Abstract: The present study has been focused widely on comparative account of probiotic qualities of Bacillus spp. for safer usage. Initially, 170 heat resistant flora were isolated and selected for non-pathogenic cultures devoid of cytK, hblD, and nhe1 virulence genes. Subsequently, through biochemical tests along with 16S rRNA gene sequencing and fatty acid profiling, the cultures were identified as Bacillus megaterium (AR-S4), Bacillus subtilis (HR-S1), Bacillus licheniformis (Csm1-1a and HN-S1), and Bacillus flexus (CDM4-3c and CDM3-1). The selected cultures showed 70–80 % survival under simulated gastrointestinal condition which was also confirmed through H+-ATPase production. The amount of H+-ATPase increased by more than 2-fold when grown at pH 2 which support for the acid tolerance ability of Bacillus isolates. The study also examined the influence of acidic pH on cellular fatty acid composition of Bacillus spp. A remarkable shift in the fatty acid profile was observed at acidic pH through an increased amount of even numbered fatty acid (C16 and C18) in comparison with odd numbered (C15 and C17). Additionally, the cultures exhibited various probiotic functional properties. Overall, the study increases our understanding of Bacillus spp. and will allow both industries and consumers to choose for well-defined probiotic with possible health benefits.

Abstract: The purpose of this study was to evaluate the incidence and characterisation of aerobic spore-forming bacteria originating from dairy milk in Tunisia. The distribution of Bacillus species in raw milk, pasteurised milk and UHT milk were 47.5%, 27.5% and 25%, respectively. Seven Bacillus species, including Bacillus pumilus (10%), Bacillus subtilis (12.5%), Brevibacillus brevis (10%), Bacillus cereus (22.5%), Bacillus sphaericus (7.5%), Bacillus licheniformis (12.5%) and Bacillus sporothermodurans (25%) were identified in different milk samples. Bacillus cereus was predominant in raw and pasteurised milk. Although B. sporothermodurans was the predominant sporogenous micro-organism in UHT milk, B. cereus, B. sphaericus and B. licheniformis were also present. This study showed that there is a high degree of diversity, both phenotypic and genotypic, among Bacillus isolates from Tunisian milk and the persistence of spoilage risk in UHT milk.

Abstract: The study presents the first report on biocontrol of brown sheath rot disease of rice caused by Pseudomonas fuscovaginae using rhizo-bacterial isolate Bacillus amyloliquefaciens Bk7. Four potential bioactive antagonists were selected from 120 Bacillus isolates. Results obtained from in vitro laboratory assay showed that rhizosphere bacterial strain Bk7 and its metabolites significantly suppressed the growth of Pseudomonas fuscovaginae with 93 % efficacy. In glasshouse experiments, strain Bk7 exhibited biocontrol efficacy of 76.6 % by reducing the disease incidence to 16.9 %, compared to 72.8 % observed in control treatment. In addition, the isolate Bk7 showed the growth promotion efficacy of plant height (GPE, 46.4 %) and fresh weight (GPE, 84.3 %). Characterization of isolate Bk7 revealed its strong capability for biofilm formation, inorganic phosphate solubilization and production of high amounts of Indole-3 acetic acid, siderophores and ammonia in vitro. Results obtained from multiplex PCR assay confirmed the presence of five lipopeptide biosynthetic gene markers (srfAA, fenD, bmyB, bacA and ituC) in the genome of strain Bk7. Moreover, Real-time qPCR of these genes demonstrated that surfactin, iturin and bacylisin coding genes were highly expressed in response to P. fuscovaginae exposure in vitro. Rhizosphere bacterial strain Bk7 was identified as B. amyloliquefaciens strain Bk7 based on the analysis of 16S rDNA internal transcribed spacer sequences and a fatty acid methyl ester analysis. The results obtained from this study showed the potential usefulness of Bk7 as a biocontrol agent in disease control of rice brown sheath rot.

