Int.J.Curr.Microbiol.App.Sci (2013) 2(10): 142-149

ISSN: 2319-7706 Volume 2 Number 10 (2013) pp. 142-149 http://www.ijcmas.com

Original Research Article Isolation, characterization of producing Bacillus sps NBtRS6 from the rhizospere soil of NBt cotton field

K.Ushasri*, P.Sivaragini and .K.Vijayalakshmi

Department of Applied Microbiology, S.P.M.V.V. Tirupati - 517 502 A. P. India *Corresponding author

A B S T R A C T

K e y w o r d s Soil samples of Bt Rhizosphere were collected from NBt cotton growing area of Andhra Pradesh, India and was used as a source material for isolation and Immobilized screening of phytase producing bacteria. 21 Bacteria were isolated from NBt P; Rhizosphere. Phytase activity of the cultures was screened on Modified Rhizosphere; phytase solubulizing medium (MPSM). The result inferred that six isolates ; NBtRS1 to NBtRS6 were strongly positive in enzyme activity than six of other Phospho- microorganisms while nine isolates were found negative and among all ,Isolate rylation; NBtRS6 produced significantly higher phytase yield than other isolates and was chosen for species identification. Preliminary identification by microscopic and Tropical phosphates Soils. biochemical tests identified the isolate NBtRS6 as Bacillus sp and designated as Bacillus sp NBtRS6.

Introduction

In nature, phosphorus cycle plays an (both organic and inorganic) to a form important role in the survival of living accessible to the plants, like organisms (Stewart and Mckercher, 1982). orthophosphate, is an important trait for a There are two components of P in soil, PGPB for increasing plant yields. organic and inorganic phosphates. A large is an enzyme that release proportion is present in insoluble forms, inorganic phosphate from organic moiety and therefore, not available for plant and complex inorganic materials. It is nutrition. Inorganic P occurs in soil, known to play an essential role in mostly in insoluble mineral complexes, phosphorus cycle, even though; roles of some of them appearing after the other various physical factors cannot be application of chemical fertilizers. These ignored. Phosphorus is the maker of the precipitated forms cannot be absorbed by energy currency and it plays important plants. Organic matter, on the other hand, roles in enumerable metabolic pathways in is an important reservoir of immobilized P living systems (Rasol and Reshi, that accounts for20 80% of soil P 2010).Cellular signaling events cascaded (Richardson, 1994). To convert insoluble with phosphorylation and

142 Int.J.Curr.Microbiol.App.Sci (2013) 2(10): 142-149 dephosphorylation, are associated with an randomly collected from three sites (1 m enzyme called phosphatase (EC 3.1.3.-). apart) to make a composite sample and Soil receives various phosphatases from this was used for bacterial screening. One living organisms that play important roles gram of each sample was suspended in 10 in the solubilization of inorganic ml of sterile distilled water & was serially phosphates (Acosta-Mortinez and diluted and 10-3&10-4 dilutions of each Tabatabai, 2000). Enzymatic activities of a sample were spread on to nutrient agar soil sample are critical index of soil medium and incubated for two days. fertility because play an important role in nutrient cycles (Dick et Screening for best phytase producing al., 1996). In particular, phosphatases play isolate a key role in phosphorous cycle by solubilizing organic and inorganic The plate screening was carried out for 21 phosphates into available forms that isolates from nutrient agar medium The support growth of crop plants colonies of nutrient agar were isolated (Wyszkowska and Wyszkowski, 2010). individually on(MPSM) modified phytase Released inorganic form of phosphate is screening media containing Na phytate- readily soluble in soil and plant system can 2g/L, NH4NO3- 5g/L, MgSO4-0.5g/L, easily uptake it as nutrient source. Soil KCl -0.5g/L,FeSO4-0.1g/L, glucose- phosphatases are heterogeneous in nature 15g/L, bactoagar-15g/L, CaCl2-8% and and the enzymes have tribal names, PH 6.5 was adjusted. The plates were according to their substrates (Alvear et al., incubated 37ºC for 24h. To visualize the 2005), such as phosphoric monoester Clear zone equal volumes of 6.25% , (EC 3.1.3.) and phosphoric ammonium molybdate and 0.42% diester hydrolases (EC 3.1.4.). Importantly ammonium vanadate solution are flooded, the first group is composed of phytase, in the plate and incubated and can be , sugar phosphatases, examined for zones of clearing indicative glycerophosphatase (Cohen, 1989). of phytase activity. Efficient phytate However, the second group contains solubulizer was selected based on the and (Speir and formation of larger clearing zones on Ross, 1978). The present study MPSM agar (Yanke et al., 1998). investigated the best phytase producer from rhizosphere of conventional cotton Identification of selected isolate field. Morphological and Biochemical tests Materials and Methods The strain was initially examined for cell Isolation of phytatase producing morphologies and cell arrangement by bacteria gram staining, presence or absence of spores and capsules and motility using Isolation of the phytase-producing bacteria microscopy. Various morphological and was carried out by sampling soil from biochemical tests were carried out by the NBt cotton fields in Andhraprdesh. Soil techniques described in the Mackie and samples (0-15 cm depth) were collected McCartney Practical Medical using a sterile stainless steel spatula into a Microbiology .The various biochemical sterile jar. Three replicate samples were tests carried out were Indole test, Methyl

