DYNAMICS OF OLIGOTROPHIC AND COPIOTROPHIC BACTERIA IN RELATION TO EARTHWORM SPECIES (Eisenia fetida)

Provedeno je mikrokozmičko istraživanje utjecaja gujavica vrste Eisenia fetida na brojnost kopiotrofnih i oligotrofnihbakterija u tlu tijekom razdoblja od šest mjeseci. Gujavice su važan element makrofaune tla koji svojim djelovanjem poboljšava svojstva tla, te povećava brojnost i aktivnost bakterija. Koristeći koncept oligotrofije-kopiotrofije nastojao sepovezati, gujavicama potaknut, efekt transformacije organske tvari u raspoloživi oblik s porastom broja bakterija, odnosnopromjenom omjera kopiotrofnih i oligotrofnih bakterija. Formirano je četiri vrste mikrokozmosa (tretmana): sterilizirano tlo s gujavicama, sterilizirano tlo bez gujavica, nesterilizirano tlo s gujavicama i nesterilizirano tlo bez gujavica. Analize su vršene svakih 28 dana, a obuhvatile su mjerenja fizikalno-kemijskih parametara tla i broja bakterija iz tla i probavila gujavica. Zabilježen je značajan pozitivan utjecaj gujavica na broj kopiotrofnih bakterija, te negativan utjecaj na broj oligotrofnih bakterija. U steriliziranom tlu njihov utjecaj je bio isti i na kopiotrofne i na oligotrofne bakterije. Kod te vrste tretmana gujavice su dovele do ranije uspostave zajednice kopiotrofnih, ali i oligotrofnih bakterija, u odnosu na kontrolna tla.Omjer kopiotrofnih i oligotrofnih bakterija je u svim tretmanima ukazivao na dominaciju oligotrofa. Nisu zabilježene značajnije oscilacije omjera osim u nesteriliziranom tlu s gujavicama, gdje su kopiotrofi krajem istraživanja nakratko preuzeli dominaciju.A microcosm study was used to assess the earthworm Eisenia fetida influence on soil copiotrophic and oligotrophic bacteria during the six month period. Earthworms as an important part of soil macrofauna can improve soil properties and increasebacterial abundance and activity. The goal was to link earthworm mediated transformation of soil organic mater within creased bacterial growth by applying oligotrophy-copiotrophy concept. Four types of microcosm (treatmans) were formed:sterilized soil with earthworms, sterilized soil without earthworms, non-sterilized soil with earthworms, and non-sterilized soil without earthworms. Analysis of soil physical-chemical properties and bacterial number from soil and earthworm gut were conducted every 28 days. In non-sterilized treatment, earthworms yielded positive effect on number of copiotrophic bacteria, and negative on number of oligotrophic bacteria. Presence of earthworms caused earlier establishment of bothcopiotrophic and oligotrophic bacterial communities in sterilized soil. The ratio of copiotrophic to oligotrophic bacteria indicated dominance of oligotrophic bacteria in all treatments. There were no significant oscillations in the ratio, except in non-sterilized soil with earthworms where copiotrophs were briefly dominant towards the end of the experiment

DYNAMICS OF OLIGOTROPHIC AND COPIOTROPHIC BACTERIA IN RELATION TO EARTHWORM SPECIES (Eisenia fetida)

Provedeno je mikrokozmičko istraživanje utjecaja gujavica vrste Eisenia fetida na brojnost kopiotrofnih i oligotrofnihbakterija u tlu tijekom razdoblja od šest mjeseci. Gujavice su važan element makrofaune tla koji svojim djelovanjem poboljšava svojstva tla, te povećava brojnost i aktivnost bakterija. Koristeći koncept oligotrofije-kopiotrofije nastojao sepovezati, gujavicama potaknut, efekt transformacije organske tvari u raspoloživi oblik s porastom broja bakterija, odnosnopromjenom omjera kopiotrofnih i oligotrofnih bakterija. Formirano je četiri vrste mikrokozmosa (tretmana): sterilizirano tlo s gujavicama, sterilizirano tlo bez gujavica, nesterilizirano tlo s gujavicama i nesterilizirano tlo bez gujavica. Analize su vršene svakih 28 dana, a obuhvatile su mjerenja fizikalno-kemijskih parametara tla i broja bakterija iz tla i probavila gujavica. Zabilježen je značajan pozitivan utjecaj gujavica na broj kopiotrofnih bakterija, te negativan utjecaj na broj oligotrofnih bakterija. U steriliziranom tlu njihov utjecaj je bio isti i na kopiotrofne i na oligotrofne bakterije. Kod te vrste tretmana gujavice su dovele do ranije uspostave zajednice kopiotrofnih, ali i oligotrofnih bakterija, u odnosu na kontrolna tla.Omjer kopiotrofnih i oligotrofnih bakterija je u svim tretmanima ukazivao na dominaciju oligotrofa. Nisu zabilježene značajnije oscilacije omjera osim u nesteriliziranom tlu s gujavicama, gdje su kopiotrofi krajem istraživanja nakratko preuzeli dominaciju.A microcosm study was used to assess the earthworm Eisenia fetida influence on soil copiotrophic and oligotrophic bacteria during the six month period. Earthworms as an important part of soil macrofauna can improve soil properties and increasebacterial abundance and activity. The goal was to link earthworm mediated transformation of soil organic mater within creased bacterial growth by applying oligotrophy-copiotrophy concept. Four types of microcosm (treatmans) were formed:sterilized soil with earthworms, sterilized soil without earthworms, non-sterilized soil with earthworms, and non-sterilized soil without earthworms. Analysis of soil physical-chemical properties and bacterial number from soil and earthworm gut were conducted every 28 days. In non-sterilized treatment, earthworms yielded positive effect on number of copiotrophic bacteria, and negative on number of oligotrophic bacteria. Presence of earthworms caused earlier establishment of bothcopiotrophic and oligotrophic bacterial communities in sterilized soil. The ratio of copiotrophic to oligotrophic bacteria indicated dominance of oligotrophic bacteria in all treatments. There were no significant oscillations in the ratio, except in non-sterilized soil with earthworms where copiotrophs were briefly dominant towards the end of the experiment

