Pseudomonas mandelii SW-3, isolated from the Napahai plateau wetland, can survive in cold environments. The mechanisms underlying the survival of bacteria in low temperatures and high altitudes are not yet fully understood. In this study, the whole genome of SW-3 was sequenced to identify the genomic features that may contribute to survival in cold environments. The results showed that the genome size of strain SW-3 was 6,538,059 bp with a GC content of 59%. A total of 67 tRNAs, a 34,110 bp prophage sequence, and a large number of metabolic genes were found. Based on 16S rRNA gene phylogeny and average nucleotide identity analysis among P. mandelii, SW-3 was identified as a strain belonging to P. mandelii. In addition, we clarified the mechanisms by which SW-3 survived in a cold environment, providing a basis for further investigation of host-phage interaction. P. mandelii SW-3 showed stress resistance mechanisms, including glycogen and trehalose metabolic pathways, and antisense transcriptional silencing. Furthermore, cold shock proteins and glucose 6-phosphate dehydrogenase may play pivotal roles in facilitating adaptation to cold environmental conditions. The genome-wide analysis provided us with a deeper understanding of the cold-adapted bacterium.

• MeSH
• DNA bakterií genetika   MeSH
• fylogeneze * MeSH
• fyziologická adaptace * genetika   MeSH
• genom bakteriální * MeSH
• nízká teplota * MeSH
• profágy genetika   MeSH
• Pseudomonas * genetika   klasifikace   MeSH
• RNA ribozomální 16S * genetika   MeSH
• sekvenování celého genomu MeSH
• zastoupení bazí MeSH
• Publikační typ
• časopisecké články MeSH

The adaptation of Anammox (ANaerobic AMMonium OXidation) to low temperatures (10-15°C) is crucial for sustaining energy-efficient nitrogen removal from the mainstream of municipal wastewater. But, current adaptation methods take months or even years. To speed up the adaption of Anammox to low temperatures, this study describes a new approach: exposing Anammox microorganisms to an abrupt temporary reduction of temperature, i.e., cold shock. Anammox biomass in a moving bed biofilm reactor was subjected to three consecutive cold shocks (reduction from 24 ± 2 to 5.0 ± 0.2°C), each taking eight hours. Before the cold shocks, Anammox activity determined in ex situ tests using the temperature range of 12.5-19.5°C was 0.005-0.015 kg-N kg-VSS-1 day-1 . Cold shocks increased the activity of Anammox at 10°C to 0.054 kg-N kg-VSS-1 day-1 after the third shock, which is similar to the highest activities obtained for cold-enriched or adapted Anammox reported in the literature (0.080 kg-N kg-VSS-1 day-1 ). Fluorescence in situ hybridization analysis showed that Ca. Brocadia fulgida was the dominant species. Thus, cold shocks are an intriguing new strategy for the adaptation of Anammox to low temperature. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:277-281, 2018.

• MeSH
• amoniové sloučeniny chemie   MeSH
• anaerobióza genetika   MeSH
• Bacteria genetika   růst a vývoj   metabolismus   MeSH
• biofilmy růst a vývoj   MeSH
• bioreaktory MeSH
• čištění vody metody   MeSH
• denitrifikace genetika   MeSH
• dusík metabolismus   MeSH
• hybridizace in situ fluorescenční MeSH
• nízká teplota MeSH
• odpad tekutý - odstraňování metody   MeSH
• oxidace-redukce MeSH
• reakce na chladový šok genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Membrane fluidity adaptation to the low growth temperature in Bacillus subtilis involves two distinct mechanisms: (1) long-term adaptation accomplished by increasing the ratio of anteiso- to iso-branched fatty acids and (2) rapid desaturation of fatty acid chains in existing phospholipids by induction of fatty acid desaturase after cold shock. In this work we studied the effect of medium composition on cold adaptation of membrane fluidity. Bacillus subtilis was cultivated at optimum (40 degrees C) and low (20 degrees C) temperatures in complex medium with glucose or in mineral medium with either glucose or glycerol. Cold adaptation was characterized by fatty acid analysis and by measuring the midpoint of phospholipid phase transition T(m) (differential scanning calorimetry) and membrane fluidity (DPH fluorescence polarization). Cells cultured and measured at 40 degrees C displayed the same membrane fluidity in all three media despite a markedly different fatty acid composition. The T(m) was surprisingly the highest in the case of a culture grown in complex medium. On the contrary, cultivation at 20 degrees C in the complex medium gave rise to the highest membrane fluidity with concomitant decrease of T(m) by 10.5 degrees C. In mineral media at 20 degrees C the corresponding changes of T(m) were almost negligible. After a temperature shift from 40 to 20 degrees C, the cultures from all three media displayed the same adaptive induction of fatty acid desaturase despite their different membrane fluidity values immediately after cold shock.

