Selection of a hyperproducing strain ofAspergillus niger for biosynthesis of citric acid on unusual carbon substrates

1990 ◽  
Vol 35 (2) ◽  
pp. 138-142 ◽  
Author(s):  
J. Pelechová ◽  
L. Petrová ◽  
E. Ujcová ◽  
L. Martínková
2017 ◽  
Author(s):  
M. Chaali ◽  
J. Lecka ◽  
G. Suresh ◽  
M. Salem ◽  
S. K. Brar ◽  
...  

ABSTRACTAn indiscriminate use of antibiotics in humans and animals has led to a widespread selection of antibiotic-resistant bacterial strains. A possible solution to counter this problem could be to develop alternatives that may boost the host immunity, thus reducing in the quantity and frequency of antibiotic use. In this work, for the first time, citric acid and laccase were used as extracellular inducers of melanin production in yeast cells and human cell lines. It is proposed that the formulation of laccase and citric acid together could further promote melatonin stimulated melanocyte derived melanin production. Melanization test as a probe of immunity, described in this study, is an easy and a quicker test than the other immunity tests and is statistically significant. The results showed the synergistic effect of citric acid and laccase on melanin production by the yeast cells, with significant statistical differences compared to all other tested conditions (P: 0.0005- 0.005). Laccase and citric acid together boosted melanin production after 8 days of incubation. An increase in melanin production by two colon human cells lines (Cacao-2/15 and HT-29) was observed when both laccase and citric acid were present in cell growth medium. A formulation with citric acid and laccase may prove to be an excellent alternative to reduce the antibiotic load in human and animal subjects.Summary statementThis study shows, for the first time, that production of melanin in yeast and human intestinal cells is induced by extracellular addition of laccase and citric acid.


2018 ◽  
Vol 16 (1) ◽  
pp. 116-132 ◽  
Author(s):  
Anna Gumieniczek ◽  
Hanna Trębacz ◽  
Łukasz Komsta ◽  
Agnieszka Atras ◽  
Beata Jopa ◽  
...  

AbstractIt is well known that drugs can directly react with excipients. In addition, excipients can be a source of impurities that either directly react with drugs or catalyze their degradation. Thus, binary mixtures of three diuretics, torasemide, furosemide and amiloride with different excipients,i.e. citric acid anhydrous, povidone K25 (PVP), magnesium stearate (Mg stearate), lactose, D-mannitol, glycine, calcium hydrogen phosphate anhydrous (CaHPO4) and starch, were examined to detect interactions. High temperature and humidity or UV/VIS irradiation were applied as stressing conditions. Differential scanning calorimetry (DSC), FT-IR and NIR were used to adequately collect information. In addition, chemometric assessments of NIR signals with principal component analysis (PCA) and ANOVA were applied.Between the excipients examined, lactose and starch did not show any interactions while citric acid, PVP, Mg stearate and glycine were peculiarly operative. Some of these interactions were shown without any stress, while others were caused or accelerated by high temperature and humidity, and less by UV/VIS light. Based on these results, potential mechanisms for the observed interactions were proposed Finally, we conclude that selection of appropriate excipients for torasemide, furosemide and amiloride is an important question to minimize their degradation processes, especially when new types of formulations are being manufactured.


2003 ◽  
Vol 2 (3) ◽  
pp. 178-184 ◽  
Author(s):  
Asad-ur-Rehman . ◽  
Sikander Ali . ◽  
Ikram-ul-Haq .
Keyword(s):  

2021 ◽  
Vol 15 ◽  
pp. 219-226
Author(s):  
T. I. DEDE ◽  
J. U. AKPOKODJE ◽  
P. I. ODILI

Simple laboratory methods were used to estimate optimal levels of acidity and osmolarity of four storage media for the boar semen. It was observed that above pH 7.0, less citric acid was needed for a unit change in pH of the sodium-citrate buffer, while above pH 8.0, more sodium carbonate and citric acid were needed for a unit change in the final Sodium-citrate buffered extender (Na-C), indicating high buffering capacity of this medium. The Glucose-glycine buffered extender (G-G), also required more sodium carbonate for a unit change of pH at above pH 6.5, also Indicating high buffering capacity of this medium. This was the same situation with the Tris-buffered extender (Tris), while the response with the Tissue - culture buffer extender (YCN) was always linear, indicating poor buffering capacity of the medium.


2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S330-S332 ◽  
Author(s):  
A. Váchová ◽  
Z. Panovská ◽  
D. Lukešová

The objective of this work was to choose an optimal rate of citric acid and sweeteners for lemon flavoured drops. Two model samples with defined concentrations of citric acid and two commercial samples were evaluated with using instrumental and sensory methods. Concentrations of sweetening agents and citric acid in the samples were determined using HPLC with a RI detector and isotachophoresis, respectively. The general pleasantness of taste and the intensity of acid and sweet tastes of four lemon drops were evaluated using sensory analysis. General pleasantness was evaluated using a ranking test. Intensities of acid and sweet tastes were evaluated using unstructured graphic scales. The best tasting lemon drops contained 11 g/kg of citric acid and 691 g/kg sweeteners related to the sweet potency of sucrose. The sample with an extremely acid taste was considered unpleasant for most assessors (Friedman, α= 0.05). Generally, the assessors preferred the lemon drops with well-balanced acid and sweet tastes.


2012 ◽  
Vol 217-219 ◽  
pp. 785-791
Author(s):  
Yan Lin ◽  
Xiao Hua Huang ◽  
Ren Qin Guo ◽  
Ai Jiao Xu ◽  
Qin Yi Shi

LiFePO4/C composite was synthesized by an easy sol-gel method using FeC2O4•H2O as iron source, citric acid and ethylene glycol as carbon source. The results showed that citric acid was inclined to leave more carbon in the synthesized material than ethylene glycol was and the carbon content increased greatly with the increasing amount of citric acid. When ethylene glycol was applied as carbon source, it left only a few amount of carbon (1.6 wt%) in the material. By optimizing the addition of carbon source, LiFePO4/C particles with uniform carbon coating and a little carbon content was obtained. The LiFePO4/C composite synthesized with 1/1 ratio of ethylene glycol to cations demonstrated the best electrochemical performance with its capacity of 143 mAh/g at 0.1C and 110 mAh/g at 1C within the voltage range of 2.5-4.2V (vs. Li/Li+). The results will provide ideas for the improvement of overall properties of LiFePO4 material for its application in the field of electric vehicles.


1982 ◽  
Vol 4 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Farouk A. Hamissa ◽  
Abou-Zeid A. Abou-Zeid ◽  
Ahmed A. Radwan

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