Biotechnology Bulletin ›› 2021, Vol. 37 ›› Issue (12): 71-81.doi: 10.13560/j.cnki.biotech.bull.1985.2021-0119

Previous Articles     Next Articles

Characteristics of Aureobasidium sp. 3A00493 from Deep Sea Sediment and Characteristic Analysis of Its Extracellular Polysaccharide

PAN Jing-yu1(), CHEN Jia-le1, QIAN Yu-cheng1, LIU Xin1, YANG Hao-ning2, LIU Li1, WEI Bu-yun1, ZHAO Hong-xin1()   

  1. 1. Zhejiang Province Key Laboratory of Plant Secondary Metabolism and Regulation,College of Life Sciences and Medicine,Zhejiang Sci-Tech University,Hangzhou 310018
    2. Department of Bioengineering,Liaoning Technical University,Fuxin 123000
  • Received:2021-01-29 Online:2021-12-26 Published:2022-01-19
  • Contact: ZHAO Hong-xin E-mail:469377080@qq.com;bxxbj2003@gmail.com

Abstract:

Pullulan is a natural microbial polysaccharide with high developed value produced by fungus Aureobasidium sp. But different strains present great differences in polysaccharide yield,biological activities and by-products. Therefore,it has always been the focus of researchers to find the excellent strains with high sugar production,strong bacteriostatic activity and less by-products. The original strain is an extracellular polysaccharide-producing microorganism isolated from deep seabed sediments in the Pacific Ocean. On the basis of its morphological and microscopic observation as well as molecular identification,the strain was identified as its genus. The growth characteristics and optimal polysaccharide production conditions were determined via changing the culturing conditions. Five common microorganisms were selected as indicator bacteria,and the antibacterial activity was determined by filter paper method,and the structure of polysaccharides was analyzed by thin layer chromatography and infrared spectroscopy. The original strain 3A00493 was marine-sourced Aureobasidium pullulans,its colony was milky white,its cell and mycelium grew in converted way,and its ITS and 18S rDNA partial sequences shared homology of ≥98% with reported Aureobasidium sp. Its optimal growth temperature was 26℃ and optimal growth pH was 4,under which the polysaccharide yield reached 24.58 g/L. The metabolites of the strain 3A00493 had well antibacterial activity against 4 pathogenic indicator microorganisms. TLC and IR spectra showed that the extracellular polysaccharide produced by the strain 3A00493 was consistent with the pullulan standard sample,thus it was determined as pullulan. In conclusion,original strain 3A00493 is a new marine-sourced A. pullulans producing pullulan,being strong antibacterial activity of its metabolite,and having little pigment byproduct. This work lays a theoretical foundation for further studying marine-sourced pullulan-producing 3A00493,providing a new strain in seeking marine-sources microbial polysaccharide,also providing references for screening and developing marine resources microorganisms.

Key words: Aureobasidium pullulans, pullulan, structure identification, antibacterial activity