This review surveys on the influence of different environmental factors like light (intensity, quality, photoperiod), temperature, season, nutrients (inorganic, organic), biotic factors (algal extracellular products, bacterial association, animals grazing), osmotic stress, pH of the medium, wave motion and mechanical shock, pollution, and radiations (UV, X-rays, gamma radiation) on the induction (or inhibition) of algal reproduction like cell division in unicellular algae, and formation of zoospores, aplanospores, akinetes, cysts, antheridia, oogonia, zygospores, etc.

• MeSH
• ekosystém * MeSH
• Eukaryota růst a vývoj   fyziologie   MeSH
• fyziologie rostlin * MeSH
• rozmnožování * MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Lyngbya major (a wall alga), survived throughout year, maximally to >80 % at atmospheric temperature (AT) of 17-36 degrees C and relative humidity (RH) 60-100 % in rainy and spring seasons, but the survival was 43-64 % in winter when AT decreased to 5 degrees C and RH was 65-98 %, and 15-23 % in summer when AT reached 48 degrees C and RH was 23-60 %. All soil algae (Lyngbya birgei, Aphanothece pallida, Gloeocapsa atrata, Oscillatoria subbrevis, O. animalis) survived >90 % in rainy season when soil moisture content (SMC) was 89-100 %. Lowering of SMC to a minimum of 55 % in spring and 39 % in winter led L. birgei, O. subbrevis and O. animalis to survive from 75, 66, and 65 %, respectively, in spring and 12, 14, and 20 % in winter, and A. pallida and G. atrata not at all in both seasons. All soil algae did not survive in summer when SMC was 12-30 %. Myxosarcina burmensis survived only in rainy and spring seasons when pond water temperature (PWT) was 19-25 degrees C and 18-26 degrees C, respectively, and not in winter and summer when PWT was 2-14 degrees C and 25-36 degrees C, respectively. L. major and A. pallida survived almost equally well under both submerged and air-exposed conditions for 15 d but less if submerged for more time than air-exposed on moist soil surface, while L. birgei, G. atrata, O. subbrevis, and O. animalis survived submergence in liquid medium better and longer than air-exposure on moist soil surface. Pond alga M. burmensis survived submergence better than air-exposure, true to its aquatic habitat. All algae survived less and died without forming any resistant cells when exposed to physical and physiological water stress (imposed by growing them on highly agarized media or in salinized liquid media), light stress (at 0, 2 and 10 micromol m(-2) s(-1) light intensity) or following UV shock (0.96-3.84 kJ/m(2)). A. pallida and G. atrata cells did not divide on 8 % agarized solid media, in > or =0.3 mol/L salinized liquid media, and in darkness. The presence of sheath over L. major and L. birgei filament cells and mucilage cover over A. pallida and G. atrata cells protect them against physical desiccation to some extent but not against UV shock.

• MeSH
• ekosystém MeSH
• fyziologický stres MeSH
• mikrobiální viabilita * účinky záření   MeSH
• půda MeSH
• půdní mikrobiologie * MeSH
• roční období MeSH
• sinice fyziologie   účinky záření   MeSH
• teplota MeSH
• ultrafialové záření MeSH
• vlhkost MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• půda MeSH

