The objective of this study was to analyze the changes in the microbiota of milk products during fermentation and storage. Two kinds of Yoghurt, one Kefir, and one Acidophilus milk were observed during the fermentation process and storage using 16S rDNA amplicon sequencing. Cow's, goat's, raw and pasteurized milk were also examined. The most represented organisms in all manufactured products were shown to be those of the phylum Firmicutes. In some products, Proteobacteria, Bacteroidetes and Actinobacteria were also present in high amounts.

• Klíčová slova
• Fermented milk products, Lactic acid bacteria, Sequencing method, Storage,
• MeSH
• Bacteria klasifikace   genetika   MeSH
• DNA bakterií chemie   genetika   MeSH
• fermentace MeSH
• fylogeneze MeSH
• kozy MeSH
• kysané mléčné výrobky mikrobiologie   MeSH
• mléko MeSH
• ribozomální DNA chemie   genetika   MeSH
• RNA ribozomální 16S genetika   MeSH
• sekvenční analýza DNA MeSH
• skladování potravin MeSH
• skot MeSH
• společenstvo * MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• DNA bakterií MeSH
• ribozomální DNA MeSH
• RNA ribozomální 16S MeSH

Fermentation pattern and yields of microbial protein were investigated in cultures of the rabbit caecal contents supplied with glucose, xylose, starch, pectin and xylan. Rabbits at the age of 4 weeks (before weaning) and 3 months were slaughtered, their caecal contents added at 1.1% to growth media and incubated anaerobically at 39 degrees C for 18 h. Caecal microorganisms of 4-week-old rabbits produced no methane and caproate, less butyrate, but more propionate than microorganisms of 3-month-old rabbits. In both groups of rabbits, fermentation of xylose produced significantly more propionate and less butyrate than fermentation of glucose. More propionate and less acetate was formed from starch than from pectin. In caecal cultures from 4-week-old rabbits with pectin, the molar percentages of acetate was significantly higher and percentages of other short-chain fatty acids (SCFA) lower than in cultures with starch or xylan. In cultures from 3-month-old rabbits, fermentation of pectin and xylan produced similar SCFA profiles, different from SCFA molar composition in cultures with starch. Average production of microbial protein was 129 mg per 1 g of carbohydrate digested (range 110 to 141 mg/g). Protein yields were the same on glucose and xylose, but nonsignificantly higher on starch than on pectin and xylan. It can be concluded that the characteristics of substrate affected fermentation pattern in mixed cultures of rabbit caecal microorganisms. Substrate effects on protein yields were not statistically significant, due to high variation.

• MeSH
• anaerobní bakterie metabolismus   MeSH
• cékum metabolismus   mikrobiologie   MeSH
• fermentace MeSH
• králíci MeSH
• metabolismus sacharidů * MeSH
• proteiny metabolismus   MeSH
• sacharidy aplikace a dávkování   MeSH
• substrátová specifita MeSH
• techniky in vitro MeSH
• věkové faktory MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• proteiny MeSH
• sacharidy MeSH

When trying to improve antibiotic processes that are already high yielding, real industrial problems have to be faced. These include the use of organisms with non-ideal growth and recombination cycles, and problems of scale up from the laboratory to the main production plant. Many of the principles derived from academic studies have to be radically modified before they can be applied in the industrial context. These issues are a challenge to those who genuinely wish to contribute to the solution of industrial problems.

