Growth Temperature Range Research Articles

Pseudodesulfovibrio alkaliphilus, sp. nov., an alkaliphilic sulfate-reducing bacterium isolated from a terrestrial mud volcano.

The diversity of anaerobic microorganisms in terrestrial mud volcanoes is largely unexplored. Here we report the isolation of a novel sulfate-reducing alkaliphilic bacterium (strain F-1T) from a terrestrial mud volcano located at the Taman peninsula, Russia. Cells of strain F-1T were Gram-negative motile vibrios with a single polar flagellum; 2.0-4.0µm in length and 0.5µm in diameter. The temperature range for growth was 6-37°C, with an optimum at 24°C. The pH range for growth was 7.0-10.5, with an optimum at pH 9.5. Strain F-1T utilized lactate, pyruvate, and molecular hydrogen as electron donors and sulfate, sulfite, thiosulfate, elemental sulfur, fumarate or arsenate as electron acceptors. In the presence of sulfate, the end products of lactate oxidation were acetate, H2S and CO2. Lactate and pyruvate could also be fermented. The major product of lactate fermentation was acetate. The main cellular fatty acids were anteiso-C15:0, C16:0, C18:0, and iso-C17:1ω8. Phylogenetic analysis revealed that strain F-1T was most closely related to Pseudodesulfovibrio aespoeensis (98.05% similarity). The total size of the genome of the novel isolate was 3.23Mb and the genomic DNA G + C content was 61.93mol%. The genome contained all genes essential for dissimilatory sulfate reduction. We propose to assign strain F-1T to the genus Pseudodesulfovibrio, as a new species, Pseudodesulfovibrio alkaliphilus sp. nov. The type strain is F-1T (= KCTC 15918T = VKM B-3405T).

Effects of Temperature, Relative Humidity, and Carbon Dioxide Concentration on Growth and Glucosinolate Content of Kale Grown in a Plant Factory.

The growth of plants and their glucosinolate content largely depend on the cultivation environment; however, there are limited reports on the optimization of ambient environmental factors for kale grown in plant factories. This study was conducted to investigate the effects of temperature, relative humidity, and the carbon dioxide (CO2) concentration on kale growth and glucosinolate content in different growth stages of cultivation in a plant factory. Kale was grown under different temperatures (14, 17, 20, 23, and 26 °C), relative humidities (45, 55, 65, 75, and 85%), and CO2 concentrations (400, 700, 1000, 1300, and 1600 ppm) in a plant factory. Two and four weeks after transplantation, leaf samples were collected to evaluate the physical growth and glucosinolate contents. The statistical significance of the treatment effects was determined by two-way analysis of variance, and Duncan’s multiple range test was used to compare the means. A correlation matrix was constructed to show possible linear trends among the dependent variables. The observed optimal temperature, relative humidity, and CO2 range for growth (20–23 °C, 85%, and 700–1000 ppm) and total glucosinolate content (14–17 °C, 55–75%, and 1300–1600 ppm) were different. Furthermore, the glucosinolate content in kale decreased with the increase of temperature and relative humidity levels, and increased with the increase of CO2 concentration. Most of the physical growth variables showed strong positive correlations with each other but negative correlations with glucosinolate components. The findings of this study could be used by growers to maintain optimum environmental conditions for the better growth and production of glucosinolate-rich kale leaves in protected cultivation facilities.

Ellipsometry Study of CdSe Thin Films Deposited by PLD on ITO Coated Glass Substrates.

Cadmium selenide (CdSe) thin films were deposited on indium tin oxide (ITO) coated glass substrates using pulsed laser deposition (PLD) technique under different growth temperatures. Samples were investigated for their structural, morphological, and optical properties through X-ray diffraction (XRD), atomic force microscopy (AFM), and UV-Vis-NIR spectroscopy. AFM analysis revealed that the surface roughness of the as-grown CdSe thin films increased with the increase in deposition temperature. The optical constants and film thickness were obtained from spectroscopic ellipsometry analysis and are discussed in detail. The optical band gap of the as-grown CdSe thin films, calculated from the Tauc plot analysis, matched with the ellipsometry measurements, with a band gap of ~1.71 eV for a growth temperature range of 150 °C to 400 °C. The CdSe thin films were found to have a refractive index of ~3.0 and extinction coefficient of ~1.0, making it a suitable candidate for photovoltaics.