Abstract: Rhizosphere bacteria are one of the most potential biological control agents in the plant disease protection. Bacillus species as a group offer several advantages over other bacteria for protection against pathogens because of their ability to form endospores, and because of the broad-spectrum activity of their antibiotics. Five soil samples from tomato rhizosphere were collected from shambat area, Khartoum State, Sudan. Bacillus isolates were isolated from the rhizosphere of tomato to use as natural bio-control agents. They were screened for antagonism in vitro against Alternaria alternata causal agents of early blight disease of tomato. Serial dilution technique was adopted for the isolation of Bacillus species. Only 27 out of 45 Bacillus isolates showed antagonistic properties. Four out of the 27 isolates showed antagonism (Bacillus B25, B35, B41, B45) were identified to the species level by bacteriological assay (morphological and biochemical tests).

Abstract: Background: In this study, we attempted to screen and investigate antibacterial activity of Bacillus species, which were isolated from conjunctiva, against other eyes pathogens. Methods: To examine predominant isolates of Bacillus subtilis, B. pumilus, B. cereus and B. mojevensis, isolated from conjunctiva for their antimicrobial activity against indicator microorganisms as Micrococcus luteus, Staphyloccocus aureus, S. epidermidis, S.hominis, S. lugdunensis, S.warneri, S. haemolyticus, B. cereus, Listeria monocytogenes, and Proteus mirabilis. Growth inhibitions of indicator microorganisms were tested using agar diffusion tests by cells and supernatants of five B. mojevensis, one B. subtilis, four B. cereus and five B. pumilus strains which were isolated from conjunctiva. Results:The Bacillus isolates showed variable ability of inhibition against the tested microorganisms. Two strains of B. pumillus, 1 strain of B. subtilis, 5 strains of B. mojevensis, 1 strain of B. cereus were efficacious against the tested microorganisms. Most resistant microorganism to these bacteria was Proteus mirabilis. Two of Gram positive bacteria, S. lugdenensis (K15-9) and S. aureus (SDA48), were also found as resistant. Conclusions: In this study, Bacillus spp isolated from conjunctiva showed antimicrobial activity against Gram-positive bacteria. Human eye-derived microorganisms and their antimicrobial effects might be a useful source of natural products for the future.

Abstract: Background and Objectives: Bacillus species are attractive industrial organisms due to their rapid growth rates leading to a short fermentation cycle and for their capacity to secrete important enzymes and proteins such as xylanase into the extracellular medium. Considering the industrial importance of xylanase, in this current study, Bacillus spp. were isolated from different soils and were screened for their xylanase production. Materials and Methods: Bacillus isolates used in this study were obtained from a national screening program carried out during 2006-2007 in which soil samples that covered areas throughout the interior of Syria were collected. The prepared inoculum from each of Bacillus isolates was aliquoted onto xylan agar plates, incubated at 30 ° C for 72 h and screened for xylanase synthesis. Results: Xylanolytic isolates were selected depending on the clear zones of xylan hydrolysis. Fifteen isolates having the highest clearing zone were determined and grown in a solid state fermentation. Of the 15 isolates, three bacilli namely SY30A, SY185C and SY190E that showed maximum xylanase production, were identified using the 16S rDNA sequencing method. According to 16S rDNA gene sequence data, the closest phylogenetic neighbor for SY30A was Bacillus pumilus and for SY185C and SY190E isolates was Bacillus subtilis. Optimal pH and temperature for xylanase activity was 7.0 and 55 ° C for SY30A and 6.0 and 60 ° C for SY185C and SY190E, respectively. Under these conditions, the following activities were found to be around 1157 ± 58, 916 ± 46 and 794 ± 39 (U/g) for SY30A, SY185C and SY190E, respectivly. Conclusions: Selected local Bacillus isolates were found to be a potential source of xylanase which was proven to be quite suitable for multiple biotechnological applications. These isolates might after extensive optimization steps be an alternative to commercially available strains.

