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International audience; In summer 2019, widespread occurrence of crown gall disease caused byAgrobacterium spp. was observed on commercially grown ornamental plants in south-ern Iran. Beside agrobacteria, pale yellow-pigmented Gram-negative strains resemblingthe members of Xanthomonas were also associated with crown gall tissues on weep-ing fig (Ficus benjamina) and Amaranthus sp. plants. The purpose of the present studywas to characterize the crown gall-associated Xanthomonas strains using plant inocula-tion assays, molecular-phylogenetic analyses, and comparative genomics approaches.Pathogenicity tests showed that the Xanthomonas strains did not induce diseasesymptoms on their host of isolation. However, the strains induced hypersensitive reac-tion on tobacco, geranium, melon, squash, and tomato leaves via leaf infiltration.Multilocus sequence analysis suggested that the strains belong to clade IA ofXanthomonas, phylogenetically close to Xanthomonas translucens, X. theicola, and X.hyacinthi. Average nucleotide identity and digital DNA-DNA hybridization valuesbetween the whole-genome sequences of the strains isolated in this study and refer-ence Xanthomonas strains are far below the accepted thresholds for the definition ofprokaryotic species, signifying that these strains could be defined as two new specieswithin clade IA of Xanthomonas. Comparative genomics showed that the strains iso-lated from crown gall tissues are genetically distinct from X. translucens, as almost allthe type III secretion system genes and type III effectors are lacking in the formergroup. The data obtained in this study provide novel insight into the breadth ofgenetic diversity of crown gall-associated bacteria and pave the way for research ongall-associated Xanthomonas-plant interactions.

Polysaccharide-based hydrogels exhibit unique properties like renewability, biocompatibility and biodegradability, thus making them ideal materials for potential utility in tissue engineering scaffolds, drug delivery vehicles, and water purification devices. In the past decade, salecan, a water-soluble β-1,3-glucan secreted by the Agrobacterium sp. ZX09, has become a vital family of polysaccharides for the construction of hydrogels owing to its biofunctionality and susceptibility to chemical modification. This review systematically summarizes for the first time, the recent progress on hydrogels containing salecan polysaccharides. We reviewed the preparation, properties and applications of various salecan-based hydrogels. Challenges and future prospects are discussed at the end of the review.

Terpene alcohol is widely used in perfumes and is known to possess antibacterial activity. Moreover, in its glycosylated form, it can be applied as a nonionic surfactant in food, and in the pharmaceutical, chemical, cosmetic, and detergent industries. Presently, chemical production of terpene glucosides is hampered by high costs and low yields. Here, we investigated the microbial glucosylation of nerol (cis-3,7-dimethylocta-2,6-dien-1-ol), a component of volatile oils, by Agrobacterium sp. M-12 isolated from soil. A microbial reaction using washed cells of Agrobacterium sp. M-12, 1 g/L of nerol, and 100 g/L of maltose under optimal conditions yielded 1.8 g/L of neryl-α-d-glucopyranoside after 72 h. The molar yield of neryl-α-D-glucopyranoside was 87.6%. Additionally, we report the successful transglucosylation of other monoterpene alcohols, such as geraniol, (-)-β-citronellol, and (-)-linalool, by Agrobacterium sp. M-12. Thus, microbial glucosylation has potential widespread applicability for efficient, low-cost production of glycosylated terpene alcohols.

We report the draft genome sequence of Agrobacterium sp. strain S2, isolated from a decaying oil palm empty fruit bunch (OPEFB) in Negeri Sembilan, Malaysia, which yields potential genes encoding lignin degradation enzymes. This genome of 9,722,071 bp exhibited 58.9% GC content, 10,416 coding genes, and 12 RNAs.

Bacteria capable of simultaneous aerobic denitrification and phosphorus removal (SADPR) are promising for the establishment of novel one-stage wastewater treatment systems. Nevertheless, insights into the metabolic potentials and engineered applications of SADPR-related bacteria are limited. Firstly, comprehensive metabolic models of two efficient SADPR bacteria, Achromobacter sp. GAD3 and Agrobacterium sp. LAD9, were obtained by high-throughput genome sequencing. With succinate as the preferred carbon source, both strains employed a complete TCA cycle as the major carbon metabolism for potentials of various organic acids and complex carbon oxidation. Complete and truncated aerobic denitrification routes were confirmed in GAD3 and LAD9, respectively, facilitated by all the major components of the electron transfer chain via oxidative phosphorylation. Comparative genome analysis revealed distinctive ecological niches involved in denitrification among different phylogenetic clades within Achromobacter and Agrobacterium. Excellent phosphorus removal capacities were contributed by inorganic phosphate uptake, polyphosphate synthesis and phosphonate metabolism. Additionally, the physiology of GAD3/LAD9 is different from that displayed by most available polyphosphate accumulating organisms, and reveals both strains to be more versatile, carrying out potentials for diverse organics degradation and outstanding SADPR capacity within a single organism. Secondly, both GAD3 and LAD9 were successfully applied for bioaugmented treatment of municipal wastewater in a pilot-scale sequencing batch reactor. At an appropriate COD/N ratio of 8, the bioaugmentation system exhibited stable and excellent carbon and nutrients removal, the averaged effluent concentrations of COD, NH4+-N, TN and TP were 20.6, 0.69, 14.1 and 0.40 mg/L, respectively, which could meet the first class requirement of the National Municipal Wastewater Discharge Standards of China (COD < 50 mg/L, TN < 15 mg/L, TP < 0.5 mg/L). Clone library and real-time polymerase chain reaction analysis revealed that the introduced bacteria greatly improved the structure of original microbial community and facilitated their aerobic nutrients removal capacities. This proposed emerging technology was shown to be an alternative technology to establish new wastewater treatment systems and upgrade or retrofit conventional systems from secondary-level to tertiary-level.

