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We report the computational structural simulation of the Cry1Ab19 toxin molecule from B. thuringiensis BtX-2 based on the structure of Cry1Aa1 deduced by x-ray diffraction. Validation results showed that 93.5% of modeled residues are folded in a favorable orientation with a total energy Z-score of -8.32, and the constructed model has an RMSD of only 1.13. The major differences in the presented model are longer loop lengths and shortened sheet components. The overall result supports the hierarchical three-domain structural hypothesis of Cry toxins and will help in better understanding the structural variation within the Cry toxin family along with facilitating the design of domain-swapping experiments aimed at improving the toxicity of native toxins.

As part of an effort to obtain a fungal 1-aminocyclopropane-1-carboxylate deaminase encoding gene from Phytophthora sojae expressed sequence Tag database, we identify and characterize the ACCD from P. sojae using bioinformatics data mining tools and techniques. Computed structural model of P. sojae ACCD was found to consist of mixed α/β motifs and probable loops. The predicted model resembles the structure of Pseudomonas ACCD (RMSD-0.44 Å). The main differences observed between them are the presence of partial length of domain one, and longer helix α4. Ramachandran plot analysis revealed that portion of all residues falling into the most favorable regions was 95.0%. The substrate - and geometrical- docking of developed structure postulated functional capability of ACCD to carry out ACC cleavage reaction. The catalytic site in homo-tetrameric structure open to opposite directions separated by ∼37.97 Å distance arranged around central axis. This study provides a comprehensive identification and characterization of the ACCD in P. sojae and it may be helpful in the transcriptional and expression based study of P. sojae pathogenesis.

Two diazotrophic cyanobacteria, Westiellopsis prolifica and Anabaena variabilis were evaluated for elucidating the possible mechanism of mineral phosphate solubilization. Phosphate starved cyanobacteria evaluated for the presence of organic acids, extracellular compounds or enzymes that might have been produced and promoted the mineral phosphate solubilization with Mussorie Rock Phosphate and Tricalcium Phosphate as substrates. Both the cultures did not reveal production of organic acids throughout the incubation period when checked for decrease in media pH of the media and thin layer chromatography. Thin layer chromatography of culture filtrates showed the presence of hydrocarbon like compound. Further analysis of the culture filtrates with gas liquid chromatography, a single peak near to the retention time of 7.6 was observed in all extracts of culture filtrates irrespective of phosphate source. UV-visible spectra of culture filtrates revealed the absorption maxima of 276 nm. Gas chromatographic-mass spectrometric analysis of culture filtrates showed most intense peak in the electron impact (EI) ionization was at m/z 149 and molecular ion peaks at m/z 207 and 167, inferring the presence of phthalic acid. Among the mechanisms in mineral phosphate solubilization, it was evident that these cyanobacteria used phthalic acid as possible mode of P solubilization.

Cry1Ab21 is a δ-endotoxin produced by Bacillus thuringiensis Bt IS5056. The toxic spectrum of this protein is reported to span Lepidopteran, Dipteran and nematodes. Here, we predict the theoretical structural model of newly reported Cry1Ab21 toxin by homology modeling on the structure of the Cry1Aa toxin (2.5 A). Cry1Ab21 resembles the Cry1Aa toxin structure by sharing a common 3D structure with three domains along with few structural deviations. The main differences being located in the length of loops, absence of α7b, α9b, β10, β11, β12 and presence of additional β0 component. Some of the components like α10a, α10b, α11a are spatially positioned at different locations. A better understanding of 3D structure will be helpful in the design of efficient biopecticides.

A total of 432 morphotypes of Streptomycetes were isolated from rhizospheric and non-rhizospheric soils of chickpea (Cicer arietinum L.) which showed significant variation in population count. The generation time at different Cu2+ concentrations (0.5, 0.75 and 1.0 mM), were recorded for S160 as (1.2, 6.0 and 14.4 h), S161 (7.2, 12.0 and 24.0 h), and S164 (4.8, 7.2 and 16.8 h), respectively. Qualitative results showed 100, 62 and 8% of non-rhizospheric isolates tolerated 0.075, 0.264 and 0.628 mM of Cu2+, respectively, while rhizospheric isolates showed tolerance of 0.264 mM CuSO4. Semi-quantitative assay showed that the rhizospheric strain S160 has the ability to withstand 3.14 mM, while non-rhizospheric isolates S161 and S164 were able to tolerate up to 3.14 and 1.88 mM CuSO4, respectively. Acid-digested pellet of S160 strain indicated 68% reduction in copper residual concentration, confirming copper accumulation capacity in Streptomyces. The ability of growth of these strains in the presence of Cu2+ was co-induced by the presence of 3.1, 2.8 and 2.1 kb plasmid, respectively. Plasmids transformation into wild strain resulted in changes in metal resistance ability along with appreciable changes in resistance to antibiotics. Cultures were identified by 16S rDNA sequencing as Streptomyces sp. (S160 and S161) and Streptomyces hygroscopicus (S164), respectively.

