Optimization of Citric Acid Production by Immobilized Cells of Novel Yeast Isolates

( Abd El-latif Hesham ),( Yasser S. Mostafa ),( Laila Essa Omar Alsharqi ) 한국균학회 2020 Mycobiology Vol.48 No.2

Citric acid is a commercially valuable organic acid widely used in food, pharmaceutical, and beverage industries. In this study, 260 yeast strains were isolated from soil, bread, juices, and fruits wastes and preliminarily screened using bromocresol green agar plates for their ability to produce organic acids. Overall, 251 yeast isolates showed positive results, with yellow halos surrounding the colonies. Citric acid production by 20 promising isolates was evaluated using both free and immobilized cell techniques. Results showed that citric acid production by immobilized cells (30-40 g/L) was greater than that of freely suspended cells (8-19 g/L). Of the 20 isolates, two (KKU-L42 and KKU-L53) were selected for further analysis based on their citric acid production levels. Immobilized KKU-L42 cells had a higher citric acid production rate (62.5%), while immobilized KKU-L53 cells showed an ~52.2% increase in citric acid production compared with free cells. The two isolates were accurately identified by amplification and sequence analysis of the 26S rRNA gene D1/D2 domain, with GenBank-based sequence comparison confirming that isolates KKU-L42 and KKU-L53 were Candida tropicalis and Pichia kluyveri, respectively. Several factors, including fermentation period, pH, temperature, and carbon and nitrogen source, were optimized for enhanced production of citric acid by both isolates. Maximum production was achieved at fermentation period of 5 days at pH 5.0 with glucose as a carbon source by both isolates. The optimum incubation temperature for citric acid production by C. tropicalis was 32 ℃, with NH₄Cl the best nitrogen source, while maximum citric acid by P. kluyveri was observed at 27 ℃ with (NH₄)₂ SO₄ as the nitrogen source. Citric acid production was maintained for about four repeated batches over a period of 20 days. Our results suggest that apple and banana wastes are potential sources of novel yeast strains; C. tropicalis and P. kluyveri which could be used for commercial citric acid production.

A New Conception in Constructive Branching Structures and Leaves using L-system

Abd El-Latif, Yasser M. Korean Institute of Information Scientists and Eng 2010 Journal of Computing Science and Engineering Vol.4 No.3

One of the important open problems in modeling plants is the extension of subdivision algorithms to branching structures. Most of the applications use the concept of L-system to produce branching structures as a sequence of lines and apply the subdivision scheme to appear as curves. In this paper, we explain how L-systems can be modified to produce branching structures. This is also very useful for generating the geometry of various shapes. The proposed technique, called an adaptive L-System, describes branching forms and leaves by making local curve without applying the subdivision steps. Advantages of the suggested algorithm over previous techniques are given. Validation of the algorithm are discussed, analyzed and illustrated by some experimental results.

An Examination of Travel Motivation and the Influential Factors of Mainland Chinese Grey Tourism Market

Tamer Hamdy Abd El Latif Ayad 세계문화관광학회 2020 International Journal of Culture and tourism Resea Vol.13 No.1

Grey tourism market is important to the tourism industry. The seniors travelers are traveling more frequently, going longer distances, staying away longer, spending more money. China is unique in its aging trend, more than 30% of the Chinese population is expected to be aged 60 or older in 2050. The primary objectives of this study were to determine the travel motivations of mainland Chinese seniors travelers and to discover what variables are influential in explaining the variances of the motivations. Using factor analysis, the knowledge-seeking factor and cleanliness & safety factor appeared to be the most important push and pull motivations, respectively. Subsequent regression analysis indicated that health status and positive and negative emotional state of seniors significantly contribute to accounting for the travel motivations of mainland Chinese seniors.

