Study on the Use of Microbial Cellulose as a Biocarrier for 1,3-Dihydroxy-2-Propanone and Its Potential Application in Industry

Can microbial cellulose (MC) be used as a bio-carrier for 1,3-dihydroxy-2-propanone (DHA)? The aim of this study was to examine the possibility of using MC as a biomaterial for DHA transferring into the stratum corneum and inducing changes in skin color. The MC patches were obtained from Gluconacetobacter xylinus strain and incubated in solutions with various concentrations of DHA (g·L−1: 20; 50; 80; 110) at 22 °C for 24 h. Afterwards; the patches were applied onto the skin for 15, 30, or 60 min. Skin color changes were assessed visually compared to a control patches without DHA. The intensity of skin color was increasing with the increase of DHA concentration and time of patches application. Application of MC patches with DHA (50 g·L−1) for 30 min ensured the color which was considered the closest to the desired natural tan effect. MC patches containing DHA can be biocarriers enabling DHA transport into the stratum corneum and causing skin color changes. Study results indicate a new possibility for industrial applications of MC; e.g., as a biocarrier in masking the symptoms of vitiligo or production of self-tanning agents in the form of masks

Valorization of Waste Glycerol to Dihydroxyacetone with Biocatalysts Obtained from <i>Gluconobacter oxydans</i>

Waste glycerol is the main by-product generated during biodiesel production, in an amount reaching up to 10% of the produced biofuel. Is there any method which allows changing this waste into industrial valuable compounds? This manuscript describes a method for valorization of crude glycerol via microbial bioconversion. It has been shown that the use of free and immobilized biocatalysts obtained from Gluconobacter oxydans can enable beneficial valorization of crude glycerol to industrially valuable dihydroxyacetone. The highest concentration of this compound, reaching over 20 g&#183;L&#8722;1, was obtained after 72 h of biotransformation with free G. oxydans cells, in a medium containing 30 or 50 g&#183;L&#8722;1 of waste glycerol. Using a free cell extract resulted in higher concentrations of dihydroxyacetone and a higher valorization efficiency (up to 98%) compared to the reaction with an immobilized cell extract. Increasing waste glycerol concentration to 50 g&#183;L&#8722;1 causes neither a faster nor higher increase in product yield and reaction efficiency compared to its initial concentration of 30 g&#183;L&#8722;1. The proposed method could be an alternative for utilization of a petrochemical waste into industry applicated chemicals

Ultrasound-Assisted Osmotic Dehydration of Apples in Polyols and Dihydroxyacetone (DHA) Solutions

The aim of this work was to analyse the effect of ultrasound-assisted osmotic dehydration of apples v. Elise on mass transfer parameters, water activity, and colour changes. Ultrasound treatment was performed at a frequency of 21 kHz with a temperature of 40 &deg;C for 30&ndash;180 min using four osmotic solutions: 30% concentrated syrups of erythritol, xylitol, maltitol, and dihydroxyacetone (DHA). The efficiency of the used solutes from the polyol groups was compared to reference dehydration in 50% concentrated sucrose solution. Peleg&rsquo;s model was used to fit experimental data. Erythritol, xylitol, and DHA solutions showed similar efficiency to sucrose and good water removal properties in compared values of true water loss. The application of ultrasound by two methods was in most cases unnoticeable and weaker than was expected. On the other hand, sonication by the continuous method allowed for a significant reduction in water activity in apple tissue in all tested solutions

Modeling of Osmotic Dehydration of Apples in Sugar Alcohols and Dihydroxyacetone (DHA) Solutions