Curdlan has wide potential application in the food and biomedical fields due to its unique thermal gel and biological activity. This study investigated the effect of six sugars including glucose, fructose, lactose, maltose, sucrose and xylose as carbon sources on production and properties of curdlan using Agrobacterium sp. DH-2. The maximum production (38.1 g/L and 37.4 g/L, respectively) and yield (0.58 g curdlan/g sucrose and 0.53 g curdlan/g maltose, respectively) of curdlan were achieved by sucrose and maltose, followed by glucose, fructose, lactose and xylose. Scanning electron micrographs showed that the surface of cells was smooth in strain growth phase, while cells were covered by curdlan matrix acted as a net in the curdlan synthesis phase. The highest glucosyltransferase activity (19.9 U/g biomass) corresponded to the maximum curdlan production using the sucrose medium. The molecular weight and gel strength of curdlan were influenced by the carbon sources. The curdlan from xylose medium resulted in a maximum molecular weight of 1.59 × 106 Da and the highest gel strength of 989.2 g/cm2, while the curdlan from sucrose medium resulted in a lowest molecular weight of 1.10 × 106 Da and gel strength of 672.8 g/cm2. The high molecular weight of curdlan had high gel strength.

Studies were carried out for the mass multiplication of native Agrobacterium sp. UHFBA-218 (MCC 2101, NCBI: KC488176; deposited as UHFBA-218[Cherry 2E-2-2]) and Rhizobium rhizogenes strain K84 at different pH, temperature, incubation period, broth media and at different air supply. The most effective pH, temperature, incubation period, broth medium and air supply for both the isolates was 7.0, 25 °C, 4 days, yeast extract mannitol broth medium and 20 L/min, respectively. These parameters were further used for mass multiplication of these strains and mixing the multiplied bacterial inoculum for studying the viability of Agrobacterium sp. UHFBA-218 and R. rhizogenes strain K84 in different carrier media—white stone powder, carboxymethyl cellulose and activated charcoal during 6 months of storage at room temperature at three different locations, mixed in one part of broth culture in exponential phase having 270 ± 10 × 1012 cfu/ml to two part of carrier and one part of broth culture mixed to five part of carrier and were compared for viable counts observed in different formulations kept at 4 °C for reference. White stone powder was superior to other carrier media tested under these studies. There were appreciable counts ranging from 34.67 to 103.3 × 108 cfu/g after 6 months of room temperature storage at different locations. However, irrespective of strains, storage at 4 °C temperature provided maximum viability of 108.50 and 155.7 × 108 cfu/g in white stone powder mixed in 1:5 and 1:2 ratios, respectively.

The report is the first of purification, overproduction, and characterization of a unique γ-butyrobetainyl CoA synthetase from soil-isolated Agrobacterium sp. 525a. The primary structure of the enzyme shares 70–95% identity with those of ATP-dependent microbial acyl-CoA synthetases of the Rhizobiaceae family. As distinctive characteristics of the enzyme of this study, ADP was released in the catalytic reaction process, whereas many acyl CoA synthetases are annotated as an AMP-forming enzyme. The apparent Km values for γ-butyrobetaine, CoA, and ATP were, respectively, 0.69, 0.02, and 0.24 mM.

Dissolved oxygen tension (DOT) is an important factor influencing curdlan fermentative production by Agrobacterium sp. ATCC 31749. Therefore, optimization of dissolved oxygen profile is crucial to improve curdlan production. In this study, an unstructured mathematical models that consider nitrogen source as growth-limiting substrates were developed to estimate the kinetic parameters of cell growth, curdlan formation, and glucose consumption during Agrobacterium sp. ATCC 31749 fermentation at various DOTs (5–75%). The estimated kinetic parameters were used to establish models with Origin 8.0. All models of kinetic parameters were coupled with the kinetic model derived from Agrobacterium sp. ATCC 31749 fermentation to determine the effect of DOT on curdlan fermentation. The combined kinetic models satisfactorily fit the experimental data. The optimal dissolved oxygen profile was obtained using genetic algorithms coupled with iterative dynamic programming algorithms in MATLAB 10b. The optimal dissolved oxygen during curdlan production (20–120 h) was approximately 52% DOT, and the maximum curdlan concentration of 48.5 g/L was obtained at this DOT profile. To our knowledge, this study is the first to optimize DOT for curdlan fermentation under nitrogen-limited conditions. This report significantly contributes to the improvement of curdlan production on an industrial scale.

