scholarly journals Detection the role of physiological factors to produce carotenoid pigment in Staphylococcus aureus

2019 ◽  
Vol 24 (7) ◽  
pp. 6
Author(s):  
Ghada A. Mohammad ◽  
Suhair Taha Daod

Three Staphylococcus aureus isolates were used in the present study for extraction and quantitation of carotenoid pigment production. Different culture conditions were used to determine optimum pigmentation such as type of culture media, different pH values, temperature, and finally daily bacterial sub-culturing for more than 2 weeks. Nutrient agar was found to be the best medium with the highest production (1.09). Optimum pH value was 6.5 and gave (1.8) carotenoid. Also results showed that pigment was produced at 37o C more than at 42oC. Daily repeated sub culturing had a negative impact on pigment production. Colonies gradualy lost pigmentation and became white in color. Also, sub-culturing was shown to affect the volume of the colonies as they became smaller on solid media.    http://dx.doi.org/10.25130/tjps.24.2019.122

Author(s):  
Suwapha Sawiphak ◽  
Aroon Wongjiratthiti ◽  
Chanankarn Saengprasan

Dioscorea alata (purple yam) is a tuber crop that contains plenty of nutrients. It is widely cultivated in Thailand, but it is underutilized. In this study, the suitability of purple yam to replace potato dextrose media for fungal growth was investigated. Mushrooms and molds were grown on purple yam dextrose agar (PYDA), whereas yeasts were cultured in purple yam dextrose broth (PYDB). Response surface methodology (RSM) with Box-Behnken design (BBD) was used to optimize the culture conditions for Saccharomyces cerevisiae biomass production. The growth profile of S. cerevisiae in PYDB under optimized culture conditions was also studied. All test mushrooms and molds recorded the highest colony diameter and mycelial dry weight on PYDA containing 40% purple yam. Similar to mushrooms and molds, yeasts in PYDB with 40% purple yam showed the highest number of cells. The growth of fungi on purple yam dextrose media was significantly higher than those on potato dextrose media under standard conditions. The optimal conditions from the RSM results for the biomass production of S. cerevisiae in PYDB were purple yam concentration of 49.61%, dextrose concentration of 4.87%, pH value of 5.74, and inoculum size of 7.00%. The biomass of S. cerevisiae in PYDB under the optimal conditions obtained from the results of the optimization by RSM was thirty times higher than S. cerevisiae biomass in potato dextrose broth under standard conditions. Our results suggest that purple yam could be an alternative to potato dextrose media for fungal cultivation.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Maria del Mar Cendra ◽  
Núria Blanco-Cabra ◽  
Lucas Pedraz ◽  
Eduard Torrents

Abstract The coexistence between species that occurs in some infections remains hard to achieve in vitro since bacterial fitness differences eventually lead to a single organism dominating the mixed culture. Pseudomonas aeruginosa and Staphylococcus aureus are major pathogens found growing together in biofilms in disease-affected lungs or wounds. Herein, we tested and analyzed different culture media, additives and environmental conditions to support P. aeruginosa and S. aureus coexistence in vitro. We have unraveled the potential of DMEM to support the growth of these two organisms in mature cocultured biofilms (three days old) in an environment that dampens the pH rise. Our conditions use equal initial inoculation ratios of both strains and allow the stable formation of separate S. aureus microcolonies that grow embedded in a P. aeruginosa biofilm, as well as S. aureus biofilm overgrowth when bovine serum albumin is added to the system. Remarkably, we also found that S. aureus survival is strictly dependent on a well-characterized phenomenon of oxygen stratification present in the coculture biofilm. An analysis of differential tolerance to gentamicin and ciprofloxacin treatment, depending on whether P. aeruginosa and S. aureus were growing in mono- or coculture biofilms, was used to validate our in vitro coculture conditions.


2019 ◽  
Vol 21 (1) ◽  
pp. 82-90
Author(s):  
Valentina Palacio-Castañeda ◽  
Alejandra Pérez-Hoyos ◽  
Daniel Carrascal-Correa ◽  
Victor Manuel Osorio-Echeverri

Prodigiosin,  a  pigment  produced  by Serratia  marcescensinhibits  the  growth  of  different  microorganisms  and  the  proliferation  of some human cancer cell lines. Prodigiosin is usually produced by fermentations of substrates such as starch and proteins, andpig-ment yield depends on the concentration of the carbon source, stirring speed of cultures, temperature and time of incubation,nitro-gen  sources,  and  pH  of  medium.  In  the  present  study,  pigment  production  was  assessed  using  two  types  of  casein  as  substrate; pigment yield was greater when casein precipitated with vinegar was used as substrate than when high purity casein was. The maxi-mum prodigiosin production was achieved with 10 g/L casein at pH 8.0. Additionally, supplementation of culture media with glu-cose was found to considerably decrease prodigiosin production and growth inhibition of Staphylococcus aureus, which is directly related to pigment yield. Production in stirred-tank bioreactor at 0.75 vvm aeration was higher than that at 0.5 and 1.0 vvm. Sub-strate type, concentration and pH affected pigment production in Erlenmeyer flasks, whereas aeration rate influenced pigment pro-duction in a stirred-tank bioreactor.