Evaluation of chemical status of Kopački rit surface water bodies through analysis of selected heavy metals through one-year period

Močvarni ekosustavi predstavljaju najproduktivnije ekosustave na Zemlji. Zbog izmjene suhe i vlažne faze osiguravaju raznolikost ekoloških uvjeta na istom staništu te podržavaju veliku bioraznolikost flore i faune. Dinamika plavljenja Kopačkog rita posljedica je njegovog geografskog smještaja na području ušća Drave u Dunav. Kemijsko stanje površinske vode utvrđuje se na temelju prosječne (PGK) i maksimalne godišnje koncentracije (MGK). Teški metali ubrajaju se u grupu najopasnijih anorganskih onečišćujućih tvari zbog bionerazgradivosti, bioakumulacije i zbog ugradnje u hranidbene mreže. Otopljeni u vodi nalaze se u ionskom obliku i ne mogu se biološki razgraditi, ali se mogu bioakumulirati. U sklopu projekta Naturavita na području Kopačkog rita provedeno je uzorkovanje i analiza žive, nikla, kadmija i olova te njihovih spojeva na 19 postaja kroz jednogodišnji period od 12 ciklusa. Prema rezultatima, za sve mjerne postaje izmjerene prosječne (PGK) i maksimalne godišnje koncentracije (MGK) ne prelaze SKVO iz Uredbe o standardu kakvoće vode (NN 96/2019) te je na svim postajama postignuto dobro kemijsko stanje.Wetlands are the most productive ecosystems on Earth. Due to the undergoing wet – dry cycles, they ensure the diversity of ecological conditions and support high biodiversity. The dynamics of the Kopački rit floodplain water regime is a consequence of its geographical location in the area of the Drava – Danube confluence. The chemical status of surface water is based on the annual average concentrations (AAC) of the substances and on the maximum annual concentration (MAC). Heavy metals are among the most dangerous inorganic pollutants due to biodegradability, bioaccumulation, toxicity and due to incorporation into food chains. Dissolved in water, they are in ionic form and non-biodegradable and tend to accumulate in living things in the process of bioaccumulation. As part of the Naturavita project in the Nature Park Kopački rit, sampling and analysis of mercury, nickel, cadmium, lead and their compounds were carried out at 19 locations through one-year period of 12 field survey cycles. According to the obtained results, at all sampling locations, the measured average (AAC) and maximum annual concentrations (MAC) do not exceed allowable concentration according to Regulation on water quality standard (OG 96/2019). Good chemical status has been achieved at all sampling locations

Ružička days : International conference 19th Ružička Days “Today Science – Tomorrow Industry” : Proceedings

Dear colleagues, we are extremely honoured to present to you the Proceedings of the international conference 19th Ružička Days, which was successfully held on September 21–23, 2022, in Vukovar, Croatia, in the hometown town of our famous Croatian scientist and first Nobel laureate, professor Leopold (Lavoslav) Ružička. The main goals of the Conference were to promote excellence, originality and innovation of interdisciplinary scientific research as well as the practical application of the obtained results through collaboration with industry, emphasizing thus the recognizable slogan of the Ružička Days conference: "Today Science – Tomorrow Industry". In addition, the Conference gave the opportunity for meetings, exchanging the ideas, opinions, experiences and cooperation among participants from different working surroundings. It is also important to point out that since 2008, within the international conference Ružička Days, Meeting of Young Chemists has also been held, where high school students, with the help of their mentors, present papers in the field of chemistry, with the aim to direct students and young people to the technical and natural sciences, especially chemistry. In its seventh issue (2011, 2013, 2015, 2017, 2019, 2021) the Proceedings publishes scientific and professional full papers of high quality in the following sections: Chemical analysis and synthesis (10), Chemical and biochemical engineering (3), Food technology and biotechnology (4), Chemistry in agriculture and forestry (1), Environmental protection (9) and 8th Meeting of Young Chemists (3). Full-length papers were subjected to an international review procedure done by eminent experts from the corresponding fields, to whom we express our gratitude, but they were not subjected to linguistic proofreading. On behalf of the Scientific and Organizing Committee of the 19th Ružička Days we cordially thank all the authors, reviewers, participants, lecturers, organizers, especially the international organizers EuCheMS and EHEDG, auspices and sponsors, and all the others who, in any way, supported the Conference and contributed to the preparation of the Proceedings, especially to our highly skilled and committed associates, who have put a lot of effort in the preparation of these Proceedings. At the very end, special thanks to our young, future scientists and their mentors who are faithful participants of the Meeting of Young Chemists of the Ružička Days conference. Enjoy the extremely interesting scientific and professional papers contained in these Proceedings, until the next 20th jubilee of Ružička Days in 2024! We are looking forward to meeting you again in Vukovar! Yours sincerely, Chief Editors Jurislav Babić Vesna Ocelić Bulatović Dajana Kučić Grgi