Ning He1, Yin Li, Jian Chen. 1. The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Southern Yangtze University, Wuxi, PR China.
Abstract
The production of a novel polygalacturonic acid bioflocculant REA-11 from a newly isolated strain, Corynebacterium glutamicum CCTCC M201005, was investigated. Sucrose was chosen as a carbon source for REA-11 production. Complex nitrogen sources containing urea and an organic nitrogen compound enhanced both bacterial growth and REA-11 production, among which urea plus corn steep liquor was shown to be the most efficient combination. A cost-effective medium for REA-11 production mainly comprised 17 g/l sucrose, 0.45 g/l urea, and 5 ml/l corn steep liquor, under which conditions the flocculating activity reached 390 U/ml. The molar ratio of carbon to nitrogen (C/N) significantly affected REA-11 production, where a C/N ratio of 20:1 was shown to be the best. Interestingly, by simultaneously feeding sucrose and urea at a C/N ratio of 20:1 at 24 h of fermentation, REA-11 production (458 U/ml) was enhanced by 17% compared to the control. In a 10 l jar fermentor, lower dissolved oxygen tension was favorable for REA-11 production: a flocculating activity of 520 U/ml was achieved at a kappaLa of 100 h(-1). REA-11 raw product is relatively thermo-stable at acidic pH ranges of 3.0-6.5. Preliminary application studies showed that REA-11 had stronger flocculating activity to Kaolin clay suspension compared to chemical flocculants. In addition, the capability of decolorizing molasses wastewater indicates the industrial potential of this novel bioflocculant.
The production of a novel polygalacturonic acid bioflocculant n class="Chemical">REA-11 from a newly isolated strain, Corynebacterium glutamicum CCTCC M201005, was investigated. Sucrose was chosen as a carbon source for REA-11 production. Complex nitrogen sources containing urea and an organic nitrogen compound enhanced both bacterial growth and REA-11 production, among which urea plus corn steep liquor was shown to be the most efficient combination. A cost-effective medium for REA-11 production mainly comprised 17 g/l sucrose, 0.45 g/l urea, and 5 ml/l corn steep liquor, under which conditions the flocculating activity reached 390 U/ml. The molar ratio of carbon to nitrogen (C/N) significantly affected REA-11 production, where a C/N ratio of 20:1 was shown to be the best. Interestingly, by simultaneously feeding sucrose and urea at a C/N ratio of 20:1 at 24 h of fermentation, REA-11 production (458 U/ml) was enhanced by 17% compared to the control. In a 10 l jar fermentor, lower dissolved oxygen tension was favorable for REA-11 production: a flocculating activity of 520 U/ml was achieved at a kappaLa of 100 h(-1). REA-11 raw product is relatively thermo-stable at acidic pH ranges of 3.0-6.5. Preliminary application studies showed that REA-11 had stronger flocculating activity to Kaolin clay suspension compared to chemical flocculants. In addition, the capability of decolorizing molasses wastewater indicates the industrial potential of this novel bioflocculant.
Authors: Anthony Ugbenyen; Sekelwa Cosa; Leonard Mabinya; Olubukola O Babalola; Farhad Aghdasi; Anthony Okoh Journal: Int J Environ Res Public Health Date: 2012-06-04 Impact factor: 3.390
Authors: Uchechukwu U Nwodo; Mayowa O Agunbiade; Ezekiel Green; Leonard V Mabinya; Anthony I Okoh Journal: Int J Mol Sci Date: 2012-07-13 Impact factor: 6.208