Xanthan gum production from acid hydrolyzed broomcorn stem as a sole carbon source by Xanthomonas campestris

Abstract

Xanthan gum is an exo-polysaccharide industrially produced by fermentation using simple sugars. In this study, broomcorn stem was introduced as a low-cost- and widely available carbon source for xanthan gum fermentation. Broomcorn stem was hydrolyzed using sulphuric acid to liberate reducing sugar which was then used as a carbon source for biosynthesis of xanthan gum by . Effects of hydrolysis time (15, 30, 45 and 60 min), sulphuric acid concentration (2, 4, 6 and 8% v/v) and solid loading (3, 4, 5 and 6% w/v) on the yield of reducing sugar and consequent xanthan production were investigated. Maximum reducing sugar yield (55.2%) and xanthan concentration (8.9 g/L) were obtained from hydrolysis of 4% (w/v) broomcorn stem with 6% (v/v) sulphuric acid for 45 min. The fermentation product was identified and confirmed as xanthan gum using Fourier transform infrared spectroscopy analysis. Thermogrvimetric analysis showed that thermal stability of synthesized xanthan gum was similar to those reported in previous studies. The molecular weight of the produced xanthan (2.23 × 10 g/mol) was determined from the intrinsic viscosity. The pyruvate and acetyl contents in xanthan gum were 4.21 and 5.04%, respectively. The chemical composition results indicated that this biopolymer contained glucose, mannose and glucoronic acid with molecular ratio of 1.8:1.5:1.0. The kinetics of batch fermentation was also investigated. The kinetic parameters of the model were determined by fermentation results and evaluated. The results of this study are noteworthy for the sustainable xanthan gum production from low-value agricultural waste.

Production and physicochemical characterization of xanthan gum by native lactose consuming isolates of Xanthomonas citri subsp. citri

“…Analysis of apparent viscosity was carried out to assess the rheological feature of the produced xanthan [16]. The viscosity of the fermentation broth was measured by using BROOK-FIELD DV-II viscometer at 25 °C [15,19]. To obtain the amount of xanthan produced, the samples were taken at specific time intervals, diluted with distilled water (1:1 v/v), and centrifuged at 10000×g for 15 min at 4 °C for separating the cells.…”

“…The colorimetric method was used for the determination of pyruvate and acetate content in xanthan product. The percenta ge of pyruvate and acetate was measured by 2 and 4 di-nitrophenylhydrazine and hydroxa mic acid methods, respectively [16,19]. The standard acetylcholine and pyruvate curves were prepared and the commercial xanthan powder (Sigma-Aldrich) was used as control.…”

“…The product of xanthan was powdered and mixed with KBr and was prepared as a pellet. Samples were analyzed using Perkin Elmer Fourier Transform Infrared, with wavelength ranging from 400 to 4000 waves/cm with 32 scans/samples [Perkin Elmer, spectrum one] [9,19].…”

Repeated cultures of Saccharomyces cerevisiae SC90 to tolerate inhibitors generated during cassava processing waste hydrolysis for bioethanol production

“…Tian et al (2011) used the wood of lodgepole trees (Pinus contorta) pretreated with bisulfite and sulfuric acid placing the wood pulp in a digester at 180 °C for 25 min. Soleymanpour et al (2018) also noted that an increase in acid concentration resulted in increased formation of inhibitory compounds and rise of the sugar decomposition rate. The source of biomass and the harshness of the pretreatment could affect types and proportions of inhibitors and sugars produced in the hydrolysate.…”

Isolation of Nanocellulose from Broomcorn Stalks and Its Application for Nanocellulose/Xanthan Film Preparation

“…It is used to fabricate brooms, brushes and decorative items. It can be grown in tropical and subtropical regions . This plant is moderately tolerant of heat and drought.…”