Abstract: Microbial lipases are the most valuable Biocatalysts with Industrial applications that show a large variety of enzymatic properties among microbial populations. This study aimed to isolate extracellular lipase-producing Bacilli and their molecular identification in the soils of western Mazandaran, Iran. A total of 50 soil samples with bacterial lipolytic potential were collected from the depth of 10-15 cm of soils in the rural areas of western Mazandaran, Iran. The samples were directly cultured on tributyrin agar medium with Lipidic glycerol butyrate substrate after heat treatment and preparation of serial dilutions. DNA was isolated from bacillus isolates with a clear zone. The molecular identification of isolates was carried out by using 16S rDNA Real Time PCR, High Resolution Melting (HRM), direct sequencing, and sequence alignment in BLAST. The primary properties of lipase enzymes produced by isolates were determined using supernatant of medium culture by spectrophotometer measurement of enzymatic activity at different temperatures, different concentrations of substrate, and relative molecular weight determination of enzymes by SDS-PAGE. Total of 5 gram-positive bacilli was isolated. After identification of biochemical and morphological characteristics, sequence alignment of their 16S rDNAs, the strains were identified as B. megaterium 37-1, Bacillus safensis 1-1, Bacillus pumilus KN-Lip2, Bacillus subtilis KN-Lip3, and Lysinibacillus fusiformis KN-Lip4 in Genbank database. The highest lipase activity of each strain was determined as 626.1069 u/ml and 422.5517 u/ml for B. megaterium 37-1 and B. safensis 1-1, respectively. The relative molecular weight of lipases produced by both strains was about 55 KDa. Vmax and km parameters were calculated by Michaeilis-Menthen hyperbola and Lineweaver-Burk plots. The Vmax value of lipase enzyme produced by B. megaterium 37-1 at 37°C was higher than that produced by B. safensis 1-1. The km values of B. megaterium 37-1 were higher and lower than that of B. safensis 1-1 at 37°C and 55°C, respectively. In this study, lipolytic bacillus isolates were collected and identified from soil of various environments in the northern part of Iran. Among 5 new strains found in this study, B. megaterium 37-1 showed a higher enzymatic activity in compare to other strains.

Abstract: This report is to our knowledge the first to study plant growth promotion and biocontrol characteristics of Bacillus isolates from extreme environments of Eastern Algeria. Seven isolates of 14 (50 %) were screened for their ability to inhibit growth of some phytopathogenic fungi on PDA and some roots exudates. The bacteria identification based on 16S r-RNA and gyrase-A gene sequence analysis showed that 71 % of the screened isolates belonged to Bacillus amyloliquefaciens and the rest were closely related to B. atrophaeus and B. mojavensis. Most of them had high spore yields (22 × 10(8)-27 × 10(8) spores/ml). They produced protease and cellulase cell wall-degrading enzymes while the chitinase activity was only observed in the B. atrophaeus (6SEL). A wide variety of lipopeptides homologous was detected by liquid chromatography-electrospray ionization-mass spectrometry analysis. Interestingly, some additional peaks with new masses were characterized, which may correspond to new fengycin classes. The isolates produced siderophores and indole-3- acetic acid phytohormone. The greenhouse experiment using a naturally infested soil with Sclerotonia sclerotiorum showed that the B. atrophaeus (6SEL) significantly increased the size of the chickpea plants and reduced the stem rot disease (P < 0.05). These results suggest that these isolates may be used further as bio-inoculants to improve crop systems.

Abstract: In the present investigation, three types of Bacilli were isolated from the intestine of Chitala chitala larvae After the morphological, physiological and biochemical characterization the isolates were identified as Bacillus subtilis, B pumilus and B licheniformis A varied extracellular enzymatic (amylolytic, proteolytic and lipolytic) activity was observed among these three isolates during the qualitative and quantitative method of in vitro culture The temperature optimum for growth of the three isolates was ranged between 30 to 40°C with an optimal pH range of 8-10 and salinity 7-9% Among the three isolates the proteolytic and lipolytic activity was found to be the highest in B licheniformis (P<005) and the amylase producing ability was found to be the highest in Bsubtilis (P<005) Thus the present preliminary study will be useful in future to develop the costeffective formulated probiotic feeds for a sustainable culture practice of this valuable species by incorporating these enzyme-producing Bacillus isolates

