Damini Kothari

Structural and biocompatibility properties of dextran from Weissella cibaria JAG8 as food additive

Abstract Dextran produced from Weissella cibaria JAG8 was purified and characterized. The molecular mass of dextran as determined by the gel filtration and copper bicinchoninate method was approximately, 800 kDa. Monosaccharide analysis revealed that the polysaccharide comprised only glucose units. Dynamic light scattering study confirmed the mono-disperse nature of dextran with hydrodynamic radius of 900 nm. Surface morphology study of dextran by scanning electron microscopy showed the porous web like structure. Cytotoxicity studies on human cervical cancer (HeLa) cell line showed non-toxic and biocompatible nature of dextran. The relative browning for dextran from W. cibaria JAG8 was similar to commercial prebiotic Nutraflora P-95 and 3-fold lower than Raftilose P-95. Synthesis of dextran by dextransucrase treated, sucrose-supplemented skimmed milk revealed the promising potential of dextran as a food additive.

Therapeutic Spectrum of Nondigestible Oligosaccharides: Overview of Current State and Prospect

Functional oligosaccharides have emerged as valuable components of food and dietary supplements. Their resistance to digestion and fermentation by colonic microbes has given them the nutritional edge. Apart from implications as dietary fibers, sweeteners, and humectants, they are hailed as prebiotics. Their beneficial effects extend from antioxidant, anti-inflammatory, immunomodulatory, antiallergic, hypotensive, hyperlipemic, neuroprotective to anticancer. The rising popularity of bioactive oligosaccharides has accelerated the search for their generation from new, sustainable sources. The surfacing crucial role in healthcare and unprecedented demand necessitates deeper investigation. The present review embodies an overview on various aspects of production, properties with emphasis on therapeutic applications of functional oligosaccharides. The biological efficacy and possible mechanisms of action of oligosaccharides have also been discussed.

Scale up of dextran production from a mutant of Pediococcus pentosaceus (SPAm) using optimized medium in a bioreactor

The mutant of Pediococcus pentosaceus (SPAm) produced earlier by UV-mutagenesis exhibiting higher dextransucrase activity as compared to wild-type was used. The generated mutant SPAm gave 12.2 mg/ml, a 20% higher dextran than wild-type. Response surface methodology was carried out for further enhancement of dextran production. To enhance dextran production by the mutant SPAm, Plackett-Burman Design and a 22 full factorial Central Composite Design was employed. After response optimization, the optimum concentration of sucrose and yeast extract was 5.115% (w/v) and 0.635% (w/v), respectively. The experimental values of dextran 36.0 mg/ml at flask level and 35.0 mg/ml at bioreactor level were in good agreement with the predicted value of 40.8 mg/ml. The increase in dextran production by the mutant SPAm using the optimized medium was 3 fold higher as compared to unoptimized medium.

Enzyme‐resistant isomalto‐oligosaccharides produced from Leuconostoc mesenteroides NRRL B‐1426 dextran hydrolysis for functional food application

The extracellular dextransucrase from Leuconostoc mesenteroides NRRL B‐1426 was produced and purified using polyethylene glycol fractionation. In our earlier study, it was reported that L. mesenteroides dextransucrase synthesizes a high‐molecular mass dextran (>2 × 106 Da) with ∼85.5% α‐(1→6) linear and ∼14.5% α‐(1→3) branched linkages. Isomalto‐oligosaccharides (IMOs) were synthesized through depolymerization of dextran by the action of dextranase. The degree of polymerization of IMOs was 2–10 as confirmed by mass spectrometry. The nuclear magnetic resonance spectroscopic analysis revealed the presence of α‐(1→3) linkages in the synthesized IMOs. The IMOs were resistant to dextranase, α‐glucosidase, and α‐amylase, and therefore can have potential application as food additives in the functional foods.