Dariusz Dziga

Dariusz Dziga
Jagiellonian University | UJ · Laboratory of Metabolomics

PhD

About

45
Publications
8,436
Reads
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937
Citations
Citations since 2017
17 Research Items
568 Citations
2017201820192020202120222023020406080100120
2017201820192020202120222023020406080100120
2017201820192020202120222023020406080100120
2017201820192020202120222023020406080100120
Additional affiliations
November 2001 - present
Jagiellonian University
Position
  • assistant lecture

Publications

Publications (45)
Article
Full-text available
Cyanobacteria play a significant role in ecosystem functioning as photosynthetic and CO2 fixing microorganisms. Whether and to what extent cyanophages alter these carbon and energy cycles in their cyanobacterial hosts is still poorly understood. In this study, we investigated changes in photosynthetic activity (PSII), expression of genes associated...
Article
Full-text available
Background Excess loads of nutrients finding their way into waterbodies can cause rapid and excessive growth of phytoplankton species and lead to the formation of cyanobacterial harmful algal blooms (cyano-HABs). Toxic cyanobacteria produce a broad range of bioactive metabolites, some of which are known as cyanotoxins. These metabolites can negativ...
Article
Full-text available
Bacterioplankton community composition has become the center of research attention in recent years. Bacteria associated with toxic cyanobacteria blooms have attracted considerable interest. However, little is known about the environmental factors driving the bacteria community, including the impact of invasive cyanobacteria. Therefore, our aim has...
Article
Full-text available
Senescence is the final stage of plant development, affecting individual organs or the whole organism, and it can be induced by several environmental factors, including shading or darkness. Although inevitable, senescence is a complex and tightly regulated process, ensuring optimal remobilization of nutrients and cellular components from senescing...
Preprint
Full-text available
Background: Cyanobacteria are phytoplankton microorganisms, also known as blue-green algae, and an essential component of the food web in all aquatic ecosystems. Excess loads of nutrients into waterbodies can cause their rapid and excessive growth which leads to the formation of cyanobacterial harmful algal blooms (cyano-HABs). Toxic species of cya...
Article
Full-text available
In their life cycle, plants are exposed to various unfavorable environmental factors including ultraviolet (UV) radiation emitted by the Sun. UV-A and UV-B, which are partially absorbed by the ozone layer, reach the surface of the Earth causing harmful effects among the others on plant genetic material. The energy of UV light is sufficient to induc...
Article
Microcystinase (MlrA) was first described in 1996. Since then MlrA peptidase activity has proven to be both the most efficient enzymatic process and the most specific catalyst of all known microcystins detox-ification pathways. Furthermore, MlrA and the MlrABC degradation pathway are presently the only en-zymatic processes with clear genetic and bi...
Article
Full-text available
Although solar light is indispensable for the functioning of plants, this environmental factor may also cause damage to living cells. Apart from the visible range, including wavelengths used in photosynthesis, the ultraviolet (UV) light present in solar irradiation reaches the Earth's surface. The high energy of UV causes damage to many cellular co...
Chapter
Microbial degradation of cyanotoxins in the natural environment is a known phenomenon. Such biodegradation could be also an alternative method of cyanotoxins elimination in water reservoirs and during drinking water treatment. In this chapter, comprehensive information regarding the biodegradation of cyanotoxins is provided and involves: descriptio...
Chapter
Biological and advanced chemical treatment of cyanotoxins and other cyanobacteria‐related contaminants such as taste and odor compounds, results in the formation of myriad transformation products (TPs) prior to their mineralization to simpler compounds such as H2O and CO2. This chapter gives an overview of the TPs formed for the major groups of cya...
Article
Full-text available
R. raciborskii is known for growing under wide ranges of temperature and light. In temperate regions, however, low temperature and high light may serve as a stressful condition for invading tropical populations. The genetic basis of R. raciborskii's adaptation to this combination of stresses are unknown. In this study, the growth rate and the expre...
Article
Full-text available
Harmful cyanobacteria and their toxic metabolites constitute a big challenge for the production of safe drinking water. Microcystins (MC), chemically stable hepatotoxic heptapeptides, have often been involved in cyanobacterial poisoning incidents. A desirable solution for cyanobacterial management in lakes and ponds would eliminate both excess cyan...
Article
Microcystins produced by several toxic cyanobacterial strains constitute an important problem for public health. Bacterial degradation of these hepatotoxins may play an important role in natural ecosystems, however the nature of the process is very poorly understood. The aim of our study was to investigate the possible interactions between cyanotox...