BACKGROUND Agrobacterium sp. IFO 13140 cells were immobilized on a loofa sponge and used to produce curdlan over five successive cycles. The interaction between microbial cells and the loofa sponge as well as the produced curdlan were characterized by Fourier transform infrared-attenuated total reflectance (FTIR-ATR) spectrometry. The purity of the curdlan was also evaluated. The storage stability of the immobilized cells was assessed and the produced curdlan was used in a functional yogurt formulation. RESULTS The average curdlan production by immobilized cells was 17.84 g L−1. The presence of the microorganism in the sponge was confirmed and did not cause alterations in the matrix, and the chemical structure of the curdlan was the same as that of commercial curdlan. The purity of both was similar. The immobilized cells remained active after 300 days of storage at −18 °C. The use of the produced curdlan in a functional yogurt resulted in a product with lower syneresis. CONCLUSION A large number of cells physically adhered to the surface of loofa sponge fibers, and its use as an immobilization matrix to produce curdlan was effective. The use of the produced curdlan in yogurt allowed the development of a more stable product. © 2015 Society of Chemical Industry

Curdlan production by Agrobacterium sp. IFO13140 immobilized on loofa sponge, alginate and loofa sponge with alginate was investigated. There was no statistically-significant difference in curdlan production when the microorganism was immobilized in different matrices. The loofa sponge was chosen because of its practical application and economy and because it provides a high stability through its continued use. The best conditions for immobilization on loofa sponge were 50 mg of cell, 200 rpm and 72 h of incubation, which provided a curdlan production 1.50-times higher than that obtained by free cells. The higher volumetric productivity was achieved by immobilized cells (0.09 g/L/h) at 150 rpm. The operating stability was evaluated, and until the fourth cycle, immobilized cells retained 87.40% of the production of the first cycle. The immobilized cells remained active after 300 days of storage at 4 °C. The results of this study demonstrate success in immobilizing cells for curdlan biosynthesis, making the process potentially suitable for industrial scale-up. Additional studies may show a possible contribution to the reduction of operating costs.

Salecan is a novel water-soluble extracellular-glucan produced by a new kind of salt-tolerant strain Agrobacterium sp. ZX09 and can be applied in food and medicine industries. In this work, Salecan (Sal) was incorporated into poly(vinyl alcohol) (PVA) to prepare novel Sal/PVA hybrid hydrogels by repeated freeze–thaw processing. Physicochemical and biological characteristics of the hydrogels were investigated to evaluate their potential as cell adhesion materials. By increasing the Salecan content in the hybrid hydrogels, their swelling capacity increased notably, while the compressive modulus decreased. Observed by SEM, Sal/PVA hydrogels had a homogeneous porous structure. The degradation rate of the hydrogels can be controlled by tailoring the composition ratio of Sal/PVA. Furthermore, cells could adhere well on the surface of Sal/PVA hydrogels. In conclusion, these results make Sal/PVA hydrogels attractive materials for biomedical applications.

In order to explore the mechanism by which Tween-80 enhances the production of curdlan produced by Agrobacterium sp., the effects of Tween-80 on the production and structure of curdlan and Agrobacterium sp. were evaluated. Maximum curdlan production (51.94g/L) was achieved when 16g/L Tween-80 was added at the beginning of the cell growth stage. The addition of Tween-80 at higher concentration inhibited cell growth. However, the addition of 16g/L Tween-80 enhanced the production of curdlan with a looser ultrastructure, significantly weakened the envelopment of curdlan on Agrobacterium sp., altered the fine structure of cell membrane, and increased the cell membrane permeability. Moreover, the efficiency of oxygen and mass transport, respiration intensity, UTP regeneration, ATP regeneration, activity of curdlan synthetase, capacity of stress response and energy supply of Agrobacterium sp. were all greatly improved by the addition of Tween-80. These findings demonstrate the mechanisms by which Tween-80 enhances curdlan production and provide a cheap and feasible approach to weaken the envelopment of water-insoluble polysaccharides on bacteria.

Background This work evaluated the improvement of curdlan production of Agrobacterium sp. ATCC 31749 by using culture medium containing juice of discarded bottom part of green Asparagus spear (MJDA). Curdlan production was carried out using Agrobacterium sp. ATCC 31749 in flasks with different volumes of MJDA and its non-juice-adding control (CK) incubated in shaker at 30 °C, 200 rpm rotation for 168 h. Results All MJDA media increased Agrobacterium sp. ATCC 31749 cell mass and enhanced the cells’ ability to utilise sucrose, the carbon source for curdlan biosynthesis, and thereby produced higher concentration of curdlan than CK which is used for commercial production of curdlan. After 168 h of fermentation, 10% MJDA produced 40.2 g/l of curdlan whiles CK produced 21.1 g/l. Curdlan production was increased by 90.4% higher in 10% MJDA than CK. Curdlan produced by 10% MJDA contains 1.2 and 1.5 µg/ml of Asparagus flavonoids and saponins respectively as additives which have wide range of health benefits. The mass of sucrose needed to produce 1.0 g curdlan by Agrobacterium sp. ATCC 31749 in CK is 1.7-fold more than in 10% MJDA. Conclusion The results strongly revealed that 5–10% MJDA is a good curdlan fermentation media which increase curdlan production yield with cheaper cost of production and simultaneously reduce environmental waste resulting from the large scaled discarded bottom parts of green Asparagus spear during Asparagus production.