Pithophora oedogonia and Cladophora glomerata survived lowest 60 and 58%, respectively, in June when the pond diurnal water temperature (PDWT) increased to a maximum of 28 degrees C. The lowering of PDWT only by 1 degrees C in July improved survivability of both algae to their almost maximum level of 100 and 96%, respectively. Further lowering of PDWT to 17-22 degrees C in November initiated akinete formation in P. oedogonia. The process of akinete initiation, maturation and germination continued till April when PDWT increased to 20-24 degrees C, but not beyond that in May when PDWT was 21-26 degrees C. By this time, probably all akinetes have germinated in situ, and the alga was entirely vegetative. P. oedogonia population is not synchronous in nature, since during the 5-6-month reproductive season, some filaments were in active vegetative stage, some had akinete initiation, some had completed akinete formation, and some had akinetes germinating. C. glomerata grew dense vegetative in November and initiated (zoo)sporangial primordia formation (to some extent) in February (when PDWT was lowest, viz. 10-14 degrees C) till April. Meanwhile, no (zoo)-sporangial primordia either produced any zoospore or germinated into a germ tube; and all released their cytoplasmic content and died (along with some vegetative cells) with an increase in PDWT to 21-26 degrees C in May. Vaucheria geminata vegetative patches appeared on the soil surface, 2nd week of January by lowering of atmospheric diurnal temperature (ADT) to 9-16 degrees C in the 1st week. The alga started sexual reproduction by the 2nd week of March (when ADT increased to 20-23 degrees C) and completed the process of reproduction by the 1st week of April (when ADT increased to 24-26 degrees C) and died thereafter. P. oedogonia, C. glomerata and V. geminata survived better and longer in submerged conditions than air-exposed (which was true for P. oedogonia and C. glomerata aquatic habitat and also indicated that the soil alga V. geminata could survive to some extent if submerged in rain water). P. oedogonia formed akinetes and C. glomerata (zoo)sporangial primordia only in submerged condition and not when air-exposed on moist soil surface. V. geminata did not complete the life cycle both under submerged and air-exposed conditions. Vegetative survival in P. oedogonia, C. glomerata, V. geminata, Aphanothece pallida, Gloeocapsa atrata, Scytonema millei, Myxosarcina burmensis, Phormidium bohneri, Oscillatoria animalis, O. subbrevis, Lyngbya birgei, L. major, Microcoleus chthonoplastes and Rhizoclonium crassipellitum, reproduction in P. oedogonia, C. glomerata and V. geminata, cell division in A. pallida and G. atrata, heterocyst and false branch formation in S. millei, all, were adversely affected at approximately 28.5 degrees C for t12 h at light intensity of approximately 160 micromol m(-2) s(-1); high intensity does not ameliorate high temperature damage to any algae. The presence of liquid water, than its absence, outside the different algae moderated the severity of heat to some extent but not when the heat was severe.

• MeSH
• Eukaryota cytologie   růst a vývoj   MeSH
• mikrobiální viabilita * MeSH
• mikroskopie MeSH
• půdní mikrobiologie * MeSH
• sladká voda mikrobiologie   MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Terrestrial blue-green algae Scytonema millei, Phormidium bohneri and Lyngbya mesotricha survived to 100 % at atmospheric temperatures of 5-36 degrees C and relative humidity 55-100 % in rainy, winter and spring seasons but the survival was 15-25 % in summer when atmospheric temperature reached 48 degrees C and relative humidity was < or =23 %. Microcoleus chthonoplastes maximum survival was =80 % in rainy season followed by a decrease to =1/2 and 1/4 level in winter and spring, respectively; it disappeared in summer but a few cells and/or trichomes enclosed within sheath may be surviving sticking to soil, not evident microscopically, since the population reappeared at the same place with the onset of rain. Terrestrial green alga Rhizoclonium crassipellitum survived only in spring and died at the onset of summer without forming any dormant cell and/or reproductive structure. Only P. bohneri survived better and longer under submerged conditions in liquid medium than air-exposed on moist soil surface in the culture chamber, while the other algae fared almost equally or slightly better air-exposed on moist soil surface (or even on 2 % agarized medium) than when suspended in liquid medium, indicating that air exposure rather than submerged conditions was needed for most of the terrestrial algae to survive. Water stress imposed on growing algae either on high-agar-solid media or in 0.2-0.6 mol/L NaCl liquid media in the culture chamber reduced vegetative survival in all; it resulted in death without any dormant cell remaining. When stored in desiccators over fused CaCl2, M. chthonoplastes died within 1/2 month, R. crassipellitum and L. mesotricha within 1 month, P. bohneri within 1/2 month, and S. millei not even within 1 1/2 month, indicating their survival pattern against atmospheric dryness to be wide; it also explained the M. chthonoplastes absence in summer and S. millei presence throughout the year. At increased atmospheric humidity the desiccation-sensitive algae (e.g., M. chthonoplastes) survived better than a desiccation-resistant alga (here S. millei). All algae survived considerable darkness (S. millei > 1 1/2 month; P. bohneri, M. chthonoplastes and R. crassipellitum >1 month, and L. mesotricha >1/2 month), and low light intensity of 2 and 10 micromol m(-2)s(-1) which explains their prolific growth in shady places. All algae were differently sensitive to wet heat (45 degrees C for 5-40 min) and to UV shock (0.96-3.84 kJ/m2).

