Microbial ribonucleases (RNases): production and application potential

WOS: 000363725700004PubMed ID: 26433394Ribonuclease (RNase) is hydrolytic enzyme that catalyzes the cleavage of phosphodiester bonds in RNA. RNases play an important role in the metabolism of cellular RNAs, such as mRNA and rRNA or tRNA maturation. Besides their cellular roles, RNases possess biological activity, cell stimulating properties, cytotoxicity and genotoxicity. Cytotoxic effect of particular microbial RNases was comparable to that of animal derived counterparts. In this respect, microbial RNases have a therapeutic potential as anti-tumor drugs. The significant development of DNA vaccines and the progress of gene therapy trials increased the need for RNases in downstream processes. In addition, RNases are used in different fields, such as food industry for single cell protein preparations, and in some molecular biological studies for the synthesis of specific nucleotides, identifying RNA metabolism and the relationship between protein structure and function. In some cases, the use of bovine or other animal-derived RNases have increased the difficulties due to the safety and regulatory issues. Microbial RNases have promising potential mainly for pharmaceutical purposes as well as downstream processing. Therefore, an effort has been given to determination of optimum fermentation conditions to maximize RNase production from different bacterial and fungal producers. Also immobilization or strain development experiments have been carried out

LEGIONELLA PNEUMOPHILA: LEGIONNARIES' DISEASE

WOS: 000278550900002Legionella pneumophila was recognized as an important human pathogen after the first discovery during an investigation of a pneumonia outbreak among American Legion convention in 1976 in Philadelphia, USA. L. pneumophila is a gram-negative, mesophilic, facultative intracellular parasitic and nonspore-forming rod-shaped bacterium belonging to the gamma-subgroup of proteobacteria. L. pneumophila inhabits natural freshwater environments at low concentration. Along with the transfer from natural aquatic habitats into man-made water systems such as cooling towers, evaporative condensers, water distribution systems, whirlpool spas and hot water tanks, L. pneumophila reaches high cell density and can cause Legionnaires' disease (pneumonic legionellosis) or Pontiac fever (severe influenza-like illness). Infection occurs primarily via the inhalation of L. pneumophila-contaminated aerosols. In aquatic habitats, L. pneumophila cells are intracellular parasites of freshwater protozoa and use a similar mechanism to multiply within mammalian cells. L. pneumophila can also multiply extracellularly within biofilms and can persist within these microbial communities for years. Transmission to human primarily occurs via the inhalation of L. pneumophila containing aerosols. The bacterium enters to human phagocytic cells by coiling or conventional phagocytosis then inhibits phagosome-lysosome fusion and multiplies in the phagosome. A number of virulence factors have been described for L. pneumophila such as surface proteins, secreted factors and putative virulence factors. L. pneumophila can be identified by using cultural, serologic and various molecular techniques such as DNA sequencing and DNA-DNA hybridization. Diagnosis can be made by culture, direct fluorescent antibody staining, serological tests, urinary antigen detection or nucleic acid detection and various subtyping techniques. In order to eradicate L. pneumophila from contaminated water systems several methods are available; Thermal or chemical shock \disinfection, UV irradiation, ozone treatment, silver-copper ionization, anodic oxidation and chlorine dioxide application

Prevalence of Thermoactinomyces thalpophilus and T. sacchari strains with biotechnological potential at hot springs and soils from West Anatolia in Turkey

WOS: 000289045600009Hot spring sediment and soil samples from West Anatolia in Turkey were investigated for the occurrence of thermophilic Actinomycetes. Isolation was done using Actinomycetes isolation agar (AIA), starch casein agar and glycerol yeast extract agar at 55 degrees C. Extracellular protease activity of the isolates were screened by using AIA plus 1% casein according to the hydrolysis zones surrounding the colonies. Antimicrobial activities of the isolates were also screened by using streaked plate method against a panel of test bacteria. Identification of the isolates was made by cultural, physiological characteristics and 16S rDNA sequence similarity. Sixty-seven thermophilic Actinomyceres isolates were classified in Thermoactinomyces thalpophilus and T. sacchari species. Among these, 62 isolates (92.5%) were found to be extracellular protease producers and 38 isolates (56.7%) were found active against methicillin resistant Staphylococcus aureus and Enterococcus faecalis. Based on these results, we suggest that the thermophilic actinomycetes, which are a part of the biodiversity of the hot springs and soils from West Anatolia in Turkey, are promising sources for novel enzymes and antimicrobial compounds.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [SBAG-2746]This study was supported by the Scientific and Technological Research Council of Turkey (TUBITAK, SBAG-2746). We also would like to thank Associate Professor Kemal Korkmaz for his valuable help with the bioinformatics analysis

Novel keratin modified bacterial cellulose nanocomposite production and characterization for skin tissue engineering

WOS: 000400720800131PubMed ID: 28415399As it is known that bacterial cellulose (BC) is a biocompatible and natural biopolymer due to which it has a large set of biomedical applications. But still it lacks some desired properties, which limits its uses in many other applications. Therefore, the properties of BC need to be boosted up to an acceptable level. Here in this study for the first time, a new natural nanocomposite was produced by the incorporating keratin (isolated from human hair) to the BC (produced by Acetobacter xylinum) to enhance dermal fibroblast cells' attachment. Two different approaches were used in BC based nanocomposite production: in situ and post modifications. BC/keratin nanocomposites were characterized using SEM, FTIR, EDX, XRD, DSC and XPS analyses. Both production methods have yielded successful results for production of BC based nanocomposite-containing keratin. In vitro cell culture experiments performed with human skin keratinocytes and human skin fibroblast cells indicate the potential of the novel BC/keratin nanocomposites for use in skin tissue engineering. (C) 2017 Elsevier B.V. All rights reserved.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114M082]; Ege University Science and Technology Centre - Scientific Research Projects Council [15BIL022]This study was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) grant number 114M082, Ege University Science and Technology Centre - Scientific Research Projects Council grant number 15BIL022. The authors would like to thank Prof. Figen Zihnioglu (Department of Biochemistry at Ege University) and Asst. Prof. Dr. Mehmet Sarikanat for their valuable contributions

A New Siderophore from Sponge Associated Pseudomonas fluorescens 4.9.3

WOS: 000361530500005In this study, Pseudomonas fluorescens 4.9.3 isolated from a sponge sample was investigated for its secondary metabolites. Two metabolites were isolated, and their structures were elucidated by 1D-, 2D NMR and LC-MS/MS experiments. The new compound (1) was established as (5R)-N-(2-(1H-imidazol-4-yDethyl)-2-(2-hydroxyphenyl)-5-methyl-4,5-dihydrooxazole-4-carboxamide, while the known metabolite was determined as pre-pseudomonine.TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [109S361]This work is supported by TUBITAK (Project No: 109S361)

Patents on Biosurfactants and Future Trends

WOS: 00046829820001