The effect of nitrogen source concentration on the production of the polysaccharide curdlan by the bacterium Agrobacterium sp. ATCC 31749 from hydrolysates of prairie cordgrass was examined. The highest curdlan concentrations were produced by ATCC 31749 when grown on a medium containing a solids-only hydrolysate and the nitrogen source ammonium phosphate (2.2 mM) or on a medium containing a complete hydrolysate and 3.3 mM ammonium phosphate. The latter medium sustained a higher level of bacterial curdlan production than the former medium after 144 hr. Biomass production by ATCC 31749 was highest after 144 hr when grown on a medium containing a solids-only hydrolysate and 2.2 or 8.7 mM ammonium phosphate. On the medium containing the complete hydrolysate, biomass production by ATCC 31749 was highest after 144 hr when 3.3 mM ammonium phosphate was present. Bacterial biomass production after 144 hr was greater on the complete hydrolysate medium compared to the solids-only hydrolysate medium. Curdlan yield produced by ATCC 31749 after 144 hr from the complete hydrolysate medium containing 3.3 mM ammonium phosphate was higher than from the solids-only hydrolysate medium containing 2.2 mM ammonium phosphate.

Stacked genetically modified (GM) maize is increasingly produced; thereby, current event-specific quantitative real-time polymerase chain reaction (qPCR) methods have led to the overestimation of GM organism (GMO) content compared with the actual weight/weight percentage of GM organism in maize samples. We developed a feasible qPCR method in which the GMO content is calculated based on the quantification of two herbicide-tolerant trait genes, 5-enolpyruvylshikimate-3-phosphate synthase from Agrobacterium sp. strain CP4 (cp4epsps) and phosphinothricin N-acetyl-transferase from Streptomyces viridochromogenes (pat) to quantify the GMO content in ground grain samples containing stacked GM maize. The GMO contents of two genes were quantified using a plasmid calibrant and summed for quantification of total GMO content. The trait-specific method revealed lower biases for examination of test samples containing stacked GM maize compared with the event-specific method. Our results clearly show that the trait-specific method is not only simple and cost-effective, but also useful in quantifying the GMO content in ground grain samples containing stacked GM maize, which are expected to be major events in the near future. The developed method would be the only feasible way to conduct the quantification of GMO content in the ground maize samples containing stacked GM maize for the verification of the labeling regulation.

To achieve high level expression of β-glucosidase from Agrobacterium sp. (Abg) in an Escherichia coli expression system, 6 rare codons at +3, +11, +158, +308, +314, and +318 of abg gene were replaced with favored codons using site-directed mutagenesis. The rare codon replacements of +3 (CCC) and +11 (CCC) positions enhanced the expression level of Abg by 2- and 3.6-fold, respectively. The double mutant, Abg-DM, where both of +3 and +11 rare codon positions were modified showed a 5.2-fold higher expression level than the original abg gene. Circular dichroism (CD) spectra of the over-expressed Abg and original Abg enzymes were identical, indicating that Abg was properly folded during over-expression.

A coupled fermentation system of Agrobacterium sp. ATCC 31749 and Trichoderma harzianum GIM 3.442 (AT-CFS) with wheat bran as the optimal nitrogen source was established for producing low-molecular-weight curdlan with high production, which can potentially reduce the cost of low-molecular-weight curdlan biosynthesis. The initial inoculate ratio, pH and the fermentation time were optimized. Compared with the curdlan from the single fermentation system of Agrobacterium sp. ATCC 31749 (A-SFS), the molecular weight (Mw) of the curdlan produced from AT-CFS decreased by 34.01% (from 110.85kDa to 73.15kDa), and the curdlan production (47.9g/L) and conversion rate of glucose to curdlan (0.60gg-1) increased by 119.93% and 36.36%, respectively. The results of RT-PCR showed high curdlan production in AT-CFS was highly correlated with aerobic respiration intensity and curdlan synthase activity. The structure of the curdlan from AT-CFS was the same as that from A-SFS.

A variety of bacteria associate with the hydrocarbon-producing microalga Botryococcus braunii , some of which may influence its growth. We report here the genome sequences for Achromobacter piechaudii GCS2, Agrobacterium sp. strain SUL3, Microbacterium sp. strain GCS4, and Shinella sp. strains GWS1 and SUS2, isolated from a laboratory culture of B. braunii , race B, strain Guadeloupe.

The mechanism of nitrogen signal regulating curdlan biosynthesis in Agrobacterium sp. ATCC 31749 was investigated. Under nitrogen limitation, more carbon flux is directed to curdlan synthesis with low specific growth rate. When ntrB and ntrC genes in Agrobacterium sp. were inactivated, NH4Cl utilization ability was significantly impaired in the ntrB and ntrC mutants and curdlan production was significantly reduced. Through proteomic analysis, nearly 40 proteins did not express in ntrC mutant compared with wild type strain. The levels of 22 proteins were significantly increased and 21 proteins were repressed after nitrogen exhaustion. Phosphoglucomutase activity in Agrobacterium sp. was also decreased. However, phosphoglucomutase activity in the ntrC mutant did not change. On that basis, an NtrC-dependent regulatory network for curdlan biosynthesis in response to nitrogen limitation in Agrobacterium sp. ATCC 31749 is proposed.

