Enzymatic and toxigenic ability of opportunistic fungi contaminating intensive care units and operation rooms at Assiut University Hospitals, Egypt

Total of 110 isolates belonging to 8 fungal species collected from intensive care units (ICUs) and operation rooms (ORs) at Assiut University hospitals were examined for their ability to produce some extracellular enzymes and mycotoxins which are considered as important factors involved in for fungal pathogenicity. The results revealed that 73, 92 and 78 out of the 110 tested isolates produced protease, lipase and urease respectively; meanwhile, 77 of the tested isolates exhibited some hemolytic activities. Chromatographic analysis (TLC) of the crude extract of the fungal isolates tested revealed that 79 isolates of them had the ability to produce at least one of these mycotoxic compounds (aflatoxins B(1), B(2), G(1), gliotoxin, fumigillin, T-2, zearalenone, roridin A & E, verrucarin A & J, trichoveroids, satratoxin H & E). These results demonstrate that the opportunistic fungal species isolated from (ICUs) and (ORs) and tested exhibited some enzymatic and mycotoxic ability which are the most effective virulence factors contributing to fungal pathogenicity indicating that the management of infection control unit at Assiut University hospitals must be aware of not only bacterial but also fungal contamination

Optimization of kojic acid production conditions from cane molasses using Plackett-Burman design

Fungal synthesis of kojic acid has gained more interest in these days as an alternative way to chemical synthetic. The aspect of the microbial fermentation process is to develop a suitable culture medium to obtain the maximum amount of kojic acid using statistical methods. In this study; different selected three isolates of Aspergillus flavus (No 1, 2 and 3) were screened for their ability to produced kojic acid and the isolate No 3 was the highest kojic acid producer one. The capability of A. flavus No 3 to produce kojic acid was improved using Plackett-Burman design. From ten different agro-industrial wastes cane molasses recorded the highest kojic acid productivity with 2.24 g/l-1 day-1 and was the most effective parameter plays a crucial role in Plackett-Burman design. Maximum kojic acid production (24.65 g/l) by A. flavus (No. 3) obtained under the fermentation conditions: incubation temperature at 25oC, incubation time 9 days, pH 3, inoculum size 0.5%, shaking rate at 150 rpm and medium constituents: Cane molasses 60 g/l, yeast extract 7 g/l, KH2PO4 2 g/l, ZnSO4·7H2O 100 µg/l and MgSO4·7H2O 1 g/l with regression analysis (R2) 99.45% and 2.33-fold increase in comparison to the production of the original level (10.6 g/l). DOI: http://dx.doi.org/10.5281/zenodo.121151

Functional Low-fat Set Yogurt Enhanced with Microbial Exo-polysaccharides-mediated Anticancer Activity

Exopolysaccharides (EPSs) are novel functional additives for low-fat yogurt. Pharmaceutical, medical, and food industries are using more LAB-based EPSs. In this study, Leuconostoc spp. was used to produce ninth bacterial EPSs in a modified molasses medium. Production of EPSs was concentration-dependent on all stains and the highest yield was obtained from the S3 strain (55.23 g/l), followed by S6 (49.95 g/l), S8 (45.68 g/l), and S7 (44.23), respectively. HPLC and FTIR analysis showed that all purified EPSs from Leuconostoc citreum (S3) and Leuconstoc holzaapfelii (S8) were related to exopolysaccharide glucan. Anticancer activity of all EPSs samples (EPSs1-9) against Caco-2 cells and normal MCR-5 cells were investigated using MTT assay. The results revealed that Caco-2 cells were more sensitive than the normal MCR-5 cells. The highest anticancer activity against Caco-2 cancer cells was recorded for EPS8 (IC50 = 22.94 µg/ml, SI=3.73), followed by EPS3 (IC50 = 36.15 µg/ml, SI=8.72), EPS1 (IC50 = 50.01 µg/ml, SI=3.73), and EPS4 (IC50 = 94.90 µg/ml, SI=3.26), respectively. The lowest cytotoxicity was recorded for EPS5 (IC50 = 130.5 µg/ml). The most active EPSs (EPS3 and EPS8) were used as fat replacements and stabilizers in low-fat set yogurt at non-toxic concentrations (0.4, 0.8, and 1.2%). EPS3 and EPS8 improved the low-fat yogurt’s organoleptic and rheological properties. EPS8 had the highest water holding capacity (77.26%), viscosity (3660 CP), and lowest syneresis (22.95%) and whey off (0.6 ml). Low-fat set yogurt enhanced with EPS3 and EPS8 recorded the highest sensory evaluation values with overall acceptability, especially EPS3b, EPS3c, EPS8c, and EPS8b; the total score point of 97.50, 97.43, 96.51, and 96.36, respectively in fresh age compared to control yogurt (92.64). In conclusion, Leuconostoc EPSs, especially EPS8, can be explored for anti-cancer effects on Caco-2 colorectal cancer cells. It could also improve the rheological and organoleptic qualities of low-fat set yogurt