• MeSH
• Bacillus subtilis fyziologie   růst a vývoj   MeSH
• diferenciální skenovací kalorimetrie MeSH
• financování organizované MeSH
• fluidita membrány MeSH
• fluorescenční polarizace MeSH
• fyziologická adaptace MeSH
• kultivační média MeSH
• nízká teplota MeSH

Polyunsaturated lipids are important components of photosynthetic membranes. Xanthophylls are the main photoprotective agents, can assist in protection against light stress, and are crucial in the recovery from photoinhibition. We generated the xanthophyll- and polyunsaturated lipid-deficient ROAD mutant of Synechocystis sp. PCC6803 (Synechocystis) in order to study the little-known cooperative effects of lipids and carotenoids (Cars). Electron microscopic investigations confirmed that in the absence of xanthophylls the S-layer of the cellular envelope is missing. In wild-type (WT) cells, as well as the xanthophyll-less (RO), polyunsaturated lipid-less (AD), and the newly constructed ROAD mutants the lipid and Car compositions were determined by MS and HPLC, respectively. We found that, relative to the WT, the lipid composition of the mutants was remodeled and the Car content changed accordingly. In the mutants the ratio of non-bilayer-forming (NBL) to bilayer-forming (BL) lipids was found considerably lower. Xanthophyll to β-carotene ratio increased in the AD mutant. In vitro and in vivo methods demonstrated that saturated, monounsaturated lipids and xanthophylls may stabilize the trimerization of Photosystem I (PSI). Fluorescence induction and oxygen-evolving activity measurements revealed increased light sensitivity of RO cells compared to those of the WT. ROAD showed a robust increase in light susceptibility and reduced recovery capability, especially at moderate low (ML) and moderate high (MH) temperatures, indicating a cooperative effect of xanthophylls and polyunsaturated lipids. We suggest that both lipid unsaturation and xanthophylls are required for providing the proper structure and functioning of the membrane environment that protects against light and temperature stress.

• MeSH
• beta-karoten metabolismus   účinky záření   MeSH
• buněčná membrána genetika   metabolismus   účinky záření   ultrastruktura   MeSH
• časové faktory MeSH
• fenotyp MeSH
• fotosyntéza genetika   účinky záření   MeSH
• fotosystém I (proteinový komplex) genetika   metabolismus   účinky záření   MeSH
• fyziologická adaptace MeSH
• fyziologický stres * MeSH
• genotyp MeSH
• membránové lipidy metabolismus   účinky záření   MeSH
• metabolismus lipidů genetika   účinky záření   MeSH
• mutace MeSH
• světlo * MeSH
• Synechocystis genetika   metabolismus   účinky záření   ultrastruktura   MeSH
• teplota * MeSH
• tylakoidy metabolismus   účinky záření   MeSH
• xanthofyly genetika   metabolismus   účinky záření   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

The genus Phodopus consists of three species--P. campbelli (Pc), P. sungorus (Ps), and P. roborovskii (Pr). They inhabit steppes, semi-deserts, and deserts in continental Asia with a climate changing from a moderate to a hard Continental one with extreme daily and seasonal variations. These different environmental challenges are likely to have consequences for hamsters' morphology, physiology, and behavior. Hamsters of all three species were investigated during the course of the year in the laboratory though using natural lighting and temperature conditions. Motor activity and body temperature were measured continuously, and body mass, testes size, and fur coloration every 1-2 weeks. With regard to the pattern of activity, nearly twice as many Pc as Ps hamsters (25 vs. 14%) failed to respond to changes of photoperiod, whereas all Pr hamsters did. Body mass and testes size were high in summer and low in winter, with the biggest relative change in Ps and the lowest in Pr hamsters. Changes of fur coloration were found in Ps hamsters only. All responding animals (that is excluding Pr), exhibited regular torpor bouts during the short winter days. In autumn, seasonal changes started considerably earlier in Ps hamsters. To investigate the putative causes of these different time courses, a further experiment was performed, to identify the critical photoperiod. Hamsters were kept for 10 weeks under different photoperiods, changing from 16 to 8 h light per day. Motor activity was recorded continuously, to identify responding and non-responding animals. Body mass was measured at the beginning and the end of the experiment, testes mass only at the end. The critical photoperiod was found to be similar in all three species. Though in a further experiment, Pc and Pr hamsters showed a delayed response, whereas the changes in Ps hamsters started immediately following transfer to short-day conditions. The results show that interspecific differences in seasonal adaptation exist, even between the closely related Ps and Pc hamsters, possibly due to different conditions in their natural habitat. Also, the impact of environmental factors like climatic conditions and food resources may differ between species.

