Tomislav Ivanković

University of Zagreb

The production of biogas is achieved during anaerobic digestion (AD) using organic matter as a substrate. In Mediterranean countries, a promising substrate is lignocellulose biomass of perennial grass Miscanthus x giganteus, due to its potentially high biogas yields, which could be comparable to maize silage. During AD, bacteria convert biomass int...

Biogas is mainly produced by anaerobic digestion (AD) using organic matter as a substrate. In Mediterranean countries, a promising substrate is lignocellulose biomass of perennial grass Miscanthus x giganteus, due to its potentially high biogas yields, which could be comparable to maize silage. During AD, bacteria convert biomass into more minor co...

Kako bi se utvrdila promjena obojenja odn. postojanost obojenja, uzorak vegetabilno štavljene kože podvrgnut je močenju u alkalnoj otopini znoja kako bi se izlučio višak tanina i drugih netaninskih tvari koje zbog svoje velike količine unutar stukture kože imaju snažan antimikrobni učinak, te u tom slučaju naknadna obrada nije potrebna. Remisijskim...

Waste, in its various forms, is a big issue worldwide but one that can be tackled [...]

Bacteria Acinetobacter baumannii is a persistent issue in hospital-acquired infections due to its fast and potent development of multi-drug resistance. To address this urgent challenge, a novel biomaterial using silver (Ag +) ions within the hydroxyapatite (HAp) lattice has been developed to prevent infections in orthopedic surgery and bone regener...

Biomimetic calcium phosphate (CaP) systems mono-substituted with zinc (Zn²⁺) and magnesium (Mg²⁺) ions were prepared from a biogenic source (cuttlefish bone) by wet precipitation method. The results revealed that the as-prepared powders were composed of calcium-deficient carbonated hydroxyapatite (HAp), octacalcium phosphate (OCP), and amorphous ca...

Biogas is mainly produced by anaerobic digestion (AD), and in the EU, the widely used substrate for AD is maize silage. Due to a rise in silage prices, the intention is to gradually replace maize with lignocellulose biomass. In the Mediterranean area, the olive industry produces large amounts of lignocellulose wastes, namely olive cake and pruned b...

Wool is considered to possibly exhibit antibacterial properties due to the ability of wool clothing to reduce the build-up of odor, which arises from the microbial activity of skin microbiota. Indeed, when tested with a widely used agar diffusion plate test method, even wool or other textiles not treated with any antimicrobial agent can be interpre...

The bioactive properties of hydroxyapatite (HAp) facilitate bone regeneration, however, its physico-chemical and bioactive properties can be further enhanced by ionic substitutions within the crystalline lattice. In this work, substitution with Sr²⁺ and Ag ⁺ ions was investigated for the improvement of osseointegration and antibacterial activity in...

Characterizing bacterial biofilm growth in porous media is important for developing reliable numerical models of biofouling in industrial biofilters. One of the promising imaging methods to do that has been a recent successful application of X‐ray microtomography. However, this technique requires a contrast agent (1‐chloronaphtalene, for example) t...

Chemical analysis of plasma samples of wild fish from the Sava River (Croatia) revealed the presence of 90 different pharmaceuticals/illicit drugs and their metabolites (PhACs/IDrgs). The concentrations of these PhACs/IDrgs in plasma were 10 to 1000 times higher than their concentrations in river water. Antibiotics, allergy/cold medications and ana...

Here we describe an additional type of bacterial migration in which bacterial cells migrate vertically across a non-nutritive solid surface carried by capillary forces. Unlike standard motility experiments, these were run on a glass slide inserted into a Falcon tube, partly immersed in a nutrient medium and partly exposed to air. Observations revea...

This paper presents the application of conventional potassium aluminium sulphate wool mordanting and a biochemical method with silver nitrate (as antimicrobial agent and mordant), alone and in combination with oxygen plasma, as part of comprehensive research into pretreatment processes for wool dyeing with natural extract from pomegranate peel (Pun...

The purpose of this research was to analyse the influence of a plasma treatment on the surface properties of cellulose-based knitwear, especially on the hydrophilicity of raw cotton material. The influence of oxygen and argon low-pressure plasma pre-treatment was analysed from the aspect of antimicrobial properties as well as in the context of appl...

