African Journal of

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12072

Full Length Research Paper

Biotransformation of indigo carmine to isatin sulfonic acid by lyophilized mycelia from Trametes versicolor

Maribel Cano1*, Myrna Solis1, Joel Diaz1, Aida Solis2, Octavio Loera3 and Maura M. Teutli4
1Centro de Investigación en Biotecnología Aplicada del Instituto Politécnico Nacional,  Carretera Estatal Santa Inés Tecuexcomac-Tepetitla Km. 1.5, Tepetitla de Lardizábal, Tlaxcala, C.P. 90700 México. 2Universidad Autónoma Metropolitana-Unidad Xochimilco, México. 3Universidad Autónoma Metropolitana-Unidad Iztapalapa, México. 4Facultad de Ingeniería, Benemérita Universidad Autónoma de Puebla, México.
Email: [email protected]

  • Article Number - 94C0B1C33959
  • Vol.10(57), pp. 12224-12231, September 2011
  •  Accepted: 24 June 2011
  •  Published: 28 September 2011


 In this work, acrylonitrile (AN) and acrylic acid (AA) monomers were directly grafted onto chitosan using ammonium persulfate (APS) as an initiator and methylenebisacrylamide (MBA) as a crosslinking agent under an inert atmosphere. The hydrogels structure was characterized by Fourier transform infrared (FTIR)spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The effect of grafting variables, that is, AA/AN weight ratio and concentration of MBA and APS, was systematically optimized to achieve a hydrogel with swelling capacity as high as possible. The water absorbency increased with increasing the AA amount in the monomer feed due to formation of polyelectrolyte. The swelling of the hydrogel samples in saline solution (0.15 mol/l NaCl, CaCl2 and AlCl3) was examined. The results indicate that the swelling capacity decreased with an increase in the ionic strength of the swelling medium. This behavior can be attributed to charge screening effect for monovalent cations, as well as ionic crosslinking for multivalent cations. Furthermore, the swelling of superabsorbing hydrogels was examined in solutions with pH values ranging between 1 and 13.


Key words: Hydrogel, chitosan, superabsorbent, acrylonitrile, acrylic acid. 

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