Cultural optimization of a new exopolysaccharide producer “Micrococcus roseus”

Hereher, Faten; El‐Fallal, Amira A.; Abou‐Dobara, M. I.; Toson, El-Shahat A.; Abdel-Aziz, Mervat Anwar

doi:10.1016/j.bjbas.2018.07.007

Cited by 22 publications

(7 citation statements)

References 53 publications

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“…A 10% inoculum size was inoculated into NB supplemented with 0.5% glycerol and 0.1% pyroligneous acid, and incubated for 72 h at 30 C with shaking at 150 rpm. 20 A 500 ml aliquot of the culture broth was centrifuged (Eppendorf centrifuge 5804R) for 20 min at 8000 rpm, 4 C. To obtain the EPS, the supernatant was precipitated with ethanol (96 GL) at a 3:1 ratio. 21 The obtained EPS was labeled colloidal EPS and stored at 4 C for 24 h. The cell pellet was suspended in 100 ml of 0.85% sterile normal saline, and the suspension was centrifuged for 20 min at 8000 rpm, 4 C. The clear supernatant was precipitated with ethanol (96 GL) as previously described.…”

Section: Extraction Of Exopolymeric Substancesmentioning

confidence: 99%

Characterization of novel extracellular polymeric substances produced by Bacillus velezensis P1 for potential biotechnological applications

Binmad

Numnuam

Kaewtatip

et al. 2022

Polymers for Advanced Techs

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Bacillus velezensis (B. velezensis) P1 released huge amount of exopolymeric substances (EPS), and its EPS was extracted and characterized. The extracted EPS strongly inhibited (88%-91%) the growth of two serious rice fungal pathogens. The main component of the EPS was protein (44%). Fourier transform infrared spectra of the EPS revealed a complex structure that contained sufficient negatively charged functional groups for the zeta potential of the compound to be highly negative (À33.83 mV).Scanning electron microscope images revealed plate-like particles with smooth, clean surfaces. The EPS showed high degrees of whiteness (L* = 94.56) and crystallinity (87%), and was thermally stable up to 500 C. Flocculation activity in a kaolin dispersion was optimal at an EPS concentration of 12 mg L À1 . The EPS preferred an alkaline condition, with the highest flocculation activity (76%) observed at pH 10. The EPS produced by B. velezensis P1 could be a potential material for applying in agriculture and industry.

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Section: Extraction Of Exopolymeric Substancesmentioning

confidence: 99%

Characterization of novel extracellular polymeric substances produced by Bacillus velezensis P1 for potential biotechnological applications

Binmad

Numnuam

Kaewtatip

et al. 2022

Polymers for Advanced Techs

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“…A high salt concentration in the medium can decrease the metabolic activity of moderately halophilic bacteria due to inadequate adaptation [ 41 ]. Micrococcus roseus produces 8 g/L after 96 h of fermentation [ 42 ] and BM39 Pantoea sp., a slightly halophilic bacterium obtained from the Tyrrhenian Sea, produces 21 g/L of EPSs in 24 h on the glucose medium during the exponential growth phase [ 43 ].…”

Section: Resultsmentioning

confidence: 99%

Molecular Characterization and Biocompatibility of Exopolysaccharide Produced by Moderately Halophilic Bacterium Virgibacillus dokdonensis from the Saltern of Kumta Coast

Andrew

Jayaraman

2022

Polymers

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The use of natural polysaccharides as biomaterials is gaining importance in tissue engineering due to their inherent biocompatibility. In this direction, the present study aims to explore the structure and biocompatibility of the EPS produced by Virgibacillus dokdonensis VITP14. This marine bacterium produces 17.3 g/L of EPS at 96 h of fermentation. The EPS was purified using ion exchange and gel permeation chromatographic methods. The porous web-like structure and elemental composition (C, O, Na, Mg, P, S) of the EPS were inferred from SEM and EDX analysis. AFM analysis revealed spike-like lumps with a surface roughness of 84.85 nm. The zeta potential value of −10 mV indicates the anionic nature of the EPS. Initial molecular characterization showed that the EPS is a heteropolysaccharide composed of glucose (25.8%), ribose (18.6%), fructose (31.5%), and xylose (24%), which are the monosaccharide units in the HPLC analysis. The FTIR spectrum indicates the presence of functional groups/bonds typical of EPSs (O-H, C-H, C-O-H, C-O, S=O, and P=O). The polymer has an average molecular weight of 555 kDa. Further, NMR analysis revealed the monomer composition, the existence of two α- and six β-glycosidic linkages, and the branched repeating unit as → 1)[α-D-Xylp-(1 → 2)-α-D-Glcp-(1 → 6)-β-D-Glcp-(1 → 5)]-β-D-Frup-(2 → 2)[β-D-Xylp-(1 → 4)]-β-D-Xylp-(1 → 6)-β-D-Fruf-(2 → 4)-β-D-Ribp-(1 →. The EPS is thermally stable till 251.4 °C. X-ray diffraction analysis confirmed the semicrystalline (54.2%) nature of the EPS. Further, the EPS exhibits significant water solubility (76.5%), water-holding capacity (266.8%), emulsifying index (66.8%), hemocompatibility (erythrocyte protection > 87%), and cytocompatibility (cell viability > 80% on RAW264.7 and keratinocyte HaCaT cells) at higher concentrations and prolongs coagulation time in APTT and PT tests. Our research unveils the significant biocompatibility of VITP14 EPS for synthesizing a variety of biomaterials.

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“…Exopolysaccharide microbial production also uses submerged fermentation techniques [36]. Cultural conditions needed both for the growth of microorganisms and the synthesis of polysaccharides are specific for each microbe and the polymer as well [37]. For enhanced yields for growing species, external conditions such as pH, temperature, aeration, and agitation must be produced and optimized [38].…”

Section: Chemical Structure and Properties Of Levanmentioning

confidence: 99%

Levan, medical applications and effect on pathogens

Zainulabdeen,

Khalaf,

Salman

2023

Reviews and Research in Medical Microbiology

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Levan is a homopolysaccharide that is composed of d-fructofuranosyl residues joined by β-2,6 linkage. It is naturally obtained from both microorganisms and plants. Microbial levans are more advantageous, industrially and economical with numerous applications and have wide range of applications in food, pharmaceutical, medicine, industry and cosmetic. Levan finds many applications due to its biodegradability, biocompatibility, and film-forming ability. It can be used as a plasma substitute, prolongator of drug activity, radio protector, coating material in drug delivery systems. Many studies reported levan's multiple beneficial effects on human and animal health. Therefore, levan is best known to have antitumor, antioxidant and anti-inflammatory effects. Levan also used as a prebiotic, which can adhere to stomach epithelial cells and promote probiotics bacteria. This mechanism, in turn, controls pathogenic bacteria and may counteract the inflammatory process by enhancing the degradation of enteral antigens, resulting in a reduction of inflammatory mediator secretion.

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Cultural optimization of a new exopolysaccharide producer “Micrococcus roseus”

Cited by 22 publications

References 53 publications

Characterization of novel extracellular polymeric substances produced by Bacillus velezensis P1 for potential biotechnological applications

Characterization of novel extracellular polymeric substances produced by Bacillus velezensis P1 for potential biotechnological applications

Molecular Characterization and Biocompatibility of Exopolysaccharide Produced by Moderately Halophilic Bacterium Virgibacillus dokdonensis from the Saltern of Kumta Coast

Levan, medical applications and effect on pathogens

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