6 results on '"Christina Ukowitz"'
Search Results
2. Monitoring the Antibacterial Effect of Rosin Acids in an Austrian Beet Sugar Plant by Amplicon-Based Sequencing and Flow Cytometry
- Author
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Cordula K. Moser, Christina Ukowitz, Ulrike Zitz, Florian Emerstorfer, Walter Hein, Wolfgang Kneifel, and Konrad J. Domig
- Subjects
beet sugar factory ,bacterial communities ,antimicrobial ,rosin acids ,flow cytometer ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
For decades, microorganisms in beet sugar production have been studied using culture-based methods. However, these methods are not sufficient to describe such a complex bacterial community. In this study, therefore, an amplicon-based sequencing technique (Illumina MiSeq platform) was applied to characterize the bacterial community and its dynamics in the extraction area and juice purification station of an Austrian beet sugar plant. Depending on the process conditions thermophilic bacteria, such as Geobacillus spp., Caenibacillus spp., and Thermus spp., and mesophilic bacteria, such as Leuconostoc spp. and Bacillus spp., were found. Besides these microbiological characteristics, the antimicrobial effect of a rosin acid-based product (Defostab 220) on the bacterial communities was investigated in industrial and laboratory trials. The antimicrobial effect of a given concentration of rosin acid varies from bacteriostatic to bactericidal effects on different occurring groups of bacteria.
- Published
- 2021
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3. Identification of the microbiota in sugar extraction juices by sequencing-based techniques
- Author
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Konrad J. Domig, Christina Ukowitz, Cordula K. Moser, Walter Hein, and Florian Emerstorfer
- Subjects
Chromatography ,Chemistry ,Extraction (chemistry) ,food and beverages ,Identification (biology) ,Sugar ,Food Science - Abstract
The importance of microorganisms in the beet sugar industry came up in 1930. Since then, several approaches have been made to describe these bacteria. For this purpose, mainly cultivation-based methods were applied. However, the majority of the microorganisms cannot be cultivated or are in the viable-but-non-culturable state. In addition, these methods are time-consuming and costly. Progress in molecular biology allows a cheaper, faster and more precise identification of the microbiota. This study evaluates the application of an 16S rDNA-based metagenomic sequencing approach based on Illumina MiSeq technology to identify the microbiota in raw juice and juice of mid-tower in a beet sugar production plant and compares the results with those obtained by cultivation-based techniques. All bacteria orders detected with cultivation-based methods could be also found with the applied metagenomic approach. In raw juice, mainly mesophilic bacteria such as Lactobacillus spp. and Leuconostoc spp. species were identified. Additionally, a partly large proportion of gram-negative bacteria belonging to the order Enterobacterales were detected by the metagenomic approach. The diversity in juice of mid-tower was much lower and predominated by mainly thermophilic genera such as Geobacillus, Caldanaerobius and Thermoanaerobacter. The last two mentioned genera belong to the class of Clostridia. Surprisingly, in the juice of mid-tower Lactobacillus species could be verified by cultivation-based methods as well as by the metagenomic approach. As a consequence, it can be presumed that lactobacilli can survive in this very specific environment at 70 °C occurring in the central part of the extraction tower.
- Published
- 2021
4. Bacterial growth dynamics and corresponding metabolite levels in the extraction area of an Austrian sugar beet factory using antimicrobial treatment
- Author
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Wolfgang Kneifel, Karl Moder, Dominik Reiter, Konrad J. Domig, Ulrike Zitz, Christina Ukowitz, Cordula K Kohout, Walter Hein, and Florian Emerstorfer
- Subjects
Sucrose ,Food Handling ,030309 nutrition & dietetics ,Aerobic bacteria ,Microorganism ,Bacterial growth ,Butyric acid ,03 medical and health sciences ,chemistry.chemical_compound ,0404 agricultural biotechnology ,Anti-Infective Agents ,Food science ,0303 health sciences ,Nutrition and Dietetics ,Bacteria ,biology ,04 agricultural and veterinary sciences ,biology.organism_classification ,Antimicrobial ,040401 food science ,Lactic acid ,chemistry ,Austria ,Beta vulgaris ,Sugars ,Agronomy and Crop Science ,Resins, Plant ,Food Science ,Biotechnology - Abstract
BACKGROUND During the manufacture of sucrose from sugar beet, different microorganisms originating from the plant material as well as from the soil enter the process. Due to the formation of polysaccharide-based slimes, these contaminants may induce several adverse effects such as filtration problems during juice purification. Certain microorganisms also metabolize sucrose, leading to product losses with financial consequences. To better understand and to prevent these negative effects, the aim of the study was to investigate the evolution of relevant bacterial groups, including their metabolites appearing during the extraction process. For this purpose, one production cycle was monitored to identify the major contamination steps and to clarify how they relate to the processing conditions. Traditionally, different antimicrobial agents such as formaldehyde, sulfur dioxide, hypochlorous acid, sodium hypochlorite, and chlorine dioxide have been added to inhibit microbial growth. In the present study, a rosin-based product derived from pine trees was applied as an alternative to those substances. RESULTS Press water, raw juice, and mid-tower juice were identified as being highly contaminated with bacteria, and processing conditions such as time, temperature and pH level significantly influenced bacterial levels and the corresponding metabolites. Among the contaminants identified, lactic acid bacteria, and mesophilic and thermophilic aerobic bacteria played a dominant role, whereas lactic acid, acetic acid, butyric acid, and ethanol were identified as typical metabolites. CONCLUSION Bacterial growth during production could be reduced by shock dosing of the rosin-based material in the extraction area. © 2020 Society of Chemical Industry.