• MeSH
• barva vlasů MeSH
• časové faktory MeSH
• cykly aktivity MeSH
• druhová specificita MeSH
• ekosystém * MeSH
• fotoperioda MeSH
• fyziologická adaptace MeSH
• křečci praví MeSH
• Phodopus růst a vývoj   fyziologie   MeSH
• pohybová aktivita MeSH
• roční období * MeSH
• tělesná hmotnost MeSH
• teplota MeSH
• termoregulace MeSH
• testis růst a vývoj   MeSH
• velikost orgánu MeSH
• vlasy, chlupy MeSH
• zvířata MeSH
• Check Tag
• křečci praví MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

The remarkable adaptability of diatoms living in a highly variable environment assures their prominence among marine primary producers. The present study integrates biochemical, biophysical and genomic data to bring new insights into the molecular mechanism of chromatic adaptation of pennate diatoms in model species Phaeodactylum tricornutum, a marine eukaryote alga possessing the capability to shift its absorption up to ~700 nm as a consequence of incident light enhanced in the red component. Presence of these low energy spectral forms of Chl a is manifested by room temperature fluorescence emission maximum at 710 nm (F710). Here we report a successful isolation of the supramolecular protein complex emitting F710 and identify a member of the Fucoxanthin Chlorophyll a/c binding Protein family, Lhcf15, as its key building block. This red-shifted antenna complex of P. tricornutum appears to be functionally connected to photosystem II. Phylogenetic analyses do not support relation of Lhcf15 of P. tricornutum to other known red-shifted antenna proteins thus indicating a case of convergent evolutionary adaptation towards survival in shaded environments.

• MeSH
• barva * MeSH
• chlorofyl metabolismus   MeSH
• fluorescence * MeSH
• fluorescenční spektrometrie MeSH
• fotosystém II (proteinový komplex) metabolismus   MeSH
• fylogeneze MeSH
• fyziologická adaptace * MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací MeSH
• rozsivky fyziologie   MeSH
• světlo MeSH
• světlosběrné proteinové komplexy metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Pseudomonas prosekii is a recently described species isolated exclusively from James Ross Island close to the Antarctic Peninsula at 64° south latitude. Here, we present two P. prosekii genome sequences and their analyses with respect to phylogeny, low temperature adaptation, and potential biotechnological applications. The genome of P. prosekii P2406 comprised 5,896,482 bp and 5324 genes (GC content of 59.71%); the genome of P. prosekii P2673 consisted of 6,087,670 bp and 5511 genes (GC content of 59.50%). Whole genome sequence comparisons confirmed a close relationship between both investigated strains and strain P. prosekii LMG 26867T. Gene mining revealed the presence of genes involved in stress response, genes encoding cold shock proteins, oxidative stress proteins, osmoregulation proteins, genes for the synthesis of protection molecules, and siderophores. Comparative genome analysis of P. prosekii and P. aeruginosa PAO1 highlighted differences in genome content between extremophile species and a mesophilic opportunistic pathogen.

• MeSH
• aklimatizace MeSH
• bakteriální proteiny genetika   MeSH
• fylogeneze MeSH
• fyziologická adaptace MeSH
• genom bakteriální * MeSH
• mapování chromozomů MeSH
• nadmořská výška MeSH
• Pseudomonas genetika   izolace a purifikace   fyziologie   MeSH
• sekvence nukleotidů MeSH
• sekvenování celého genomu MeSH
• zastoupení bazí MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Antarktida MeSH

Changes in environmental temperature represent one of the major stresses faced by microorganisms as they affect the function of the cytoplasmic membrane. In this study, we have analyzed the thermal adaptation in two closely related respiratory pathogens Bordetella pertussis and Bordetella bronchiseptica Although B. pertussis represents a pathogen strictly adapted to the human body temperature, B. bronchiseptica causes infection in a broad range of animals and survives also outside of the host. We applied GC-MS to determine the fatty acids of both Bordetella species grown at different temperatures and analyzed the membrane fluidity by fluorescence anisotropy measurement. In parallel, we also monitored the effect of growth temperature changes on the expression and production of several virulence factors. In response to low temperatures, B. pertussis adapted its fatty acid composition and membrane fluidity to a considerably lesser extent when compared with B. bronchiseptica Remarkably, B. pertussis maintained the production of virulence factors at 24 °C, whereas B. bronchiseptica cells resumed the production only upon temperature upshift to 37 °C. This growth temperature-associated differential modulation of virulence factor production was linked to the phosphorylation state of transcriptional regulator BvgA. The observed differences in low-temperature adaptation between B. pertussis and B. bronchiseptica may result from selective adaptation of B. pertussis to the human host. We propose that the reduced plasticity of the B. pertussis membranes ensures sustained production of virulence factors at suboptimal temperatures and may play an important role in the transmission of the disease.