Exploring the antibacterial potential of plant extracts and essential oils against Bacillus thermophilus in beet sugar for enhanced sucrose retention: a comparative assessment and implications

Sugar beet is one of the greatest sources for producing sugar worldwide. However, a group of bacteria grows on beets during the storage process, leading to a reduction in sucrose yield. Our study focused on identifying common bacterial species that grow on beets during manufacturing and contribute to sucrose loss. The ultimate goal was to find a potential antibacterial agent from various plant extracts and oils to inhibit the growth of these harmful bacteria and reduce sucrose losses. The screening of bacterial species that grow on beet revealed that a large group of mesophilic bacteria, such as Bacillus subtilis, Leuconostoc mesenteroides, Pseudomonas fluorescens, Escherichia coli, Acinetobacter baumannii, Staphylococcus xylosus, Enterobacter amnigenus, and Aeromonas species, in addition to a dominant thermophilic species called Bacillus thermophilus, were found to be present during the manufacturing of beets. The application of 20 plant extracts and 13 different oils indicated that the extracts of Geranium gruinum, Datura stramonium, and Mentha spicata were the best antibacterials to reduce the growth of B. thermophilus with inhibition zones equal to 40, 39, and 35 mm, respectively. In contrast, the best active oils for inhibiting the growth of B. thermophilus were Mentha spicata and Ocimum bacilicum, with an inhibitory effect of 50 and 45 mm, respectively. RAPD-PCR with different primers indicated that treating sugar juice with the most effective oils against bacteria resulted in new recombinant microorganisms, confirming their roles as strong antibacterial products. The characterization of Mentha spicata and Ocimum bacilicum oils using GC/MS analysis identified cis-iso pulegone and hexadecanoic acid as the two main bioactive compounds with potential antibacterial activity. An analysis of five genes using DD-PCR that have been affected due to antibacterial activity from the highly effective oil from Mentha spicata concluded that all belonged to the family of protein defense. Our findings indicate that the application of these pure antibacterial plant extracts and oils would minimize the reduction of sucrose during sugar production.Peer Reviewe

2-Aminoethanaminium 2-(ethoxycarbonyl)-4,6-dinitrophenolate as a greener route in reducing sugar quantification

3,5-dinitrosalicylic acid (DNS) reducing sugar assay is the most convenient method for quantification of total reducing sugar in biomass hydrolysate, fermentation samples, sugar industry and biotechnology laboratories. The dimeric proton transfer salt 2-aminoethanaminium 2-(ethoxycarbonyl)-4,6-dinitrophenolate (AED) is an intensely colored derivative of DNS and in turn its reduced form intense color showed a superior properties in reducing sugar quantification eliminating phenol and rochelle salt additives using the same practical methodology of DNS giving an overall methodology advantageous than using DNS assay as a greener route.The proton transfer salt has already been X-ray imaged and deposited in Cambridge Crystallographic Data Centre CCDC 1441586 and a comparison was done between DNS and this salt using a salt and sodium hydroxide concentrations as the same as DNS assay as well as the latter phenol-rochelle salt free environment giving correlation coefficient 0.999 and absorptivity nearly two thirds the obtained in case of use DNS assay with added phenol for enhancing absorptivity and rochelle salt for produced color stabilization for the same detection range 0.1-0.5 mg/ml according to Miller procedures. The sensitivity and the reduced form color stability of this proton transfer salt could be interpreted on both of its molecular structure has a double oxidizing groups as well as it has an intense color as compared with DNS and a good reduced form solubility respectively. • DNS in reducing sugar quantification, Miller procedures involving phenol and rochelle salt addition. • AED in reducing sugar quantification as the same detection range as DNS with the elimination of phenol and rochelle salt from the assay. • A greener convenient route in reducing sugar quantification. Method name: AED in reducing sugar quantification, Keywords: Organic proton transfer salts, AED, DNS, Application in reducing sugar determination, Greener rout