Abstract: Aim: Quorum quenching of Pseudomonas aeruginosa homoserine lactone signal molecules represents a new approach for control of infection of this pathogenic highly resistant microorganism. The present study aimed at screening of soil for quorum sensing inhibitory bacteria active against clinically isolated P. aeruginosa together with the characterization of their activity and finally identification of promising isolates. Methodology and results: Using a fast, reliable and simple screening method, 161 bacterial isolates collected from soil from different places in Egypt were screened for their quorum quenching activity against synthetic hexanoyl homoserine lactone using Chromobacterium violaceum mutant strain (CV026) as a biosensor. All 32 positive isolates were found to belong to Bacillus species. Secondary screening against the signals extracted from seven Pseudomonas isolates, analyzed by thin layer chromatography, was done. The activity of all the positive isolates was found to be intracellular. Activity against different concentrations of synthetic hexanoyl homoserine lactone showed that some isolates could degrade more than 20 µM even when diluted 100 fold. Selected isolates were found to have broad spectrum activity against other synthetic homoserine lactone standards. Maximum activity for most of the selected isolates was found to occur between 25-60 °C. Crude enzyme extracts of the promising isolates were collected by sonication, protein concentrations of the obtained extracts were measured and their activities were compared by well diffusion method. Finally, the isolates with promising quorum quenching activities were identified using 16S ribosomal RNA sequencing. Conclusion, significance and impact of study: Having high activity against homoserine lactone autoinducers, the enzyme produced by Bacillus isolates represents a new promising antipathogenic drug suppressing Pseudomonas virulence.

Abstract: In order to extend the shelf life of 2 high potential Bacillus probiotic isolates which were Bacillus KKU02 and Bacillus KKU03, the spore forms of these 2 Bacillus isolates were studied for using as probiotic instead. The low cost medium for spore production of these 2 Bacillus isolates was examined in order to produce probiotic spores for feeding the shrimps. It was found that cassava at 100 g L(-1) and supplemented with 20.0 g L(-1) dextrose, 0.1 g L(-1) MgSO4 and 2.0 g L(-1) (NH4)2SO4 showed the highest spore concentration at about 1 x 10(8) CFU mL(-1). The effects of feeding these 2 Bacillus spores on the growth of giant freshwater prawns were further examined. The spores of Bacillus KKU02 and Bacillus KKU03 (-10(7) spore mL(-1)) in pure and mixed culture forms were mixed with commercial prawn feed (200 mL kg(-1)) to give six feed treatments. Body length and weight of the prawns in mixed spore culture tanks after rearing for 90 days (13.5 cm and 59.8 g, respectively) were significantly higher (p = 0.05) than other treatments. The treated prawns were further challenged with Aeromonas hydrophila for 7 days. The percentages of survival after the challenge in the prawns fed with the mixed spores (46.8%) were also found significantly higher (p = 0.05) than others groups, except the mixed live cell treatment (60%). These results indicated that the spores of Bacillus KKU02 and Bacillus KKU03 had a high potential for using as commercial probiotics.

Abstract: Out of fifty-five Bacillus isolates obtained from ten different regional locations and sources, seven showed the ability to consistently produce specific extracellular polymeric substance (EPS) on rich as well as synthetic but nonspecific media which did not contain glutamic acid. The isolates were identified as either Bacillus licheniformis or Bacillus subtilis. The EPS from all isolates was resistant to alpha protease, proteinase K, and was thus of high molecular weight. Further it was detected after SDS-PAGE by methylene blue but not by coomassie blue R staining as in case of proteins with high proportion of acidic amino acids. Cell-free EPS, after acid hydrolysis, showed absence of carbohydrates and presence of only glutamic acid. Thus the native the EPS from all seven isolates was confirmed to be gamma polyglutamic acid (PGA) and not exopolysaccharide. The Bacillus isolate T which produced maximum polymer on all media tested had higher amylase: protease activity as compared to other strains. If inoculum was developed in rich medium as compared to synthetic medium, the PGA produced increased by twofold in the subsequent synthetic production medium. Similarly, use of inoculum consisting of young and vegetative cells also increased the PGA production by twofold though amount of inoculum did not affect yield of PGA. Though PGA was produced in even in the absence of glutamic acid supplementation in the production medium by all isolates, the yield of PGA increased by fourfold in the presence glutamic acid and the maximum yield was 30 g/l for isolate K. The supplementation of glutamine instead of glutamic acid into the medium caused an increase in the viscosity of the non-Newtonian solution of PGA.

