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Optimization of production and intrinsic viscosity of an
exopolysaccharide from a high yielding Virgibacillus salarius BM02: Study
of its potential antioxidant, emulsifying properties and application in the
mixotrophic cultivation of Spirulina platensi

Research Authors
Mohamed Gomaa, Naeima Yousef
Research Abstract

Virgibacillus salarius BM02 was identified as a highly exopolysaccharide (EPS) producing bacterium. The EPS production
and its physico-chemical properties (intrinsic viscosity and total sugars/protein (TS/P) ratio) were optimized
using Box-Behnken experimental design. Maximum EPS production of 5.87 g L
−1
with TS/P ratio of 12.56
and intrinsic viscosity of 0.13 dL g
−1
was obtained at optimal conditions of sucrose (4.0% w/v), peptone (0.75% w/
v) and incubation period of 4.69 day. The monosaccharide composition of EPS was mannose, arabinose and glucose
at a molar ratio of 1.0:0.26:0.08. The EPS showed high water solubility (38.5%), water holding capacity
(514.46%) and foaming capacity (55.55%). The EPS showed moderate antioxidant activity in vitro and good emulsion
stabilizing properties against several hydrophobic compounds. The emulsifying activity was stable at different
temperatures, pH and ionic strength. Additionally, the acid hydrolysate of the EPS was evaluated as a carbon
source for the mixotrophic cultivation of industrially important Spirulina platensis. It induced an enhancement of
not only biomass production of S. platensis, but also cellular contents (pigments, proteins and lipids) leading to
higher nutritional value.

Research Journal
International Journal of Biological Macromolecules
Research Publisher
Elsevier
Research Rank
1
Research Vol
149
Research Website
NULL
Research Year
2020
Research Pages
552-561