Salecan is a novel soluble glucan produced by Agrobacterium sp. ZX09, displaying the ability to inhibit pancreatic amylase and reduce postprandial glucose. The research here provides an investigation of the rheological properties of Salecan solution over a wide range of shear rate (0.001–1000 s−1), frequency (0.1–100 rad/s), concentrations (0.3%, 0.5%, 1.0% and 1.5%), temperature (5–95 °C) and pH (1.0–13.0). The power law model well described the rheological behavior of the solutions, in the shear-thinning region, with high determination coefficients, R2. Salecan solutions showed a non-Newtonian viscosity behavior at all concentrations and temperatures. The solutions exhibited excellent stability below 55 °C. Viscosities were not affected after being frozen (−20 °C). Over a wide pH range from 6.0 to 12.0, the viscosity almost kept invariant. With increasing frequency, the storage and loss moduli G′ and G″ of Salecan solution increased and complex viscosities decreased continuously, which showed an elastic behaviour. All data indicated that Salecan has excellent rheological properties and could be utilized in food industry as a new source of thickening agent.

A significant problem in scale-down cultures, rarely studied for metabolic characterization and curdlan-producing Agrobacterium sp. ATCC 31749, is the presence of dissolved oxygen (DO) gradients combined with pH control. Constant DO, between 5% and 75%, was maintained during batch fermentations by manipulating the agitation with PID system. Fermentation, metabolic and kinetic characterization studies were conducted in a scale-down system. The curdlan yield, intracellular nucleotide levels and glucose conversion efficiency into curdlan were significantly affected by DO concentrations. The optimum DO concentrations for curdlan production were 45-60%. The average curdlan yield, curdlan productivity and glucose conversion efficiency into curdlan were enhanced by 80%, 66% and 32%, respectively, compared to that at 15% DO. No apparent difference in the gel strength of the resulting curdlan was detected. The comparison of curdlan biosynthesis and cellular nucleotide levels showed that curdlan production had positive relationship with intracellular levels of UTP, ADP, AMP, NAD(+), NADH and UDP-glucose. The curdlan productivity under 45% DO and 60% DO was different during 20-50 h. However, after 60 h curdlan productivity of both conditions was similar. On that basis, a simple and reproducible two-stage DO control process for curdlan production was developed. Curdlan production yield reached 42.8 g/l, an increase of 30% compared to that of the single agitation speed control process.

The Agrobacterium sp. HN1 was isolated from the soil and used to adsorb rare earth ions La3+ and Ce3+. The results showed that the pretreatments of Agrobacterium sp. HN1 did not enhance the adsorption of La3+ and Ce3+. The pH, temperature, time and bacterial age affected the dynamics of adsorption of La3+ and Ce3+. The optimum adsorption conditions for Agrobacterium sp. HN1 were as follows: 15 mg/L La3+ of initial concentration, 10 mg/L Ce3+, 300 mg/L (dry wt. cell) biomass for sorption, 6.8 pH, 30°C temperature, 150 r/min rotational speed, 2 h adsorption time and 28 h bacterial age. The adsorption kinetics of La3+ and Ce3+ for Agrobacterium sp. HN1 followed the pseudo-second order equation.

Withanolides (WTDs), well-known medicinally important compounds of Withania somnifera, including the anticancer compound withaferin A (WFA), are biosynthesized from their dedicated precursor squalene. Condensation of farnesyl pyrophosphate (FPP) molecules to produce squalene is catalyzed by squalene synthase (SQS). In the present study, the Arabidopsis thaliana squalene synthase gene ( AtSQS1) was transformed in W. somnifera by Agrobacterium tumefaciens C58C1 (pRiA4). The AtSQS1 gene was detected in 87.88 % of induced transformed hairy roots (THRs). The results showed that the growth index (GI) of THRs after five weeks of culture was 2-fold higher than that of adventitious hairy roots (AHRs). The biomass doubling time of THRs and AHRs was 18 and 30 days, respectively. Quantitative evaluation of WFA in the studied roots showed that THRs contain 1.51-fold more WFA (330±0.87μg g−1 dry weight (DW)) than AHRs (218±0.17μg g−1 DW). These findings can be used for the production of WFA as a valuable anticancer compound through controlled and scaled up cultures of W. somnifera THRs.