- Published
- 2020
5. Short-Chain Cello-oligosaccharides: Intensification and Scale-up of Their Enzymatic Production and Selective Growth Promotion among Probiotic Bacteria
- Author
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Chao Zhong, Bernd Nidetzky, Christina Ukowitz, and Konrad J. Domig
- Subjects
0106 biological sciences ,Sucrose ,Lactobacillus paracasei ,Phosphorylases ,medicine.medical_treatment ,Inulin ,Oligosaccharides ,Cellobiose ,01 natural sciences ,Article ,chemistry.chemical_compound ,Lactobacillus rhamnosus ,Bacterial Proteins ,medicine ,process intensification ,Food science ,Clostridium butyricum ,biology ,Lacticaseibacillus rhamnosus ,Prebiotic ,Probiotics ,010401 analytical chemistry ,Lactococcus lactis ,food and beverages ,General Chemistry ,Dietary fibers ,biology.organism_classification ,0104 chemical sciences ,Lactobacillus ,Prebiotics ,chemistry ,cello-oligosaccharides ,glycoside phosphorylases ,Bifidobacterium ,cascade biocatalysis ,General Agricultural and Biological Sciences ,functional carbohydrates ,dietary fibers and prebiotics ,010606 plant biology & botany - Abstract
Short-chain cello-oligosaccharides (COS; degree of polymerization, DP≤6) are promising water-soluble dietary fibers. An efficient approach to their bottom-up synthesis is from sucrose and glucose using glycoside phosphorylases. Here, we show intensification and scale up (20 mL; gram scale) of COS production to 93 g/L product and in 82 mol % yield from sucrose (0.5 M). The COS were comprised of DP 3 (33 wt %), DP 4 (34 wt %), DP 5 (24 wt %) and DP 6 (9 wt %) and involved minimum loss (≤10 mol %) to insoluble fractions. After isolation (≥95% purity; ≥90% yield), the COS were examined for growth promotion of probiotic strains. Benchmarked against inulin, trans-galacto-oligosaccharides and cellobiose, COS showed up to 4.1-fold stimulation of cell density forClostridium butyricum,Lactococcus lactissubsp.lactis,Lactobacillus paracaseisubsp.paracaseiandLb. rhamnosusbut were less efficient withBifidobacteriumsp. This study shows the COS as selectively functional carbohydrates with prebiotic potential and demonstrates their efficient enzymatic production.
- Published
- 2020
6. Monitoring the Antibacterial Effect of Rosin Acids in an Austrian Beet Sugar Plant by Amplicon-Based Sequencing and Flow Cytometry
- Author
-
Ulrike Zitz, Walter Hein, Wolfgang Kneifel, Konrad J. Domig, Cordula K. Moser, Florian Emerstorfer, and Christina Ukowitz
- Subjects
beet sugar factory ,flow cytometer ,rosin acids ,Microorganism ,lcsh:Technology ,lcsh:Chemistry ,03 medical and health sciences ,Leuconostoc ,General Materials Science ,Food science ,Sugar ,lcsh:QH301-705.5 ,Instrumentation ,030304 developmental biology ,Fluid Flow and Transfer Processes ,0303 health sciences ,biology ,lcsh:T ,030306 microbiology ,Chemistry ,Process Chemistry and Technology ,Thermus ,General Engineering ,food and beverages ,Amplicon ,bacterial communities ,Antimicrobial ,biology.organism_classification ,lcsh:QC1-999 ,Computer Science Applications ,lcsh:Biology (General) ,lcsh:QD1-999 ,lcsh:TA1-2040 ,antimicrobial ,lcsh:Engineering (General). Civil engineering (General) ,lcsh:Physics ,Bacteria ,Mesophile - Abstract
For decades, microorganisms in beet sugar production have been studied using culture-based methods. However, these methods are not sufficient to describe such a complex bacterial community. In this study, therefore, an amplicon-based sequencing technique (Illumina MiSeq platform) was applied to characterize the bacterial community and its dynamics in the extraction area and juice purification station of an Austrian beet sugar plant. Depending on the process conditions thermophilic bacteria, such as Geobacillus spp., Caenibacillus spp., and Thermus spp., and mesophilic bacteria, such as Leuconostoc spp. and Bacillus spp., were found. Besides these microbiological characteristics, the antimicrobial effect of a rosin acid-based product (Defostab 220) on the bacterial communities was investigated in industrial and laboratory trials. The antimicrobial effect of a given concentration of rosin acid varies from bacteriostatic to bactericidal effects on different occurring groups of bacteria.
- Published
- 2021
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