143

Int.J.Curr.Microbiol.App.Sci (2013) 2(10): 142-149 red test, Voges proskauer test, Citrate utilization tests, catalase, oxidase, urease, Result and Discussion nitrate reduction, starch hydrolysis, gelatin hydrolysis, H2S production and Phytase producing bacteria was identified carbohydrate fermentation tests. The by Morphological, Cultural and isolate was tested for fermentation of Biochemical characteristics of the selected various sugars like Glucose, Lactose, bacterial isolate NBtRS6 was carried out Mannitol, Maltose, Sucrose, Xylose and according to the Guidelines of Bergey s Galactose, growth at various temperatures Manual of Systemic Bacteriology. (4, 10, 30, 37, 40, 45, 50, 55), NaCl Morphological studies had revealed that requirement (2,4,6,8,10),growth at the NBtRS6 was was aerobic endospore different pH (5,6,7,8,9). forming, non pigmented and wrinkled with concentric rings. The organism was positive for growth under anaerobic Phytase production by the isolate conditions. The growing cells were Gram positive, motile with rod shape. BtRS6 The six phytase producers NBtRS1 to showed positive results for casein NBtRS6 were inoculated in to Tryptone hydrolysis, Voges proskauer, Citrate Soya broth and incubated at 37ºC for 24 h. utilization, Urease, H2S production, Starch 40 L calcium phytate was added as an hydrolysis, Lecithinase, Gelatin inducer. The phosphate liberated was liquefaction, Arginine dihydrolysis, and quantified after 2 days. Culture broth was Phosphate solubilization reactions. The centrifuged at 5,000 rpm for 5 min and NBtRS6 was also positive for the 350 L of 0.1 M Tris malate buffer to utilization of sugars like Starch, Maltose, 50 L supernatant to which 4 L of sodium Glucose, Lactose, Mannitol ,Maltose, phytate was added and incubated at 37ºC Sucrose, Galactose, Glycerol. Negative for 30 min. 100 L reaction sample was towards suucinate, R -Alanine, L- added to the solution containing 10mM Histidine, L-Lucine, D-Alanine. ammonium molybdate solution: 5 N H2SO4 : acetone in the ratio of 1:1:2. The isolate grew well in nutrient broth at Enzyme reaction was allowed for 30 min pH range of 7.0 to 9.0 and showed salt and the observance of sample was tolerance at NaCl concentration up to 10 measured at 405 nm (Heinonenand Lahti, (w/v) .Bacterial growths was observed in 1981). the temperature ranging from 4ºC 55ºC with an optimum growth around 37ºC. It The liberation of reducing sugar was was identified as Bacillus sps and measured by dinitrosalicylic acid (DNS) designated as Bacillus NBtRS6.After method (Miller, 1959). One unit (U) of Identification of bacterial culture, the phytase was defined as the amount of efficacy of the organism for phytase enzyme required to liberate one micromole production was determined using the basal inorganic phosphate per min under the mineral salts medium. Phytase activity given assay conditions. Bacillus sps was of NBtRS6 isolate was determined NBtRS6 exhibited highest phytase activity according to Tryptic Soya Method. in terms of calcium phytate Units.

144

Int.J.Curr.Microbiol.App.Sci (2013) 2(10): 142-149

Table.1 Hydrolysis efficiency of the isolates

Colony diameter, Halo diameter, Hydrolysis Efficiency, Isolate C (mm) Z (mm) Z-C/C(%) NBtRS1 11 22 100 NBtRS2 12 27 125 NBtRS3 10 21 110 NBtRS4 15 32 113 NBtRS5 11 23 109 NBtRS6 12 30 150 NBtRS7 30 35 17 NBtRS8 8 9 12.5 NBtRS9 33 36 9 NBtRS10 30 32 7 NBtRS11 28 33 18 NBtRS12 20 24 20

A total of 21 colonies showed growth on there is no large atmospheric source that nutrient agar media plates on incubation. can be made biologically available (Ezawa Out of 21 colonies, six were strongly et al., 2002). Root development, stalk and positive in enzyme activity than six of stem strength, flower and seed formation, other microorganisms, as indicated by the crop maturity and production-fixation in clear zone of hydrolysis around them. legumes, crop quality, and resistance to While NINE isolates were found negative plant diseases are the attributes associated for phytase production on MPSM. And are with phosphorus nutrition.. Soil P designated as NBtRS1-NBtRS21. Among dynamics is characterized by the 21 isolates, NBtRS6 isolate which physicochemical (sorption-desorption) and showed maximum activity was biological (immobilization-mineralization) characterized as Bacillus sps NBtRS6. processes.