ON INTUITIONISTIC FUZZY SUBSPACES

Ramadan, Ahmed Abd El-Kader,El-Latif, Ahmed Aref Abd Korean Mathematical Society 2009 대한수학회논문집 Vol.24 No.3

We introduce a new concept of intuitionistic fuzzy topological subspace, which coincides with the usual concept of intuitionistic fuzzy topological subspace due to Samanta and Mondal [18] in the case that $\mu=X_A$ for A $\subseteq$ X. Also, we introduce and study some concepts such as continuity, separation axioms, compactness and connectedness in this sense.

A New Conception in Constructive Branching Structures and Leaves using L-system

Yasser M. Abd El-Latif 한국정보과학회 2010 Journal of Computing Science and Engineering Vol.4 No.3

One of the important open problems in modeling plants is the extension of subdivision algorithms to branching structures. Most of the applications use the concept of L-system to produce branching structures as a sequence of lines and apply the subdivision scheme to appear as curves. In this paper, we explain how L-systems can be modified to produce branching structures. This is also very useful for generating the geometry of various shapes. The proposed technique, called an adaptive L-System, describes branching forms and leaves by making local curve without applying the subdivision steps. Advantages of the suggested algorithm over previous techniques are given. Validation of the algorithm are discussed, analyzed and illustrated by some experimental results.

Soft supra strongly semi* generalized closed sets

A. M. Abd El-latif 원광대학교 기초자연과학연구소 2017 ANNALS OF FUZZY MATHEMATICS AND INFORMATICS Vol.13 No.1

In this paper, we introduce the concept of soft supra strongly semi$^{*}$ generalized closed sets (soft supra strongly semi$^{*}$ $g$-closed for short) in a supra soft topological space $(X,\mu,E)$ and study their properties in detail. The relationship between soft supra strongly semi$^{*}$ generalized closed sets and other existing soft sets have been investigated. It has been pointed out in this paper that many of these parameters studied have, in fact, applications in real world situations and therefore I believe that this is an extra justification for the work conducted in this paper.

ON FUZZY BITOPOLOGICAL SPACES IN ŠOSTAK'S SENSE (II)

Ramadan, Ahmed Abd El-Kader,Abbas, Salah El-Deen,El-Latif, Ahmed Aref Abd Korean Mathematical Society 2010 대한수학회논문집 Vol.25 No.3

In this paper, we have use a fuzzy bitopological space (X, $\tau_1$, $\tau_2$) to create a family $\tau_{ij}^s$ which is a supra fuzzy topology on X. Also, we introduce and study the concepts of r-($\tau_i$, $\tau_j$)-generalized fuzzy regular closed, r-($\tau_i$, $\tau_j$)-generalized fuzzy strongly semi-closed and r-($\tau_i$, $\tau_j$)-generalized fuzzy regular strongly semi-closed sets in fuzzy bitopological space in the sense of $\check{S}$ostak. Also, these classes of fuzzy subsets are applied for constructing several type of fuzzy closed mapping and some type of fuzzy separation axioms called fuzzy binormal, fuzzy mildly binormal and fuzzy almost pairwise normal.

Polymorphism in Macrophage Migration Inhibitory Factor -173GC in Pediatric Patients with Autoimmune Hepatitis

Mona Abdel Latif Alsayed,Shymaa Mohsen Elbeah,Manal M. El-Desoky,Shereen Magdy Elziny,Ahmed Megahed 대한소아소화기영양학회 2020 Pediatric gastroenterology, hepatology & nutrition Vol.23 No.1