Article
Full-text available
Under some conditions the growth of toxic cyanobacteria must be controlled by treatment with algicidal compounds. Hydrogen peroxide has been proposed as an efficient and relatively safe chemical which can remove cyanobacteria from the environment selectively, without affecting other microorganisms. However, the uncontrolled release of secondary met...
Article
In this report, we establish proof-of-principle demonstrating for the first time genetic engineering of a photoautotrophic microorganism for bioremediation of naturally occurring cyanotoxins. In model cyanobacterium Synechocystis sp. PCC 6803 we have heterologously expressed Sphingopyxis sp. USTB-05 microcystinase (MlrA) bearing a 23 amino acid N-t...
Article
Cyanobacterial blooms and cyanotoxins occur in freshwater lakes and reservoirs all over the world. Bacterial degradation of microcystins (MC), hepatotoxins produced by several cyanobacterial species, has also been broadly documented. However, information regarding MC biodegradation in European water bodies is very limited. In this paper, the occurr...
Article
Full-text available
Bacterial degradation of toxic microcystins produced by cyanobacteria is a common phenomenon. However, our understanding of the mechanisms of these processes is rudimentary. In this paper several novel discoveries regarding the action of the enzymes of the mlr cluster responsible for microcystin biodegradation are presented using recombinant protei...
Article
Full-text available
The occurrence of the cyanobacterial toxin cylindrospermopsin (CYN) in freshwater reservoirs is a common phenomenon. However, the biodegradation of this toxin in environmental samples has been observed only occasionally. In this work the biodegradation ability of cylindrospermopsin was investigated based on isolates from lakes with previous cyanoto...
Article
Full-text available
Cellulose is a major component of plant biomass and could be applied in the production of biofuels, especially bioethanol. An alternative approach is production of a clean fuel - hydrogen from cellulosic biomass. In this paper an innovatory model of cellulosic waste degradation has been proposed to verify the possibility of utilization of cellulose...
Article
Full-text available
An important aim of white (grey) biotechnology is bioremediation, where microbes are employed to remove unwanted chemicals. Microcystins (MCs) and other cyanobacterial toxins are not industrial or agricultural pollutants; however, their occurrence as a consequence of human activity and water reservoir eutrophication is regarded as anthropogenic. Mi...
Article
Full-text available
Microcystins (MCs), cyclic heptapeptides produced by cyanobacteria constitute a significant risk to humans. Several bacteria with MCs degradation capability are known, however their practical usage is questionable due to low MC elimination efficiency. As an alternative bacteria with significantly enhanced activity toward these hepatotoxins may be c...
Article
Oral treatment with maltol or bis(maltolato)oxovanadi- um(IV) [BMOV] alters the biochemical activity of the rat liver Golgi marker enzyme, i.e., galactosyltrans- ferase (GalT), and the organelle morphology in a relatively short time. Four groups of rats were investigated: control (C), treated with BMOV for 2 days (pVC), treated with BMOV for 7 days...
Article
Full-text available
Hepatotoxic microcystins that are produced by freshwater cyanobacteria pose a risk to public health. These compounds may be eliminated by enzymatic degradation. Here, we review the enzymatic pathways for the degradation of these hepatotoxins, some of which are newly discovered processes. The efficiencies of microcystin biodegradation pathways are d...
Article
The MlrC protein from Sphingomonas ACM-3962 strain was heterologously expressed in Escherichia coli strain BL21(DE3) and purified to investigate participation of this enzyme in the biodegradation of two microcystin variants. In contrast with previous reports, our results indicated that MlrC cleaves linear microcystins, thus shedding new light on th...
Article
Full-text available
The first enzyme in the microcystin (MC) degradation pathway identified in bacterial strains is coded by mlrA gene and is referred to as microcystinase. To date, there has been no biochemical characterisation of this enzyme. The results presented herein show a successful heterologous expression of MlrA as well as mutational studies, partial purific...
Article
Full-text available
Toxic cyanobacteria have been reported in lakes and reservoirs in several countries. The presence of toxins in drinking water creates a potential risk of toxin transference for water consumers. Besides chemical and physical methods of cyanotoxin removal from water, biodegradation methods would be useful. The aim of the current study was to identify...
Article
Several cyanobacterial species have a high potential to dominate in marine environments and freshwater reservoirs, and the ecological and physiological reasons for this phenomenon are not understood comprehensively. In this study, the ability of a Microcystis aeruginosa Kütz. strain to produce free dissolved enzymes was documented. We have observed...
