Ethanol production from crude whey by Kluyveromyces marxianus (original) (raw)
Related papers
Bulletin of Chemical Reaction Engineering & Catalysis, 2013
Whey is the liquid remaining after milk has been curdled and strained. It is a by-product of the manufacture of cheese or casein and has several commercial uses. In environmental point of view, whey is kind of waste which has high pollution level due to it's contain high organic compound with BOD and COD value 50 and 80 g/L respectively. On the other side, whey also contain an amount of lactose (4.5%-5%); lactose can be used as carbon source and raw material for producing ethanol via fermentation using yeast strain Kluyveromyces marxianus. The objective of this research is to investigate the kinetics of ethanol production from crude whey through fermentation using Kluyveromyces marxianus and to estimate the kinetics parameter using available model. The yeast was able to metabolize most of the lactose within 16 h to give 8.64 g/L ethanol, 4.43 g/L biomass, and remain the 3.122 g/L residual lactose. From the results presented it also can be concluded that common kinetic model for microbial growth, substrate consumption, and product formation is a good alternative to describe an experimental batch fermentation of Kluyveromyces marxianus grown on a medium composed of whey. The model was found to be capable of reflecting all batch culture phases to a certain degree of accuracy, giving the parameter value: µmax, Ks, YX/S, α, β : 0.32, 10.52, 0.095, 1.52, and 0.11 respectively.
Energy Procedia, 2014
Cheese whey, is a byproduct of cheese or dairy industry, as raw material for ethanol production, because it contains 4.8% of lactose. This study used Fed-batch process during fermentation. The advantage of this process is to prevent the reduction in substrate for fermentation. The aim of this study is examine the optimum temperature operating conditions on ethanol production through fed-batch fermentation using Kluyveromycess marxianus with variations of temperature 30 0 C, 35 0 C, 40 0 C respectively. Results showed that the highest biomass and the ethanol concentration was achieved at temperature 30 0 C, with μ (0.186/h), Y p/s (0.21 g/g), and Y x/s (0.32 g/g).
International Journal of Renewable Energy Development (IJRED), 2013
Nowadays reserve of fossil fuel has gradually depleted. This condition forces many researchers to find energy alternatives which is renewable and sustainable in the future. Ethanol derived from cheese industrial waste (whey) using fermentation process can be a new perspective in order to secure both energy and environment. The aim of this study was to compare the operation modes (batch and fed-batch) of fermentation system on ethanol production from whey using Kluyveromyces marxianus. The result showed that the fermentation process for ethanol production by fed-batch system was higher at some point of parameters compared with batch system. Growth rate and ethanol yield (YP/S) of fed-batch fermentation were 0.122/h and 0.21 gP/gS respectively; growth rate and ethanol yield (YP/S) of batch fermentation were 0.107/h, and 0.12 g ethanol/g substrate, respectively. Based on the data of biomass and ethanol concentrations, the fermentation process for ethanol production by fed-batch syste...
African Journal of Microbiology Research, 2013
An application of the co-culture of Kluyveromyces marxianus and Saccharomyces cerevisiae for ethanol production from deproteinized cheese whey was established. Among several co-cultures examined, the co-culture of S. cerevisiae UFLA KFG33 (ethanol over-producer) and K. marxianus (UFLA KF22) showed the highest value of ethanol production (16.02±0.11 g L-1) and the highest yield of ethanol by fermentation time (0.22±0.05 g L h-1), according to Qp (volumetric productivity). These yeasts also showed the highest value of cell mass concentration in final fermentation (1.02±0.01 g L-1). The cocultures were performed in 72 h fermentation at 28°C with shaking at 100 rpm. The results indicate that this methodology is a promising technique for the production of ethanol using deproteinized cheese whey.
We investigated the bioconversion of whey and whey permeate into ethanol by Kluyveromyces marxianus immobilized in Ca-alginate, in both batch and continuous cultivations. Different strains of K. marxianus and cultivation media were tested in batch mode and the effects of dilution rate (D) and substrate concentration were investigated in continuous bioreactors. In shaker cultivations, the highest ethanol yield (0.51 g g À1 ) and ethanol productivities (0.77e1.15 g L À1 h À1 ) were obtained by strains CBS 6556, CCT 4086, and CCT 2653 in raw (not supplemented) whey permeate. These strains were immobilized in Ca-alginate beads and cultivated in batch fluidized-bed bioreactors, where the highest ethanol productivity (2.53 g L À1 h À1 ) was observed for strain CCT 4086. The effects of D (0.1e0.3 h À1 ) and whey permeate concentration (C WP , 60e180 g L À1 ) were also investigated in continuous fluidized-bed bioreactors using K. marxianus CCT 4086, and the highest ethanol productivity (6.01 g L À1 h À1 ) was achieved at D of 0.3 h À1 and C WP of 150 g L À1 , whereas the highest ethanol yield (0.51 g g À1 ) and concentration (42.8 g L À1 ) were observed for D 0.1 h À1 and C WP of 90 g L À1 . Two continuous fluidized-bed bioreactors operated in sequence were tested, showing increased ethanol productivities and concentrations to 6.97 g L À1 h À1 and 70.4 g L À1 , respectively. Continuous immobilized-cell bioreactor showed promising results to improve the performance of ethanol production from whey fermentation processes.
