Agrobacterium

The crystal structure of the halohydrin dehalogenase from the soil bacterium Agrobacterium radiobacter ADI, HheC, has been solved [129]. HheC is structurally related to the family of NAD(P)H-dependent short-chain dehydrogenases/reduc-... 

Table 3.1 Parameters of growth and exopolysaccharide production for Agrobacterium radiobacter grown in chemostat culture on various carbon sources. Data obtained from Linton J. D. et al (1987) Journal of General Microbiology 133, 2979-2987.

Temperature can influence the characteristics of the product. For example, the sucdonoglycan from Agrobacterium radtobader grown at 306C has a lower viscosity than that grown at a temperature of 35°C, although the final concentration is similar. 

An even more elegant approach for the production of D-phydroxyphenylglydne on an industrial scale uses foe bacterium. Agrobacterium radiobacter (Figure A8.8). The organism is able to produce both D-hydantoinase and a second enzyme, N-carbamoyl-D-amino acid aminohydrolase, which catalyse the hydrolysis of N-carbamoyl-D-amino add. 

In another study that appeared prior to the advent of CASTing, the traditional combination of epPCR and DNA shuffling was used to enhance the enantioselectivity of the hydrolytic kinetic resolution of p-nitro phenyl glycidyl ether and other epoxides catalyzed by the EH from Agrobacterium radiobacter [59]. Several mutants were obtained with up to 13-fold improved enantioselectivity. The amino acid exchanges took place around the active site. 

Wagner V. Matthysse A. G. (1992) Involvement of a vitronectine-like protein in attachment of Agrobacterium tumefaciens to carrot suspension culture cells // J. Bacteriol. V. 174. P. 5999-6003. 

Fig. 1. Infection and transformation of a suitable host plant by Agrobacterium tumefaciens (from Bryant, 1988).

Fig. 2. Schematic representation of the Ti-plasmid of Agrobacterium, showing the genes involved in transformation of host plants. Note that the genetic map is not to scale in reality, the T-region makes up about 10% of the total plasmid genome (from Bryant, 1988).

Leaf discs are floated on a suspension of Agrobacterium ceWs that contain genetically engineered Ti-plasmids. The bacterium infects cells around the edges of the discs, and the T-DNA is transferred to the chromosomes of the infected cells. 

Under natural conditions. Agrobacterium does not appear to infect monocotyledonous plants. Genetic manipulation of cereal crops using a Ti-plasmid delivered by Agrobacterium therefore seems out of the question. However, there are some data to suggest that Agrobacterium can, under certain circumstances, infect monocots, but that it does not cause... 

Grimsley, N., Hohn, T., Davies, J.W. Hohn, B. (1987). Agrobacterium-mediated delivery of infectious maize streak virus into maize plants. Nature, 325, 177-9. 

Hooykaas-van Slogteren, G.M.S., Hooykaas, P.J.J. Schilperoort, R.A. (1984). Expression of Ti plasmid genes in monocotyledonous plants infected with Agrobacterium tumefaciens. Nature, 311, 763-4. 

Tzfira, T. and Citovsky, V., Agrobacterium-mediated genetic transformation of plants biology and biotechnology. Cum. Opin. Biotechnol. 17, 147, 2006. 

A novel decarboxylase, 2,6-dihydroxybenzoate decarboxylase, was found in Agrobacterium tumefaciens 1AM 12048 at first. Thereafter, the same activity was found in Rhizobium species by two groups independently. Furthermore, Pandoraea sp. 12B-2, the most powerful producer of 2,6-dihydroxybenzoate decarboxylase, was isolated. These enzymes have been purified and characterized. 

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