Diversity of aerophytic cyanobacteria and algae in biofilm from selected caves in Serbia

Predmet ove doktorste disertacije je analiza zajednice aerofitskih cijanobakterija i algi iz biofilma sa stenovitog supstrata ulaza petnaest odabranih pećina iz Srbije kao i nekoliko tačaka u blizini veštačkog osvetljenja. Akcenat istraživanja bio je na fototrofnim mikroorganizmima iz biofilma, dok su kao dodatak endolitski predstavnici identifikovani iz nekoliko uzoraka stene. Analizirana je i morfologija, stepen razvijenosti biofilma, kao i udeo sadržaja vode, organske i neorganske materije u biofilmu. U svim pećinama, mereni su ekološki parametri i određene su primarna produkcija (preko koncentracije hlorofila a) i petrografska analiza stenovitog supstrata. Na odabranim uzorcima rađena je kvantitativna i sezonska analiza cijanobakterija i algi. Statističke analize su poslužile kao alat za sagledavanje odnosa zabeleženih fototrofnih mikroorganizama i različitih ekoloških i opisnih parametara. Zabeleženo je prisustvo ukupno 290 taksona cijanobakterija i algi koje su svrstane u 4 razdela: Cyanobacteria (134 taksona, od kojih 82 taksona pripada kokoidnim formama), Bacillariophyta (129 taksona), Chlorophyta (26 taksona) i Xanthophyta (1 takson). Najveći broj taksona Cyanobacteria zabeležen je u rodovima Gloeocapsa, Chroococcus, Gloeothece, Leptolyngbya i Scytonema. U razdelu Bacillariophyta se izdvajaju rodovi Luticola i Humidophila, a u razdelu Chlorophyta rod Cosmarium. Iz biofilma Božanine pećine opisana je nova vrsta cijanobakterije za nauku, Nephrococcus serbicus S. Popović, G. Subakov Simić i J. Komárek, sp. nov. pri čemu je sam rod po prvi put zabeležen na teritoriji Evrope. Cyanobacteria po broju taksona dominiraju na svim lokalitetima, osim Rćanske i Bogovinske pećine. Najveći broj pripadnika Bacillariophyta i Chlorophyta zabeležen je u Rćanskoj (usled prisustva vode na biofilmu) i pećini Samar (zbog sezonskog uzorkovanja). Upravo se značaj sezonskog uzorkovanja biofilma u pećinama Samar i Jezava pre svega ogleda kroz znatno veći diverzitet aerofitskih cijanobakterija i algi u odnosu na druge pećine. Predstavnici Cyanobacteria dominirali su u pećinama čiji je supstrat rekristalisali i organogeni krečnjak, a Bacillariophyta na klastičnom i mikritskom krečnjaku...The aim of this PhD thesis is the analysis of the aerophytic cyanobacterial and algal community from biofilm developed on stone substrate at the entrance of fifteen selected caves from Serbia and several sites near the artificial light in caves. The focus of the study was on phototrophic microorganisms from the biofilm, while endolithic representatives were additionaly identified from several stone samples. Morphology, degree of biofilm development, as well as the content of water, organic and inorganic matter in biofilm were also observed. At all sampling sites, ecological parameters, primary production (through concentration of chlorophyll a), as well as petrographic analysis of rocky substrates were measured and determined. Quantitative and seasonal analyzes of cyanobacteria and algae were assessed in selected samples. Statistical analyzes have served as a tool for examining the relationship between recorded phototrophic microorganisms and various ecological and descriptive parameters. A total of 290 cyanobacterial and algal taxa were recorded and classified into 4 divisions: Cyanobacteria (134 taxa, of which 82 taxa belong to the coccoid forms), Bacillariophyta (129 taxa), Chlorophyta (26 taxa) and Xanthophyta (1 taxon). The highest number of cyanobacterial taxa was documented within the following genera: Gloeocapsa, Chroococcus, Gloeothece, Leptolyngbya and Scytonema. Luticola and Humidophila were the most diverse genera within Bacillariophyta division, while in Chlorophyta Cosmarium had the highest number of species. A new cyanobacterial taxon, Nephrococcus serbicus S. Popović, G. Subakov Simić & J. Komárek, sp. nov., was described from a biofilm sample of Božana Cave. This also represents the first record of the genus Nephrococcus in Europe. Cyanobacteria were dominant in all caves, except Rćanska and Bogovinska cave. The largest number of Bacillariophyta and Chlorophyta was recorded in the Rćanska cave (due to the presence of water on samplins sites) and in the Samar Cave (due to seasonal sampling). The significance of the seasonal biofilm sampling in Samar and Jezava caves is primarily reflected through the higher diversity of aerophytic cyanobacteria and algae in comparison to other caves..

