title: Lactose consuming strains of Xanthomonas citri subsp. citri (Xcc) insight into the emergence of natural field resources for xanthan gum production.
abstract: Xanthomonas genus possesses a low level of β-galactosidase gene expression and is therefore unable to produce xanthan gum in lactose-based media. In this study, we report the emergence of some natural field strains of Xanthomonas citri subsp. citri (Xcc) capable to use lactose as a sole carbon source to produce xanthan gum. From 210 Xcc strains isolated from key lime (C. aurantifolia), 27 showed the capacity to grow on lactose containing medium. Xcc lactose consuming strains demonstrated a good level of xanthan production. Amongst all, NIGEBK37 produced the greatest (14.62 g/l) amount of xanthan gum in experimental laboratory conditions. By evaluating the viscosity of the biopolymer at 25 °C, it was demonstrated that xanthan synthesized by strain NIGEBK37 has the highest viscosity (44,170.66 cP). Our results were indicative for the weakness of a commercial strain of Xanthomonas campestris pv. Campestris DSM1706 (Xcc/DSM1706) to produce xanthan in lactose containing medium.
authors: Department of Plant Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), 17th Kilometer Tehran-Karaj Highway, Pajouhesh Blvd. NIGEB, P. O. Box14965/161, Tehran, Iran.
authors: Aghdas
authors: A
authors: Ramezani
authors: Mahyat
authors: M
authors: Jafari
authors: Tannaz
authors: T
authors: Goodarzi
authors: Seyed Mehdi
authors: SM
authors: Alavi
authors: Ali Hatef
authors: AH
authors: Salmanian
authors: Mehrdad
authors: M
authors: Azin
mesh_terms: D032082:Citrus aurantiifolia / Q000382:microbiology; D003470:Culture Media / Q000737:chemistry; D007218:Industrial Microbiology; D007785:Lactose / Q000378:metabolism*; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D013696:Temperature; D014783:Viscosity; D014974:Xanthomonas / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*
chemical_list: D003470:Culture Media; D011135:Polysaccharides, Bacterial; D007785:Lactose; C002563:xanthan gum