Mineral Kissiris Research Articles

Continuous acidogenesis of sucrose, raffinose and vinasse using mineral kissiris as promoter

The use of kissiris as promoter (culture immobilization carrier) in anaerobic acidogenesis of sucrose, raffinose and vinasse is reported. Initially, the effect of pH (4–8) and fermentation temperature (18–52°C) on the accumulation of low molecular weight organic acids (OAs) during sucrose acidogenesis, was evaluated. The promoting effect of kissiris was confirmed compared to free cells, resulting in 80% increased OAs production. The optimum conditions (pH 8; 37°C) were used during acidogenesis of sucrose/raffinose mixtures. A continuous system was also operated for more than 2months. When sucrose and sucrose/raffinose mixtures were used, lactic acid type fermentation prevailed, while when vinasse was used, butyric acid type fermentation occurred. Total OAs concentrations were more than 14g/L and ethanol concentrations were 0.5–1mL/L. Culture adaptation in vinasse was necessary to avoid poor results. The proposed process is promising for new generation ester-based biofuel production from industrial wastes.

Biodegradation of Phenol by Ralstonia eutropha in a Kissiris‐Immobilized Cell Bioreactor

This study examined the biodegradation of phenol by Ralstonia eutropha in a Kissiris-immobilized cell bioreactor (ICB), operated in a repeated batch recycling mode. The steady biodegradation rate of 23.7 mg/g/h, over a wide range of the initial phenol concentrations up to 1400 mg/L in the ICB, indicated an increased tolerance limit of the Kissiris-immobilized cells towards phenol. Both Haldane and Luong substrate inhibition models were used to describe biodegradation kinetic of free cells system. The Haldane equation gave the following values for the biokinetic parameters: micro(max) = 0.36 h(-1), Ks = 40.48 mg/L, and Ki = 181.9 mg/L. However, according to the Luong model, these parameters were micromax) = 0.23 h(-1), Ks = 24.8 mg/L, Sm = 1018 mg/L, and n = 1.3. By following appropriate operational conditions and use of the ICB, it was found to be possible to extend the efficiency of the highly porous structure of the siliceous mineral Kissiris in cell immobilization. This holds significant promise for pollutant biodegradation issues.

Use of Phanerochaete chrysosporium Immobilized on Kissiris for Synthetic Dye Decolourization: Involvement of Manganese Peroxidase

The mineral Kissiris, which is formed from the thickened foam of volcanic lava, was tested to approximate its mineral composition using energy-dispersive X-ray (EDX) analysis. The solid mineral contains silicon dioxide at about 16 (w/w). The considerable surface roughness of Kissiris along with its extensive porosity made this natural solid cell support an attractive candidate for manganese peroxidase (MnP) production for synthetic dye decolourization, at low cost. The white rot fungus Phanerochaete chrysosporium immobilized on the mineral Kissiris was grown in both stationary and agitated cultures (rotary shaker, 100 rev/min) using either carbon- or nitrogen-limited growth medium to study the ability of the fungus to degrade the synthetic dye methylene blue (MB). The value of residual dye for MB used at 60 ppm was 6% within 8 days of the incubation of the nitrogen-limited culture under the shaken conditions. Production of (MnP) occurred simultaneously in nitrogen-limited culture medium with the added MnSO4 at 100 ppm. The MnP activity was at relatively high level (170 U/l).

A qualitative outline to industrialize alcohol production by catalytic multistage fixed bed tower (MFBT) bioreactor

The possibility for industrialization of the catalytic Multistage Fixed Bed Tower (MFBT) bioreactor using the mineral kissiris as a promoting material is examined in a large-scale pilot plant using 7000 and 100,000 L bioreactors separately. The stability of kissiris’ structure, the viability of culture, and the formation of volatile compounds were studied from batch to batch. This mineral, being a volcanic and foaming silicious rock with an average cost of $60/t, was examined by X-ray defractometer and found to mainly consist of anorthite. The stability of the catalyst not being infected was studied by an electron microscope and the viability of culture was estimated by the percentage of dead cells and the percentage of bacteria. Therefore, viability of culture was at a good level and the structure of catalyst, as related with low-residual sugar, remained constant from batch to batch, even after a preservation process of at least 6 mo. Likewise, ethyl-acetate was increased and higher alcohols were decreased in the overall period of experiments.

Ethanol production at 45°C using preparations of Kluyveromyces marxianus IMB3 immobilized in calcium alginate and kissiris

The thermotolerant yeast, K. marxianus IMB3, was grown in free and immobilized states in batch-fed culture at 45°C and ethanol production was examined over a 61-day period. The organism was grown in the free state, in the free state with mineral kissiris, immobilized in calcium alginate and immobilized in calcium alginate together with kissiris. Initially, reactors were fed every two days with 10% (w/v) glucose-containing media and no significant difference in ethanol production was observed. In subsequent refeeding experiments, reactors were re-fed every two days with 15% (w/v) sucrose-containing media. Although overall ethanol concentrations decreased, production in the immobilized systems was higher. In the final stages fermentations were re-fed every 3 days and although overall ethanol production decreased further, production remained highest in the systems containing calcium alginate and kissiris.

