Search results for "fermentation"

Sewage sludge acidogenic fermentation for organic resource recovery towards carbon neutrality: an experimental survey testing the headspace influence

2022

Volatile fatty acids (VFAs) produced by acidogenic digestion of sewage sludge are very interesting bio-products which can contribute to carbon neutrality of wastewater treatment plants. Studies on the production of VFAs from sewage sludge from fermenters with membrane are limited. In view of above, VFAs from a fermenter pilot plant equipped with a membrane bioreactor and fed with real sewage sludge has been monitored. The effect of headspace volume (HdV) on VFA production was studied for the first time to elucidate the optimal operation conditions. Specifically, three fermenter HdV values (namely, 20, 40 and 60% of the total volume) have been investigated. Results revealed that the HdV of 2…

Biotechnological and environmental microbiological research in the Baltic region

2014

Significance of pantothenate for glucose fermentation by Oenococcus oeni and for suppression of the erythritol and acetate production.

2001

The heterofermentative lactic acid bacterium Oenococcus oeni requires pantothenic acid for growth. In the presence of sufficient pantothenic acid, glucose was converted by heterolactic fermentation stoichiometrically to lactate, ethanol and CO2. Under pantothenic acid limitation, substantial amounts of erythritol, acetate and glycerol were produced by growing and resting bacteria. Production of erythritol and glycerol was required to compensate for the decreasing ethanol production and to enable the synthesis of acetate. In ribose fermentation, there were no shifts in the fermentation pattern in response to pantothenate supply. In the presence of pantothenate, growing O. oeni contained at l…

The influence of fermentation conditions on biomass composition during ethanol biosynthesis from cheese whey lactose concentrate by Kluyveromyces mar…

2014

Influence of indigenous Hanseniaspora uvarum and Saccharomyces cerevisiae from sugar-rich substrates on the aromatic composition of loquat beer

2022

The demand for unique and exclusive food products and beverages is constantly on the increase. One of the products that mostly evolved to encounter market dynamics in the last decade is craft beer. For a long time, craft breweries have included fruit in beer production to enrich flavour and aroma profile of different beer styles. In this study, for the first time, the use of Saccharomyces and non-Saccharomyces yeast strains isolated from high -sugar matrices (manna and fermented honey by-products) were investigated to diversify fruit craft beer pro-duction, in order to improve the fermentation process and highlight the complexity of aroma profiles generated during alcoholic fermentation. Tw…

Pembuatan dan Analisis Bioetanol dari Pati Sagu (Metroxylon Sago) Asal Papua

2012

Preparation and bio-ethanol analysis of sago (M. sago) starch from Papua have been carried out. The preparation of bioethanol was conducted by hydrolysis, fermentation, distillation and purification. The length of fermentation applied is 3, 4, 5, 6, 7 and 8 days. Bioethanol then was analyzed qualitatively and quantitatively. Qualitative analyses were boiling point and molecular weight determination. Quantitative analyses were determination of the volume of bioethanol content and the composition of bioethanol of every length of fermentation. Based on the qualitative analyses, the samples obtained was ethanol with boiling point of 79 oC and molecular weight of 46 gram/mol. Whereas, based on t…

Fructan Biosynthesis by Intra- and Extracellular Zymomonas mobilis Levansucrase after Simultaneous Production of Ethanol and Levan

2003

Summary The chemical composition of the Zymomonas mobilis biomass and the culture liquid after ethanol and levan synthesis were studied. The activities of intra- and extracellular levansucrase produced by the Z. mobilis strain 113 ”S” under optimum conditions both for levan and fructooligosaccharide (FOS) synthesis were also determined. It was shown that levan production relates to the reduction of the carbohydrate and lipid content in the biomass by increasing the nucleic acid and protein content. The levan producing activity of cellular levansucrase after ethanol and levan synthesis was approximately 30–40% of the total activity in the second fermentation stage. It was established that th…

Flame-burned stainless steel wire spheres as carriers ofZymomonas mobilis cells and extracellular levansucrase

1999

In the present work, the use of flame-burned WS as carriers of Z. mobilis and extracellular levansucrase and the effect of the cell fixation method by dehydration on system productivity were investigated. Lyophilization and convective drying of Z. mobilis biomass at 30°C to a moisture content of 10–14% gave the best results for the repeated batch fermentations of a sucrose medium to obtain levan and ethanol. Significant correlation between the product formation and the concentration of free cells in the fermentation medium was established. Clearly, the cells were weakly bound to the newly generated WS and were washed out into the medium during fermentation. Here the hypothesis is presented …

Sugar Beet Juice Fermentation byZymomonas mobilis Attached to Stainless Steel Wire Spheres

2001

The fermentation of sugar beet juice as well as juice syrup medium by Zymomonas mobilis inoculum attached to stainless steel wire spheres was investigated. A semi-synthetic sucrose medium enriched with mineral salts and yeast extract was used as the control. It was established that raw sugar beet juice ensured good Zymomonas mobilis culture growth and slightly decreased ethanol synthesis applying both flame-burned and TiCl 4 -treated wire spheres as carriers (Q x = 0.05-0.06 g/l × h: Q eth = 1.02-1.22 g/l × h). High ethanol yield was also observed in juice medium (Y = 0.45-0.46 g/g), however, levan synthesis with this medium decreased. The application of juice syrup brought about less growt…

Sucrose medium osmolality as a regulator of anabolic and catabolic parameters inZymomonas culture

1996

This study focuses on the growth of Zymomonas mobilis strain 113 S and its ethanol and levan production under the conditions of increasing sucrose medium osmolality caused by NaCl, KCl, sorbitol or maltose. The increase in medium osmolality (700-1,500 mosml/kg) was accompanied by the inhibition of growth (growth rate, biomass yield) and ethanol production (specific productivity and yield). In contrast, levan synthesis was less affected or even stimulated and, as a consequence, levan specific productivity was increased significantly. A decrease in the anabolic growth parameters correlated with a parallel inhibition of glucose-6-P dehydrogenase and alcohol dehydrogenase (isoenzyme ADH II) act…