Degradation of the insecticidal toxin produced by Bacillus thuringiensis var. kurstaki by extracellular proteases produced by Chrysosporium sp.

Aims:  Some Cry proteins produced by the soil bacterium Bacillus thuringiensis (Bt) or by transgenic Bt plants persist in agricultural soils for an extended period of time, which may pose a hazard for nontarget soil organisms. The aims of our study were to screen for soil fungi capable of degrading the Cry1Ac toxin and to identify the mechanisms that lead to the inactivation of this protein.Methods and Results:  Of the eight fungal strains screened, only one, Chrysosporium sp., was found to produce extracellular proteases capable of degrading the 66-kDa Cry1Ac at the N-terminal end of amino acid 125 (alanine). The proteolytic products of the Cry1Ac toxin did not exhibit any insecticidal activity against Helicoverpa armigera, in contrast to its high toxicity exhibited in the native form.Conclusions:  Proteases elaborated by the Chrysosporium sp. degrade the Cry1Ac toxin in a way that it looses its insecticidal activity against H. armigera.Significance and Impact of the Study: Chrysosporium sp., a specific soil micro-organism capable of producing proteases that degrade the Cry1Ac toxin into inactive products under controlled conditions is being reported for the first time. Application of this observation needs to be further tested in field conditions

Fresolimumab Treatment Decreases Biomarkers and Improves Clinical Symptoms in Systemic Sclerosis Patients

BACKGROUND. TGF-β has potent profibrotic activity in vitro and has long been implicated in systemic sclerosis (SSc), as expression of TGF-β–regulated genes is increased in the skin and lungs of patients with SSc. Therefore, inhibition of TGF-β may benefit these patients. METHODS. Patients with early, diffuse cutaneous SSc were enrolled in an open-label trial of fresolimumab, a high-affinity neutralizing antibody that targets all 3 TGF-β isoforms. Seven patients received two 1 mg/kg doses of fresolimumab, and eight patients received one 5 mg/kg dose of fresolimumab. Serial mid-forearm skin biopsies, performed before and after treatment, were analyzed for expression of the TGF-β–regulated biomarker genes thrombospondin-1 (THBS1) and cartilage oligomeric protein (COMP) and stained for myofibroblasts. Clinical skin disease was assessed using the modified Rodnan skin score (MRSS). RESULTS. In patient skin, THBS1 expression rapidly declined after fresolimumab treatment in both groups (P = 0.0313 at 7 weeks and P = 0.0156 at 3 weeks), and skin expression of COMP exhibited a strong downward trend in both groups. Clinical skin disease dramatically and rapidly decreased (P \u3c 0.001 at all time points). Expression levels of other TGF-β–regulated genes, including SERPINE1 and CTGF, declined (P = 0.049 and P = 0.012, respectively), and a 2-gene, longitudinal pharmacodynamic biomarker of SSc skin disease decreased after fresolimumab treatment (P = 0.0067). Dermal myofibroblast infiltration also declined in patient skin after fresolimumab (P \u3c 0.05). Baseline levels of THBS1 were predictive of reduced THBS1 expression and improved MRSS after fresolimumab treatment. CONCLUSION. The rapid inhibition of TGF-β–regulated gene expression in response to fresolimumab strongly implicates TGF-β in the pathogenesis of fibrosis in SSc. Parallel improvement in the MRSS indicates that fresolimumab rapidly reverses markers of skin fibrosis

Grapevine rootstocks shape underground bacterial microbiome and networking but not potential functionality

BackgroundThe plant compartments of Vitis vinifera, including the rhizosphere, rhizoplane, root endosphere, phyllosphere and carposphere, provide unique niches that drive specific bacterial microbiome associations. The majority of phyllosphere endophytes originate from the soil and migrate up to the aerial compartments through the root endosphere. Thus, the soil and root endosphere partially define the aerial endosphere in the leaves and berries, contributing to the terroir of the fruit. However, V. vinifera cultivars are invariably grafted onto the rootstocks of other Vitis species and hybrids. It has been hypothesized that the plant species determines the microbiome of the root endosphere and, as a consequence, the aerial endosphere. In this work, we test the first part of this hypothesis. We investigate whether different rootstocks influence the bacteria selected from the surrounding soil, affecting the bacterial diversity and potential functionality of the rhizosphere and root endosphere.MethodsBacterial microbiomes from both the root tissues and the rhizosphere of Barbera cultivars, both ungrafted and grafted on four different rootstocks, cultivated in the same soil from the same vineyard, were characterized by 16S rRNA high-throughput sequencing. To assess the influence of the root genotype on the bacterial communities’ recruitment in the root system, (i) the phylogenetic diversity coupled with the predicted functional profiles and (ii) the co-occurrence bacterial networks were determined. Cultivation-dependent approaches were used to reveal the plant-growth promoting (PGP) potential associated with the grafted and ungrafted root systems.ResultsRichness, diversity and bacterial community networking in the root compartments were significantly influenced by the rootstocks. Complementary to a shared bacterial microbiome, different subsets of soil bacteria, including those endowed with PGP traits, were selected by the root system compartments of different rootstocks. The interaction between the root compartments and the rootstock exerted a unique selective pressure that enhanced niche differentiation, but rootstock-specific bacterial communities were still recruited with conserved PGP traits.ConclusionWhile the rootstock significantly influences the taxonomy, structure and network properties of the bacterial community in grapevine roots, a homeostatic effect on the distribution of the predicted and potential functional PGP traits was found