2019 ◽  
Vol 8 (11) ◽  
pp. 1853 ◽  
Author(s):  
Harshad Lade ◽  
Joon Hyun Park ◽  
Sung Hee Chung ◽  
In Hee Kim ◽  
Jung-Min Kim ◽  
...  

Staphylococcus aureus (S. aureus) causes persistent biofilm-related infections. Biofilm formation by S. aureus is affected by the culture conditions and is associated with certain genotypic characteristics. Here, we show that glucose and sodium chloride (NaCl) supplementation of culture media, a common practice in studies of biofilms in vitro, influences both biofilm formation by 40 S. aureus clinical isolates (methicillin-resistant and methicillin-sensitive S. aureus) and causes variations in biofilm quantification. Methicillin-resistant strains formed more robust biofilms than methicillin-sensitive strains in tryptic soy broth (TSB). However, glucose supplementation in TSB greatly promoted and stabilized biofilm formation of all strains, while additional NaCl was less efficient in this respect and resulted in significant variation in biofilm measurements. In addition, we observed that the ST239-SCCmec (Staphylococcal Cassette Chromosome mec) type III lineage formed strong biofilms in TSB supplemented with glucose and NaCl. Links between biofilm formation and accessory gene regulator (agr) status, as assessed by δ-toxin production, and with mannitol fermentation were not found. Our results show that TSB supplemented with 1.0% glucose supports robust biofilm production and reproducible quantification of S. aureus biofilm formation in vitro, whereas additional NaCl results in major variations in measurements of biofilm formation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Enikő Horváth ◽  
Lívia Dályai ◽  
Erna Szabó ◽  
Teréz Barna ◽  
László Kalmár ◽  
...  

AbstractBiological control against microbial infections has a great potential as an alternative approach instead of fungicidal chemicals, which can cause environmental pollution. The pigment producer Metschnikowia andauensis belongs to the antagonistic yeasts, but details of the mechanism by which it inhibits growth of other microbes are less known. Our results confirmed its antagonistic capacity on other yeast species isolated from fruits or flowers and demonstrated that the antagonistic capacity was well correlated with the size of the red pigmented zone. We have isolated and characterized its red pigment, which proved to be the iron chelating pulcherrimin. Its production was possible even in the presence of 0.05 mg/ml copper sulphate, which is widely used in organic vineyards because of its antimicrobial properties. Production and localisation of the pulcherrimin strongly depended on composition of the media and other culture factors. Glucose, galactose, disaccharides and the presence of pectin or certain amino acids clearly promoted pigment production. Higher temperatures and iron concentration decreased the diameter of red pigmented zones. The effect of pH on pigment production varied depending of whether it was tested in liquid or solid media. In addition, our results suggest that other mechanisms besides the iron depletion of the culture media may contribute to the antagonistic capacity of M. andauensis.


1997 ◽  
Vol 24 (2) ◽  
pp. 195 ◽  
Author(s):  
Teresa Cubo ◽  
Francisco Romero ◽  
Jose M. Vinardell ◽  
Jose E. Ruiz-Sainz