Phenotypic and Genotypic Characterization of Exopolysaccharide Producing Bacteria Isolated from Fermented Fruits, Vegetables and Dairy Products

Exopolysaccharides (EPS) particularly, from Lactic acid bacteria have received increasing attention in food, medical, and pharmaceutical applications. The present work aims to isolate, characterize and identify exopoly saccharide-producing bacteria from fermented fruits and vegetables and dairy products. A total of 55 isolates were isolated from fermented fruits, vegetables, and dairy products depending on the mucoid appearance of the colonies. Based on total EPS production, the most promising nine strains were selected, phenotypically and genotypically characterized. They were facultative anaerobe, arranged in pairs/chains (cocco bacillus), oxidase, and catalase-negative, non-spore forming and non-motile Gram-positive bacteria. All the strains were capable of growing at optimum pH between 5-7, tolerate to NaCl up to 7% (w/v), growing at 20-37°C with optimum growth at 30°C, no growth was observed at 45°C. In addition they could utilize small range of organic compounds, except isolate S1 was differ from the others by their ability to utilize a varied range of organic compounds. Construction of phylogenetic tree, on the basis of partial 16S rRNA gene sequences indicated that isolate S1 was similar to Leuconostoc citreum with similarity of 91.3%, while, isolates S2 and S3 were similar to Leu. fallax and Leu. mesenteroides with similarity of 99.40 % and 97.73%, respectively. Isolates S4, S5, S7, S8, and S9 were similar to Leu. holzaapfelii with similarity of 98.3, 98.7 and 99.8, 98.5 and 98.1, respectively, while isolate S6 was similar to Leu. lactis with similarity of 97.9%. None of sugars such as lactose, glucose, and fructose except sucrose were support EPS production from these strains. The highest yield of EPS was recorded for isolates S6, S1 and S7 which were 61.90, 61.80 and 60 gl-1, respectively, followed by isolates S4, S9, S5 and S8 which were 58.40, 53.06, 51.61 and 33.53 gl-1, respectively. Although, the lowest yield was observed for the isolates S3 and S2 which were 22.08 and 18.80 g l-1, respectively. Finally, it could be concluded that EPS production from these strains in the current study, considering them to be the alternative choice for enhancing production of EPS with increased yields, with promising realistic importance in food, pharmaceutical, as well as dairy industries

Table_1_Exploring the antibacterial potential of plant extracts and essential oils against Bacillus thermophilus in beet sugar for enhanced sucrose retention: a comparative assessment and implications.pdf

Sugar beet is one of the greatest sources for producing sugar worldwide. However, a group of bacteria grows on beets during the storage process, leading to a reduction in sucrose yield. Our study focused on identifying common bacterial species that grow on beets during manufacturing and contribute to sucrose loss. The ultimate goal was to find a potential antibacterial agent from various plant extracts and oils to inhibit the growth of these harmful bacteria and reduce sucrose losses. The screening of bacterial species that grow on beet revealed that a large group of mesophilic bacteria, such as Bacillus subtilis, Leuconostoc mesenteroides, Pseudomonas fluorescens, Escherichia coli, Acinetobacter baumannii, Staphylococcus xylosus, Enterobacter amnigenus, and Aeromonas species, in addition to a dominant thermophilic species called Bacillus thermophilus, were found to be present during the manufacturing of beets. The application of 20 plant extracts and 13 different oils indicated that the extracts of Geranium gruinum, Datura stramonium, and Mentha spicata were the best antibacterials to reduce the growth of B. thermophilus with inhibition zones equal to 40, 39, and 35 mm, respectively. In contrast, the best active oils for inhibiting the growth of B. thermophilus were Mentha spicata and Ocimum bacilicum, with an inhibitory effect of 50 and 45 mm, respectively. RAPD-PCR with different primers indicated that treating sugar juice with the most effective oils against bacteria resulted in new recombinant microorganisms, confirming their roles as strong antibacterial products. The characterization of Mentha spicata and Ocimum bacilicum oils using GC/MS analysis identified cis-iso pulegone and hexadecanoic acid as the two main bioactive compounds with potential antibacterial activity. An analysis of five genes using DD-PCR that have been affected due to antibacterial activity from the highly effective oil from Mentha spicata concluded that all belonged to the family of protein defense. Our findings indicate that the application of these pure antibacterial plant extracts and oils would minimize the reduction of sucrose during sugar production.</p