Continuous ethanol production from nonsterilized carob pod extract by immobilizedSaccharomyces cerevisiae on mineral kissiris using a two-reactor system

The continuous production of ethanol from nonsterilized carob pod extract by immobilized Saccharomyces cerevisiae on mineral kissiris using one- and two-reactor systems has been investigated. A maximum ethanol productivity of 9.6 g/L/h was obtained at an initial sugar concentration of 200 g/L and D = 0.4 h-1 with 68% of theoretical yield and 34% of sugar utilization using the one-reactor system. At S0 = 200 g/L, D = 0.05 h-1, 83% of theoretical yield, and 64% of sugar utilization, an ethanol productivity of 2.6 g/L/h was achieved. In the two-reactor system, a maximum ethanol productivity of 11.4 g/L/h was obtained at S0 = 200 g/L and D = 0.4 h-1 with 68.5% of theoretical yield and 41.5% of sugar utilization. The two-reactor system was operated at a constant dilution rate of 0.3 h-1 for 60 d without loss of the original immobilized yeast activity. In this case, the average ethanol productivity, ethanol yield (% of theoretical), and sugar utilization were 10.7 g/L/h, 71.5%, and 48%, respectively.

A catalytic multistage fixed-bed tower bioreactor in an industrial-scale pilot plant for alcohol production

This article describes the development of an industrial-scale, multistage fixed-bed tower (MFBT) bioreactor using the promoter mineral kissiris for industrial alcohol production using free cells. Specifically, we examined the parameters needed to maintain operational stability from batch to batch for long periods. Pilot plant operations used one- and two-stage fixed-bed, 7000-L bioreactors. Likewise a 100,000-L, multistage fixed-bed tower system containing layered kissiris confirmed the laboratory results. Compared with a continuous stirred tank fermentor (CSTF) with recycle, a 30% reduction of energy demand and 10%-20% of the production costs are obtained. The latter are attributed to the increased ethanol concentration and alcohol productivity. (c) 1996 John Wiley & Sons, Inc.

Kissiris-Supported Yeast Cells: High Biocatalytic Stability and Productivity Improvement by Successive Preservations at 0 °C

Successive preservations at 0 °C of cells of the strain Visanto-1 immobilized on mineral kissiris increased the biocatalytic stability of the cells and the ethanol and wine productivities. Specifically, immobilized yeast cells were viable for 2.5 years, producing wines by both batch and continuous processes. In addition, the ethanol and wine productivities were at least fivefold higher compared with those obtained from immobilized cells on the same support without successive preservations at low temperature. The results with preservation showed higher conversion and ethanol concentration than those in fermentations with kissiris-supported biocatalyst without successive preservations at 0 °C. Keywords: Wine; ethanol; productivity; immobilized yeast cells; psychrophile; stain; preservation; mineral; kissiris; fermentation technology

Ethanol production from carob pod extract by immobilizedsaccharomyces cerevisiaecells on the mineral kissiris

Abstract The production of ethanol from carob pod extract by immobilized S. cerevisiae cells on the mineral kissiris was investigated. The optimum conditions for carob pod extract fermentations were pH 3.5 ‐ 6.5, temperature 30°C and initial sugar concentration of 250g/l. A maximum ethanol concentration (64.5g/l), ethanol yield (28.3%) and sugar utilization (94%) was achieved at an initial sugar concentration of 250, 200 and 250g/l, respectively. In repeated batch fermentations, the immobilized S. cerevisiae cells on kissiris retained their ability to produce ethanol for 30 days.

Anaerobic Bioconversion of Sucrose to Biogas Promoted by the Mineral Kissiris

The effect of the mineral kissiris on the fermentation of sucrose solutions in an Up-Flow Plug Anaerobic Bioreactor (UPAB) was examined. Increased acid generation and a decrease in the time needed for the start-up of the process were obtained. Biogas was produced at volatile fatty acid (VFA) concentrations of 10·48–17·72 g/litre and at a pH close to 6. Loadings in the range of 13·3–37·4 g COD/litre/day and 43–68% COD removal efficiencies after a day were also obtained. In the absence of kissiris no methane fermentation was produced.

Low-temperature wine making by immobilized cells on mineral kissiris

Kissiris-supported biocatalyst, prepared by immobilization of the alcohol resistant and psychrophile strain Visanto 1 on mineral kissiris, was found to be suitable for low-temperature (5-16 o C continuous vine making. It is also reported that the ethanol productivity at 5 o C by continuous fermentation was equal to what should be observed at 22-25 o C by natural fermentation. The important productivity obtained at low temperatures can be attributed to the reduction of the activation engery E a , caused by the support mineral kissiris

Continuous potable alcohol production by immobilizedSaccharomyces cerevisiae on mineral kissiris

A biocatalyst prepared by the immobilization of Saccharomyces cerevisiae on the surface of the mineral kissiris was used in the present study for continuous potable-alcohol production. An ethanol productivity (calculated on the basis of liquid volume) of 10.5 g/L/h was obtained at a 0.7/h dilution rate, 121 g/L sucrose content, and 29.6% conversion employing molasse as feed material. Glucose, raisin extracts, and molasse were successively used as feed materials without stopping the operation of the reactor for 6 mo. The ethanol productivity and yield remained constant during the operational-stability study of the reactor, carried out for 44 d. Biomass productivity, yield, and free-cell concentration in glucose, raisin extracts, and molasse were examined. Finally, a system with two continuous reactors joined successively was also studied in the present investigation.

Kissiris: A mineral support for the promotion of ethanol fermentation by Saccharomyces cerevisiae

Ethanol production using Saccharomyces cerevisiae, promoted by the mineral kissiris, is reported on. A three-fold increase of ethanol productivity in the fermentation of molasses was achieved. An ethanol yield factor 0.43 g/g and conversion of 93.3% at an initial sugar concentration (ISC) 208.5 g/ l were obtained in the presence of this mineral in molasses fermentation, compared to 0.21 g/g and 44.2% in its absence. It is also shown that the fermentation of molasses takes place even at relatively higher ethanol levels, with kissiris contributing to a 35% reduction of the energy demand in grade-fuel and potable ethanol production. The proposed mineral was shown to have a smaller effect in fermentations carried out in synthetic media containing glucose or saccharose.