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Not AvailableA simple, sensitive and indirect spectrophotometric method for the determination of protein precipitable polyphenols (tannins) has been developed, based on the ability of the polyphenols to precipitate the synthetic, brown coloured azo-pro- tein, bovine serum albumin±benzidine conjugate (BSA±benzidine, mole ratio 1:7), which shows an absorption maxima at 405 nm. The amount of unprecipita- ted BSA±benzidine is measured directly at 405 nm, which is inversely related to the polyphenol concentration. Tannic acid was used as a reference standard. The microassay was performed in citrate/phosphate bu er (0.1 m), pH 4.8. The method was found to be linear in the range of 5±150 g (3±88 nmol) of tannic acid (y=1.0+(ÿ0.007)x; r=ÿ0.989). Spiking studies carried out with various levels of tannic acid (0.01, 0.1 and 1.0%) indicated a recovery in the range of 94± 101% and 94±98% in rice and sorghum samples, respectively. Free phenolics, when added in the range of 50±150 g (catechin, chlorogenic acid, ferulic acid, ca eic acid and p-coumaric acid) had no in¯uence on the protein precipitation in the microassay. Also spectral analysis of free phenolics and acid-methanolic sor- ghum extracts showed no interference in the present method. The conjugate was found to be stable over a period of 24 weeks in a freeze-dried condition and at 4 C, with <5% deterioration in aqueous condition. The microassay method developed has been used for the quantitation of protein precipitable polyphenols in various sorghum (Sorghum bicolor L. Moench) genotypes and compared with the widely used Folin±Denis chemical method of analysis.Not Availabl

Mineral phosphate solubilization by rhizosphere bacteria and scope for manipulation of the direct oxidation pathway involving glucose dehydrogenase

Microbial biodiversity in the soil plays a significant role in metabolism of complex molecules, helps in plant nutrition and offers countless new genes, biochemical pathways, antibiotics and other metabolites, useful molecules for agronomic productivity. Phosphorus being the second most important macro-nutrient required by the plants, next to nitrogen, its availability in soluble form in the soils is of great importance in agriculture. Microbes present in the soil employ different strategies to make use of unavailable forms of phosphate and in turn also help plants making phosphate available for plant use. Azotobacter, a free-living nitrogen fixer, is known to increase the fertility of the soil and in turn the productivity of different crops. The glucose dehydrogenase gene, the first enzyme in the direct oxidation pathway, contributes significantly to mineral phosphate solubilization ability in several Gram-negative bacteria. It is possible to enhance further the biofertilizer potential of plant growth-promoting rhizobacteria by introducing the genes involved mineral phosphate solubilization without affecting their ability to fix nitrogen or produce phytohormones for dual benefit to agricultural crops. Glucose dehydrogenases from Gram-negative bacteria can be engineered to improve their ability to use different substrates, function at higher temperatures and EDTA tolerance, etc., through site-directed mutagenesis

Bioremediation of industrial toxic metals with gum kondagogu (<i>Cochlospermum gossypium</i>): A natural carbohydrate biopolymer