Glyphosate is a broad spectrum herbicide that inhibits the activity of endogenous plant 5-enolpyruvylshlkimate-3-phosiahate synthase (EPSPS). Glyphosate resistance has been engineered in multiple crops by constitutive expression of an EPSPS variant from Agrobacterium sp. CP4 (CP4 EPSPS) that binds glyphosate less efficiently. The first glyphosate-resistant cotton (Gossypium hirsutum L.) event, MON 1445, was developed utilizing this CP4 EPSPS and commercially introduced in 1997. Due to insufficient expression of CP4 EPSPS in male reproductive tissues, over-the-top glyphosate applications must be limited to the four-leaf stage of growth. In an attempt to generate events with complete constitutive expression, multiple constructs consisting of different promoters driving cp4 epsps were transformed into cotton. The MON 88913 event was identified as providing exceptional vegetative and reproductive resistance to glyphosate based on more than 8 yr of field testing. Cotton containing MON 88913 has a comparable agronomic profile to the respective negative isoline, the event is stably inherited over multiple generations, and the insertion site is simple with minimal disruption of the cotton genome. As a result, the MON 88913 event was commercially introduced in 2006 as Roundup Ready Flex Cotton (Monsanto Co., St. Louis, MO).

International audience; Curdlan from Agrobacterium sp. was oxidized using 2,2,6,6,-tetramethylpiperidine-1-oxyl radical (TEMPO)–NaBr–NaClO systems at pH 11. The effects of oxidation conditions on degrees of oxidation and polymerization of the products obtained were studied using SEC–MALLS, NMR and IR analyses. Different families of water-soluble β-(1,3)-polyglucuronic and β-(1,3)-polyglucoglucuronic acid sodium salts were quantitatively generated with a yield of 80% and without significant loss of their molecular weights.Given that β-(1,3)-polyglucuronic acids prepared from the regioselective oxidation of curdlan by the TEMPO–NaBr–NaClO systems regularly consist of the glucuronic acid repeating unit; they may open new biotechnological fields for the utilizations of water soluble forms of curdlan.

An aerobic bacterium was isolated from activated sludge in a medium containing l-glutamate-N,N-diacetate (l-GLDA) as sole carbon and energy source. The isolate was identified as a Rhizobium radiobacter species. Besides l-GLDA, the strain utilized nitrilotriacetate (NTA) and proposed intermediates in l-GLDA metabolism such as glyoxylate and l-glutamate. l-GLDA-grown cells oxidized l-GLDA, l-glutamate but not iminodiacetate (IDA), and trans-ketoglutaconate, indicating removal of a carboxymethyl group as an initial degradation reaction. The removal of the first carboxymethyl group of l-GLDA is catalyzed by an NADH-dependent mono-oxygenase. The oxidative deamination of l-glutamate by a dehydrogenase resulting in the formation of oxoglutarate was also detected in cell-free extracts of R. radiobacter sp. A pathway for the metabolism of l-GLDA R. radiobacter sp. is proposed: First, l-GLDA leads to l-glutamate-N-monoacetate (l-GLMA) which in turn leads to l-glutamate. Then, l-glutamate leads to oxoglutarate, an intermediate of the TCA cycle.

Tumorigenic strains of Agrobacterium spp. are responsible for crown gall disease of numerous plant species. We present here draft genome sequences of nonpathogenic Agrobacterium nepotum strain 39/7 T (CFBP 7436 T , LMG 26435 T ), isolated from crown gall tumor on Prunus cerasifera , and tumorigenic Agrobacterium sp. strain KFB 330 (CFBP 8308, LMG 28674), isolated from galls on raspberry.

Continuous fermentation process for the production of soluble glucan using mutant Agrobacterium sp. ATCC31750 has been developed in this research. When the concentration of soluble glucan was higher than 6 g/l, the viscosity of the fermented broth was too high and it needs complex separation process to separate from culture broth. Mathematical models which describe the cell growth and glucan production was developed and they kinetic parameters were estimated with experimental data. They are used for the optimization of continuous fermentation process and calculate optimal dilution rate for easy separation of glucan 4 g/l. With continuous fermentation, glucan production rate was increased 1.8 times more than that with batch fermentation.

Agrobacterium isolated from soil samples produced two extracellular polysaccharides: succinoglycan, an acidic soluble polymer, and curdlan gum, a neutral, insoluble polymer. Maize glucose, cassava glucose, and maize maltose were used in fermentation medium to produce insoluble polysaccharide. Two Agrobacterium sp. strains which were used (ATCC 31749 and IFO 13140) in the production of insoluble exopolysaccharide presented equal or superior yields compared to the literature. The strain ATCC 31749 yielded better production when using maize maltose, whose yield was 85%, whereas strain IFO 13140 produced more when fed maize glucose, producing a yield of 50% (on reducing sugars).

Based on glycosidase inhibitory activities of some known 1,4-iminoalditols, four aldofuranosides, (4-nitro)phenyl β- d -glucofuranoside, -β- d -galactofuranoside, -α- l -idofuranoside and -α- l -altrofuranoside, were identified as possible substrates of glucosidases and galactosidases. Three of them were found to be accepted by the β-glucosidase from Agrobacterium sp.

