African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12236

Full Length Research Paper

Fermentative intensity of L-lactic acid production using self-immobilized pelletized Rhizopus oryzae

Shuizhong Luo
  • Shuizhong Luo
  • Key Laboratory for Agricultural Products Processing of Anhui Province, College of Food Science and Engineering, Institute of Agricultural Products Processing Technology, Hefei University of Technology, Hefei, Anhui, 230009, China
  • Google Scholar
Xuefeng Wu
  • Xuefeng Wu
  • Key Laboratory for Agricultural Products Processing of Anhui Province, College of Food Science and Engineering, Institute of Agricultural Products Processing Technology, Hefei University of Technology, Hefei, Anhui, 230009, China
  • Google Scholar
Yu Zhu
  • Yu Zhu
  • Key Laboratory for Agricultural Products Processing of Anhui Province, College of Food Science and Engineering, Institute of Agricultural Products Processing Technology, Hefei University of Technology, Hefei, Anhui, 230009, China
  • Google Scholar
Xingjiang Li
  • Xingjiang Li
  • Key Laboratory for Agricultural Products Processing of Anhui Province, College of Food Science and Engineering, Institute of Agricultural Products Processing Technology, Hefei University of Technology, Hefei, Anhui, 230009, China
  • Google Scholar
Shaotong Jiang
  • Shaotong Jiang
  • Key Laboratory for Agricultural Products Processing of Anhui Province, College of Food Science and Engineering, Institute of Agricultural Products Processing Technology, Hefei University of Technology, Hefei, Anhui, 230009, China
  • Google Scholar
Zhi Zheng
  • Zhi Zheng
  • Key Laboratory for Agricultural Products Processing of Anhui Province, College of Food Science and Engineering, Institute of Agricultural Products Processing Technology, Hefei University of Technology, Hefei, Anhui, 230009, China
  • Google Scholar


  •  Received: 25 May 2015
  •  Accepted: 28 April 2016
  •  Published: 25 May 2016

Abstract

L-Lactic acid is a promising three-carbon building-block chemical, widely used in the food, pharmaceutical, leather and textile industries and Rhizopus oryzae is an important filamentous fungus for the production of L-lactic acid with high optical purity. This study investigated the medium compositions for the maximum biomass cultivation of R. oryzae L-lactic acid fermentation, and optimized the operation parameters for semi-continuous repeated fermentation in a stirred tank fermentor using response surface method (RSM) analysis. The results indicated that a higher biomass cultivation of 3.750±0.05 g/L was achieved when the medium was composed of 12% (w/v) glucose, 0.4% (w/v) ammonium sulfate and 0.045% (w/v) monopotassium phosphate. The optimal fermentation conditions for the initial batch were as follows: the aeration was 0.75 L/(L·min), inoculation of germs was 11% and agitation speed was 560 rpm. The fermentative intensity of the initial batch and the sequentially repeated batches with self-immobilized pelletized R. oryzae were 2.162 g/(L·h) and 3.704 g/(L·h), respectively.

 

Key words: Self-immobilized, Rhizopus oryzae, pellet, lactic acid, response surface method (RSM).