Abstract: Dual experiments were carried out in 2007 at the laboratories of the National Center of Research, to test the antagonistic efficacy of three Trichoderma spp and 23 Bacillus isolates, for the control of chickpea wilt and root- rot pathogens: Fusarium oxysporum f. sp. ciceris and F. solani adopting CRD. Trichoderma harzianum was found highly antagonistic compared to Trichoderma viride isolates as it inhibited the mycelial growth of F. oxysporum f. sp. ciceris and F. solani by 85.29% and 86.21% after 12 days of in-vitro incubation, whereas T. viride (isolate Tv1) gave an inhibition percentage of 81.88% and 76.64%. Antagonistic hyphae of T. harzianum showed parasitic behavior against Fusarium spp. The parasite reached and recognized F. oxysporum f. sp. ciceris by coiling around the hyphae of the pathogen and disintegrating the hyphae and spores. Only 17 out of 23 Bacillus isolates from 130 colonies of bacteria screened showed significantly antagonistic properties against wilt pathogens. Only B3, B16, B2, B15and B20 proved to be the most effective among the rest of isolates and were considered strongly antagonistic against F. oxysporum f. sp. ciceris and F. solani in-vitro, with an inhibition percentage range of 57.57% - 64.65%. The management of Chickpea root/rot wilt complex disease incited by F. oxysporum f. sp. ciceris and F. solani could be achieved successively by the use of bioagents derived from various fungal and bacterial isolates.

Abstract: Proteases are well known enzymes for their wide range application in food industry, detergent industry and pharmaceuticals industry. They are also widely used in leather industry for dehairing and bating of hides as an alternative for toxic chemicals which in turn hamper the environment. In the present investigation bacteria were isolated from the leather industry soil sample. A total of 8 bacteria were isolated from soil by serial dilution method on gelatin agar medium. Among eight, three Bacillus sp. showing highest skim milk hydrolysis were selected for the production of alkaline protease and were named as isolate - 3, isolate - 5 and isolate -7. The effect of pH, temperature, incubation period, carbon sources and nitrogen sources on production of alkaline protease was investigated by one factor-at-a-time method. The enzyme activity was observed maximum at pH 8 and temperature 37°C for all Bacillus isolates. Among the three Bacillus isolates, Bacillus isolate -7 had maximum enzyme activity than other two isolates. Bacillus isolate -7 exhibited the highest alkaline protease activity (3.32U) on submerged fermentation. The wild strain Bacillus isolate 7 was subjected to strain improvement through U.V irradiation. Induction of mutation in Bacillus strain was carried out by 0, 5, 10, 15 and 20 min exposure times of U.V irradiation. The wild type exhibited 3.45U protease activity where as mutant Bacillus isolate 7 showed 4.78 U protease activities.

Abstract: Clusterbean (Cyamopsis tetragonoloba (L.) Taub) is a kharif legume crop grown under arid zone in India. Root rot is the major disease in clusterbean caused by Rhizoctonia solani during rainy season and may result upto 21.60% loss at pre-and post-emergence stages. Forty two isolates of r hizobacteria were obtained from soil samples collected from rhizosphere of clusterbean and thirteen bacterial isolates were obtained from dilution plating of farmyard manureobtained from clusterbean grown field. All the 55 bacterial isolates were screened for antagonistic interactions against Rhizoctonia solani on PDA medium plates. Pseudomonas/Bacillus isolates HCS2, HCS4, HCS30, HCS36, HCS43 and HFS12 showed significant antagonistic activity. Eleven rhizobactrial isolates showed stimulation of root and shoot growth of clusterbean on water agar plates and Isolates HCS2, HCS4, HCS12, HCS13, HCS30, HCS36, HCS39, HCS43, HFS8, HFS10 and HFS12 showed retadation as compared to uninoculated seedlings. Rhizobium isolate GSA110 formed 45 nodules and nodule weight observed was 388.3 mg/plant, and 228.19% increase in shoot dry weight was observed as compared to uninoculated control at 60 days of plant growth. Coinoculation ofBradyrhizobium GSA11, Bacillus isolate HCS43 with fungus showed increase in nodulation (50 nodules/plant), nodule weight (317.7 mg/plant) leading to increase in shoot dry weight (209.6%) as compared to single inoculated control. Inoculation with Bacillus isolate HCS43 and Bradyrhizobium strain GSA11 showed disease suppression and browning of collar root was reduced.