Many different Rhizobium strains produce melanin (Mel+) when grown on solid media supplemented with L-tyrosine. The composition of the media and the culture conditions are of great importance for pigment production. Previous reports showed that some Rhizobium leguminosarum biovar phaseoli strains that produce the pigment in complete solid media (TY) failed to produce the pigment in minimal media (SY) supplemented with L-tyrosine or in TY liquid media. In this paper we have investigated different R. fredii, R. meliloti, R. etli and R. leguminosarum bv. trifolii and phaseoli strains (all of them Mel+ in solid media) for their ability to produce the pigment in liquid media. All Rhizobium species tested, except Rhizobium etli, were Mel+ in liquid media and in all cases the pigment yielded maximum absorption peaks at 280 and 315 nm. Melanin production by other bacteria (such as Vibrio, Streptomyces or Azospirillum) is enhanced by the presence of amino acids other that tyrosine. In this paper we show that the addition of L-methionine, which is not a precursor of rhizobial melanins, stimulated pigment production by Rhizobium cultures supplemented with L-tyrosine. The role of melanin production by Rhizobium strains is unclear. One hypothesis is that the Rhizobium tyrosinase, a bifunctional copper-containing enzyme that is essential for melanin biosynthesis, could detoxify polyphenolic compounds which might accumulate in senescing nodules. We show here that R. etli and R. fredii bacteroids produced melanin, which supports the idea that bacteroids contain the enzyme tyrosinase. Previous reports showed that, in R. leguminosarum bv. phaseoli strain 8002, the expression of the tyrosinase gene (melA) is dependent on the presence of nifA, a regulatory gene that is located in the symbiotic plasmid. However, transfer of R. leguminosarum bv. phaseoli melA gene to pSym-cured derivatives of R. leguminosarum bv. trifolii and viciae, R. fredii and Rhizobium sp. (Hedysarum) produced Mel+ transconjugants. DNA-hybridisation experiments showed that the pSym-cured strains did not contain any copy of nifA. Therefore, in contrast to the results reported on R. leguminosarum bv. phaseoli strain 8002, the expression of the melA gene in other rhizobia is not nifA-dependent. Key words: Rhizobium, melanin.


1999 ◽  
Vol 65 (10) ◽  
pp. 4334-4339 ◽  
Author(s):  
Takato Nakayama ◽  
Yoshihisa Homma ◽  
Yasuyuki Hashidoko ◽  
Junya Mizutani ◽  
Satoshi Tahara

ABSTRACT Three antifungal compounds, designated xanthobaccins A, B, and C, were isolated from the culture fluid of Stenotrophomonassp. strain SB-K88, a rhizobacterium of sugar beet that suppresses damping-off disease. Production of xanthobaccin A in culture media was compared with the disease suppression activities of strain SB-K88 and less suppressive strains that were obtained by subculturing. Strain SB-K88 was applied to sugar beet seeds, and production of xanthobaccin A in the rhizosphere of seedlings was confirmed by using a test tube culture system under hydroponic culture conditions; 3 μg of xanthobaccin A was detected in the rhizosphere on a per-plant basis. Direct application of purified xanthobaccin A to seeds suppressed damping-off disease in soil naturally infested by Pythiumspp. We suggest that xanthobaccin A produced by strain SB-K88 plays a key role in suppression of sugar beet damping-off disease.


2020 ◽  
Vol 35 (2) ◽  
pp. 283-292 ◽  
Author(s):  
L Delaroche ◽  
P Oger ◽  
E Genauzeau ◽  
P Meicler ◽  
F Lamazou ◽  
...  

Abstract STUDY QUESTION How do manufacturers perform embryotoxicity testing in their quality control programs when validating IVF consumables? SUMMARY ANSWER The Mouse Embryo Assay (MEA) and Human Sperm Survival Assay (HSSA) used for IVF disposables differed from one manufacturer to another. WHAT IS KNOWN ALREADY Many components used in IVF laboratories, such as culture media and disposable consumables, may negatively impact human embryonic development. STUDY DESIGN, SIZE, DURATION Through a questionnaire-based survey, the main manufacturers of IVF disposable devices were contacted during the period November to December 2018 to compare the methodology of the MEA and HSSA. We focused on catheters for embryo transfer, catheters for insemination, straws, serological pipettes, culture dishes and puncture needles used in the ART procedures. PARTICIPANTS/MATERIALS, SETTING, METHODS We approached the manufacturers of IVF disposables and asked for details about methodology of the MEA and HSSA performed for toxicity testing of their IVF disposable devices. All specific parameters like mouse strains, number of embryos used, culture conditions (media, temperature, atmosphere), extraction protocol, subcontracting, and thresholds were registered and compared between companies. MAIN RESULTS AND THE ROLE OF CHANCE Twenty-one companies were approached, of which only 11 answered the questionnaire. Significant differences existed in the methodologies and thresholds of the MEA and HSSA used for toxicity testing of IVF disposables. Importantly, some of these parameters could influence the sensitivity of the tests. LIMITATIONS, REASONS FOR CAUTION Although we approached the main IVF manufacturers, the response rate was relatively low. WIDER IMPLICATIONS OF THE FINDINGS Our study confirms the high degree of heterogeneity of the embryotoxicity tests performed by manufacturers when validating their IVF disposable devices. Currently, no regulations exist on this issue. Professionals should call for and request standardization and a future higher degree of transparency as regards embryotoxicity testing from supplying companies; moreover, companies should be urged to provide the users clear and precise information about the results of their tests and how testing was performed. Future recommendations are urgently awaited to improve the sensitivity and reproducibility of embryotoxicity assays over time. STUDY FUNDING/COMPETING INTEREST(S) This study did not receive any funding. L.D. declares a competing interest with Patrick Choay SAS. TRIAL REGISTRATION NUMBER N/A


Author(s):  
David Alors ◽  
Pradeep K. Divakar ◽  
Anjuli Meiser ◽  
Imke Schmitt ◽  
Ana Crespo ◽  
...  