• MeSH
• antibakteriální látky biosyntéza   MeSH
• fermentace * MeSH
• genetické inženýrství MeSH
• geny MeSH
• houby genetika   metabolismus   MeSH
• mikrobiální genetika * MeSH
• mutace MeSH
• průmysl * MeSH
• rekombinace genetická MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antibakteriální látky MeSH

Microbial transglutaminase (MTG) is an enzyme widely used in the food industry because it creates cross-links between proteins, enhancing the texture and stability of food products. Its unique properties make it a valuable tool for modifying the functional characteristics of proteins, significantly impacting the quality and innovation of food products. In this study, response surface methodology was employed to optimize the fermentation conditions for microbial transglutaminase production by the strain Streptoverticillium cinnamoneum KKP 1658. The effects of nitrogen dose, cultivation time, and initial pH on the activity of the produced transglutaminase were investigated. The significance of the examined factors was determined as follows: cultivation time > nitrogen dose > pH. The interaction between nitrogen dose and cultivation time was found to be crucial, having the second most significant impact on transglutaminase activity. Optimal conditions were identified as 48 h of cultivation with a 2% nitrogen source dose and an initial medium pH of approximately 6.0. Under these conditions, transglutaminase activity ranged from 4.5 to 5.5 U/mL. The results of this study demonstrated that response surface methodology is a promising approach for optimizing microbial transglutaminase production. Future applications of transglutaminase include the development of modern food products with improved texture and nutritional value, as well as its potential use in regenerative medicine for creating biomaterials and tissue scaffolds. This topic is particularly important and timely as it addresses the growing demand for innovative and sustainable solutions in the food and biomedical industries, contributing to an improved quality of life.

• Klíčová slova
• MTG, Response surface methodology, Streptoverticillium, Transglutaminase,
• MeSH
• dusík metabolismus   MeSH
• fermentace * MeSH
• koncentrace vodíkových iontů MeSH
• kultivační média chemie   metabolismus   MeSH
• transglutaminasy * biosyntéza   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• dusík MeSH
• kultivační média MeSH
• transglutaminasy * MeSH

Physical properties of suspensions of Saccharomyces cerevisiae, Candida utilis and Escherichia coli (density, viscosity and surface tension) were measured in synthetic suspensions formed of centrifuged biomass and supernatants from various stages of batch cultivation in the range from 0 to 10% w/v for yeasts and from 0 to 0.25% w/v for bacteria. Surface tension was also measured in native suspensions in the range of 0 less than or equal to Cm less than or equal to 2.0% w/v. All single cell suspensions were found to be Newtonian in behaviour. Densities strictly obey the mixing law, viscosities of Saccharomyces cerevisiae suspensions were correlated by an empirical relation in dependence of Cm and t, surface tensions were correlated graphically for suspensions of Saccharomyces cerevisiae and Escherichia coli, since experiments with both microorganisms have shown that the previously published approximate correlation can safely be used.

• MeSH
• Candida * MeSH
• denzitometrie MeSH
• Escherichia coli * MeSH
• fermentace MeSH
• povrchové napětí MeSH
• Saccharomyces cerevisiae * MeSH
• suspenze MeSH
• viskozita MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• suspenze MeSH

Previous studies indicated an intrinsic relationship between infant diet, intestinal microbiota composition and fermentation activity with a strong focus on the role of breastfeeding on microbiota composition. Yet, microbially formed short-chain fatty acids acetate, propionate and butyrate and other fermentation metabolites such as lactate not only act as substrate for bacterial cross-feeding and as mediators in microbe-host interactions but also confer antimicrobial activity, which has received considerably less attention in the past research. It was the aim of this study to investigate the nutritional-microbial interactions that contribute to the development of infant gut microbiota with a focus on human milk oligosaccharide (HMO) fermentation. Infant fecal microbiota composition, fermentation metabolites and milk composition were analyzed from 69 mother-infant pairs of the Swiss birth cohort Childhood AlleRgy nutrition and Environment (CARE) at three time points depending on breastfeeding status defined at the age of 4 months, using quantitative microbiota profiling, HPLC-RI and 1H-NMR. We conducted in vitro fermentations in the presence of HMO fermentation metabolites and determined the antimicrobial activity of lactate and acetate against major Clostridiaceae and Peptostreptococcaceae representatives. Our data show that fucosyllactose represented 90% of the HMOs present in breast milk at 1- and 3-months post-partum with fecal accumulation of fucose, 1,2-propanediol and lactate indicating fermentation of HMOs that is likely driven by Bifidobacterium. Concurrently, there was a significantly lower absolute abundance of Peptostreptococcaceae in feces of exclusively breastfed infants at 3 months. In vitro, lactate inhibited strains of Peptostreptococcaceae. Taken together, this study not only identified breastfeeding dependent fecal microbiota and metabolite profiles but suggests that HMO-derived fermentation metabolites might exert an inhibitory effect against selected gut microbes.