Abstract: Bacillus species constitute a diverse group of bacteria widely distributed in soil. In this study, sixteen Bacillus local strains isolated from different Egyptian soils and three identified strains; (Bacillus thuringiensis subsp. Kurstaki (B.t.40), Bacillus subtilis subsp. subtilis strain ATCC 168(B.s) and Bacillus licheniforms strain ATCC 14580) (B.l); were identified by detailed conventional biochemical methods, plasmid pattern and partial 16S rRNA sequencing. All isolates were Gram-positive, aerobic, and motile, Oxidase-positive, rod shaped, endospore-forming bacteria. These isolate was phenotypically identified as Bacillus. The crude polysaccharides were separated from the supernatant and examined for sulphate content. In this study, five different isolates were selected according to their plasmids patterns and polysaccharide production, the primary aim was to characterize these isolates using 16S rRNA partial gene amplification and sequencing. The five isolates were assigned as Bacillus cereus strain and Bacillus sp BAB3450 16S rRNA gene. All Bacillus strains were characterized by whole-cell protein profiles using sodium dodecyl sulfate-polyacrylamide gel electrophoresis

Abstract: Background: Alkaline phosphatase (ALPase) has vital applications in many aspects of life as molecular biology and genetic engineering applications is used in non-radioactive detection techniques, probing, blotting and sequencing systems and in immunology, diagnosis, linked enzymes in ELISA. Thus it is commercially produced from calf intestine and Escherichia coli. Bacterial enzyme located in periplasmic space of E.coli cells that require costlier extraction method and complex downstream processes. Whereas Bacillus spp. capable to produce Extracellular ALPase which is extracted and purified from crude filtrate and the amount of ALPase is more and easier downstream processes. The present paper amid to isolate new bacterial producer for ALPase regarded to Bacillus sp. and optimize some environmental conditions of enzyme production. Methodology: We used fifteen Bacillus isolates were isolated previously from different soil and waste sources were collected from polluted area, in Advanced Biotechnology and Genetic Engineering Laboratory , College of Science in Babylon University ,Iraq. The production of extracellular ALPase enzymes were screened, in liquid media and the best isolate was selected and identified, subsequently it was grown in different cultural conditions as pH, temperature, incubation periods and aeration and agitation to optimize enzyme production. Results: twelve out of fifteen isolates had capable to produce extracellular ALPase enzymes at variant levels. The best one ( Bacillus sp.I) was selected to produce the enzyme depending for its high value of specific activity of ALPase. After that the environmental conditions for enzyme production were optimize and results revealed that the optimum conditions of extracellular ALPase production in fermentation medium were pH 8.2, 40°C for four days in stand incubator. Conclusion: Most Bacillus isolate produce

Abstract: In this study, Bacillus sp. was isolated from the soil seeded with Hordeum sp. and Vicia sp. and was identified. 121 Bacillus isolates were derived from soil samples. It was determined that 114 isolates gave 16SrRNA pcr products with primers specific for Bacillus genus. Classical methods were used to identify the species: Bacillus subtilis, B. mycoides, B. megaterium and B. amyloliquefaciens species. It was determined that metabolic products of four isolates inhibited Escherichia coli and Micrococcus luteus growth. The relationship between antimicrobial effect of species and plasmid presence was tested and plasmid contents was only observed in B. subtilis

Abstract: Article History This study investigated the ability of Bacillus species isolated from soil and water samples to degrade some petroleum products and pesticides as well as its ability antimicrobial potency against selected pathogens. Bacillus species were isolated from soil collected from dumping site and water samples from Ado-Ekiti, Nigeria on Luria Bertani agar. The biodegradative and antimicrobial activities of the isolates were conducted using minimal nutrient medium and agar well diffusion methods respectively. Commercial antibiotics were used as positive control. All the Bacillus isolates showed varied degree of degradation on petroleum products and pesticides. Only B. polymyxa showed antimicrobial activity against Staphylococcus aureus with zone of inhibition of 18.00mm. The commercial antibiotics were most inhibitory to most of the test pathogens in varying degrees.The isolates can be used in mitigating pollution caused by oil spillage and overuse or abusive use of herbicides and fungicides. However, these isolates are not good candidate as antibacterial agents for the selected test pathogens.