The amount of soluble reducing sugars Soil microorganisms play a key role in soil that was glucose released from production P dynamics and subsequent availability of sugars was determined. Phytase activity phosphate to plants (Richardson, 2001). was expressed in terms of inorganic Release of organic anions, and production phosphate released. The volume of of siderophores and by NBtRS6 isolate filterate responsible for Plant roots / microbes (Yadaf and release of 1 mole of phytase per min was Tarafdar, 2001) or considered to be one unit of inorganic (Tarafdar and Claasen, 1988) enzymes phosphate. Since Bacillus NBtRS6 had hydrolyze the soil organic P or split P been detected to exhibit highest phytase from organic residues. The largest portion activity in terms of 0.08U/ml . of extracellular soil phosphatases is derived from the microbial population Phosphorus (P) is a major growth-limiting (Dodor and Tabatabai, 2003 nutrient, and unlike the case for nitrogen,

145

Int.J.Curr.Microbiol.App.Sci (2013) 2(10): 142-149

Table.2 Morphological and biochemical tests for identification of Bacterial isolate

Identification tests Bacterial isolate Colony morphology Configuration Round, Concentric, Cream, Wrinkled Margins Entire Surface Butyraceous Elevation Slightly Raised Pigmentation - Opacity Opaque Gram s reaction Positive Cell shape Rods Size( m) 3-5 m in length, width 1.0 -1.2 m in width Spores + Motility +

Physiological tests

Growth at temperature 40C - 100 C - 300 C + 370 C + 400 C + 450 C + 500 C + 550 C +

Growth in NaCl (%)

2 + 4 + 6 + 8 + 10 +

Growth at Ph

5 - 6 - 7 + 8 + 9 + Growth under anaerobic condition +

146

Int.J.Curr.Microbiol.App.Sci (2013) 2(10): 142-149

Biochemical tests

Indole test Methyl red test - Voges proskauer test + Citrate utilization test - H2S production - Gelatin hydrolysis + Urea hydrolysis + Starch hydrolysis + Lectinase + (Tween 80 hydrolysis) - Catalase test + Oxidase test - Denitrification - Arginine dihydrolase + Phosphate solubilization + Chitinase + Casein hydrolysis + Degradation of Tyrosine + Nutritional characteristics Starch + Maltose + Glucose + Lactose+ Mannitol + Maltose+ Sucrose+ Galactose+ Xylose- Glycerol + suucinate - L-Alanine - L-histidine - L-lucine - D-alanine

Microorganisms are integral to the soil the dephosphorylating action on organic phosphorus (P) cycle and as such play an compounds by a wide spectrum of important role in mediating the availability enzymes released from microorganisms. It of P to plants. Organic phosphate can be is essential to bring about some microbial solubilized by bacterial Organic acids, transformations of both inorganic and after which free phosphates may organic compounds in soil to make sometimes be liberated by hydrolysis or available of this element to plants.

