Research outputs from Pure / Zinātniskās darbības rezultāti no ZDIS Pure

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Browsing Research outputs from Pure / Zinātniskās darbības rezultāti no ZDIS Pure by Subject "1.7 Other natural sciences"

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    Changes in Bacterial Community Structure in Wastewaters in the presence of Saccharomyces Cerevisiae and Benzalkonium Chloride
    (2022-03-10) Žorža, L.; Kalniņš, M.; Gudrā, D.; Megnis, K.; Fridmanis, D.; Rapoport, A.; Muter, O.
    The benefit of bioaugmentation of activated sludge (AS) with yeasts was tested using AS and wastewaters (WW) that originated from the chemical industry, as well as synthetic WW. A stimulating effect of Saccharomyces cerevisiae on microbial respiration intensity in AS was shown. The added yeast biomass maintained viability in AS, an inhibitory effect of BAC on Bacilli was found; however, the addition of yeasts to AS reduced this effect.
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    Dominance of Fructose-Associated Fructobacillus in the Gut Microbiome of Bumblebees (Bombus terrestris) Inhabiting Natural Forest Meadows
    (2022-01) Krams, Ronalds; Gudra, Dita; Popovs, Sergejs; Willow, Jonathan; Krama, Tatjana; Munkevics, Maris; Megnis, Kaspars; Jõers, Priit; Fridmanis, Davids; Garduño, Jorge Contreras; Krams, Indrikis A.
    Bumblebees are key pollinators in agricultural landscapes. However, little is known about how gut microbial communities respond to anthropogenic changes. We used commercially produced colonies of buff-tailed bumblebees (Bombus terrestris) placed in three habitats. Whole guts (midgut, hindgut, and rectum) of B. terrestris specimens were dissected from the body and analyzed using 16S phylogenetic community analysis. We observed significantly different bacterial community composition between the agricultural landscapes (apple orchards and oilseed rape (Brassica napus) fields) and forest meadows, whereas differences in gut communities between the orchards and oilseed rape fields were nonsignificant. Bee-specific bacterial genera such as Lactobacillus, Snodgrassella, and Gilliamella dominated gut communities of B. terrestris specimens. In contrast, the guts of B. terrestris from forest meadows were dominated by fructose-associated Fructobacillus spp. Bacterial communities of workers were the most diverse. At the same time, those of males and young queens were less diverse, possibly reflecting greater exposure to the colony’s inner environment compared to the environment outside the colony, as well as bumblebee age. Our results suggest that habitat quality, exposure to environmental microbes, nectar quality and accessibility, and land use significantly affect gut bacterial composition in B. terrestris.
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    Impact of Anthropogenic Activities on Microbial Community Structure in Riverbed Sediments of East Kazakhstan
    (2024-01-24) Muter, Olga; Gudrā, Dita; Daumova, Gulzhan; Idrisheva, Zhanat; Rakhymberdina, Marzhan; Tabors, Guntis; Dirnena, Baiba; Dobkeviča, Linda; Petrova, Olga; Apshikur, Baitak; Luņģe, Megija; Fridmanis, Dāvids; Dennisov, Igor; Bekishev, Yerkebulan; Kasparinskis, Raimonds; Mukulysova, Zarina; Polezhayev, Stanislav
    Heavy metal (HMe) pollution in regions with mining and metallurgy activities is known to be a serious environmental problem worldwide. Hydrological processes contribute to the dissemination of HMes (drainage, precipitation, flow rate). The aim of the present study is to investigate the microbial community structure in ten river sediments sampled in different regions of East Kazakhstan, which are contaminated with HMes. The overall degree of sediment contamination with HMes (Cr, Cu, Zn, Pb, and Cd) was assessed using the pollution index Zc, which ranged from 0.43 to 21.6, with the highest in Ridder City (Zc = 21.6) and Ust-Kamenogorsk City, 0.8 km below the dam of the hydroelectric power station (Zc = 19.6). The tested samples considerably differed in organic matter, total carbon, nitrogen, and phosphorus content, as well as in the abundance of HMe-related functional gene families and antibiotic resistance genes. Metagenomic analysis of benthic microorganisms showed the prevalence of Proteobacteria (88.84–97.61%) and Actinobacteria (1.21–5.98%) at the phylum level in all samples. At the class level, Actinobacteria (21.68–57.48%), Betaproteobacteria (19.38–41.17%), and Alphaproteobacteria (10.0–39.78%) were the most common among the classified reads. To the best of our knowledge, this is the first study on the metagenomic characteristics of benthic microbial communities exposed to chronic HMe pressure in different regions of East Kazakhstan.
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    The role of Strontium enriched hydroxyapatite and tricalcium phosphate biomaterials in osteoporotic bone regeneration
    (2019-02-01) Zarins, Janis; Pilmane, Mara; Sidhoma, Elga; Salma, Ilze; Locs, Janis; Institute of Anatomy and Anthropology; Department of Oral and Maxillofacial Surgery and Oral Medicine
    Background: Strontium (Sr) enriched biomaterials have been used to improve bone regeneration in vivo. However, most studies provide only two experimental groups. The aim of our study was to compare eleven different bone sample groups from osteoporotic and healthy rabbits' femoral neck, as it is the most frequent osteoporotic fracture in humans. Methods: Osteoporotic bone defects were filled with hydroxyapatite 30% (HA) and tricalcium phosphate 70% (TCP), 5% Sr-enriched HA 30 /TCP 70 , HA 70 /TCP 30 , or Sr-HA 70 /TCP 30 granules and were compared with intact leg, sham surgery and healthy non-operated bone. Expression of osteoprotegerin (OPG), nuclear factor kappa beta 105 (NFkB-105), osteocalcin (OC), bone morphogenetic protein 2/4 (BMP-2/4), collagen I (Col-1α), matrix metalloproteinase 2 (MMP- 2), tissue inhibitor of matrix metalloproteinase 2 (TIMP-2), interleukin 1 (IL-1) and interleukin 10 (IL-10) was analyzed by histomorphometry and immunohistochemistry. Results: Our study showed that Sr-HA 70 /TCP 30 induced higher expression of all above-mentioned factors compared to intact leg and even higher expression of OC, MMP-2 and NFkB-105 compared to Sr-HA 30 /TCP 70 . HA 70 /TCP 30 induced higher level of NFkB-105 and IL-1 compared to HA 30 /TCP 70 . Conclusion: Sr-enriched biomaterials improved bone regeneration at molecular level in severe osteoporosis and induced activity of the factors was higher than after pure ceramic, sham or even healthy rabbits.