Improved curdlan production with discarded bottom parts of Asparagus spear

Abstract

BackgroundThis 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.ResultsAll 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.ConclusionThe 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.

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

“…It was concluded that cassava starch waste hydrolysate could serve as a substitute for glucose as a carbon source which could lower the production cost of curdlan [24]. The juice extracted from the discarded bottom part of asparagus spears was investigated for its possible use as a supplement to support curdlan production by ATCC 31749 in a sucrose-containing medium [45]. When the 10% juice was added to the sucrose-containing culture medium, ATCC 31749 produced 40.2 g/L curdlan after 168 h of growth at 30 • C [45].…”

“…The juice extracted from the discarded bottom part of asparagus spears was investigated for its possible use as a supplement to support curdlan production by ATCC 31749 in a sucrose-containing medium [45]. When the 10% juice was added to the sucrose-containing culture medium, ATCC 31749 produced 40.2 g/L curdlan after 168 h of growth at 30 • C [45]. The juice supplement was found to support a higher level of curdlan production by ATCC 31749 compared to when the strain was grown in the sucrose-containing medium alone [45].…”

“…When the 10% juice was added to the sucrose-containing culture medium, ATCC 31749 produced 40.2 g/L curdlan after 168 h of growth at 30 • C [45]. The juice supplement was found to support a higher level of curdlan production by ATCC 31749 compared to when the strain was grown in the sucrose-containing medium alone [45]. It was thought that the enhanced curdlan production was due to the juice extracted from the discarded asparagus spears being rich in minerals and vitamins [45].…”

“…The juice supplement was found to support a higher level of curdlan production by ATCC 31749 compared to when the strain was grown in the sucrose-containing medium alone [45]. It was thought that the enhanced curdlan production was due to the juice extracted from the discarded asparagus spears being rich in minerals and vitamins [45]. The utilization of a mixed species fermentation system involving Agrobacterium sp.…”

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“…The inoculated flasks were kept for shaking incubation at room temperature for 76 h at 180 rpm. The extraction of curdlan was done by centrifuging the culture medium at 12,000 × g for 30 min 17,18 . The extracted pellet was mixed with the same ratio of 0.5N Sodium hydroxide at 4 ºC.…”