Production of an immunosuppressive polysaccharide, AZ9, in the culture of Klebsiella oxytoca strain TNM3

Exopolysaccharides from Klebsiella oxytoca: anti-inflammatory activity

“…a p < 0.05 compared with normal rats (ANOVA, Tukey's test). Literature data report that K. oxytoca EPS isolated from the soil, and produced under the same cultivation conditions as that employed in this work, have an average molecular weight of approximately 200 kDa (Sugihara et al, 2000;Sugihara et al, 2001) and KEPSC and KEPS are probably high molecular weight macromolecules.…”

“…The K. oxytoca strain (1.5 × 10 8 CFU/mL standard bacterial suspension) was cultured in liquid medium (10 mL/L inoculum) as described by Sugihara et al (2001). Cultures were grown in Sugihara medium (SM) (5.0 g/L K 2 HPO 4 , 0.5 g/L MgSO 4 .7H 2 O, 2.0 g/L polypeptone, and 20 g/L glucose) in 100 mL Erlenmeyer flasks at 28 °C with shaking at 200 rpm for 48 h. The bacterial culture was then transferred aseptically to 2000 mL Erlenmeyer flasks containing 900 mL of SM, incubated at 28 °C for 120 h then maintained at 4 °C prior to EPS isolation.…”

“…The supernatant was collected and concentrated to 100 mL in a rotary evaporator at 50 °C. Following this, the concentrated solution containing EPS was precipitated from the clear supernatant by adding three volumes of cold acetone and maintained at 4 °C for 48 h. The crude exopolysaccharides from K. oxytoca (KEPSC) were obtained by filtration, lyophilized and weighed to calculate the yield (Kazy et al, 2002;Sugihara et al, 2000;Sugihara et al, 2001;Sugihara et al, 2002). Once isolated, the KEPSC solution was deproteinized with trichloracetic acid (20%, w/v) at a ratio of 1:1, maintained at 4 °C for 2 h, and then centrifuged (12,000 × g for 20 min at 5 °C).…”

“…The carbohydrate polymers secreted by a wide variety of bacteria are known as exopolysaccharides (EPS), which exhibit important biological activities, including immunomodulation, antioxidant, prebiotic, and anti-proliferative properties (Shi, 2016;Zha et al, 2015;Sugihara et al, 2001;Wang et al, 2015).…”

Experimental immunology Immunosuppressive effect of systemic administration of Lactobacillus rhamnosus KL37C-derived exopolysaccharide on the OVA-specific humoral response

“…Interestingly, it has been documented that EPSs, the major components of lactobacilli biofilm matrix, show a significant impact on lactic bacteria immunoregulatory properties, including enhancement of the humoral response [3]. Moreover, to our knowledge, apart from our investigations [11], only a few reports have described the immunosuppressive effects of bacterial EPSs [5,31]. All these data support a common opinion that biological functions of lactobacilli (EPSs) are not only strainspecific but the final effect also depends on a route of bacteria (EPS) administration, i.e.…”