• MeSH
• Chlorophyta fyziologie   účinky záření   MeSH
• ekosystém * MeSH
• hypertonický solný roztok MeSH
• roční období MeSH
• sinice fyziologie   účinky záření   MeSH
• teplota MeSH
• ultrafialové záření MeSH
• vlhkost MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• hypertonický solný roztok MeSH

Atrazine solutions (0.1, 1, 10 and 100 microg/L) inoculated with Escherichia coli and Enterococcus faecalis under natural conditions significantly increased (p < or = 0.05) the population levels of both test bacteria; it indicates the ability of bacterial cells to degrade atrazine and to use the original compound or its degradation products as nutrient(s). In some cases, alterations in the morphology of the colonies were also observed on selective solid media. Biochemical differentiation was also found and, on the other hand, a loss of culturability was recorded; this suggests that bacteria have entered in a viable but nonculturable state. A re-appearance of the colonies occurred after inoculation on tryptone-soy agar with atrazine.

• MeSH
• atrazin farmakologie   MeSH
• chemické znečištění vody * MeSH
• Enterococcus faecalis účinky léků   růst a vývoj   metabolismus   MeSH
• Escherichia coli účinky léků   růst a vývoj   metabolismus   MeSH
• herbicidy farmakologie   MeSH
• kultivační média MeSH
• mikrobiologie vody * MeSH
• monitorování životního prostředí metody   MeSH
• počet mikrobiálních kolonií MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• Názvy látek
• atrazin MeSH
• herbicidy MeSH
• kultivační média MeSH

Euglena ignobilis cells in natural puddle water of pH 7.8, when kept at 21 +/- 2 degrees C and under continuous light (intensity of approximately 30 micromol m(-2) s(-1)) in a culture chamber, decreased their speed of movement from > or = 78000 microm/min (after a 12-h cultivation), to 850-1300 microm/min after 18 h. Simultaneously initiated were changes in morphology from the usual elongated motile forms to round motile ones by curving and contraction. Water stress (2 and 4 % agarized puddle water, puddle water with 0.2-1 mol/L NaCl), temperature shock (< or = 10 degrees C, > or = 30 degrees C), darkness and low-light intensity, UV exposure (0.96-2.88 kJ/m2), pH extremes (< or = 6.5 and > or = 10), presence of 'heavy' metals (1-100 ppm Fe, Cu, Zn, Co, Ni, Hg) or organic substances in puddle water (25-1000 ppm 2,4-D, captan, urea, DDT, thiourea), all these factors rapidly (after 5 to 30 min) decreased the speed of the elongated motile form to < or = 300 microm/min, and induced all morphological changes leading to formation of round motile and round nonmotile forms. These features in the alga (i.e. sudden speed reduction and morphological changes from elongate motile to round motile form) may thus be suggested to be used in assessing water quality.

• MeSH
• Euglena růst a vývoj   fyziologie   ultrastruktura   MeSH
• koncentrace vodíkových iontů MeSH
• organické látky farmakologie   MeSH
• pohyb * MeSH
• reakce na tepelný šok * MeSH
• teplota MeSH
• těžké kovy MeSH
• voda MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• organické látky MeSH
• těžké kovy MeSH
• voda MeSH