Hospital wastewaters can become a route for dissemination of antibiotic-resistant bacteria to the environment if not properly treated. Some of these bacteria are able to survive conventional disinfection treatments (e.g. chlorination, UV irradiation), which evokes the need for novel disinfection methods. The metal-exchanged zeolites were tested as...

Acinetobacter baumannii is an opportunistic pathogen causing infections in immunocompromised patients. Recent studies recorded its persistence in a variety of abiotic conditions, but data regarding the biotic interactions with other microorganisms is limited. The aim was to assess the interaction of clinically relevant A. baumannii with common faec...

Bacterium Acinetobacter baumannii is an emergent pathogen associated with nosocomial infections, which can be also found in natural waters. The impact of ecological factors on A. baumannii is insufficiently investigated. The aim was to examine the influence of temperatures (-20 to 80 °C) and pH values (2 to 12) on the survival of environmental and...

The carbapenem-resistant bacteria (CRB) are currently at the top of the WHO priority list of bacteria that pose the greatest threat to human health. Considering that soil is one of the important environments for the emergence of antibiotic-resistant bacteria, we isolated and quantified cultivable CRB in soils across Croatia, including ones affected...

Bacterium Acinetobacter baumannii is an emerging human pathogen whose presence in the aquatic environment raises the issue of public health risk. Fish colonization represents the potential route of pathogen transmission to humans. The aim was to examine the colonization of A. baumannii to freshwater fish Poecilia reticulata. An extensively drug-res...

Wastewater treatment plants have been considered potential sources of antibiotic resistance gene exchange and release into the environment. The aim of our study was to quantify environmental and human-associated carbapenem-resistant bacterial populations (CRBPs) across wastewater treatment stages and correlate bacterial counts to physicochemical an...

The aim of this study was to determine the susceptibility of hospital and environmental Acinetobacter baumannii isolate biofilms on ceramics and glass to common disinfectants benzalkonium chloride and chlorhexidine. For this purpose we developed a new method for biofilm cultivation and quantification on ceramics. The biofilm bacteria were more resi...

Background: Acinetobacter baumannii is a leading emerging pathogen that is frequently recovered from patients during hospital outbreaks. The role of environmental A. baumannii reservoirs is therefore of great concern worldwide. Aim: To investigate the connection between A. baumannii causing hospital outbreaks and environmental isolates from hosp...

The development of a reliable model allowing accurate predictions of biofilm growth in porous media relies on a good knowledge of the temporal evolution of biofilm structure within the porous network. Since little is known about the real 3-D structure of biofilms in porous media, this work was aimed at developing a new experimental protocol to visu...

From the perspective of the lab exercises leader and teaching assistant for the Bioremediation course, it was very difficult to design and conduct a set of exercises that would fit the course curriculum and satisfactorily demonstrate bioremediation basics through practical laboratory work. Thus, Bioremediation course students designed the experimen...

From the perspective of the lab exercises leader and teaching assistant for the Bioremediation course, it was very difficult to design and conduct a set of exercises that would fit the course curriculum and satisfactorily demonstrate bioremediation basics through practical laboratory work. Thus, Bioremediation course students designed the experimen...

Every surface that is immersed in seawater becomes rapidly covered with an unavoidable biofi lm. Such biofi lm formation, also known as fouling, is a complex multi-stage process and not yet thoroughly investigated. In this study, the succession of diatoms and bacteria was investigated during a one month exposure on an artifi cial substrate of plexi...

Abstract Wood fly ash is an industrial by-product of the combustion of different wood materials and is mostly disposed of as waste on landfills. In our preliminary experiments, wood ash exhibited antibacterial activity against urban wastewater bacteria and we focused on wood fly ash as a potential substrate for wastewater disinfection. The addition...

Any natural or artificial substrate that is immersed in seawater is rapidly covered by unavoidable biofouling. Growth of such fouling also known as biofilm formation is complex and not yet thoroughly investigated. Roughly known stages of biofilm generation are: adsorption of organic and inorganic macromolecules; migration of microbial cells to the...

