The present study investigated that chitosan production of Rhizopus oryzae NRRL 1526 and Aspergillus niger ATCC 16404. Fungal chitosans were characterized by scanning electron microscopy (SEM)‐energy dispersive X‐ray analysis, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimeter and deacetylation degrees of fungal chitosans were determined. The percentage yield of Ro‐chitosan and An‐chitosan were determined as 18.6% and 12.5%, respectively. According to percentage of chitosan yield and the results of the characterization studies, chitosan that obtained from Rhizopus oryzae NRRL 1526 was selected for subsequent studies. Cytotoxicity of chitosan obtained from Rhizopus oryzae NRRL 1526 was determined by MTT assay on human dermal fibroblast cell line. Acording to results of the cytotoxicity test fungal chitosan was nontoxic on cells. The high cell viability was observed 375 μg/mL concentration at 24th, 48th h periods and at the 187.5 μg/ml 72nd h periods on cells. The fungal chitosan obtained from Rhizopus oryzae NRRL 1526 was used to fabrication of electrospun nanofibers. Fungal chitosan based polymer solutions were prepared by adding different substances and different electrostatic spinning parameters were used to obtain most suitable nanofiber structure. Characterization studies of nanofibers were carried out by SEM, FTIR and X‐ray diffraction. The most suitable nanofiber structure was determined as F4 formula. The nanofiber structure was evaluated to be thin, bead‐free, uniform, flexible and easily remove from surface and taking the shape of the area. After the characterization analysis of fungal chitosan it was determined that the chitosan, which obtained from Rhizopus oryzae NRRL 1526 is actually chitosan polymer and this polymer is usable for pharmaceutical areas and biotechnological applications. The electrospun nanofiber that blends fungal chitosan and PCL polymers were fabricated successfully and that it can be used as fabrication wound dressing models.Research HighlightsExtraction of chitosan from Rhizopus oryzae NRRL 1526 and Aspergillus niger ATCC 16404 and characterization scanning electron microscopy‐energy dispersive X‐ray analysis, Fourier transform infrared spectroscopy, differential scanning calorimeter. Fabrication and characterization of the fungal chitosan/PCL electrospun nanofibers.

Halophilic organisms are a novel attractive option as cell factories for the production of industrially valuable bioproducts.Halomonas elongata is the cell factory of choice for ectoine production, but its levan production has not been well researched. Based on this scientific motivation, in this study, we evaluated the chemical and biological properties of levan produced by the halophilic extremophile Halomonas elongata 153B (HeL). First, the central composite design was used to determine the optimal process variables for maximum levan biosynthesis. Then, the levan produced from HeL was purified, quantified, and chemically characterized with FTIR, 1 H-NMR, and GPC analyses. This was followed by antioxidant, anti-inflammatory, antibiofilm, and antimicrobial activity tests to assess its biological activities as well as a cytotoxcity assay. Maximum levan yields of 5.13 ± 0.38 g/L were achieved after dialysis at the optimum levels of process variables. The 1 H-NMR spectrum of HeL revealed characteristic signals. It showed a strong antioxidant activity of 67.88% and the best radical scavenger. At a concentration of 400 µg/mL, HeL showed the most anti-inflammatory efficacy. Also, at all indicated concentrations (250, 500, 750, and 1000 μg/mL) HeL, acted against biofilms formed by Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 11778, Candida albicans ATCC 10231. Furthermore, HeL displayed antimicrobial activities against all strains tested. Finally, HeL showed high Cell viability in all dosages and no cytotoxicity was observed. In light of these results, HeL may have high potential in the medical, pharmaceutical and dermo-cosmetics industries.

Bu çalışmada, kitosan bazlı film üretilerek bu filmlerin yüzey özellikleri incelenmiş ve en uygun formülasyon belirlenmiştir. Film yapısının karakterizasyonu, taramalı elektron mikroskobu, fourier dönüşümlü kızılötesi spektroskopisi, x-ışınları difraksiyonu analizleri yapılarak değerlendirilmiştir. Bu formülasyon farklı konsantrasyonlarda çay ağacı ve\veya melisa uçucu yağı ilavesi yapılarak antimikrobiyal etkinlikleri karşılaştırılmıştır. Filmler mikroyapı açısından değerlendirildiğinde homojen ve esnek bir yüzey yapısı oluşturmuştur. Film yapılarının antimikrobiyal aktivitesi Listeria monocytogenes ATCC 19115, Staphylococcus aureus ATCC 25923, Klebsiella pneumoniae NRRLB 4420, Enterococcus faecalis ATCC 51289, Escherichia coli ATCC 35218, Bacillus subtilis NRS 744, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 12600, Pseudomonas aeruginosa ATCC 11778 ve Candida albicans ATCC 10231 üzerinde test edilmiştir. Test edilen film yapıları patojen mikroorganizmalar üzerinde antimikrobiyal etki göstermiştir. Uçucu yağların antimikrobiyal aktiviteyi arttırdığı belirlenmiştir.

Hypericum perforatum L. is a popular and widespread medicinal plant used in a wide range of therapy, including gastrointestinal diseases, heart diseases, and skin-related diseases. The rapid development of nanotechnology and its applications in pharmacology have enabled the controlled release of drugs and bioactive components. This study aimed to investigate liposomal formulation for controlled release enriched with methanol and ethanol extract of H. perforatum, which has antioxidant, antimicrobial, and proliferative effects. In this context, firstly, the biological activity (antimicrobial, antioxidant, and cell viability) of H. perforatum methanol (Hp-MeOH) and ethanol (Hp-EtOH) extracts obtained by ultrasonic extraction method was revealed. Hp-MeOH and Hp-EtOH extracts have a larger zone of inhibition against Enterococcus faecalis ATTC 51289 and Pseudomonas aeruginosa ATCC 11778, respectively than the positive control amikacin (30mg/ml). Hp-MeOH and Hp-EtOH extracts were found to have a high total antioxidant status and low total oxidant status and oxidative stress index value. Hp-MeOH and Hp-EtOH extracts have a scavenging capacity of DPPH radicals between 23-89% and 27-90%, respectively in the studied concentration range. In addition, the effect of Hp-MeOH and Hp-EtOH extracts on cell viability of dermal fibroblast cells was evaluated for 24, 48, and 72 hours and induction of proliferation of fibroblasts was observed. Highly stable liposomes were successfully developed which encapsulated 82.6 ± 3.63% and 89.8 ± 2.74% Hp-MeOH and Hp-EtOH extracts, respectively. Liposomal structures loaded with Hp-MeOH and Hp-EtOH extracts showed a more controlled and slower release than the free extract.