., and Barin M. 2016. Modeling Phosphate Solubilization by Pseudomonas fluorescens Using Response Surface Methodology. Water and Soil Science 4.2: 299-324. (In Persian with English abstract)
4- Ashrafi-Saeidlou S., Rasouli-Sadaghiani M.H., Asadzadeh F., and Barin M. 2017a. Quantitative Modeling of the Potassium Release from Feldspar by Bacillus sp. Iranian Journal of Soil and Water Research 1: 95-103. (In Persian with English abstract)
5- Ashrafi-Saeidlou S., and Rasouli-Sadaghiani M.H. 2017b. Potassium release kinetics from K-bearing minerals in presence of silicate-solubilizing microorganisms. Iranian Journal of Soil and Water Research 3: 639-649. (In Persian with English abstract)
6- Ashrafi-Saeidlou1 S., Rasouli-Sadaghiani M.H., Samadi A., Barin M., and Sepehr E. 2018. Evaluation of non-exchangeable potassium release from K-bearing minerals by different extractants. Journal of Water and Soil 31(6): 1740-1754. (In Persian with English abstract)
7- Avakyan Z.A., Belkanova N.P., Karavaiko G.I., and Piskunov V.P. 1985. Silicon compounds in solution bacteria quartz degradation. Microbiology 54(2): 250-256.
8- Bin L. 1998. A study on how silicate bacteria GY92 dissolves potassium from illite. Acta Mineralogica Sinica 2: 018.
9- Chapman H.D., and Pratt P.F. 1978. Methods of analysis for soils, plants and waters. p. 30-43. Division of Agricultural Sciences. University of California, Berkeley, USA.
10- Chen H., and Chen T. 1960. Characteristics of morphology and physiology and ability to weather mineral baring phosphorus and potassium of silicate bacteria. Microorganism 3: 104–112.
11- Cunningham J.E., and Kuiack C. 1992. Production of citric acid and oxalic acid and solubilization calcium phosphate by penicillium billai. Applied and Environmental Microbiology 58: 1451–1458.
12- Dordipour E., Farshadi-Raad A., and Arzanesh M. 2010. Effect of Azotobacter chrococoum and Azospirillum lipoferum on the release of soil potassium in pot culture of soybean (Glycine max var. Williams) Journal of Agroecology 2: 593-599. (In Persian with English abstract)
13- Friedrich S., Platonova N.P., Karavaiko G.I., Stichel E., and Glombitza F. 1991. Chemical and microbiological solubilization of silicates. Acta Biotechnologica 11(3): 187-196.
14- Gangoliya S.S., Kishor G., and Singh N.D. 2015. Phytase production through response surface methodology and molecular characterization of Aspergillus fumigatus NF191. Indian Journal of Experimental Biology 53: 350-355.
15- Garrido‐Vidal D., Pizarro C., and Gonzalez‐Saiz J.M. 2003. Study of process variables in industrial acetic fermentation by a continuous pilot fermentor and response surfaces. Biotechnology progress 19(5): 1468-1479.
16- Hosseinpur A.R. 2004. Application of Kinetic Models in Describing Non-exchangeable Potassium Release in Some Soils of Hamadan. Journal of Sciences and Technology of Agriculture and Natural Resources 8: 3.85-94. (In Persian)
17- Illmer P., and Schinner F. 1992. Solubilization of hardly-soluble AlPO4 with P-solubilizing microorganisms. Soil Biology and Biochemistry 24: 389-395.
18- Lian B., Fu P.Q., Mo D.M., and Liu C.Q. 2002. A comprehensive review of the mechanism of potassium releasing by silicate bacteria. Acta Mineralogica Sinica 22(2): 179-183.
19- Lian B., Wang B., Pan M., Liu C., and Teng H.H. 2008. Microbial release of potassium from K-bearing minerals by thermophilic fungus Aspergillus fumigatus. Geochimica et Cosmochimica Acta 72(1): 87-98.
20- Liu W., Xu X., Wu X., Yang Q., Luo Y., and Christie P. 2006. Decomposition of silicate minerals by Bacillus mucilaginosus in liquid culture. Environmental Geochemistry and Health 28(1-2): 133-140.
