Production of Citric Acid from the Fermentation of Pineapple Waste by Aspergillus niger



Augustine. O. Ayeni1, *, Michael O. Daramola3, Olugbenga Taiwo2, Omowonuola I. Olanrewaju1, Daniel T. Oyekunle1, Patrick T. Sekoai4, Francis B. Elehinafe1
1 Chemical Engineering Department, College of Engineering, Covenant University, Ota, Nigeria
2 Biological Sciences Department, College of Science and technology, Covenant University, Ota, Nigeria
3 School of Chemical and Metallurgical Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, Wits 2050, Johannesburg, South Africa
4 Hydrogen Infrastructure Centre of Competence, Faculty of Engineering, North-West University, Potchefstroom, South Africa

Abstract

Background:

Citric acid, aside from its uses as a cleaning agent, has varied applications in the chemical, pharmaceutical, and food industries. A biotechnological fermentation process is one of the easiest ways to satisfy the demands for this useful commodity.

Methods:

The fermentation of pineapple waste by Aspergillus niger for the production of citric acid was investigated in this study. STATISTICA 8 release 7 (Statsoft, Inc. USA) statistical software was used for the design of experiments, evaluation, and optimization of the process using the central composite design (CCD), a response surface methodology approach. Lower–upper limits of the design for the operating parameters were temperature (25–35 oC), fermentation time (35–96 h), pH (3–6), methanol concentration (1–7%) and glucose (15–85 g/L). Twenty-seven duplicated experimental runs were generated for the CCD route.

Results & Conclusion:

The optimal operating conditions were validated at 38 g/L of glucose concentration, 3% (v/v) of methanol, 50 h of fermentation time, pH of 4.3 and temperature of 30 oC which yielded15.51 g/L citric acid. The statistical significance of the model was evaluated using a one-way analysis of variance. The validated predicted response values obtained from the statistical model showed close relationships with the experimental data.

Keywords: Citric acid, Central composite design, Pineapple waste, Fermentation, Statistical optimization, Aspergillus niger.


Abstract Information


Identifiers and Pagination:

Year: 2019
Volume: 13
Publisher Item Identifier: EA-TOCENGJ-2019-4

Article History:

Received Date: 04/03/2019
Revision Received Date: 03/05/2019
Acceptance Date: 07/05/2019
Electronic publication date: 28/05/2019
Collection year: 2019

© 2019 Ayeni et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


* Address correspondence to this author at the Chemical Engineering Department, College of Engineering, Covenant University, Ota, Nigeria;
Tel: +2348055745627; Emails: augustine.ayeni@covenantuniversity.edu.ng;
aoayeni@gmail.com