This study is on the optimization of the medium for solubilization of phosphate based on the Box-Behnken design and response surface methodology. Optimization of the liquid medium for phosphate solubilization using Serratia marcescens strain AGKT4 was carried out by varying the concentrations of 3 ingredients; the fructose, peptone and inoculum size of bacteria. A mathematical model derived from the response surface methodology was then validated statistically for the target test variables. The highest phosphate solubilization in the medium was achieved at the optimal concentrations of fructose and peptone at 6% (w/v) and 0.6% (w/v), respectively. The maximum phosphate solubilization at these concentrations was 239.12 µg/mL. Under the same conditions, the bacterial growth in the medium was 9 log10 CFU.
___
Ashraf AN, Zulkefly S, Adekunle SM, Samad MYA. 2017. Growth and Biomass yield of Oil Palm (Elaeis guineensis) Seedlings as Influenced by Different Rates of Vermicompost. Euro J of Engineer Res and Sci., 2: 17-21. Available from: http://ejers.org/index.php/ejers/article/view/405/188. [31.08.2017].
Beringer JE. 1974. R factor transfer in Rhizobium leguminosarum. Microbio., 84: 188-198. Available from:http://www.microbiologyresearch.org/docserver/fulltext/m icro/84/1/mic-84(1)/[188].pdf. [20.7.2017].
Chabot R, Antoun H, Cescas MP. 1996. Growth promotion of maize and lettuce by phosphate-solubilizing Rhizobium leguminosarum biovar. phaseoli. Plant and soil, 184: 311-321. Available from: https://link.springer.com/article /10.1007/BF00010460.[25.05.2017].
Chang CH, Yang SS. 2009. Thermo-tolerant phosphate-solubilizing microbes for multi-functional biofertilizer preparation. Bioresource Tech. 100: 1648-1658. Available from: http://www.sciencedirect.com/science/article/pii/S09608524080 0775X. [15.6.2017].
Chen YP, Rekha PD, Arun AB, Shen FT, Lai WA,Young CC. 2006. Phosphate solubilizing bacteria from subtropical soil and their tricalcium phosphate solubilizing abilities. Appl soil ecolo., 34: 33-41. Available from: http://www.sciencedirect.com/science/ article/pii/S0929139306000047. [21.6.2017].
Chen Z, Ma S, Liu LL. 2008. Studies on phosphorus solubilizing activity of a strain of phosphobacteria isolated from chestnut type soil in China. Bioresource tech. 99: 6702-6707. Available from: http://www.sciencedirect.com/science/article/pii/ S0929139306000047. [16.7.2017].
Design Expert® Version 7.1.5. (2007). Stat-Ease, Inc. 2021 E. Hennepin Ave., Suite 480 Minneapolis, MN 55413-2726.
Dong CH, Xie X.Q, Wang XL, Zhan Y, Yao YJ. 2009. Application of Box-Behnken design in optimisation for polysaccharides extraction from cultured mycelium of Cordyceps sinensis. Food and bioprod proc., 87: 139-144. Available from: http://www.sciencedirect.com/science/article/pii/S09603085080 00588. [23.5.2017].
Ebrahimpour A, Rahman RNZRA, Ch'ng DHE, Basri M, Salleh AB. 2008. A modeling study by response surface methodology and artificial neural network on culture parameters optimization for thermostable lipase production from a newly isolated thermophilic Geobacillus sp. strain ARM. BMC biotech. 8: 96. Available from: https://bmcbiotechnol.biomedcentral.com/ articles/10.1186/1472-6750-8-96.[27.6.2017].
El-Tarabily KA, Nassar AH, Sivasithamparam K. 2008. Promotion of growth of bean (Phaseolus vulgaris L.) in a calcareous soil by a phosphate-solubilizing, rhizosphere-competent isolate of Micromonospora endolithica. Appl soil ecolo., 39: 161-171. Available from: http://www.sciencedirect.com/science/article/ pii/S0929139307001837 [13.6.2017].
Guanrong H, Dehui D, Welian H, and Jiaxin J. 2008. Optimization of medium composition for thermostable protease production by Bacillus sp. HS08 with a statistical method. Afr J Biotech 7: 1115-1122. Available from: https://www.ajol.info/index.php/ ajb/article/view/58630.[15.7.2017].
Gurkok S, Cekmecelioglu D, Ogel ZB. 2011. Optimization of culture conditions for Aspergillus sojae expressing an Aspergillus fumigatus α-galactosidase. Bioresource tech.102: 4925-4929. Available from: http://www.sciencedirect.com/ science/article/pii/S0960852411001040. [10.07. 2017].