Glyphosate tolerant wheat MON 71800, simply referred to as MON 71800, contains a 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) protein from Agrobacterium sp. strain CP4 (CP4 EPSPS) that has a reduced affinity for glyphosate as compared to the endogenous plant EPSPS enzyme. The purpose of this work was to evaluate the compositional equivalence of MON 71800 to its nontransgenic parent as well as to conventional wheat varieties. The compositional assessment evaluated the levels of proximates, amino acids, fatty acids, minerals, vitamins, secondary metabolites, and antinutrients in wheat forage and grain grown during two field seasons across a total of eight sites in the United States and Canada. These data demonstrated that with respect to these important nutritional components, the forage and grain from MON 71800 were equivalent to those of its nontransgenic parent and commercial wheat varieties. These data, together with the previously established safety of the CP4 EPSPS protein, support the conclusion that glyphosate tolerant wheat MON 71800 is as safe and nutritious as commercial wheat varieties.

Curdlan is a linear polysaccharide considered a dietary fiber and with gelation properties. This study evaluated the structure, morphology and the physicochemical and technological properties of curdlan produced by Agrobacterium sp. IFO 13140 recovered by pre-gelation and precipitation methods. Commercial curdlan submitted or otherwise to the pre-gelation process was also evaluated. The data obtained from structural analysis revealed a similarity between the curdlan produced by Agrobacterium sp. IFO 13140 (recovered by both methods) and the commercial curdlans. The results showed that the curdlans evaluated differed significantly in terms of dispersibility and gelation, and only the pre-gelled ones had significant potential for food application, because this method influence on the size of the particles and in the presence of NaCl. In terms of technological properties, the curdlan produced by Agrobacterium sp. IFO 13140 (pre-gelation method) had a greater water and oil holding capacity (64% and 98% greater, respectively) and a greater thickening capacity than the pre-gelled commercial curdlan. The pre-gelled commercial curdlan displayed a greater gelling capacity at 95°C than the others. When applied to food, only the pre-gelled curdlans improved the texture parameters of yogurts and reduced syneresis. The curdlan gels, which are rigid and stable in structure, demonstrated potential for improving the texture of food products, with potential industrial use.

1-Amino-1,2,5-trideoxy-2,5-imino- d -mannitol was fluorescently tagged by reaction with dansyl chloride at N-1 or by attachment of a dansyl amide bearing spacer to this centre. Compounds obtained are highly potent inhibitors of β-glucosidase exhibiting K i values in the single figure nanomolar range. The 1- N -dansyl substituted inhibitor was successfully exploited for binding studies with β-glucosidase from Agrobacterium sp. employing fluorescence spectrometric methods.

The pH control was important for curdlan production with Agrobacterium sp. ATCC31750. Specific cell growth rate was the highest at pH 7 and the specific curdlan production rate was at pH 5.5. The pH profiles maximizing curdlan production was changed from pH 7 optimal for cell growth to pH 5.5 optimal for curdlan production after ammonium consumption. The feedback inferential control methods, with easily measurable variables such as NaOH addition for pH control and dissolved oxygen (DO), were also applied. The pH was successfully controlled to follow optimal profiles and the maximal production of curdlan (60 g l−1 in 120 h) was achieved with feedback optimal control.

Agrochelin (1), a new cytotoxic thiazole alkaloid, has been isolated from the fermentation broth of a marine unicellular bacterium belonging to genus Agrobacterium. Its structure was determined from spectral data and chemical transformations. Agrochelin showed chelating properties to the Zn2+ ion.

A study of bacterial populations in metropolitan Adelaide domestic reticulation pipes was conducted to investigate a possible link between copper in drinking water and biofilms. Biofilm densities from cold water copper pipes at 10 sample sites were measured by viable cell counts. The range detected was from < 2 x 10(1) to 3.25 x 10(7) cfu cm-2. Five isolates were selected for further experiments as they represented a range of responses to solvated copper and relative tendency for adhesion on glass slides. Drinking water supplied to the Adelaide Hills is high in total organic carbon (TOC; 22.57 mg Cl-1) and has a negative Langelier Index (LI;-1.16), whereas Adelaide metropolitan water undergoes filtration and has both a lower TOC and LI (10.72 mg Cl-1, LI,-0.49). Copper coupons were exposed to biofilm isolates (24h), washed and resuspended in Adelaide metropolitan and Adelaide Hills water. Copper coupons not exposed to biofilm isolates were suspended in respective waters as a control. After 5 d of incubation, the copper content of Adelaide Hills water (4.71 +/- 0.87 mg Cu l-1), in which the copper coupons were suspended, consistently exceeded values obtained in the metropolitan Adelaide water (1.17 +/- 0.249 mg Cu l-1). The concentration of copper in the Adelaide Hills water was influenced by the bacterial species forming the biofilm on the coupon, with Agrobacterium sp. producing significantly higher levels of soluble copper than the control. The experiments reported here indicate that the suspended organic carbon, the aggressivity of the water and the biofilm may independently or synergistically increase the dissolution of copper from pipes into drinking water.

The synthesis of several oligosaccharides, in yields up to 65%, has been achieved by utilizing the transglycosylation activity of Agrobacterium sp. β-glucosidase (EC 3.2.1.21). The regioselectivity of the glycosylation reaction was investigated using p -nitrophenyl β- d -galactopyranoside, β- d -mannopyranosyl fluoride and d -glucal as glycosyl donors and a series of phenyl 1-thio-, benzyl 1-thio-, and benzyl β- d -glycopyranosides as glycosyl acceptors. The isolated products were determined to contain a mixture of β -(1 → 3) and/or β -(1 → 4) glycosidic linkages for all glycosyl acceptors, except for β- d - galacto -configured acceptors where a mixture of β -(1 → 3) and β -(1 → 6) linkages was observed. The wide range of glycosyl donors and acceptors utilized by the enzyme in transglycosylation experiments demonstrates the versatility of this system for the aqueous-phase synthesis of oligosaccharides.