Extreme environmental conditions, such as pH fluctuations, high concentrations of toxicants or grazing of protozoa, can potentially be found in wastewater treatment systems. This study was carried out to provide specific evidence on how 'bioparticles' can resist these conditions. The term 'bioparticle' is used to describe a particle comprising natu...

The antibacterial activity of natural zeolitized tuffs containing 2.60wt.% Cu(2+), 1.47 Zn(2+) or 0.52 Ni(2+) were tested. Antibacterial activities of the zeolites against Escherichia coli and Staphylococcus aureus were tested after 1h and 24h of exposure to 1g of the zeolite in 100mL of three different media, namely Luria Bertani, synthetic wastew...

Sepiolite in its original (OS) and purified form (PS) was tested as a carrier of the phosphate-accumulating bacteria Acinetobacter junii. The numbers of A. junii immobilized onto sepiolite were 5.57 and 8.12 × 109 CFU g− 1 for OS and PS, respectively. The immobilized bacteria were metabolically active and removed phosphate from synthetic wastewater...

Three different forms of perlite (non-expanded, semi-expanded and expanded) were tested as carriers of phosphate-accumulating bacterium Acinetobacter junii. The highest rate of immobilization of A. junii (12.65 × 109 CFU g−1) was obtained for expanded perlite, followed by semi-expanded (5.57 × 109 CFU g−1) and non-expanded (1.68 × 109 CFU g−1) perl...

The goal of this study was to determine the concentrations of Mg, Ca and K ions required for the formation of metabolically active population of phosphate (P)-accumulating bacterium Acinetobacter junii. The availability of Mg, Ca and K originating from natural minerals in the conditions of severe shortage of these cations was tested. In the case of...

Surfactants in the Environment Surfactants are a diverse group of chemicals that are best known for their wide use in detergents and other cleaning products. After use, residual surfactants are discharged into sewage systems or directly into surface waters, and most of them end up dispersed in different environmental compartments such as soil, wate...

The survival of two heterotrophic bacteria in conditions of various concentrations of NaCl was tested. Both bacteria can commonly enter marine environments through sewage or wastewater treatment plant effluents; the Escherichia coli is a common enteric bacterium and Acinetobacter junii is a phosphate-accumulating bacterium inhabiting activated slud...

The aim of this study was to determine the potential of phosphate (P) removal from wastewater by biosolids prepared by the immobilization of P-accumulating bacteria onto organic bentonite. Organic bentonite was prepared by treating bentonite clay with quaternary ammonium salt — cetyltrimetylammonium (CTA) bromide. Cation exchange capacity (CEC) of...

The toxicity of twelve commercial surfactants to phosphate-accumulating bacterium Acinetobacter junii was tested. The tested products were selected to cover a variety of surfactant types and classes (anionic, cationic, amphoteric and nonio- nic). One surfactant proved to be highly toxic (EC50 < 1 mg L -1 ), six surfactants were toxic (EC50 values b...

The goal of this study was to determine the dynamics and yield of immobilization of the phosphate-accumulating bacterium Acinetobacter junii on mineral carriers. As mineral carriers natural clinoptilolite tuff from Turkey (T) and Serbia (S) and natural bentonite (TER), in original and magnesium (Mg)-exchanged form were used. The key feature which d...

The antibacterial effect of cationic surfactants against the pure culture of phosphate (P)-accumulating bacterium Acinetobacter junii was investigated. The estimated EC50 values of the N-dodecylpyridinium chloride (DPC) for growth inhibition was 1.4±0.5 × 10−6 mol L−1 and for the inhibition of the P-uptake rates 7.3±2.6 × 10−5 mol L−1. The estimate...

The harmful effects of surfactants to the environment are well known. We were interested in investigating their potential toxicity in a pure culture of Acinetobacter junii, a phosphate (P)-accumulating bacterium. Results showed a high acute toxicity of sodium dodecyl sulfate (SDS) and hexadecyltrimethylammonium bromide (HDTMA) against A. junii. The...

This paper describes formal model of the MBMS (multimedia broadcast/multicast service) support in UMTS (universal mobile telecommunication system). The formal model is based on the reference architecture and implementation suggestion, which was proposed by 3GPP (third generation partnership project) specification TS23.246. The main goal was to buil...

First Page of the Article