Ethanol production from non-food substrate is strongly recommended to avoid competition with food production. Whey, which is rich in nutrients, is one of the non-food substrate for ethanol production by Kluyveromyces spp. The purpose of this study was to optimize ethanol from different crude (non-deproteinized, non-pH adjusted, and non-diluted) whey using K. marxianus ETP87 which was isolated from traditional yoghurt. The sterilized and non-sterilized whey were employed for K. marxianus ETP87 substrate to evaluate the yeast competition potential with lactic acid and other microflora in whey. The effect of pH and temperature on ethanol productivity from whey was also investigated. Peptone, yeast extract, ammonium sulfate ((NH 4) 2 SO 4), and urea were supplemented to whey in order to investigate the requirement of additional nutrient for ethanol optimization. The ethanol obtained from non-sterilized whey was slightly and statistically lower than sterilized whey. The whey storage at 4 °C didn't guarantee the constant lactose presence at longer preservation time. Significantly high amount of ethanol was attained from whey without pH adjustment (3.9) even if it was lower than pH controlled (5.0) whey. The thermophilic yeast, K. marxianus ETP87, yielded high ethanol between 30 and 35 °C, and the yeast was able to produce high ethanol until 45 °C, and significantly lower ethanol was recorded at 50 °C. The ammonium sulfate and peptone enhanced ethanol productivity, whereas yeast extract and urea depressed the yeast ethanol fermentation capability. The K. marxianus ETP87, the yeast isolated from traditional yoghurt, is capable of producing ethanol from non-sterilized and non-deproteinized substrates.
Bioresource Technology, 2011
Anaerobic batch fermentations of ricotta cheese whey (i.e. containing lactose) were performed under different operating conditions. Ethanol concentrations of ca. 22 g L À1 were found from whey containing ca. 44 g L À1 lactose, which corresponded to up to 95% of the theoretical ethanol yield within 15 h. The experimental data could be explained by means of a simple knowledge-driven biochemically structured model that was built on bioenergetics principles applied to the metabolic pathways through which lactose is converted into major products. Use of the model showed that the observed concentrations of ethanol, lactose, biomass and glycerol during batch fermentation could be described within a ca. 6% deviation, as could the yield coefficients for biomass and ethanol produced on lactose. The model structure confirmed that the thermodynamics considerations on the stoichiometry of the system constrain the metabolic coefficients within a physically meaningful range thereby providing valuable and reliable insight into fermentation processes.
Studies on production of ethanol from cheese whey using Kluyveromyces marxianus
Materials Today: Proceedings, 2016
Whey, the residue remaining following cheese/casein production, represents a major disposal problem for the dairy industry as this has been considered as a highly polluting stream. Typically, whey contains lactose, proteins and fat. Due to lactose content, liquid whey can be considered as a cheap resource for production of bio-ethanol. Bio-ethanol can help to meet global fuel demand in the present scenario of depleting fossil fuel reserve. Direct fermentation of cheese whey or whey permeate yields low ethanol concentration due to poor lactose content, thus making the process uneconomical. Cheese whey powder (CWP), a dried and concentrated form of cheese whey, containing high concentration of lactose, can be an attractive source for ethanol production. In the present study, ethanol was produced from CWP with initial lactose concentration of 150 g/L at a temperature of 35°C and pH 4.5 using lactose positive microorganism, Kluyveromyces marxianus NCIM 3217. Maximum ethanol production was found to be 43.71 g/L and almost all the lactose was consumed within 72 h. Maximum biomass concentration at the end of fermentation was found to be 6.02 g/L. From the experimental data, it was found that the microbial growth followed Monod kinetic model. Ethanol production using K. marxianus NCIM 3217 was found to follow Luedeking-Piret equation and it was mixed-growth-associated. Thus, cheese whey powder could be an attractive substrate for bio-ethanol production and and hence can solve the environmental pollution problem created by whey surplus.
Batch kinetics and modelling of ethanolic fermentation of whey
International Journal of Food Science and Technology, 2005
The fermentation of whey by Kluyveromyces marxianus strain MTCC 1288 was studied using varying lactose concentrations at constant temperature and pH. The increase in substrate concentration up to a certain limit was accompanied by an increase in ethanol formation, for example, at a substrate concentration of 10 g L−1, the production of ethanol was 0.618 g L−1 whereas at 50 g L−1 it was 3.98 g L−1. However, an increase in lactose concentration to 100 g L−1 led to a drastic decrease in product formation and substrate utilization. The maximum ethanol yield was obtained with an initial lactose concentration of 50 g L−1. A method of batch kinetics was utilized to formulate a mathematical model using substrate and product inhibition constants. The model successfully simulated the batch kinetics observed at S0 = 10 and 50 g L−1 but failed in case of S0 = 100 g L−1 because of strong substrate inhibition.