Purpose: Autoimmune hepatitis (AIH) is a chronic disease that may lead to cirrhosis. The immunopathogenesis of AIH is not fully understood and it mainly involves T-cell mediated mechanism. Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that promotes T cell response and its polymorphism may serve as a severity marker of AIH. No previous study has considered investigating MIF polymorphism in children with AIH. Methods: Forty-two children with definite diagnosis of AIH were enrolled along with 100 age and sex matched controls. All participants were tested for polymorphism at -173GC (rs755622) of MIF gene. All patients received the standard protocol of steroid plus azathioprine to achieve remission. Liver biopsy was performed at time of diagnosis for all patients and only 18 of them underwent a second biopsy after treatment. Results: No statistically significant differences in the frequency of the genotypes GG and GC or in allele distribution were found in both patient and control groups (p=0.590, 0.640 respectively). Initial alanine aminotransferase (ALT) levels at the time of presentation was significantly higher in the GC group than GG group (p=0.020). GC genotype significantly correlated with disease relapse (r=0.41, p=0.007). Regression of necroinflammation and the fibrosis score in the second liver biopsy was statistically significant in the GG group (p<0.0001, p=0.010 respectively). Conclusion: MIF -173GC polymorphism is associated with clinically significant markers of pediatric AIH, including increased initial serum ALT levels, may help predict necroinflammatory/fibrosis regression effectively, following immunosuppressive treatment.

Purification, Characterization and Application of a Cold Active Lipase from Marine Bacillus cereus HSS

Hassan Sahar WM.,Latif Hala H. Abd El,Ehab A. Beltagy 한국미생물·생명공학회 2022 한국미생물·생명공학회지 Vol.50 No.1

Lipases (triacylglycerol acylhydrolases [EC 3.1.1.3]) are water-soluble enzymes. They catalyze the hydrolysis of fats and oils. A cold-active lipase from marine Bacillus cereus HSS, isolated from the Mediterranean Sea, Alexandria, Egypt, was purified and characterized. The total purification depending on lipase activity was 438.9 fold purification recording 632 U/mg protein. The molecular weight of the purified lipase was estimated to be 65 kDa using sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The optimum substrate concentration, enzyme concentration, pH, and temperature were 1.5 mM, 100 μl, pH 6 and 10℃, respectively. The lipase was tolerant to NaCl concentrations ranging from 1.5 to 4.5%. The lipase was affected by the tested metal ions, and its activity was inhibited by 16% in the presence of 0.05 M SDS. The application of the cold-active lipase for the removal of an oil stain from a white cotton cloth showed that it is a promising biological agent for the treatment of oily wastes and other related applications. To the best of our knowledge, this is the first report of the purification and characterization of a lipase from marine B. cereus HSS isolated from the Mediterranean Sea.

Polymorphism in Macrophage Migration Inhibitory Factor -173GC in Pediatric Patients with Autoimmune Hepatitis

Alsayed, Mona Abdel Latif,Elbeah, Shymaa Mohsen,El-Desoky, Manal M.,Elziny, Shereen Magdy,Megahed, Ahmed The Korean Society of Pediatric Gastroenterology 2020 Pediatric gastroenterology, hepatology & nutrition Vol.23 No.1

Purpose: Autoimmune hepatitis (AIH) is a chronic disease that may lead to cirrhosis. The immunopathogenesis of AIH is not fully understood and it mainly involves T-cell mediated mechanism. Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that promotes T cell response and its polymorphism may serve as a severity marker of AIH. No previous study has considered investigating MIF polymorphism in children with AIH. Methods: Forty-two children with definite diagnosis of AIH were enrolled along with 100 age and sex matched controls. All participants were tested for polymorphism at -173GC (rs755622) of MIF gene. All patients received the standard protocol of steroid plus azathioprine to achieve remission. Liver biopsy was performed at time of diagnosis for all patients and only 18 of them underwent a second biopsy after treatment. Results: No statistically significant differences in the frequency of the genotypes GG and GC or in allele distribution were found in both patient and control groups (p=0.590, 0.640 respectively). Initial alanine aminotransferase (ALT) levels at the time of presentation was significantly higher in the GC group than GG group (p=0.020). GC genotype significantly correlated with disease relapse (r=0.41, p=0.007). Regression of necroinflammation and the fibrosis score in the second liver biopsy was statistically significant in the GG group (p<0.0001, p=0.010 respectively). Conclusion: MIF -173GC polymorphism is associated with clinically significant markers of pediatric AIH, including increased initial serum ALT levels, may help predict necroinflammatory/fibrosis regression effectively, following immunosuppressive treatment.