113-120The ability of gum kondagogu [Cochlospermum gossypium (L.) DC.], a natural carbohydrate biopolymer, was investigated for adsorptive removal of toxic metal ions Cd2+, Cu2+, Fe2+, Pb2+, Ni2+, Zn2+, Hg2+ and total Cr present in industrial effluents. Various physico-chemical parameters, such as, pH, temperature, equilibrium contact time, % biosorption and adsorption capacity, were investigated. Metal biosorption (%) and adsorption capacity of the biopolymer was determined by ICP-MS. Gum kondagogu was capable of competitively biosorb 8 toxic metal ions from the samples of industrial effluents tested. The adsorption capacity was observed to be in the following order, Cd2+ > Cu2+ > Fe2+ > Pb2+ > Hg2+ > total Cr > Ni2+ > Zn2+. The maximum adsorption capacity of metals by gum kondagogu varied in the range of 31-37 mg g-1 for Fe2+ and minimum of 5.5-9.3 mg g-1 for Hg2+ in the effluent samples tested. The equilibrium adsorption data were fitted to Langmuir isotherm models for all the metal ions adsorbed. FT-IR studies were carried out to understand the type of functional groups in gum kondagogu responsible for metal biosorption process. Desorption studies on biosorbed metal ions showed that HCl was a good eluant for all metals tested. The re-adsorption capacity of the recycled gum kondagogu biopolymer sustained its biosorption property at 90% level, even after 3 cycle of desorption. Gum kondagogu biopolymer has the potential to be used as an effective, non-toxic, economical and an efficient biosorbent clean-up matrix for removal of toxic metals from industrial effluents

Purification and characterization of mycoferritin from <i>Aspergillusflavus</i> MTCC 873

360-365The fungus Aspergillus flavus MTCC 873, a non-toxigenic isolate demonstrated its capability to synthesize mycoferritin (MF) upon induction with iron in yeast extract sucrose (YES) medium. The molecular mass, yield, iron and carbohydrate contents of the MF were 440 kDa, 0.015 mg/g of wet mycelia, 0.8 and 30.4%, respectively. Native gel-electrophoresis revealed a band corresponding to dimeric form of equine spleen ferritin (ESF). Subunit analysis by SDS-PAGE revealed a single protein band with an apparent molecular mass of 24 kDa, suggesting similar sized subunits in the structure of apoferritin shell. Immunological cross-reactivity was observed with the anti-fish liver ferritin. Transmission electron microscopy (TEM) revealed an apparent particle size of 100 Å. N-terminal amino acid sequence of MF revealed a sequence of SLPLQDYA, which showed identities with other eukaryotic ferritin sequences. The spectral characteristics (UV/VIS, fluorescence and circular dichroic spectra) were similar to ESF. The fungus, unlike A. parasiticus 255 (non-toxigenic) was incapable of producing aflatoxins, when grown in YES media

<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region"> Surface morphology, chemical and structural assignment of gum Kondagogu (<i style="">Cochlospermum gossypium</i> DC.): An exudate tree gum of India </smarttagtype></smarttagtype>

181-192 Indian forests are a major source of large number of non-wood forest products. One such product is an exudate tree gum, regionally called as gum Kondagogu (Cochlospermum gossypium DC.), belonging to the family Bixaceae. This gum is collected by tribals in the state of Andhra Pradesh and marketed by Girijan Cooperative Society, Andhra Pradesh, India. Experimental work carried out in our laboratory on this gum has resulted in assigning a separate identity to this gum as compared to the well established and commercially exploited gum Karaya. Gum kondagogu has unique physiochemical properties as compared to other tree gums. Proximate analysis of the gum indicates that it has high volatile acidity and water-binding capacity. Elemental composition of gum kondagogu was determined by Energy dispersive X-ray fluorescence spectrometry (EDXRF). Surface morphological studies based on SEM analysis showed irregular shape with sharp edges in the native gum, while the deacetylated gum showed a fibrilar and porous structure. AFM analysis indicated that native gum was visualized as spherical lumps, suggesting an inter- or intra-molecular aggregation. TEM image of native gum kondagogu showed that the polymer was an extending linear chain with branch points. FT-IR spectrum of native gum indicated the predominant presence of acetyl group (12%w/w). Analytical data on gum kondagogu indicated that the major neutral sugars were arabinose, mannose, a-D-glucose, b-D-glucose, rhamnose and galactose, whereas uronic acids (D-Glucuronic acid, b-D-galacturonic acid and a-D-galacturonic acid) were the major acidic sugars. Structural assignment was carried out using acid hydrolysis, Smith degradation and NMR studies [1H, 13C, 2-D NMR (TOCSY and NOESY)]. Smith degradation analysis indicated that the back bone structure of gum kondagogu was that of a-D-GalpA-(1®4)-a-L-Rhap and can be grouped under rhamnogalacturonan type of gum. The experimental work provides enough evidence to exploit this natural biopolymer in food, textile and pharmaceutical industry. </smarttagtype