Soil samples were collected from Panchamarhi dry deciduous forest in Satpuda Biosphere Reserve, India to determine the effect of hill slopes and altitude on the population size of methanotrophic bacteria. Population size, in range of 4×105–3.6×107 g−1 dry soil, was negatively correlated with altitude and increased exponentially ( r 2 = 0.97 , P r 2 = 0.97 , P

The theoretical homology based structural model of Cry1Ab15δ-endotoxin produced byBacillus thuringiensisBtB-Hm-16 was predicted using the Cry1Aa template (resolution 2.25 Å). The Cry1Ab15 resembles the template structure by sharing a common three-domain extending conformation structure responsible for pore-forming and specificity determination. The novel structural differences found are the presence ofβ0 andα3, and the absence ofα7b,β1a,α10a,α10b,β12, andα11a whileα9 is located spatially downstream. Validation by SUPERPOSE and with the use of PROCHECK program showed folding of 98% of modeled residues in a favourable and stable orientation with a total energyZ-score of −6.56; the constructed model has an RMSD of only 1.15 Å. These increments of 3D structure information will be helpful in the design of domain swapping experiments aimed at improving toxicity and will help in elucidating the common mechanism of toxin action.

Two diazotrophic cyanobacteria, Westiellopsis prolifica and Anabaena variabilis were evaluated for elucidating the possible mechanism of mineral phosphate solubilization. Phosphate starved cyanobacteria evaluated for the presence of organic acids, extracellular compounds or enzymes that might have been produced and promoted the mineral phosphate solubilization with Mussorie Rock Phosphate and Tricalcium Phosphate as substrates. Both the cultures did not reveal production of organic acids throughout the incubation period when checked for decrease in pH of the media and thin layer chromatography Thin layer chromatography of culture filtrates showed the presence of hydrocarbon like compound. Further analysis of the culture filtrates with gas liquid chromatography, a single peak near to the retention time of 7.6 was observed in all extracts of culture filtrates irrespective of phosphate source. UV-visible spectra of culture filtrates revealed the absorption maxima of 276 nm. Gas Chromatographic-Mass Spectrometric analysis of culture filtrates showed most intense peak in the electron impact (EI) ionization was at m/z 149 and molecular ion peaks at m/z 207 and 167, inferring the presence of phthalic acid. Among the mechanisms in mineral phosphate solubilization, it was evident that these cyanobacteria used phthalic acid as possible mode of P solubilization.

A total of 23 phosphate solubilizing bacteria (PSB) and 35 phosphate solubilizing fungi (PSF) were isolated from 19 samples of salt affected soils. The ability of 12 selected PSB and PSF to grow and solubilize tricalcium phosphate in the presence of different concentrations of NaCl was examined. Among 12 PSB, Aerococcus sp. strain PSBCRG1-1 recorded the highest (12.15) log viable cell count at 0.4 M NaCl concentration after 7 days after incubation (DAI) and the lowest log cell count (1.39) was recorded by Pseudomonas aeruginosa strain PSBI3-1 at 2.0 M NaCl concentration after 24 h of incubation. Highest mycelial dry weight irrespective of NaCl concentrations was recorded by the Aspergillus terreus strain PSFCRG2-1 (0.567 g). The percent P i release, in general, was found to increase with increase in NaCl concentration up to 0.8 M for bacterial solubilization and declined thereafter. At 15 DAI, strain Aerococcus sp. strain PSBCRG1-1 irrespective of NaCl concentrations showed the maximum P-solubilization (12.12%) which was significantly superior over all other isolates. The amount of P i released in general among PSF was found to decrease with increase in NaCl concentration at all the incubation periods. Aspergillus sp. strain PSFNRH-2 (20.81%) recorded the maximum P i release irrespective of the NaCl concentrations and was significantly superior over all other PSF at 7 DAI.