TITLE:
Isolation and Identification of Symbiotic Bacteria from Brasenia schreberi and Analysis of their Polysaccharide Producing Characteristics and Antioxidant Activity
AUTHORS:
Chenglong Li, Xueyang Song, Qiuyu Zhang, Hanyu Gong, Guanghui Yu
KEYWORDS:
Brasenia schreberi, Endosymbiont, HPLC, IR Spectrum, Polysaccharide
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.11 No.3,
March
6,
2020
ABSTRACT: Brasenia
schreberi (water shield), a perennial freshwater aquatic plant
of the family Nymphaeaceae, is rich
in polysaccharides with positive biological activity and potential application
value. As an indicator plant of the environment in wetlands, B. schreberi original and wild water
environment faced increasing deterioration and has been listed as a critically
endangered species in several countries of East Asia. Seeking an alternative
method to produce B. schreberi mucilage
polysaccharide is of top priority. The morphological structure of the stem and
leaf of B. schreberi was studied. Well-developed glandular cells and
aerenchyma tissue were observed in the stem and leaves of water shield, which
were related to its aquatic habitat and polysaccharide secretion and then three
endophytic bacteria were successfully isolated and purified from its stem and
leaf and identified as Micromonospora sp.
YG-1, Xylariaceae sp. strain UT-X and Psychrobacter pulmonis strain T-15. Symbiotic bacteria from B. schreberi produced polysaccharides
with similar spectral peaks and chemical functional groups to those of B. chinensis. Further, analysis of
hydroxyl free radicals showed that symbiotic bacteria in water shield had
significant antioxidant activity against hydroxyl free radicals. This study
provides a theoretical and practical basis for further study using symbiotic
bacteria to produce polysaccharides to overcome the environmental limitations
of the growth and development of B.
schreberi.