• Klíčová slova
• Exclusively breastfeeding, HMO fermentation metabolites, Peptostreptococcaceae, gut microbiota, lactate,
• MeSH
• acetáty metabolismus   MeSH
• antiinfekční látky * metabolismus   MeSH
• Clostridiales metabolismus   MeSH
• dítě MeSH
• feces mikrobiologie   MeSH
• fermentace MeSH
• kojenec MeSH
• kojení MeSH
• kyselina mléčná metabolismus   MeSH
• lidé MeSH
• mateřské mléko chemie   MeSH
• oligosacharidy metabolismus   MeSH
• střevní mikroflóra * MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acetáty MeSH
• antiinfekční látky * MeSH
• kyselina mléčná MeSH
• oligosacharidy MeSH

In order to develop a multi-microbe probiotic preparation of Lactobacillus reuteri G8-5 and Bacillus subtilis MA139 in solid-state fermentation, a series of parameters were optimized sequentially in shake flask culture. The effect of supplementation of B. subtilis MA139 as starters on the viability of L. reuteri G8-5 was also explored. The results showed that the optimized process was as follows: water content, 50 %; initial pH of diluted molasses, 6.5; inocula volume, 2 %; flask dry contents, 30∼35 g/250 g without sterilization; and fermentation time, 2 days. The multi-microbial preparations finally provided the maximum concentration of Lactobacillus of about 9.01 ± 0.15 log CFU/g and spores of Bacillus of about 10.30 ± 0.08 log CFU/g. Compared with pure fermentation of L. reuteri G8-5, significantly high viable cells, low value of pH, and reducing sugar in solid substrates were achieved in mixed fermentation in the presence of B. subtilis MA139 (P < 0.05). Meanwhile, the mixed fermentation showed the significantly higher antimicrobial activity against E. coli K88 (P < 0.05). Based on the overall results, the optimized process enhanced the production of multi-microbe probiotics in solid-state fermentation with low cost. Moreover, the viability of L. reuteri G8-5 could be significantly enhanced in the presence of B. subtilis MA139 in solid-state fermentation, which favored the production of probiotics for animal use.

• MeSH
• Bacillus subtilis růst a vývoj   MeSH
• bakteriální nálož MeSH
• fermentace MeSH
• koncentrace vodíkových iontů MeSH
• kultivační média chemie   MeSH
• Limosilactobacillus reuteri růst a vývoj   izolace a purifikace   fyziologie   MeSH
• mikrobiální interakce MeSH
• mikrobiální viabilita * MeSH
• probiotika izolace a purifikace   MeSH
• sacharidy MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kultivační média MeSH
• sacharidy MeSH

This study investigates the techno-economic viability of synthesizing polyhydroxyalkanoates (PHA) from lignocellulosic biomass through the utilization of extremophilic microorganisms, framed within the context of Next-Generation Industrial Biotechnology (NGIB). Microbial platforms characterized by halophilic and thermophilic properties, specifically Halomonas halophila and Caldimonas thermodepolymerans, were utilized to tackle issues related to sterility demands, process efficiency, and sustainability. Scenarios incorporating rice straw and discarded softwood, which are low-cost feedstocks that do not interfere with the human food supply, were modeled as resources for PHA biosynthesis. Additionally, a comparison was conducted between traditional chloroform extraction methods and environmentally friendly hypotonic lysis for the recovery of PHA from extremophilic microbial cultures prone to this treatment. Economic indicators such as net present value, internal rate of return, and payback period, were analyzed to evaluate the economic viability of the process. Findings indicate that the incorporation of extremophilic microorganisms alongside waste valorization techniques could make PHA production economically viable, thereby decreasing dependence on fossil-derived plastics while simultaneously addressing ecological issues. This initial study highlights the necessity for subsequent scale-up investigations to authenticate the proposed methodology, which shows potential for the sustainable production of PHA.