21- Liu D., Lian B., and Dong H. 2012. Isolation of Paenibacillus sp. and assessment of its potential for enhancing mineral weathering. Geomicrobiology Journal 29(5): 413-421.
22- Malakouti M.J., Shahabi A., and Bazargan K. 2006. Potassium in Iran agriculture. Sana publication, Tehran, Iran. (In Persian)
23- Mao J., Kwak I., Sathishkumar M., Sneha K., and Yun Y.S. 2011. Preparation of PEI-coated bacterial biosorbent in water solution: optimization of manufacturing conditions using response surface methodology. Bioresource Technology 102: 1462– 1467.
24- Meena V.S., Maurya B.R., Verma J.P., Aeron A., Kumar A., Kim K., and Bajpai V.K. 2015. Potassium solubilizing rhizobacteria (KSR): isolation, identification, and K-release dynamics from waste mica. Ecological Engineering 81: 340-347.
25- Mousavi A., Khiamim F., and Shariatmadari H. 2015. The kinetics of potassium release from K-feldspar, compared with muscovite under the influence of different extractants. Journal of Sciences and Technology of Agriculture and Natural Resources 67: 229-240. (In Persian with English abstract)
26- Padmavathi T. 2015. Optimization of phosphate solubilization by Aspergillus niger using plackett-burman and response surface methodology. Journal of Soil Science and Plant Nutrition 15(3): 781-793.
27- Prasad M.P. 2014. Optimization of fermentation conditions of phosphate solubilizing bacteria- a potential bio fertilizer. Merit Research Journal of Microbiology and Biological Sciences 2(2): 031-035.
28- Sarikhani M.R., Oustan S., Ebrahimi M., and Aliasgharzad N. 2018. Isolation and identification of potassium-releasing bacteria in soil and assessment of their ability to release potassium for plants. European Journal of Soil Science 69: 1078–1086.
29- Shahab S., and Ahmed N. 2008. Effect of various parameters on the efficiency of zinc phosphate solubilization by indigenous bacterial isolates. African Journal of Biotechnology 7 (10): 1543-1549.
30- Sharmila M., Ramanand K., and Sethunathan N. 1989. Effect of yeast extract on the degradation of organophosphorus insecticides by soil enrichment and bacterial cultures. Canadian Journal of Microbiology 35: 1105-1110.
31- Sheng X.F., and Huang W.Y. 2002. Study on the conditions of potassium release by strain NBT of silicate bacteria. Scientia Agricola 35: 673-677.
32- Singh G., Biswas D.R., and Marwaha T.S. 2010. Mobilization of potassium from waste mica by plant growth promoting rhizobacteria and its assimilation by maize (Zea mays) and wheat (Triticum aestivum L.): a hydroponics study under phytotron growth chamber. Journal of Plant Nutrition 33(8): 1236-1251.
33- Sparks D. L. 1989. Kinetics of Soil Chemical Processes. Academic Press, Sandiego, CA.
34- Štyriakova I., Štyriak I., Nandakumar M.P., and Mattiasson B. 2003. Bacterial destruction of mica during bioleaching of kaolin and quartz sands by Bacillus cereus. World Journal of Microbiology and Biotechnology 19(6): 583-590.
35- Swetha S., Varma A., and Padmavathi T. 2014. Statistical evaluation of the medium components for the production of high biomass, a-amylase and protease enzymes by Piriformospora indica using Plackett–Burman experimental design. Biotechnology 4: 439–445.
36- Tisdale S.L., Nelson W.L., Beaton J.D., and Havlin J.L. 2003. Soil Fertility and Fertilizers. Prentice-Hall of India, New Delhi, India.
37- Ullman W.J. Kirchman D.L. Welch S.A., and Vandevivere P. 1996. Laboratory evidence for microbioally mediated silicate mineral dissolution in nature. Chemical Geology 132(1): 11-17.
38- Whitelaw M.A. 2007. Growth promotion of plants inoculated with phosphate solubilizing fungi. Advances in Agronomy 69: 99-151.