Abstract: Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae) is one of the most destructive pests of several vegetables and fruits worldwide. In spite of various control methods, this pest has still continued to cause significant damage. In this study, the culturable bacterial flora of S. littoralis was determined. New isolates from S. littoralis, as well as 12 different Bacillus isolates belong to 5 species that were previously isolated from different pests, were tested on S. littoralis larvae. In total, 9 bacteria were characterized based on their morphological, biochemical, physiological, and molecular characteristics. The bacterial flora of S. littoralis was determined as Flavobacterium sp. (SL1), Klebsiella pneumonia (SL2), Enterobacter sp. (SL3), Enterobacter sp. (SL4), Klebsiella sp. (SL5), Serratia marcescens (SL6), Pseudomonas aeruginosa (SL7), Acinetobacter baumannii (SL8), and Staphylococcus sp. (SL9). The insecticidal activity tests were performed on the third-instar larvae of S. littoralis. SL1 and SL5 from S. littoralis caused the highest mortalities with 67% and 77%, respectively. Among previously isolated Bacillus isolates, Bacillus thuringiensis subsp. kurstaki (MnD) and B. thuringiensis subsp. kurstaki (BnBt) were found to be the most effective, causing 100% mortality within 10 days after treatment. A concentration-response test was conducted with these isolates and it was found that the isolate MnD was more effective than BnBt. Therefore, further bioassay experiments were conducted with the isolate MnD and results were discussed with respect to the biocontrol potential of the bacterial isolates.

Abstract: The use of plant growth promoting rhizobacteria (PGPR) for the benefits of agriculture is gaining worldwide importance and acceptance and appears to be the trend for the future. PGPR are bio-resources which may be viewed as a novel and potential tool for providing substantial benefits to the agriculture. Plant growth promoting rhizobacteria (PGPR) are known to influence plant growth by various direct or indirect mechanisms. In search of efficient PGPR strains with multiple activities, a total of 58 isolates belonging to Pseudomonas, Azotobacter and Bacillus were isolated from wheat rhizospheric soils collected from various districts of Uttar Pradesh. These rhizospheric isolates were biochemically characterized and screened for their plant growth promoting traits like production of indole acetic acid (IAA), ammonia production, siderophore production, phosphate solubilization, salt tolerance and antibiotic sensitivity test activity. The isolates of Pseudomonas (86.36%), and Azotobacter (76.13%) produced IAA, whereas only 38.09% of Bacillus isolates were able to produce IAA. Ammonia production was most common trait of Pseudomonas (90.89%), and Azotobacter (66.43) and Bacillus (76.19%). Phosphorus solubilization was detected in the isolates of Azotobacter (66.23%), Pseudomonas (45.35%), and Bacillus (23.80%). Siderophore production was exhibited by 9.61 to 20.17% of isolates. On the basis of multiple plant growth promoting activities eighteen isolates (nine Azotobacter, six Pseudomonas and three Bacillus) were evaluated for quantitative IAA production, antibacterial and salt tolerance. All the Azotobacter isolates were shown to produce higher range (95.60 to 175.20 µg/ml) of IAA, while Pseudomonas produced (44.40 to 95.60 µg/ml) IAA. The isolate Bc2 also showed potential of producing high amount of IAA. The isolate Azt5, Azt9, Ps2, Bc2 and Bc3 were found resistant even at 20 µg/ml concentration of tetracycline in the medium. Salt tolerance even at 7% NaCl concentration was observed in Azt5, Bc1 and Bc3 isolates. This study has pointed out that few isolates could exhibit PGP traits, which may promote plant growth directly and indirectly. Key words: Plant growth promoting rhizobacteria (PGPR), wheat, indole acetic acid, ammonia, siderophore, P solubilization, salt tolerance, antibacterial activity.