• Klíčová slova
• Caldimonas thermodepolymerans, Halomonas halophila, Polyhydroxyalkanoates, Process simulation, Techno-economic assessment,
• MeSH
• biomasa MeSH
• biotechnologie metody   ekonomika   MeSH
• fermentace MeSH
• Halomonas metabolismus   MeSH
• lignin * metabolismus   MeSH
• polyhydroxyalkanoáty * biosyntéza   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• lignin * MeSH
• lignocellulose MeSH Prohlížeč
• polyhydroxyalkanoáty * MeSH

The degradation fo steroid glycoalkaloids (SGAs) has been studied in model solutions. The number of colony forming units (CFU) was determined using a nondirect (cultivation) method during all stages of fermentation. The changes in SGAs content were observed by HPLC on the Supelcosil LC-NH2 column. The changes in alpha-tomatine concentration added to fermented Lactobacillus MRS broth have been studied. A mathematical model of steroid glycoalkaloids degradation during lactic fermentation was proposed. The mathematical model was based on the experimental data of SGA and glucose concentration and should be used for study and prediction of SGA concentration changes of fermented samples. The ratio of SGA degradation rate by fermentation and by lactic acid hydrolysis was calculated. The experimental data evaluated by proposed mathematical model for the selected strain of Lactobacillus plantarum 976H show real feasibility for SGA degradation by lactic acid fermentation.

• MeSH
• alkaloidy metabolismus   MeSH
• chemické modely * MeSH
• fermentace MeSH
• glykosidy metabolismus   MeSH
• hydrolýza MeSH
• kinetika MeSH
• kultivační média MeSH
• kyselina mléčná metabolismus   MeSH
• Lactobacillus metabolismus   MeSH
• matematika MeSH
• počet mikrobiálních kolonií MeSH
• steroidy metabolismus   MeSH
• tomatin metabolismus   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alkaloidy MeSH
• glykosidy MeSH
• kultivační média MeSH
• kyselina mléčná MeSH
• steroidy MeSH
• tomatin MeSH

Syngas fermentation to acetate offers a promising solution for its valorisation, particularly when syngas contains a high N2 concentration, which otherwise impedes the utilisation of syngas biomethanation gaseous product in cogeneration or upgrading units. In this study, continuous lab-scale syngas fermentation assessing the effects of acidic pH and psychrophilic conditions (28 °C and 20 °C) on bioconversion efficiency and anaerobic consortium diversity was studied. The results showed that as temperature and pH decrease, acetate yield increases. The highest H2 and CO consumption rates were observed at 20 °C and pH 4.5, reaching 48.4 mmol/(L·d) and 31.5 mmol/(L·d), respectively, and methanogenic activity was not completely suppressed. The microbial community composition indicated an enhanced abundance of acetate-producing bacteria and hydrogenotrophic methanogens at 28 °C. The PICRUSt2 prediction of metabolic potential indicated that temperature and pH changes appear to have a more pronounced impact on acetotrophic methanogenesis genes than carbon dioxide-based methanogenesis genes.

• Klíčová slova
• Acetate, Acidic, Anaerobic culture, Psychrophilic, Syngas fermentation,
• MeSH
• acetáty MeSH
• anaerobióza MeSH
• bioreaktory * mikrobiologie   MeSH
• fermentace MeSH
• methan metabolismus   MeSH
• plyny * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• acetáty MeSH
• methan MeSH
• plyny * MeSH