The purpose of this paper is twofold: on the one hand, we verify effectiveness of alternatives solutes to sucrose solution as osmotic agents, while on the other hand we intend to analyze modeling transfer parameters, using different models. There has also been proposed a new mass transfer parameter&mdash;true water loss, which includes actual solid gain during the process. Additional consideration of a new ratio (Cichowska et al. Ratio) can be useful for better interpretation of osmotic dehydration (OD) in terms of practical applications. Apples v. Elise were dipped into 30% concentrated solutions of erythritol, xylitol, maltitol, and dihydroxyacetone (DHA) to remove some water from the tissue. To evaluate the efficiency of these solutes, 50% concentrated sucrose solution was used as a control. All of the tested osmotic agent, except maltitol, were effective in the process as evidenced by high values in the true water loss parameter. Solutions of erythritol and xylitol in 30% concentrate could be an alternative to sucrose in the process of osmotic dehydration. Peleg&rsquo;s, Kelvin&ndash;Voigt, and Burgers models could fit well with the experimental data. modeling of mass transfer parameters, using Peleg&rsquo;s model can be satisfactorily supplemented by Kelvin&ndash;Voigt and Burgers model for better prediction of OD within the particular periods of the process

Selected aspects of enterococci presence in artisan cheeses®

Enterokoki są dobrze przystosowane do funkcjonowania w środowisku sera i wraz z innymi bakteriami mlekowymi stanowią grupę niestarterowych bakterii mlekowych. Ich aktywność proteolityczna i lipolityczna przyczynia się do rozwoju typowych właściwości sensorycznych serów. Dzięki wytwarzaniu bakteriocyn enterokoki wpływają na mikrobiotę sera, z jednej strony ograniczając ewentualny rozwój drobnoustrojów patogennych i powodujących psucie a z drugiej strony stymulują procesy autolityczne innych bakterii mlekowych. Dzięki tym cechom drobnoustroje te mają potencjał do stosowania jako kultury dodatkowe lub ochronne do serów. Niektóre gatunki Enterococcus wykazują cechy wirulencji i antybiotykooporność i z tego powodu rodzaj ten nie posiada statusu QPS (qualified presumption of safety).Enterococci are well adapted to function in the cheese environment and, along with other lactic acid bacteria, constitute a group of non-starter lactic bacteria. Their proteolytic and lipolytic activity contributes to the development of typical sensory properties of cheeses. By producing bacteriocins, enterococci influence the cheese microbiota, on the one hand, limiting the possible development of pathogenic and spoilage microorganisms, and, on the other hand, stimulating the autolytic processes of other lactic bacteria. Due to these characteristics, enterococci have the potential to be used as adjunct or protective cultures for cheeses. Some Enterococcus species show virulence and antibiotic resistance and therefore the genus does not have qualified presumption of safety status (QPS)

Bioactive peptides from milk proteins®

Najliczniejszymi białkami mleka są α-kazeina, β-kazeina, κ-kazeina, β-laktoglobulina i α-laktoalbumina. Poza wysoką wartością odżywczą, białka mleka mają ogromny wpływ na właściwości technologiczne mleka, takie jak między innymi: stabilność cieplną, podatność na koagulację pod wpływem podpuszczki, zdolności emulgujące czy pianotwórcze. Białka te są także głównym źródłem składników bioaktywnych w mleku. Bioaktywne peptydy pochodzące z białek mleka cieszą się dużym zainteresowaniem naukowym i aplikacyjnym ze względu na ich różnorodność i potencjalne korzyści zdrowotne. Peptydy te wykazują m.in. aktywność przeciwnadciśnieniową, immunomodulującą, przeciwnowotworową, przeciwzakrzepową, przeciwbakteryjną i cytotoksyczną. Ze względu na wiele znanych i domniemanych korzyści dla zdrowia ludzkiego, bioaktywne peptydy z mleka są stosowane jako składniki nutraceutyków.The most abundant milk proteins are α-casein, β-casein, κ-casein, β-lactoglobulin and α-lactalbumin. In addition to the high nutritional value, milk proteins have a huge impact on the technological properties of milk, such as, among others, heat stability, susceptibility to rennet coagulation, emulsifying and foaming abilities. These proteins are also the main source of bioactive ingredients in milk. Bioactive peptides derived from milk proteins are of great scientific and application interest due to their diversity and potential health benefits. These peptides show, inter alia, antihypertensive, immunomodulating, antitumor, anticoagulant, antibacterial and cytotoxic activity. Due to many known and alleged benefits to human health, bioactive milk peptides are used as ingredients in nutraceuticals