Agrochelin (1), a new cytotoxic thiazole alkaloid, has been isolated from the fermentation broth of a marine unicellular bacterium belonging to genus Agrobacterium. Its structure was determined from spectral data and chemical transformations. Agrochelin showed chelating properties to the Zn2+ ion.

N-Alkylation at the ring nitrogen of the D-galactosidase inhibitor 1-deoxygalactonojirimycin with a functionalised C6 alkyl chain followed by modification with different aromatic substituents provided lipophilic 1-deoxygalactonojirimycin derivatives which exhibit inhibitory properties against β-glycosidases from E. coli and Agrobacterium sp. as well as green coffee bean α-galactosidase. In preliminary studies, these compounds also showed potential as chemical chaperones for GM1-gangliosidosis related β-galactosidase mutants.

牛久畑地土壌から単離した Agrobacterium sp. (B-7, B-15およびB-17) と Acinetobacter sp. (B-60) による (R)P体および (S)P体のサリチオン (2-メトキシ-4H-1,3,2-ベンゾジオキサホスホリン-2-スルフィド) の代謝について, フェニル環の炭素を14Cで標識した化合物を用いて比較検討した. B-7は (S)P体を (R)P体よりも3.1倍速く分解し, その立体選択性は P-O-アリールおよびP-O-アラルキル結合の立体選択的開裂に起因していた. B-15は両光学異性体を同様な速度および代謝様式で分解した. B-17は (S)P体を (R)P体よりも3.5倍速く分解し, 両光学異性体間で異なる代謝様式を示した. (S)P体ではP-O-アリールおよびP-O-アラルキル結合の開裂が主代謝経路であったのに対し, (R)P体では脱メチル化が主代謝経路であった. B-60は両光学異性体をすみやかに分解し, それらの代謝経路における立体特異性は, B-17の場合とは逆であった. また, いずれの分解菌においてもエピマー化は認められなかった. 分解菌によるサリチオン光学異性体の代謝における立体選択性は, 土壌中におけるサリチオンの立体選択的な分解の結果とよく一致した.

Curdlan-producing Agrobacterium sp. is unique in possessing a highly efficient UDP-glucose regeneration system. A broad-host-range expression strategy was successfully developed to exploit the unique metabolic capability for UDP-galactose regeneration during oligosaccharide synthesis. The engineered Agrobacterium cells functioned as a UDP-galactose regeneration system, allowing galactose-containing disaccharides to be synthesized from glucose or other simple sugars. Unexpectedly, a lag period of 24 h preceded the active synthesis, which could be eliminated with rifampicin. An intracellular nucleotide profiling revealed that the UMP level was elevated by 3.8 fold in the presence of rifampicin, suggesting that rifampicin simulated a nitrogen-limitation condition that triggered the metabolic change. Product selectivity was improved nearly 40-fold by using high acceptor concentration and restricting glucose supply. N -acetyllactosamine concentration near 20 mM (7.5 g/l) was obtained, demonstrating the effectiveness of the engineered strain in UDP-galactose regeneration. This organism could be engineered to regenerate other UDP-sugar nucleotides using the same strategy as illustrated here.

We performed experiments on in vitro digestion of newly expressed proteins by SGF (simulated gastric fluid) and SIF (simulated intestinal fluid) to assess the allergenicity of food components derived from biotechnological modification. For newly expressed proteins, we chose CP4-EPSPS (5-enolpyruvylshikimate-3-phosphate synthase from Agrobacterium sp. strain CP4) and Cry1Ab derived from Bacillus thuringiensis subsp. kurstaki strain HD-1. The former is expressed in GM-soybeans and the latter is expressed in GM-corns. Firstly, we examined the digestibility of purified CP4-EPSPS and Cry1Ab by SGF. Both proteins were rapidly digested within 60 sec. After preheating, the digestibility by SGF was slightly increased. Secondly, CP4-EPSPS in GM-soybean extracts and Cry1Ab in GM-corn extracts were digested by SGF. The digestion time of both proteins by SGF was almost the same as that of the purified proteins. Thirdly, the digestibility of CP4-EPSPS and Cry1Ab by SIF was examined. The digestion time of these proteins was 240 min or more. However, digestibility of these proteins by SIF was dramatically increased by preheating, and the digestion time was less than 5 sec. Fourthly, CP4-EPSPS in GM-soybean extracts and Cry1Ab in GM-corn extracts were digested by SIF. Digestion time of both proteins by SIF was almost the same as that of the purified proteins. From these results, we concluded that the digestibility of both CP4-EPSPS and Cry1Ab by SGF and SIF was increased by preheating. Therefore, we suggest that the allergenicity of both proteins should be extremely low because of the easy digestibility of these proteins by SGF and also by SIF with preheating.