ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Isolation of sporopollenin-like biopolymer from Aspergillus niger and its characterisation

Murari Lal Soni, Manish Gupta, and Kamta Prasad Namdeo

SLT Institute of Pharmaceutical Sciences, Guru GhasidasVishwavidyalaya; Bilaspur 495009 (C.G.), India

E-mail: drkpnamdeo@gmail.com

Abstract: The study sought to isolate asporopollenin-like biopolymer from Aspergillus niger (A. niger) spore. The spore exine (Sp-exine) from A. niger was isolated using four different methods. The highest isolation efficiency (9.32 %) was found for the method based on H₂SO₄ treatment. Optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed that the isolated Sp-exine had a spherical shape with a spun morphology and was highly uniform in size. The elemental compositions of the bodies of the Sp-exine materials, as well as their surfaces, were observed by means of CHN combustion analysis and SEM with energy-dispersive X-ray spectroscopy (SEM-EDX), respectively. The result demonstrates C, H and O to be the main structural elements in all the Sp-exine samples. Fourier-transform infrared (FTIR) spectroscopy coupled with solid state ¹³C nuclear magnetic resonance (solid state ¹³C NMR) spectroscopy and UV-Vis spectroscopy were used to compare the changes in the functional groups of the Sp-exine samples isolated using the different methods. A thermogravimetric analysis (TGA) study demonstrated all the Sp-exine samples showed high thermal stability. Among all tested methods, the treatment with H₂SO₄ and alcoholic potassium hydroxide exhibited the best results in removing cellular and other contents with minimal drastic effect on the structure and morphology and is proposed as the best method for isolating Sp-exine since it required minimal isolation time and showed good isolation efficiency.

Keywords: sporopollenin; spore exine; Aspergillus niger; biopolymer

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2016-0099

Chemical Papers 70 (12) 1556–1567 (2016)