The application of benthic diatoms in water quality assessment (Mlava River, Serbia)

The main objective of this study was to assess the ecological status of the Mlava River based on epilithic diatoms and to test the use of diatom indices as a tool for estimating the quality of flowing waters in Serbia. Quantitative analysis showed that in April Achnanthidium minutissimum was dominant at each site, except at the fi fth site, where Amphora pediculus was dominant. In July and September, Achnanthidium minutissimum, Achnanthidium pyrenaicum, Amphora pediculus, Denticula tenuis, Diatoma vulgaris, Gomphonema elegantissimum, Cocconeis pseudolineata and Cocconeis placentula var. lineata dominated. Detrended correspondence analysis (DCA) was used to detect the major patterns of variation in species composition. The first DCA axis summarizes the distribution of the diatom community, mainly through temperature, conductivity, oxygen and water hardness gradient. The second DCA axis was weakly correlated with few variables. Based on the average values of the pollution sensitivity index (IPS), commission for economical community metric (CEE) and biological diatom index (IBD), the water of the Mlava River belonged to water class I during all three seasons. Values of the diatom-based eutrophication/pollution index (EPI-D) indicated class II water quality. According to calculated trophic diatom index (TDI) values, water of the Mlava River was characterized by intermediate nutrient concentrations during three seasons. Principal components analysis was used to represent the correlation between diatom indices, and the highest correlation among the selected diatom indices is seen between EPI-D, IPS and IBD

Physicochemical and sensory characteristics of promising plum (Prunus domestica L.) genotypes bred at fruit research institute, Čačak

Five plum hybrids (38/62/70, IV/63/81, 32/21/87, 34/41/87 and 22/17/87) and newly released cultivar ‘Nada’, obtained by planned hybridisation and singled out within breeding programme at Fruit Research Institute, Čačak, were assessed for the main physical (fruit and stone weight and flesh percentage), chemical (soluble solids content, total and inverted sugars content, sucrose content, total acids content, pH value of fruit juice, ratio of soluble solids and total acids content and ratio of total sugars and total acids content) and sensorial (attractiveness, taste, aroma and consistency) traits compared with the standard cultivar ʻČačanska Lepoticaʼ. Results showed that the studied plum genotypes differed significantly in all of the assessed traits. Regarding the physical features, the best results were shown by hybrid 38/62/70, which had the highest fruit weight (56.92 g) and flesh percentage (96.91%), as well as by the new cultivar ‘Nada’, for which a larger fruit was observed in comparison to the standard (45.54 g and 42.24 g, respectively). Also, ‘Nada’ had better sensorial properties such as attractiveness, taste, aroma and consistency in relation to the other promising hybrids and the standard cultivar. From the aspect of all the studied sensorial characteristics, in addition to ‘Nada’, only hybrid 38/62/70 was aligned with the standard cultivar. Out of the studied genotypes, late ripening hybrid 22/17/87 had the best values of parameters of fruit chemical composition such as the soluble solids content (17.01%), total and inverted sugars contents (12.31% and 8.96%, respectively). The highest sucrose content (3.39%), pH value of fruit juice (3.51), as well as the highest ratio between soluble solids and total acids content (43.72) and ratio between total sugars and total acids content (32.58) were found in cultivar ‘Nada’. The highest total acids content (1.42%) was recorded in hybrid 32/21/87. Compared to ʻČačanska Lepoticaʼ, the same or better results in terms of the fruit chemical composition were determined in cultivar ‘Nada’ and hybrids 34/41/87 and 22/17/87. The study revealed existence of significant correlations between individual studied parameters of the fruit physical, chemical and sensorial properties

Цијанобактерије и алге из биофилма са улазне зоне Петничке пећине

The importance of biofilms in caves, the diversity of microorganisms in them, their mutual relationship and relationship with the substratum are among the advancing research topics in microbial biospeleology. This research is making contribution to the knowledge about biofilms at cave entrances and phototrophic communities in them. In that manner, biofilms from the entrance zone of the Petnica Cave were examined. Light microscopy showed that cyanobacteria were exclusively dominant phototrophs (34 taxa out of 39 total taxa recorded) with coccoid forms prevailing (28 taxa); simple trichal forms were present to a lesser extent, while heterocytous ones were completely absent. Genera Gloeocapsa, Chroococcus,Gloeothece and Leptolyngbya were the most diverse. Four green algal genera characteristic for aerophytic habitats (Apatococcus, Desmococcus, Haematococcus and Trentepohlia) were also recorded, while Bacillariophyta were observed sporadically. Three groups of sampling sites were distinguished based on recorded taxa, their richness and similarity, using non-metric multidimensional scaling (NMDS). Quantitative biofilm characteristics were also assessed – the content of chlorophyll a (Chl a) was determined, as well as the contents of water, organic and inorganic matter. Chl a had a significant positive correlation with the content of organic matter (r=0.904, P=0.013).Значај биофилмова у пећинама, разноврсност микроорганизама у њима, њихов међусобни однос, као и однос са супстратом, спадају у водеће теме истраживања у пољу микробијалне биоспелеологије. Ово истраживање доприноси општем познавању биофилмова на улазима пећина, као и познавању фототрофних заједница које се налазе у њиховом саставу. Имајући то у виду, испитивани су биофилмови са улазне зоне Петничке пећине. Светлосна микроскопија је показала да су цијанобактерије искључиво доминантни фототрофи (забележено је 34 од укупно 39 таксона), са изузетном доминацијом кокоидних форми (28 таксона); трихалне форме (хомоцитни представници) су у биофилму заступљене у мањој мери, док су хетероцитне потпуно одсутне. У родовима Gloeocapsa, Chroococcus, Gloeothece и Leptolyngbya документован је највећи број таксона. Четири рода зелених алги која су иначе карактеристична за аерофитска станишта (Apatococcus, Desmococcus, Haematococcus и Trentepohlia) су такође забележена, док су представници раздела Bacillariophyta нађени спорадично. Статистичка анализа NMDS је показала да су се према сличности, односно на основу таксона који су идентификовани, одвојиле три групе тачака узорковања. Kвантитативне карактеристике биофилма су такође процењене – одређен је садржај хлорофила а (Chl a), као и садржај воде, органске и неорганске материје. Значајнa позитивна корелација (r=0.904, P=0.013) уочена је између садржаја органске материје и Chl a