We cultured Parmelina carporrhizans and P. quercina in Corn Meal Agar and 0.2% glucose Malt Yeast Agar for 160 days. Chemosyndrome of natural thalli and mycobiont cultures were analyzed by HPLC. Lecanoric acid, atranorin, chloratranorin and ergosterol were detected in P. carporrhizans thalli, while lecanoric acid, chloratranorin and aliphates were found in P. quercina thalli. The secondary methabolites pattern between thalli and mycobiont culture was completely different in both species. Both species secreted the phenalenone myeloconone C in culture media and was also detected in P. quercina mycobiont aggregates. Interestingly, the phenolic compounds produced by the mycobiont culture of P. carporrhizans are related to those produced by natural thallus by the same biosynthetic pathway, while the chemosyndrome of P. quercina mycobiont implies switch of biosynthetic pathway from acetate-polymalonate pathway to shikimic acid pathway, with pulvinic acid as major compound of mycobiont culture. The role of Myelochonone C, confluentic acid and pulvinic acid produced by mycobiont culture is discussed as possible adaptive vantage in field as photoprotective agent or as byproduct result of stressing artificial culture conditions.


2019 ◽  
pp. 22-29
Author(s):  
Н. В. Фрадкіна

The purpose and tasks of the work are to analyze the contemporary Ukrainian mass culture in terms of its value and humanistic components, as well as the importance of cultural studies and Ukrainian studies in educational disciplines for the formation of a holistic worldview of modern youth.Analysis of research and publications. Scientists repeatedly turned to the problems of the role of spirituality in the formation of society and its culture. This problem is highlighted in the publications by O. Losev, V. Lytvyn, D. Likhachev, S. Avierintsev, M. Zakovych, I. Stepanenko and E. Kostyshyn.Experts see the main negative impact of mass culture on the quality approach, which determines mass culture through the market, because mass culture, from our point of view, is everything that is sold and used in mass demand.One of the most interesting studies on this issue was the work by the representatives of Frankfurt School M. Horkheimer and T. Adorno «Dialectics of Enlightenment» (1947), devoted to a detailed analysis of mass culture. Propaganda at all socio-cultural levels in the form is similar in both totalitarian and democratic countries. It is connected, according to the authors, with the direction of European enlightenment. The tendency to unify people is a manifestation of the influence of mass culture, from cinema to pop. Mass culture is a phenomenon whose existence is associated with commerce (accumulation in any form – this is the main feature of education), in general, the fact that it exists in this form is related to the direction of the history of civilization.Modern mass culture, with its externally attractive and easily assimilated ideas and symbols, appealing to the trends of modern fashion, becomes a standard of prestigious consumption, does not require intense reflection, allows you to relax, distract, not teach, but entertains, preaches hedonism as the main spiritual value. And as a consequence, there are socio-cultural risks: an active rejection of other people, which leads to the formation of indifference; cruelty as a character trait; increase of violent and mercenary crime; increase in the number of alcohol and drug addicts; anti-patriotism; indifference to the values of the family and as a result of social orphanhood and prostitution.Conclusions, perspectives of research. Thus, we can conclude that modern Ukrainian education is predominantly formed by the values of mass culture. Namely, according to the «Dialectic» by Horkheimer and Adorno, «semi-enlightenment becomes an objective spirit» of our modern society.It is concluded that only high-quality education can create the opposite of the onset of mass culture and the destruction of spirituality in our society. It is proved that only by realizing the importance of cultivating disciplines in the educational process and the spiritual upbringing of the nation, through educational reforms, humanitarian knowledge will gradually return to student audiences.Formation of youth occurs under the influence of social environment, culture, education and self-education. The optimal combination of these factors determines both the process of socialization itself and how successful it will be. In this context, one can see the leading role of education and upbringing. It turns out that the main task of modern education is to spread its influence on the development of spiritual culture of the individual, which eventually becomes a solid foundation for the formation of the individual. Such a subject requires both philosophical and humanitarian approaches in further integrated interdisciplinary research, since the availability of such research will provide the theoretical foundation for truly modern educational and personal development.


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