147 Int.J.Curr.Microbiol.App.Sci (2013) 2(10): 142-149

Enterobacter agglomerans solubilizes phosphatases of microbiological hydroxyapatite and hydrolyze the organic origin. Inositol phosphate P (Kim et al ., 1998). Mixed cultures of intermediates in the dephosphorylation PSMs (Bacillus, Streptomyces, and of the hexaphosphates of myo-inositol, Pseudomonas etc.) are most effective in scylloinositol, and D-chiroinositol by a mineralizing organic phosphate (Molla et bacterial (Pseudomonas sp.) phytase. al., 1984). The mineralization of Aust. J. Biol. Sci. 23: 1207-1220. organically bound phosphorus, which Dodor, D. E., and Tabatabai, A.M. 2003. forms a major fraction of the soil P capital Effect of cropping systems on (Harrison, 1979), is essential to the phosphatases in soils. J. Plant Nutr. maintenance of the phosphorus cycle and Soil Sci. 166:7 13. the Replenishment of the available P in the Ezawa, T., S. E. Smith and Smith, F.A. soil in forest ecosystems (Harrison, 1985). 2002. P metabolism and transport in AM fungi. Plant Soil 244:221- The insightful microbial contribution to 230.Richardson, A. E. 2001. Prospects plant P nutrition and opportunities for for using soil microorganisms to manipulating specific microorganisms to improve the acquisition of phosphorus enhance P availability in soil has therefore by plants. Aust. J. Plant Physiol. been of considerable interest over many 28:897-906. decades. This interest is accentuated by P Harrison, A.F., 1985. Effects of deficiency being common in weathered environment and management on and tropical soils throughout the world, by phosphorus cycling in terrestrial rising costs of P fertilizer, and because the ecosystems. J .Environ. Manage. 20 efficiency of P use by plants from soil and :163 179 fertilizer sources is often poor despite Heinonen, J. K., and Lahti, R. J. 1981. A many soils containing a relatively large new and convenient colorimetric amount of total P that is only sparingly determination of inorganic available to plants.. Exploitation of orthophosphate and its application to microorganism s to increase the the assay of inorganic availability of P in soil therefore is an pyrophosphatase. Anal. Biochem.113: attractive suggestion for developing a 313-317. more sustainable agriculture. Joel, R., Cherry, E. Glenn and Falholt, N.P. 2003. Encyclopedia of References environmental microbiology Enzymes: Biotechnological Applications. Barbaric, S., B. Kozulic, B. Reis, and Kim, K. Y., D., Jordan and McDonald, Mildner, P. 1984. Physicochemical and G.A. 1998. Effect of phosphate- kinetic properties of acid phosphatase solubilizing bacteria and vesicular- from Saccharomyces cerevisiae. J. arbuscular mycorrhizae on tomato Biol. Chem. 259: 878-879. growth and soil microbial activity. Cappuccino, J. G., and Sherman, N. 2010. Biol. Fert.Soils. 26:79-87. phosphate solubulization. In Latif, A. E., and Hashem. 2011. Microbiology a Laboratory Manual. Molecular Genetic Identification of International student edition.8th Ed. Yeast Strains Isolated from Egyptian Addison Wesely Publication. 343-344. Soils for Solubilization of Inorganic Cosgrove, D. J., 1970. Inositol phosphate Phosphates and Growth Promotion of

148 Int.J.Curr.Microbiol.App.Sci (2013) 2(10): 142-149

Corn Plants. J. Microbiol. Biotechnol. 21(1): 55-61. Rodriguez, H., R. Fraga, T. Gonzalez and Miller, G. L. 1959. Use of dinitrosalicylic Bashan, Y. 2007. Genetics of acid reagent for determination of phosphate solubilization and its reducing sugars. Analytical Chemistry. potential applications for improving 31: 426-428. plant growth-promoting bacteria. Molla, M. A. Z., A. A. Chowdhury, A. Developments in Plant. Soil. Sci. 102: Islam and Hoque, S. 1984. Microbial 15-21. mineralization of organic phosphate in Tarafdar, J. C., and Claasen.N. 1988. soil. Plant. Soil. 78: 393-399. Organic phosphorus compounds as a Nannipieri P., J. Ascher, M.T. Ceccherini, phosphorus source for higher plants L. Landi, G. Pietramellara and Renella, through the activity of phosphatases G. 2003. Microbial diversity and soil produced by plant roots and functions. European. J. Soil Sci. 54: microorganisms. Biol. Fert. Soils 655 670. 5:308-312. Pandey, A., P. Trivedi and Palni, L.M.S. Turner, B. L., A.E. Richardson and 2004. Carrier-based Preparations of Mullaney, E. J. 2007. Inositol Plant Growth-promoting Bacterial Phosphates:Linking Agriculture and Inoculants Suitable for use in Cooler the Environment. CAB International, Regions. World J. Microbiol. Wallingford, UK. pp. 304. Biotechnol. 21(6-7): 941-945. Yadaf, R. S., and Tarafdar, J.C. 2001. Powar, V. K., and Jagannathan, V. 1982. Influence of organic and inorganic Purification and properties of phytate- phosphorus supply on the maximum specific phosphatase from Bacillus secretion of acid phosphatase by subtilis. J. Bacteriol.151: 1102-1108. plants. Biol. Fert. Soils. 34:140-143. Richardson, A. E., T.S. George, M. Hens Yanke, L. J., H.D. Bae, L.B. Selinger and and Simpson, R. J. 2005.Utilization of Cheng, K. J. 1998. Phytase activity of soil organic phosphorus by higher anaerobic ruminal bacteria. Microbiol. plants. In B.L. Turner, E. Frossard, and 144: 1565-1573. D. Baldwin. (Ed.), Organic Phos- phorus in the Environment. CABI Publishing, Wallingford, UK. pp.165- 184.

149