Direct fermentation of potato starch wastewater to lactic acid by Rhizopus oryzae and Rhizopus arrhizus

Abstract

The biochemical kinetic of direct fermentation for lactic acid production by fungal species of Rhizopus arrhizus 3,6017 and Rhizopus oryzae 2,062 was studied with respect to growth pH, temperature and substrate. The direct fermentation was characterized by starch hydrolysis, accumulation of reducing sugar, and production of lactic acid and fungal biomass. Starch hydrolysis, reducing sugar accumulation, biomass formation and lactic acid production were affected with the variations in pH, temperature, and starch source and concentration. A growth condition with starch concentration approximately 20 g/l at pH 6.0 and 30 degrees C was favourable for both starch saccharification and lactic acid fermentation, resulting in lactic acid yield of 0.87-0.97 g/g starch associated with 1.5-2.0 g/l fungal biomass produced in 36 h fermentation. R. arrhizus 3,6017 had a higher capacity to produce lactic acid, while R. oryzae 2,062 produced more fungal biomass under similar conditions.

ORIGINAL RESEARCH: Direct fermentation oftriticale starch to lactic acid byRhizopus oryzae

“…25 Several other studies involved the use of CaCO 3 , as well as experimenting on the time of addition, dosage, and ratio of fermentation substrate-to-CaCO 3 . 11,23,[26][27][28][29] Our results indicated that time of addition together with dosage of CaCO 3 was an important factor for LA production. Addition of CaCO 3 immediately at the beginning of fermentation was not a good strategy, as it actually reduced LA yields compared to the control conditions.…”

Production of a newly isolated Paenibacillus polymyxa biocontrol agent using monosodium glutamate wastewater and potato wastewater

“…PW is also a high concentration of COD wastewater. A few studies have focused on the utilization of such high concentration of organic matter wastewater (Bai et al, 2004;Mishra et al, 2004;Huang et al, 2005). As far as the authors are aware, no article has been published on utilization of both MGW and PW in one process.…”

Utilization of Sweat Potato Starch Wastewater and Monosodium Glutamate Wastewater for Cultivation of an Anti-Fungal Biocontrol Agent Paenibacillus Polymyxa

“…SPW also contains high COD and nutrient loadings. A few studies have already focused on the utilization of such high organic loading wastewater as substrates or production media in fermentation processes (Bai et al, 2004;Mishra et al, 2004;Huang et al, 2005). As far as the authors are aware, no papers have been published on utilization of both MGW and SPW in one process.…”