@article{MTMT:34749976,
	title = {Chemotactic Interactions of Scenedesmus sp. and Azospirillum brasilense Investigated by Microfluidic Methods},
	url = {https://m2.mtmt.hu/api/publication/34749976},
	author = {Greipel, Erika and Nagy, Krisztina and Csákvári, Eszter and Dér, László and Galajda, Péter and Kutasi, József},
	doi = {10.1007/s00248-024-02366-3},
	journal-iso = {MICROB ECOL},
	journal = {MICROBIAL ECOLOGY},
	volume = {87},
	unique-id = {34749976},
	issn = {0095-3628},
	abstract = {The use of algae for industrial, biotechnological, and agricultural purposes is spreading globally. Scenedesmus species can play an essential role in the food industry and agriculture due to their favorable nutrient content and plant-stimulating properties. Previous research and the development of Scenedesmus -based foliar fertilizers raised several questions about the effectiveness of large-scale algal cultivation and the potential effects of algae on associative rhizobacteria. In the microbiological practice applied in agriculture, bacteria from the genus Azospirillum are one of the most studied plant growth-promoting, associative, nitrogen-fixing bacteria. Co-cultivation with Azospirillum species may be a new way of optimizing Scenedesmus culturing, but the functioning of the co-culture system still needs to be fully understood. It is known that Azospirillum brasilense can produce indole-3-acetic acid, which could stimulate algae growth as a plant hormone. However, the effect of microalgae on Azospirillum bacteria is unclear. In this study, we investigated the behavior of Azospirillum brasilense bacteria in the vicinity of Scenedesmus sp . or its supernatant using a microfluidic device consisting of physically separated but chemically coupled microchambers. Following the spatial distribution of bacteria within the device, we detected a positive chemotactic response toward the microalgae culture. To identify the metabolites responsible for this behavior, we tested the chemoeffector potential of citric acid and oxaloacetic acid, which, according to our HPLC analysis, were present in the algae supernatant in 0.074 mg/ml and 0.116 mg/ml concentrations, respectively. We found that oxaloacetic acid acts as a chemoattractant for Azospirillum brasilense .},
	year = {2024},
	eissn = {1432-184X}
}

@article{MTMT:34441845,
	title = {Spatial ecology of cells living in micro-structured environments},
	url = {https://m2.mtmt.hu/api/publication/34441845},
	author = {Wetherington, Miles T. and Galajda, Péter and Keymer, Juan E.},
	doi = {10.3389/fevo.2023.1325165},
	journal-iso = {FRONT ECOL EVOL},
	journal = {FRONTIERS IN ECOLOGY AND EVOLUTION},
	volume = {11},
	unique-id = {34441845},
	issn = {2296-701X},
	keywords = {ECOLOGY; landscape ecology; persistence; Spatial biology; cell communities},
	year = {2023},
	eissn = {2296-701X}
}

@article{MTMT:33288049,
	title = {Ecological succession and the competition-colonization trade-off in microbial communities},
	url = {https://m2.mtmt.hu/api/publication/33288049},
	author = {Wetherington, Miles T and Nagy, Krisztina and Dér, László and Ábrahám, Ágnes and Noorlag, Janneke and Galajda, Péter and Keymer, Juan E.},
	doi = {10.1186/s12915-022-01462-5},
	journal-iso = {BMC BIOL},
	journal = {BMC BIOLOGY},
	volume = {20},
	unique-id = {33288049},
	issn = {1741-7007},
	year = {2022},
	eissn = {1741-7007},
	orcid-numbers = {Keymer, Juan E./0000-0001-6566-3778}
}

@article{MTMT:32832922,
	title = {Viable protoplast formation of the coral endosymbiont alga Symbiodinium spp. in a microfluidics platform},
	url = {https://m2.mtmt.hu/api/publication/32832922},
	author = {Bashir, Faiza and Kovács, Sándor and Ábrahám, Ágnes and Nagy, Krisztina and Ayaydin, Ferhan and Kelemen-Valkony, Ildikó and Ferenc, Györgyi and Galajda, Péter and Tóth, Szilvia Zita and Sass, László and Kós, Péter and Vass, Imre and Szabó, Milán},
	doi = {10.1039/D2LC00130F},
	journal-iso = {LAB CHIP},
	journal = {LAB ON A CHIP},
	volume = {22},
	unique-id = {32832922},
	issn = {1473-0197},
	abstract = {Symbiodiniaceae is an important dinoflagellate family which lives in endosymbiosis with reef invertebrates, including coral polyps, making them central to the holobiont. With coral reefs currently under extreme threat from climate change, there is a pressing need to improve our understanding on the stress tolerance and stress avoidance mechanisms of Symbiodinium spp. Reactive oxygen species (ROS) such as singlet oxygen are central players in mediating various stress responses; however, the detection of ROS using specific dyes is still far from definitive in intact Symbiodinium cells due to the hindrance of uptake of certain fluorescent dyes because of the presence of the cell wall. Protoplast technology provides a promising platform for studying oxidative stress with the main advantage of removed cell wall, however the preparation of viable protoplasts remains a significant challenge. Previous studies have successfully applied cellulose-based protoplast preparation in Symbiodiniaceae; however, the protoplast formation and regeneration process was found to be suboptimal. Here, we present a microfluidics-based platform which allowed protoplast isolation from individually trapped Symbiodinium cells, by using a precisely adjusted flow of cell wall digestion enzymes (cellulase and macerozyme). Trapped single cells exhibited characteristic changes in their morphology, cessation of cell division and a slight decrease in photosynthetic activity during protoplast formation. Following digestion and transfer to regeneration medium, protoplasts remained photosynthetically active, regrew cell walls, regained motility, and entered exponential growth. Elevated flow rates in the microfluidic chambers resulted in somewhat faster protoplast formation; however, cell wall digestion at higher flow rates partially compromised photosynthetic activity. Physiologically competent protoplasts prepared from trapped cells in microfluidic chambers allowed for the first time the visualization of the intracellular localization of singlet oxygen (using Singlet Oxygen Sensor Green dye) in Symbiodiniaceae, potentially opening new avenues for studying oxidative stress.},
	year = {2022},
	eissn = {1473-0189},
	pages = {2986-2999},
	orcid-numbers = {Ferenc, Györgyi/0000-0002-3456-319X}
}