Article
Cyanobacterial dominance in eutrophic lakes causes water quality problems due to the production of toxins harmful to humans and animals, as well as a number of odorous compounds. Cylindrospermopsin (CYN) is a potent cytotoxic cyanobacterial metabolite involved in triggering illness in humans. The occurrence of CYN has been mostly associated with tr...
Article
Cylindrospermopsin (CYN) is a cyanobacterial alkaloid that has been implicated in outbreaks of human morbidity and animal mortality. The principal mode of action for CYN is inhibition of protein and glutathione synthesis, and its toxicity seems to be mediated by cytochrome P-450-generated metabolites. It was also shown that CYN might be responsible...
Article
Plant-producing phenols could strongly inhibit the growth of toxic cyanobacteria genera, but the ecological consequences of this action are still unknown. In this work, the activity of selected phenols in relation to the strain Microcystis aeruginosa was investigated. We have found that the mechanism of the growth inhibition could involve both the...
Article
We investigated the activity of liverwort Riccia fluitans against the toxic cyanobacteria strain Microcystis aeruginosa. The incubation of homogenized tissues of R. fluitans inhibited the growth of M. aeruginosa. This inhibition was associated with decrease in the microcystin-LR concentration in the environment. These results suggest that biotransf...
Article
Full-text available
This article presents the effects of nitrate/ammonium ( NO(3)(-)/NH(4)(+)), applied at different proportions to the root media with or without 5 mmol bicarbonate ( HCO(3)(-)), on the yield and chemical composition of tomato fruit. Tomato plants were grown hydroponically ( pH 6.9) in glasshouse conditions. The yield of fruit fresh matter from four c...
Article
Microcystin-LR (MC-LR), a potent inhibitor of PP1 and PP2A protein phosphatases, is related to tumor promotion and initiation. Although the genotoxic properties of this toxin have been extensively investigated with a variety of non-mammalian and mammalian test systems, the existing results are contradictory. Based on our previous results regarding...
Article
Full-text available
The genotoxic activity of microcystin-LR (MC-LR) is a matter of debate. MC-LR is known to be a phosphatase inhibitor and it may be expected that it is involved in the regulation of the activity of DNA-dependent protein kinase (DNA-PK), the key enzyme involved in the repair of radiation-induced DNA damage. We studied the effect of MC-LR on the repai...
Article
Tomato plants were cultivated (from 2 to 23 days after germination) in media with NO 3 − , NH 4 + , or a mixture of both forms in different proportions used as the N source given with or without 5 mol dm−3 HCO 3 − . The accumulation of soluble sugars (reducing sugars and sucrose) and free amino acids was higher in the roots and leaves of NH 4 + -fe...
Article
The results of the experiments discussed here present changes in the chemical composition of xylem sap of tomato seedlings cultivated in hydroponics on media containing 5 mmol HCO3- and an N-source given as NO3-, NH4+ or these two forms in different proportions. The occurrence of free NH4+ in the xylem sap of NH4+-seedlings and in NO3--seedlings in...
Article
Twenty years ago, we detected the interdependence between structure and function of rat liver Golgi complexes that are characteristic for streptozotocin diabetes, which served us in further investigations as a useful indicator of the effectiveness of drugs we were testing. This work presented results obtained in eight groups of rats (four control a...
Article
Full-text available
The Fenton reagent was applied to decompose microcystin-LR. The reaction was studied using chromatographic and mass spectrometric techniques. Several suggestions concerning the mechanism could be retrieved from the results. The complete disappearance of toxicity was already observed after 30 min of reaction and the reaction products were found to b...
Article
The activity of galactosyltransferase (GalT), the Golgi apparatus marker enzyme, together with the morphology of this organelle in rat liver, are so characteristic that we have used them for twenty years as a test of streptozotocin-diabetes, and of the efficacy of different drugs. Bis(maltolato)oxovanadium(IV) (BMOV), an oral vanadium complex with...
Article
Oral treatment with maltol or bis(maltolato)oxovanadium(IV) [BMOV] alters the biochemical activity of the rat liver Golgi marker enzyme, i.e., galactosyltransferase (GalT), and the organelle morphology in a relatively short time. Four groups of rats were investigated: control (C), treated with BMOV for 2 days (pVC), treated with BMOV for 7 days (C+...
Article
The relation between bis(maltolato)oxovanadium(IV) (BMOV) influencing the biochemical activity of rat liver Golgi apparatus and the morphology of this organelle was studied in normal and streptozotocin-diabetic rat livers. Ultrastructural examinations revealed marked differences in the morphology of Golgi apparatus in three groups of animals. In th...

