Production and downstream processing of (1→3)-β-D-glucan from mutant strain of Agrobacterium sp. ATCC 31750

Abstract

We isolated a mutant that produced higher levels of curdlan than the wild strain Agrobacterium sp. ATCC 31750 by chemical mutagenesis using N-methyl-N-nitro-nitrosoguanidine. The mutant strain produced 66 g/L of curdlan in 120 h with a yield of (0.88) while, the wild strain produced 41 g/L in 120 h with a yield of (0.62) in a stirred bioreactor. The mutant could not produce curdlan when the pH was shifted from 7.0 to 5.5 after nitrogen depletion as followed for wild strain. In contrast, pH optimum for cell growth and curdlan production for mutant was found to be 7.0. We optimized the downstream processing of curdlan by varying different volumes of NaOH and HCl for extraction and precipitation of curdlan. The molecular weight of the purified curdlan from the wild and mutant strain was 6.6 × 105 Da and 5.8 × 105 Da respectively. The monosaccharide analyses confirm that curdlan from both wild and mutant strain contains only glucose units. From the NMR and FTIR data, it has been confirmed that curdlan was exclusively composed of β (1 → 3)-D-glucan residues.

Electrospun Nanofibers of Curdlan (β‐1,3 Glucan) Blend as a Potential Skin Scaffold Material

“…The 1 H and 13 C spectra (Figure S1, Supporting Information) of the curdlan produced from Agrobacterium sp. ATCC 31750 are consistent with the earlier reports . The peaks at 4.6–5.2 ppm in the 1 H NMR spectrum indicate anomeric protons while those at 3.0–3.9 indicate sugar protons.…”

“…Curdlan was produced from Agrobacterium sp. ATCC 31750 as reported earlier . The seed medium containing (in g L −1 ): sucrose 20, yeast extract 5, and peptone 5 at pH 7.0, was inoculated.…”

Green synthesis of silver nanoparticles by seed of Phoenix sylvestris L. and their role in the management of cosmetics embarrassment

“…According to the IR spectrum, the broad peak at 3300 cm −1 is due to stretching vibration of O-H of phenols and peak at 1600 cm −1 is due to N-H bond of primary amines, whereas two minor peaks at 2900 and 2850 cm −1 can be due to the -O-H-and C = O stretching vibrations. Proposing that the O-H group of phenols, amide groups of proteins aromatic and carbonyl groups of the protein forming a layer of the NPs and these act as potential capping agents to prevent accumulation of the particle and provide stability to the medium (32,33).…”

Silver Loaded Nanofibrous Curdlan Mat for Diabetic Wound Healing: An In Vitro and In Vivo Study

“…Curdlan was produced from Agrobacterium sp. ATCC 31750 and characterized as reported earlier . Curdlan (7 wt%) in formic acid was blended with PVA (10 wt%) in water at a weight ratio of 1:2 and mixed with different concentrations of silver nitrate (1, 3, and 5 wt%).…”