Hameeda B, Harini G, Rupela OP, Wani SP, Reddy G. 2008. Growth promotion of maize by phosphate-solubilizing bacteria isolated from composts and macrofauna. Microbiol Res 163: 234-42. Available from: http://www.sciencedirect.com/ science/article/pii/S0944501306000589.[12.5.2017].
Rahi P, Pathania V, Gulati A, Singh B, Bhanwra RK., Tewari R. 2010. Stimulatory effect of phosphate-solubilizing bacteria on plant growth, stevioside and rebaudioside-A contents of Stevia rebaudiana Bertoni. Appl soil ecolo, 46:222-229. Available from: http://www.sciencedirect.com/science/article/pii/ S0929139310001344. [27.8.2017].
Lai YF, Shieh CJ. 2000. Application of response surface methodology to the study of Methyl glucoside polyester synthesis Parameters in a Solvent–free System. J Agric Food Chem, 48: 1124-1128. Available from: http://pubs.acs.org/doi/abs/10.1021/jf990460f [27.7.2017].
Nautiyal CS. 1999. An efficient microbiological growth medium for screening phosphate solubilizing microorganisms. FEMS microbiology Letters, 170: 265-270. Available from: https://academic.oup.com/femsle/article/170/1/265/454487/[26. 8.2017].
Ratti N, Kumar S, Verma HN, Gautam SP. 2001. Improvement in bioavailability of tricalcium phosphate to Cymbopogon martinii var. motia by rhizobacteria, AMF and Azospirillum inoculation. Microbiolog research, 156: 145-149. Available from: http://www.sciencedirect.com/science/article/pii/S09445013047 00221[14.7.2017].
Rudresh DL, Shivaprakash MK, Prasad RD. 2005. Effect of combined application of Rhizobium, phosphate-solubilizing bacterium and Trichoderma spp on growth, nutrient uptake and yield of chickpea (Cicer aritenium). Appl Soil Ecol, 28: 139- 146. Available from: http://www.sciencedirect.com/science/ article/pii/S092913930400099X[13.6.2017
Ryad A, Lakhdar K, Majda KS, Samia A, Mark A, Corinne AD, Eric G. 2010. Optimization of the culture medium composition to improve the production of hyoscyamine in elicited Datura stramonium L. Hairy roots using the response surface methodology (RSM). Int J Mol Sci, 11: 4726-4740. Available from: http://www.mdpi.com/1422-0067/11/11/4726/htm [29.7.2017].
Adekunle SM. 2014. Influence of fertilizer rates on growth of selected immature rubber (Hevea brasiliensis Muell. arg) clones grown on two soil series. M.Sc. Thesis. UPM, Malaysia.
Son HJ, Park GT, Cha MS, Heo MS. 2006. Solubilization of insoluble inorganic phosphates by a novel salt-and pH-tolerant Pantoea agglomerans R-42 isolated from soybean rhizosphere. Bioresource Techn. 97: 204-210. Available from: http://www.sciencedirect.com/science/article/pii/S09608524050 01434[13.5.2017].
Subba Rao NS. 1982. Biofertilizers in Agriculture. A.A.Balkema, Rotterdam
Vohra A, Satyanarayana T. 2002. Statistical optimization of the medium components by response surface methodology to enhance phytase production by Pichia anomala. Process Biochemistry, 37: 999-1004. Available from: http://www.sciencedirect.com/science/article/pii/S00329592010 03089[14.8.2017].
Wu SC, Cao ZH, Li ZG, Cheung KC, Wong MH. 2005. Effects of biofertilizer containing N-fixer, P and K solubilizers and AM fungi on maize growth: a greenhouse trial. Geoderma, 125:155- 166. Available from: http://www.sciencedirect.com/science/ article/pii/S0016706104001922[26.6.2017].
Ye D, Xu ZN, Cen PL. 2008. Medium optimization for enhanced production of cytosine-substituted mildiomycin analogue (MILC) by Streptoverticillium rimofaciens, ZJU 5119. J Zhejiang Univ (Sci. B) 9: 77-84. Available from: https://link.springer.com/article/10.1631/jzus.B071372[15.07.20 17].
Yusoff MAS. 2008. Effect of carbon and nitrogen sources on phosphate solubilization by selected bacterial isolates. Unpublished raw data.
Zhang J, Gao N. 2007. Application of response surface methodology in medium optimization for pyruvic acid production of Torulopsis glabrata TP19 in batch fermentation. J Zhejiang Univ (Sci. B) 8: 98-104. Available from: https://link.springer.com/article/10.1631/jzus.2007.B0098[ 24.6.2017].
Tadijan Dodić J, Maširević S, Grahovac J, Vućurović D, Dodić S. 2014. Effect of carbon sources on the production of the biofungicide by Streptomyces hygroscopicus. Acta Univ. Sapientiae Alimentaria 7: 54-62.