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Projects (3)
Project
Cyanophages maintain the vital functions of their hosts by introducing a number of rearrangements in metabolic processes. The aim of this project is to characterize physiological, biochemical, transcriptomic and proteomic changes in the course of a viral infection.
Project
This study aims to provide understanding of the adaptive potential of R. raciborskii and other bloom-forming cyanobacteria in terms of flexible physiology and new gene acquisition. Poland lies on the boundary of R. raciborskii’s current habitat range and thus represents the most extreme environment that R. raciborskii can inhabit. Phylogeography suggests that these strains have migrated from Australia, so strains from this region represent the ancestral state. Therefore, comparing strains from these two continents is relevant. The question to be answered is how the R. raciborskii strains adapt to given environmental conditions and how such conditions can influence their invasive character. Thus, the aim of the project is to investigate comprehensively the adaptation mechanisms of this cyanobacterium, including genetic, biochemical, physiological and environmental backgrounds. Preliminary research indicated that several genes of the Polish strain AMU-DH-30 have been up-regulated in the chill/light stress, whereas the CS 505 strain from Australia has not expressed such a response (Antosiak et al., 2020). The project (carried out in cooperation with M. Kokociński from UAM, Poland and Anusuya Willis, Australian National Algae Culture Collection, Australia), combines a set of laboratory-based experiments and a field sampling campaign as well as chemical, morphological and next generation RNA sequencing analyses supplemented by sophisticated physiological analyses. By bringing together the data from both parts of the project and their critical verification, the study will provide insights into how R. raciborskii strains manage under the chill/light stress. This is important for fundamental understanding of the functioning of this important part of microbial community and for practical applications of risk assessment and management of harmful freshwater cyanobacterial blooms.
Project
A molecular and biochemical characterisation of the enzymes involved in hepatotoxic cyanopeptide (microcystin - MC) biodegradation was performed in our laboratory by recombinant protein synthesis (Dziga et al, 2012 and Dexter et al., 2021). The subsequent steps of MC hydrolysis and their derivatives were significantly extended and a new scheme of MC biodegradation was proposed. The documented activity of Mlr proteins sheds new light on the specificity of these enzymes and their actual role in complete MC utilization. We have recently focused on the MlrA expression in autotrophic hosts. The production of MlrA (microcystinase that detoxifies cyanotoxin microcystins) in cyanobacterial chassis constitutes a focal point for exploration and development of cyanobacterial synthetic biology. In a paper of Dexter et al. (2018) successful MlrA expression in Synechocystis PCC 6802 was documented. A collaboration with McCormick lab was established to extend our project for better understanding of heterologous protein production in cyanobacterial chassis. The final aim is heterologous production of an industrially relevant enzyme via photoautotrophic biomass from wastewaters. Such a product (MlrA) may be utilized as an alternative/complementary factor in cyanobacterial management in lakes and ponds which would eliminate both excess cyanobacteria and hepatotoxic microcystins which they potentially produce and release upon lysis. Hydrogen peroxide (HP) has recently been advocated as an efficient means of lysing cyanobacteria in lakes and ponds, however it cannot degrade microcystins efficiently. We showed that the combined use of HP and MlrA is promising in the elimination of both excess cyanobacteria and their hepatotoxic heptapeptide in environmental waters (Dziga et al., 2019).