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001-es BibID:	BIBFORM094879
Első szerző:	Hörcsik Zsolt Tibor
Cím:	Effects of chromium (VI) on growth, element and photosynthetic pigment composition of Chlorella pyrenoidosa / Zsolt Hörcsik, Viktor Oláh, Árpád Balogh, Ilona Mészáros, László Simon, Gyula Lakatos
Dátum:	2006
ISSN:	1588-385X
Megjegyzések:	he effects of Cr(VI) were investigated on the growth rate, element, photosyn-thetic pigment and amino acid composition of Chlorella pyrenoidosa. Cr(VI) is toxic to Chlorella pyrenoidosa. The influence of chromium on cell density and cell number followed very similar trends, indicating that these growth responses might be correlated. The EC50 value for Cr(VI) were 2.0 mg dm-3, the lethal concentration of chromium appears to be approximately 20 mg dm-3for Chlorella pyrenoidosa. We have investigated the concentrations of chromium, calcium, mag-nesium and iron. The cells were fractionated into three fractions: cell wall fraction, membrane fraction, soluble fraction after the cells were disrupted. The amount of metals in whole cells and in each cell fraction was determined. Chromium uptake at each concentration was high within 3 days. Chlorella pyrenoidosa can accumulate chromium mainly (approximately 70%) in the cell wall. The concentrations of chromium and calcium show parallel changes with each other. A higher calcium concentration can be observed along with an increasing chromium concentration, both in the cell wall system and in the whole cells. Iron and magnesium concentration show a decreasing tendency. Cr(VI) caused a changes both in free amino acids and proline content. Both free amino acids and proline content increase with the increasing concentration of chro-mium. Chlorophyll a and b content show a decreasing , while OH-chlorophylls show increasing tendency. Rate of carotene ? and ? change grows with the increasing chromium concentration. The toxic properties of Cr(VI) can arise from the possibly free diffusion across cell membranes and strong oxidative potential. The toxicological impact of Cr(VI) originates from the action of this form itself as an oxidizing agent, as well as from the formation of free radicals during the reduction of Cr(VI) to Cr(III) occuring inside the cell.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény hazai lapban folyóiratcikk Chlorella pyrenoidosa chromium element composition pigment pattern
Megjelenés:	Acta Biologica Szegediensis. - 50 : 1-2 (2006), p. 19-23. -
További szerzők:	Oláh Viktor (1980-) (biológus) Balogh Árpád Mészáros Ilona (1952-) (biológus) Simon László (1963-) (okleveles tartósítóipari mérnök) Lakatos Gyula (1949-) (ökológus)
Internet cím:	Szerző által megadott URL Intézményi repozitóriumban (DEA) tárolt változat
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001-es BibID:	BIBFORM031056
Első szerző:	Kovácsné Koncz Nóra (agrármérnök, biológus)
Cím:	Histological study of quercus galls of Neuroterus quercusbaccarum (Linnaeus, 1758) (Hymenoptera: Cynipidae) / Nóra Kovácsné Koncz, László J. Szabó, Csaba Máthé, Katalin Jámbrik, Márta M-Hamvas
Dátum:	2011
Megjegyzések:	The aim of this study is to reveal the histological structure of galls induced by Neu-roterus quercusbaccarum and to identify accumulated secondary metabolism products and stor-age materials in gall tissue by histochemical methods. The galls induced by N. quercusbaccarum showed a concentrical layer tissue structure under light microsope. Directly next to the chamber, a protein and lipid containing nutritive tissue can be found, which is covered by sclerenchyma layer consisted of two large cell plates in the lenticular galls of the unisexual generation, while the bisexual generation induced grape shaped galls lack lignifed sheaths. Our results confirm previous findings. The outer layer of the gall is the voluminous parenchymatic cortex with a supplying vascular network and covered epidermis. We proved with histological methods, that the galls really contain accumulated nutritives -proteins, lipids and starch- in large quantities. The concentration of these nutrients from the chamber toward the border of inner-gall, show a decreasing gradient in the case of proteins and lipids, and an increasing gradient for starch. We present the differences and similarities in histological structure among galls induced by two generations of N. quercusbaccarum and the well studied Biorrhiza pallida.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény hazai lapban gall Neuroterus quercusbaccarum Biorrhiza pallida histology
Megjelenés:	Acta Biologica Szegediensis. - 55 : 2 (2011), p. 247-253. -
További szerzők:	Szabó László József (1955-) (ökológus, hidrobiológus) Máthé Csaba (1966-) (biológus) Jámbrik Katalin Mikóné Hamvas Márta (1963-) (biológus)
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001-es BibID:	BIBFORM082914
Első szerző:	Oláh Viktor (biológus)
Cím:	Cadmium-induced turion formation of Spirodela polyrhiza (L.) Schleiden / Viktor Oláh, Anna Hepp, Gyula Lakatos, Ilona Mészáros
Dátum:	2014
ISSN:	1588-385X
Megjegyzések:	Spirodela polyrhiza (L.) Schleiden (giant duckweed) is an extensively studied representative of duckweeds (Lemnoideae subfamily, Araceae). Despite its widespread application in numerous research areas and well-known capability for producing turions, the effects of various toxicants on turion production are sporadically discussed in the scientific literature. Our aim was to study the growth of S. polyrhiza under cadmium stress and to test its potential interference with turion production. Effects of cadmium were assessed in axenic cultures of a local S. polyrhiza clone in 7-days-long duckweed growth inhibition tests. Our results indicated that higher cadmium concentrations decreased the relative growth rates of cultures within 3 days and growth inhibition reached its maximum between the 3rd and 5th days with 0.080 mg l-1 IC50. Parallel with slowed frond production - by mirror image pattern - induction of turion formation was observed. The first turions protruded by the 5th day of treatments in the 0.075-0.75 mg l-1 concentration range. Such rapid onset of turion formation is indicative of an almost immediate switch between normal and turion mode of meristem function upon cadmium stress. The consideration of this mechanism in practical applications of S. polyrhiza is recommended.
Tárgyszavak:	Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény hazai lapban folyóiratcikk
Megjelenés:	Acta Biologica Szegediensis. - 58 : 2 (2014), p. 103-108. -
További szerzők:	Hepp Anna (1991-) (biotechnológus) Lakatos Gyula (1949-) (ökológus) Mészáros Ilona (1952-) (biológus)
Pályázati támogatás:	TÁMOP-4.2.2.B-10/1 TÁMOP TÁMOP-4.2.3-12/1/KONV-2012-0048 TÁMOP TÁMOP 4.2.4. A/2-11-1-2012-0001 TÁMOP
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