Substrate type selection in diatom based lake water quality assessment

Various studies report contrasting results on the substrate-type effect on diatom community composition, but the particularly important question is whether or not it affects diatom-based assessments of water quality. We investigated whether the substrate type is a significant predictor of the diatom community composition and if it affects lake water quality assessment based on diatom indices. This study took place in Sava Lake (Serbia). We used glass, ceramic, willow and yew tree tiles as artificial substrates for periphyton development, and pebbles from the lake littoral as natural substrate. Results revealed differences in both the diatom community composition and diatom indices values related to the substrates. A distinction was recognized between natural, artificial wooden, and artificial inert substrates. However, the final lake quality assessment based on diatom indices was more or less similar in all substrate types in our study, and depended on value ranges associated with water quality classification and on diatom index choices. Artificial substrates in our study did show potential as an alternative for natural substrate, but further studies are required, particularly in various types of lentic ecosystems to confirm our findings and support artificial substrate employment in lake water quality assessment

Supplementary data for the article: Pešić, M. B.; Milinčić, D. D.; Kostić, A.; Stanisavljević, N. S.; Vukotić, G. N.; Kojić, M. O.; Gašić, U. M.; Barać, M. B.; Stanojević, S. P.; Popović, D. A.; et al. In Vitro Digestion of Meat- and Cereal-Based Food Matrix Enriched with Grape Extracts: How Are Polyphenol Composition, Bioaccessibility and Antioxidant Activity Affected? Food Chem. 2019, 284, 28–44. https://doi.org/10.1016/j.foodchem.2019.01.107

Supplementary material for: [https://doi.org/10.1016/j.foodchem.2019.01.107]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2843]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/2867

Determination of inorganic anions in herbal tea infusions using ion chromatography

The ionic content was examined in nine aqueous tea extracts in which time of boiling, acidification of the medium using lemon juice and way of preparation were observed as factors. Ion chromatography was used for determination of inorganic anion content, and data were processed using CANOCO program for multivariate analysis. The variations in ionic content were observed among different tea samples. The highest concentrations of chloride, nitrate, phosphate, and sulphate ions were found in nettle, while the highest concentrations of fluorides were detected in elderflower tea infusion. The effect of boiling time (5, 10, and 20 min), acidification of the medium and different preparation procedure (boiling and cooling at room temperature) were statistically presented using principal component analysis. The examined factors did not have a significant effect on the ionic concentration in tea infusions. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 176018 and Grant No. 172001

The impact of currently used oral antihyperglycemic drugs on dysfunctional adipose tissue

Obesity is a disease with pandemic frequency, often accompanied by chronic metabolic and organic complications. Type 2 diabetes mellitus (T2DM) is among the most common metabolic complications of obesity. The first step in the treatment of T2DM is medical nutrition therapy combined with moderate physical activity and with advice to patients to reduce their body weight. Pharmacotherapy starts with metformin, and in the case of inadequate therapeutic response, another antihyperglycemic agent should be added. The most clinical experience exists with sulfonylurea agents, but their use is limited due to high incidence of hypoglycemia and increase in body weight. Based on the fact that dysfunction of adipose tissue can lead to the development of chronic degenerative complications, precise use of drugs with a favorable effect on the functionality of adipose tissue represents an imperative of modern T2DM treatment. Antihyperglycemic drugs of choice in obese individuals are those which cause maturation of adipocytes, improvement of secretion of protective adipokines, and redistribution of fat mass from visceral to subcutaneous depots. Oral antihyperglycemic agents that can affect the functionality of adipose tissue are metformin, SGLT-2 inhibitors, DPP-4 inhibitors, and thiazolidinediones