Antibacterial Activity of Biocellulose with Oregano Essential Oil against Cronobacter Strains

Biocellulose, named &ldquo;the biomaterial of the future&rdquo;, is a natural and ecologically friendly polymer, produced by selected acetic acid bacteria strains. Biocellulose impregnated with antimicrobial agents can be used as a novel, safe, and biodegradable food packaging material, helping extend the shelf life of some products and may also have the chance to replace typical plastic packaging, which is a big environmental problem these days. This study aimed to evaluate if cellulose impregned with natural oregano essential oil could show antibacterial activity against Cronobacter strains, which can occur in food, causing diseases and food poisoning. Bacterial cellulose was obtained from two acetic bacteria strains, Gluconacetobacter hansenii ATCC 23769 and Komagataeibacter sp. GH1. Antibacterial activity was studied by the disc-diffusion method against chosen Cronobacter strains, isolated from the plant matrix. Oregano essential oil has been shown to penetrate into the structure of bacterial cellulose, and after applying cellulose to the solid medium, it showed the ability to migrate. Biopolymer from the strain K. sp. GH1 was able to better absorb and retain essential oregano oil (OEO) compared to bacterial cellulose (BC) produced by the G. hansenii ATCC 23769. Bacterial cellulose with oregano essential oil from strain Komagataeibacter GH1 showed generally greater inhibitory properties for the growth of tested strains than its equivalent obtained from G. hansenii. This was probably due to the arrangement of the polymer fibers and its final thickness. The largest zone of inhibition of strain growth was observed in relation to C. condimenti s37 (32.75 mm &plusmn; 2.8). At the same time, the control sample using filter paper showed an inhibition zone of 36.0 mm &plusmn; 0.7. A similar inhibition zone (28.33 mm &plusmn; 2.6) was observed for the C. malonaticus lv31 strain, while the zone in the control sample was 27.1 mm &plusmn; 0.7. Based on this study, it was concluded that bacterial cellulose impregnated with oregano essential oil has strong and moderate antimicrobial activity against all presented strains of the genus Cronobacter isolated from plant matrix. Obtained results give a strong impulse to use this biopolymer as ecological food packaging in the near future

The exopolysaccharides biosynthesis by Candida yeast depends on carbon sources

Background: The exopolysaccharides (EPS) produced by yeast exhibit physico-chemical and rheological properties, which are useful in the production of food and in the cosmetic and pharmaceutical industries as well. The effect was investigated of selected carbon sources on the biosynthesis of EPS by Candida famata and Candida guilliermondii strains originally isolated from kefirs. Results: The biomass yields were dependent on carbon source (sucrose, maltose, lactose, glycerol, sorbitol) and ranged from 4.13 to 7.15 g/L. The highest biomass yield was reported for C. guilliermondii after cultivation on maltose. The maximum specific productivity of EPS during cultivation on maltose was 0.505 and 0.321 for C. guilliermondii and C. famata, respectively. The highest EPS yield was found for C. guilliermondii strain. The EPS produced under these conditions contained 65.4% and 61.5% carbohydrates, respectively. The specific growth rate (μ) of C. famata in medium containing EPS as a sole carbon source was 0.0068 h-1 and 0.0138 h-1 for C. guilliermondii strain. Conclusions: The most preferred carbon source in the synthesis of EPS for both Candida strains was maltose, wherein C. guilliermondii strain showed the higher yield of EPS biosynthesis. The carbon source affected the chemical composition of the resulting EPS and the contribution of carbohydrate in the precipitated preparation of polymers was higher during supplementation of maltose as compared to sucrose. It was also found that the EPS can be a source of carbon for the producing strains