Innovative approaches to nisin production

Nisin is a bacteriocin produced by Lactococcus lactis that has been approved by the Food Drug Administration for utilization as a GRAS status food additive. Nisin can inhibit spore germination and demonstrates antimicrobial activity against Listeria, Clostridium, Staphylococcus, and Bacillus species. Under some circumstances, it plays an immune modulator role and has a selective cytotoxic effect against cancer cells, although it is notable that the high production cost of nisin-a result of the low nisin production yield of producer strains-is an important factor restricting intensive use. In recent years, production of nisin has been significantly improved through genetic modifications to nisin producer strains and through innovative applications in the fermentation process. Recently, 15,400 IU ml-1 nisin production has been achieved in L. lactis cells following genetic modifications by eliminating the factors that negatively affect nisin biosynthesis or by increasing the cell density of the producing strains in the fermentation medium. In this review, innovative approaches related to cell and fermentation systems aimed at increasing nisin production are discussed and interpreted, with a view to increasing industrial nisin production.Peer reviewe

Molecular Detection of Helicobacter pylori vacA and cagA Genes in Gastric Tissue Specimens of Patients with Peptic Ulcer Disease and Non-Ulcer Dyspepsia

Helicobacter pylon can colonize the gastric mucosa and is considered as a risk factor for chronic active gastritis, peptic ulcer, gastric adenocarcinoma and primary gastric lymphoma. Among its various virulence factors, vacuolating cytotoxin encoded by vacA and cytotoxin-associated toxin encoded by cagA gene play an important role. The aims of this study were the detection of H.pylori vacA s and m genotypes, investigation of the association between vacA genotypes and cagA gene presence, and evaluation of the correlation between those factors and the clinical diagnosis. Gastric tissue specimens of patients who were clinically diagnosed as peptic ulcer disease (PUD) and non-ulcer dyspepsia (NUD) were included in the study. A total of 29 patients (age range: 18-74 years, mean age: 47.8 +/- 13.6 years; 19 were female) without any familial relationship were evaluated. Thirteen (44.8%) of the patients were diagnosed clinically as PUD, while 16 (55.2%) as NUD. All of the patients' gastric tissue samples obtained by endoscopy were urease positive. H.pylori DNA was extracted from the tissue specimens by proteinase-K, phenol-chloroform-isoamyl alcohol method and vacA s, m1, m2 and cagA regions were identified by polymerase chain reaction (PCR) using four different primer sets. In addition, DNA sequencing was performed for the protected 785 base-pairs region of vacA m gene in all of the samples, and the sequences were aligned with Gene-Bank sequences, creating a phylogenetic tree. The distribution of vacA genotypes between 29 H.pylori positive patients were found as; s1m1 (n= 16), s1m2 (n= 6) and s2m2 (n= 7), while 19 patients yielded positive results for cagA gene. CagA positivity was detected in all of the 16 patients harboring s1m1 genotype, and 13 of those were the patients diagnosed as PUD (p= 0.008). Genotyping data achieved by phylogenetic analysis of the vacA m region were compatible with m genotypes identified by PCR. In conclusion, we detected a significant relationship between PUD and vacA s1m1 and cagA positivity. It was also determined that PCR would be a reliable, simpler and cheaper alternative to nucleotide sequencing for the identification of H.pylori vacA m genotypes

Reliability and Validity of Subjective Well-Being Under Neuroleptics Scale-Short Form-Turkish Version

Reliability and validity of "subjective well-being under neuroleptics scale-short form", Turkish versio

Assessment of distribution of heavy metals and activity level of 210Pb in biota from the northern coast of the Marmara Sea and Western Black Sea

© 2020 Elsevier LtdIn this study, heavy metals (Cd, Co, Cu, Ni, Pb, Zn, V) and 210Pb analyses have been performed in the marine biota (scaldfish, sea lettuce, crab). Samples were collected from 5 different parts of the Marmara Sea and Western Black Sea in January 2020. The results indicated that the highest Cu and Zn content was found in algae samples, but it was observed that heavy metal concentrations such as Co, Cu, Cd and V were generally low and under permissible limit. Also, 210Pb (radioactive isotope of Pb) activity levels were determined to vary from 23.20 Bq kg−1 to 52.67 Bq kg−1 dry weight. It was clearly seen that there was a linear correlation between the toxic and radioactive Pb when the obtained data were compared

A non-surgical option in large bronchopleural fistulas: Bronchoscopic conical stent application

Background: This study aims to compare the results of the open surgical approach versus endobronchial conical stent application in the treatment of extensive fistulas