• MeSH
• aklimatizace * MeSH
• anizotropie MeSH
• bakteriální proteiny metabolismus   MeSH
• Bordetella bronchiseptica cytologie   fyziologie   MeSH
• Bordetella pertussis cytologie   fyziologie   MeSH
• buněčná membrána metabolismus   MeSH
• cytoplazma metabolismus   MeSH
• druhová specificita MeSH
• faktory virulence metabolismus   MeSH
• fluorescenční spektrometrie MeSH
• fosforylace MeSH
• lidé MeSH
• mastné kyseliny chemie   MeSH
• plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
• signální transdukce MeSH
• tělesná teplota MeSH
• teplota * MeSH
• transkripční faktory metabolismus   MeSH
• virulence MeSH
• životní prostředí MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The strategies used by living organisms to survive under low and freezing temperatures reveal the extraordinary adaptability of life on Earth. Understanding the molecular mechanisms underlying cold adaptation and freezing survival will provide new insights into the existing relationships between living organisms and their environment, and the possibility of developing multiple biotechnological applications. In the case of plants, the use of classical genetic and new "omics" approaches is allowing to the identification of new elements involved in regulating the cold acclimation response. The challenge ahead is to determine temperature-perception molecules and mechanisms, to uncover new internodes of multiple responses, and to integrate the regulation not only at the transcriptome but also at proteome and metabolome levels. Attaining these goals will significantly contribute global understanding the adaptive strategies plants have evolved to cope with hostile environmental conditions, and to the development biotechnological strategies to improve crop tolerance to freezing and other important abiotic stresses.

• MeSH
• adaptorové proteiny signální transdukční genetika   imunologie   MeSH
• aklimatizace fyziologie   genetika   imunologie   MeSH
• Arabidopsis cytologie   genetika   imunologie   MeSH
• biologická adaptace fyziologie   genetika   imunologie   MeSH
• biotechnologie metody   trendy   MeSH
• cytosol chemie   metabolismus   MeSH
• financování organizované MeSH
• fyziologická adaptace fyziologie   genetika   imunologie   MeSH
• metabolomika metody   MeSH
• molekulární biologie metody   MeSH
• nízká teplota škodlivé účinky   MeSH
• permeabilita buněčné membrány fyziologie   genetika   imunologie   MeSH
• proteomika metody   MeSH
• regulace genové exprese genetika   imunologie   MeSH
• rostliny MeSH
• Publikační typ
• přehledy MeSH

Many ectotherms effectively reduce their exposure to low or high environmental temperatures using behavioral thermoregulation. In terrestrial ectotherms, thermoregulatory strategies range from accurate thermoregulation to thermoconformity according to the costs and limits of thermoregulation, while in aquatic taxa the quantification of behavioral thermoregulation have received limited attention. We examined thermoregulation in two sympatric newt species, Ichthyosaura alpestris and Lissotriton vulgaris, exposed to elevated water temperatures under semi-natural conditions. According to a recent theory, we predicted that species for which elevated water temperatures pose a lower thermal quality habitat, would thermoregulate more effectively than species in thermally benign conditions. In the laboratory thermal gradient, L. vulgaris maintained higher body temperatures than I. alpestris. Semi-natural thermal conditions provided better thermal quality of habitat for L. vulgaris than for I. alpestris. Thermoregulatory indices indicated that I. alpestris actively thermoregulated its body temperature, whereas L. vulgaris remained passive to the thermal heterogeneity of aquatic environment. In the face of elevated water temperatures, sympatric newt species employed disparate thermoregulatory strategies according to the species-specific quality of the thermal habitat. Both strategies reduced newt exposure to suboptimal water temperatures with the same accuracy but with or without the costs of thermoregulation. The quantification of behavioral thermoregulation proves to be an important conceptual and methodological tool for thermal ecology studies not only in terrestrial but also in aquatic ectotherms.

• MeSH
• druhová specificita MeSH
• fyziologická adaptace * MeSH
• Salamandridae fyziologie   MeSH
• sympatrie fyziologie   MeSH
• tělesná teplota MeSH
• termoregulace fyziologie   MeSH
• voda * MeSH
• vysoká teplota * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH