Publications by authors named "Can Holyavkin"

With its versatile metabolism including aerobic and anaerobic respiration, photosynthesis, photo-fermentation and nitrogen fixation, can adapt to diverse environmental and nutritional conditions, including the presence of various stressors such as heavy metals. Thus, it is an important microorganism to study the molecular mechanisms of bacterial stress response and resistance, and to be used as a microbial cell factory for biotechnological applications or bioremediation. In this study, a highly cobalt-resistant and genetically stable strain was obtained by evolutionary engineering, also known as adaptive laboratory evolution (ALE), a powerful strategy to improve and characterize genetically complex, desired microbial phenotypes, such as stress resistance.

View Article and Find Full Text PDF

Introduction: Despite the numerous studies demonstrating gut microbiota dysbiosis in obese subjects, there is no data on the association between obesity and gastric microbiota. The aim of this study was to address this gap in literature by comparing the composition of gastric microbiota in obese patients and a control group which included normal weight volunteers diagnosed with functional dyspepsia (FD).

Methodology: A total of 19 obese patients, and 18 normal weight subjects with FD and normal endoscopy results were included in the study.

View Article and Find Full Text PDF

2-Phenylethanol is an aromatic compound commonly used in the food, cosmetic, and pharmaceutical industries. Due to increasing demand for natural products by consumers, the production of this flavor by microbial fermentation is gaining interest, as a sustainable alternative to chemical synthesis or expensive plant extraction, both processes relying on the use of fossil resources. However, the drawback of the fermentation process is the high toxicity of 2-phenylethanol to the producing microorganism.

View Article and Find Full Text PDF

Phage DNA analysis gives opportunity to understand living ecosystem of the environment where the samples are taken. In the present study, we analyzed phage DNA obtained from wastewater sample of university hospital sewage. After filtration, long high-speed centrifugation was done to collect phages.

View Article and Find Full Text PDF

Silver is a non-essential metal used in medical applications as an antimicrobial agent, but it is also toxic for biological systems. To investigate the molecular basis of silver resistance in yeast, we employed evolutionary engineering using successive batch cultures at gradually increased silver stress levels up to 0.25-mM AgNO in 29 populations and obtained highly silver-resistant and genetically stable Saccharomyces cerevisiae strains.

View Article and Find Full Text PDF

Chiari malformation type I (CMI) is a brain malformation that is characterized by herniation of the cerebellum into the spinal canal. Chiari malformation type I is highly heterogeneous; therefore, an accurate explanation of the pathogenesis of the disease is often not possible. Although some studies showed the role of genetics in CMI, the involvement of genetic variations in CMI pathogenesis has not been thoroughly elucidated.

View Article and Find Full Text PDF

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and associated with severe respiratory illness emerged in Wuhan, China, in late 2019. The virus has been able to spread promptly across all continents in the world. The current pandemic has posed a great threat to public health concern and safety.

View Article and Find Full Text PDF

Iron plays an essential role in all organisms and is involved in the structure of many biomolecules. It also regulates the Fenton reaction where highly reactive hydroxyl radicals occur. Iron is also important for microbial biodiversity, health and nutrition.

View Article and Find Full Text PDF

Caffeine is a naturally occurring alkaloid, where its major consumption occurs with beverages such as coffee, soft drinks and tea. Despite a variety of reports on the effects of caffeine on diverse organisms including yeast, the complex molecular basis of caffeine resistance and response has yet to be understood. In this study, a caffeine-hyperresistant and genetically stable Saccharomyces cerevisiae mutant was obtained for the first time by evolutionary engineering, using batch selection in the presence of gradually increased caffeine stress levels and without any mutagenesis of the initial population prior to selection.

View Article and Find Full Text PDF

Phenolic inhibitors in lignocellulosic hydrolysates interfere with the performance of fermenting microorganisms. Among these, coniferyl aldehyde is one of the most toxic inhibitors. In this study, genetically stable Saccharomyces cerevisiae mutants with high coniferyl aldehyde resistance were successfully obtained for the first time by using an evolutionary engineering strategy, based on the systematic application of increasing coniferyl aldehyde stress in batch cultures.

View Article and Find Full Text PDF

High-throughput aging studies with yeast as a model organism involve transposon-mutagenesis and yeast knockout collection, which have been pivotal strategies for understanding the complex cellular aging process. In this study, a chronologically long-lived Saccharomyces cerevisiae mutant was successfully obtained by using another high-throughput approach, evolutionary engineering, based on systematic selection in successive batch cultures under gradually increasing levels of caloric restriction. Detailed comparative physiological and transcriptomic analyses of the chronologically long-lived mutant and the reference strain revealed enhanced levels of respiratory metabolism, upregulation of genes related to carbohydrate metabolic processes, glycogen-trehalose pathways, stress response, and repression of protein synthesis-related genes in the long-lived mutant SRM11, already in the absence of caloric restriction.

View Article and Find Full Text PDF