@article{MTMT:32824517,
	title = {Variance in Landscape Connectivity Shifts Microbial Population Scaling},
	url = {https://m2.mtmt.hu/api/publication/32824517},
	author = {Wetherington, Miles T and Nagy, Krisztina and Dér, László and Noorlag, Janneke and Galajda, Péter and Keymer, Juan E.},
	doi = {10.3389/fmicb.2022.831790},
	journal-iso = {FRONT MICROBIOL},
	journal = {FRONTIERS IN MICROBIOLOGY},
	volume = {13},
	unique-id = {32824517},
	issn = {1664-302X},
	abstract = {Understanding mechanisms shaping distributions and interactions of soil microbes is essential for determining their impact on large scale ecosystem services, such as carbon sequestration, climate regulation, waste decomposition, and nutrient cycling. As the functional unit of soil ecosystems, we focus our attention on the spatial structure of soil macroaggregates. Emulating this complex physico-chemical environment as a patchy habitat landscape we investigate on-chip the effect of changing the connectivity features of this landscape as Escherichia coli forms a metapopulation. We analyze the distributions of E. coli occupancy using Taylor's law, an empirical law in ecology which asserts that the fluctuations in populations is a power law function of the mean. We provide experimental evidence that bacterial metapopulations in patchy habitat landscapes on microchips follow this law. Furthermore, we find that increased variance of patch-corridor connectivity leads to a qualitative transition in the fluctuation scaling. We discuss these results in the context of the spatial ecology of microbes in soil.},
	keywords = {DYNAMICS; landscape ecology; Scaling laws; Power-law; Taylor's law; metapopulations; spatial microbial ecology},
	year = {2022},
	eissn = {1664-302X}
}

@article{MTMT:32801357,
	title = {Emergence of Resistant Escherichia coli Mutants in Microfluidic On-Chip Antibiotic Gradients},
	url = {https://m2.mtmt.hu/api/publication/32801357},
	author = {Nagy, Krisztina and Dukic, Barbara and Hodula, Orsolya and Ábrahám, Ágnes and Csákvári, Eszter and Dér, László and Wetherington, Miles T and Noorlag, Janneke and Keymer, Juan E. and Galajda, Péter},
	doi = {10.3389/fmicb.2022.820738},
	journal-iso = {FRONT MICROBIOL},
	journal = {FRONTIERS IN MICROBIOLOGY},
	volume = {13},
	unique-id = {32801357},
	issn = {1664-302X},
	abstract = {Spatiotemporal structures and heterogeneities are common in natural habitats, yet their role in the evolution of antibiotic resistance is still to be uncovered. We applied a microfluidic gradient generator device to study the emergence of resistant bacteria in spatial ciprofloxacin gradients. We observed biofilm formation in regions with sub-inhibitory concentrations of antibiotics, which quickly expanded into the high antibiotic regions. In the absence of an explicit structure of the habitat, this multicellular formation led to a spatial structure of the population with local competition and limited migration. Therefore, such structures can function as amplifiers of selection and aid the spread of beneficial mutations. We found that the physical environment itself induces stress-related mutations that later prove beneficial when cells are exposed to antibiotics. This shift in function suggests that exaptation occurs in such experimental scenarios. The above two processes pave the way for the subsequent emergence of highly resistant specific mutations.},
	keywords = {IDENTIFICATION; MUTATIONS; TOLERANCE; EVOLUTION; EVOLUTION; biosynthesis; MOLECULAR-MECHANISMS; motility; Antibiotic resistance; Microfluidics; disulfide bond formation; antibiotic gradients},
	year = {2022},
	eissn = {1664-302X}
}

@article{MTMT:32597266,
	title = {Microfluidic Platforms Designed for Morphological and Photosynthetic Investigations of Chlamydomonas reinhardtii on a Single-Cell Level},
	url = {https://m2.mtmt.hu/api/publication/32597266},
	author = {Széles, Eszter and Nagy, Krisztina and Ábrahám, Ágnes and Kovács, Sándor and Podmaniczki, Anna and Nagy, Valéria and Kovács, László and Galajda, Péter and Tóth, Szilvia Zita},
	doi = {10.3390/cells11020285},
	journal-iso = {CELLS-BASEL},
	journal = {CELLS},
	volume = {11},
	unique-id = {32597266},
	year = {2022},
	eissn = {2073-4409},
	orcid-numbers = {Nagy, Valéria/0000-0001-7105-3546}
}

@article{MTMT:31172892,
	title = {Optikai csipesz és nagy energiájú ultragyors lézerimpulzusok: a 2018. évi fizikai Nobel-díjakról},
	url = {https://m2.mtmt.hu/api/publication/31172892},
	author = {Galajda, Péter and Varjú, Katalin},
	doi = {10.1556/2065.180.2019.6.13},
	journal-iso = {MAGYAR TUDOMÁNY},
	journal = {MAGYAR TUDOMÁNY},
	volume = {180},
	unique-id = {31172892},
	issn = {0025-0325},
	year = {2019},
	eissn = {1588-1245},
	pages = {904-911},
	orcid-numbers = {Varjú, Katalin/0000-0001-6577-7417}
}

@article{MTMT:3369018,
	title = {Application of Microfluidics in Experimental Ecology: The Importance of Being Spatial.},
	url = {https://m2.mtmt.hu/api/publication/3369018},
	author = {Nagy, Krisztina and Ábrahám, Ágnes and Keymer, JE and Galajda, Péter},
	doi = {10.3389/fmicb.2018.00496},
	journal-iso = {FRONT MICROBIOL},
	journal = {FRONTIERS IN MICROBIOLOGY},
	volume = {9},
	unique-id = {3369018},
	issn = {1664-302X},
	abstract = {Microfluidics is an emerging technology that is used more and more in biology experiments. Its capabilities of creating precisely controlled conditions in cellular dimensions make it ideal to explore cell-cell and cell-environment interactions. Thus, a wide spectrum of problems in microbial ecology can be studied using engineered microbial habitats. Moreover, artificial microfluidic ecosystems can serve as model systems to test ecology theories and principles that apply on a higher level in the hierarchy of biological organization. In this mini review we aim to demonstrate the versatility of microfluidics and the diversity of its applications that help the advance of microbiology, and in more general, experimental ecology.},
	year = {2018},
	eissn = {1664-302X}
}

@article{MTMT:3223949,
	title = {Expression of pattern recognition receptors and activation of the non-canonical inflammasome pathway in brain pericytes},
	url = {https://m2.mtmt.hu/api/publication/3223949},
	author = {Nyúl-Tóth, Ádám and Kozma, Mihály and Nagyőszi, Péter and Nagy, Krisztina and Fazakas, Csilla and Haskó, János and Molnár, Kinga and Farkas, Elek Attila and Végh, Attila Gergely and Váró, György and Galajda, Péter and Wilhelm, Imola Mária and Krizbai, István Adorján},
	doi = {10.1016/j.bbi.2017.04.010},
	journal-iso = {BRAIN BEHAV IMMUN},
	journal = {BRAIN BEHAVIOR AND IMMUNITY},
	volume = {64},
	unique-id = {3223949},
	issn = {0889-1591},
	abstract = {Cerebral pericytes are mural cells embedded in the basement membrane of capillaries. Increasing evidence suggests that they play important role in controlling neurovascular functions, i.e. cerebral blood flow, angiogenesis and permeability of the blood-brain barrier. These cells can also influence neuroinflammation which is highly regulated by the innate immune system. Therefore, we systematically tested the pattern recognition receptor expression of brain pericytes. We detected expression of NOD1, NOD2, NLRC5, NLRP1-3, NLRP5, NLRP9, NLRP10 and NLRX mRNA in non-treated cells. Among the ten known human TLRs, TLR2, TLR4, TLR5, TLR6 and TLR10 were found to be expressed. Inflammatory mediators induced the expression of NLRA, NLRC4 and TLR9 and increased the levels of NOD2, TLR2, inflammasome-forming caspases and inflammasome-cleaved interleukins. Oxidative stress, on the other hand, upregulated expression of TLR10 and NLRP9. Activation of selected pattern recognition receptors can lead to inflammasome assembly and caspase-dependent secretion of IL-1beta. TNF-alpha and IFN-gamma increased the levels of pro-IL-1beta and pro-caspase-1 proteins; however, no canonical activation of NLRP1, NLRP2, NLRP3 or NLRC4 inflammasomes could be observed in human brain vascular pericytes. On the other hand, we could demonstrate secretion of active IL-1beta in response to non-canonical inflammasome activation, i.e. intracellular LPS or infection with E. coli bacteria. Our in vitro results indicate that pericytes might have an important regulatory role in neuroinflammation.},
	year = {2017},
	eissn = {1090-2139},
	pages = {220-231},
	orcid-numbers = {Fazakas, Csilla/0000-0001-7822-5881; Végh, Attila Gergely/0000-0003-0524-0946; Wilhelm, Imola Mária/0000-0003-2366-7337}
}