Production of the polysaccharide curdlan by anAgrobacteriumstrain grown on a plant biomass hydrolysate

Abstract

Production of the commercially available polysaccharide curdlan by Agrobacterium sp. strain ECP-1, isolated as a mutant strain from ATCC 31749, on a medium containing a hydrolysate of the plant prairie cordgrass with selected ammonium phosphate concentrations was investigated for a period of 144 h. Although several ammonium phosphate concentrations supported curdlan production by the strain, the optimal concentration after 120 or 144 h was 3.3 mmol·L⁻¹. Only ammonium phosphate concentrations of 1.1 or 8.7 mmol·L⁻¹ failed to support curdlan production by the strain after 120 or 144 h. Biomass production by strain ECP-1 on the hydrolysate-containing medium after 120 or 144 h was comparable, independent of the ammonium phosphate concentration present. The curdlan yield from the cordgrass hydrolysate indicated that the grass was an effective plant biomass substrate for polysaccharide production.

Production of the Polysaccharide Curdlan by Agrobacterium species on Processing Coproducts and Plant Lignocellulosic Hydrolysates

“…If the plant biomass is treated at high temperature and pressure, it is possible to release a high concentration of cellulose from the biomass [50]. Subsequent enzymatic treatment by cellulase and cellobiase can be used to degrade cellulose to glucose which is a substrate for curdlan production [47,48]. Using a prairie cordgrass hydrolysate to support curdlan production by ATCC 31749, exogenous nitrogen source addition to a hydrolysate-containing medium was shown to be important.…”

“…Cellular biomass production by ATCC 31749 after 144 h of growth on the complete hydrolysate medium was greater than its biomass production on the solids-only hydrolysate medium [47]. The ability of a curdlan overproducer mutant strain to utilize a prairie cordgrass hydrolysate to support curdlan production by ATCC 31749 was also examined in relation to the ammonium phosphate concentration present in the medium [48]. The highest curdlan concentration and yield was produced by the mutant strain grown at 30 • C and 144 h on a medium containing the complete hydrolysate and 3.3 mM ammonium phosphate [48].…”

“…The ability of a curdlan overproducer mutant strain to utilize a prairie cordgrass hydrolysate to support curdlan production by ATCC 31749 was also examined in relation to the ammonium phosphate concentration present in the medium [48]. The highest curdlan concentration and yield was produced by the mutant strain grown at 30 • C and 144 h on a medium containing the complete hydrolysate and 3.3 mM ammonium phosphate [48]. Curdlan production by the mutant strain grown under the same culture conditions on the complete prairie cordgrass hydrolysate as its parent strain ATCC 31749 was 1.8-fold higher (Table 1).…”

Rheological Behavior and Pharmaceutical Applications of Bacterial Exopolysaccharides

“…The monosaccharide present in this linear (1→3)-β-D-glucan is D-glucose linked in (1→3) manner. The average molecular weight has been found to vary between 5.3 X 10 4 to 2.0 X 10 6 Da in 0.3 M NaOH (West and Peterson, 2014;Curdlan monograph;Zhang, 2015).…”

Improved curdlan production with discarded bottom parts of Asparagus spear

“…strains (ATCC 31749 and IFO 13140) from alternative fermentation media using glucose from maize and cassava starch hydrolysate, and maltose from maize starch hydrolysate as the main carbon source. Other literatures reveal that cordgrass hydrolysate and condensed corn distiller soluble have been applied as effective carbon sources for curdlan production [21, 22]. Another study, indicated the possibility of using date palm juice by-products as the main carbon source for curdlan production by Rhizobium radiobacter ATCC 6466 [17, 23].…”