Ability of Cronobacter sakazakii to adhesion and invasion AMGM5 cell line

Background: Cronobacter sakazakii is gram-negative bacteria , rod–shaped , facultative anaerobic the growth temperature range is 6–45 ° C . It is have many virulence factor such OmpA , flagella and extracellular glycoproteins help to adhesion and invasion of the host and found in macrophage to use invasion other organs in body .Aim of the study: Study ability of bacterial to adhesion on non-living surfaces (polystyrene) and living surfaces (brain cancer cell line) and its invasion , its cytotoxicity.Patients and methodsFifteenth of C. sakazakii were obtained from previous studies ( 5 infant formula , 5 spinal fluid and 5 bloods ) . Study of movement ability of bacteria , adhesion to polystyrene , adhesion to AMGM5 , invasion of AMGM5 and its cytotoxicity .Results: In this study , the number of C. sakazakii colony adherent to polystyrene plate more than 300 CFU for four isolated , while adhesion to (AMGM5 ) in dilution (1 : 10 and 1 : 100) were more than 300 CFU to four isolated , the number of invasioncolonies to AMGM5 were CSF5 ( 285 CFU ) , A1C ( 220 CFU ) , B1 ( <300 CFU ) , C1 ( 235 CFU ) . Cytotoxicity of C . sakazakii was 45. 81 % when using A1C isolate.Conclusion: C . sakazakii have the ability to movement , adhesion to polystyrene , adhesion and invasion to Cerebral glioblastomamultiforme and cytotoxic.

Multi-colour light emission from InGaN nanowires monolithically grown on Si substrate by MBE

InGaN nanostructures are among the most promising candidates for visible solid-state lighting and renewable energy sources. To date, there is still a lack of information about the influence of the growth conditions on the physical properties of these nanostructures. Here, we extend the study of InGaN nanowires growth directly on Si substrates by plasma-assisted molecular beam epitaxy. The results of the study showed that under appropriate growth conditions a change in the growth temperature of just 10 °C leads to a significant change in the structural and optical properties of the nanowires. InGaN nanowires with the areas containing 4%–10% of In with increasing tendency towards the top are formed at the growth temperature of 665 °C, while at the growth temperatures range of 655 °C–660 °C the spontaneously core–shell NWs are typically presented. In the latter case, the In contents in the core and the shell are about an order of magnitude different (e.g. 35% and 4% for 655 °C, respectively). The photoluminescence study of the NWs demonstrates a shift in the spectra from blue to orange in accordance with an increase of In content. Based on these results, a novel approach to the monolithic growth of In x Ga1−x N NWs with multi-colour light emission on Si substrates by setting a temperature gradient over the substrate surface is proposed.

Biotreatment of oil sludge containing hydrocarbons by Proteus mirabilis SB

The release of petroleum hydrocarbons in the form of oil sludge poses a serious threat to people and the environment. At present, biodegradation of oily sludge is regarded as one of the most promising harmless treatment technologies, where the screening of high efficient degrading strains is the key to its implementation. In the present study, a strain Proteus mirabilis SB was isolated from oil sludge of Jingbian Oil Field. The strain grew and reproduced rapidly with petroleum hydrocarbon as the sole carbon source in the optimal growth temperature range of 30–35 °C, and salinity less than 6%. Its effective emulsification function was attributed to the production of biosurfactants, mainly rhamnolipids, through metabolism. Analysized by gas chromatography (GC) and four-fraction the degradation efficiency of total petroleum hydrocarbon (TPH) reached 70.5% within 2 weeks in the liquid culture medium, while the degradation efficiencies of saturated hydrocarbons, aromatics, resins and asphaltenes were 90.8%, 69.2%, 16.3% and 31.5%, respectively. For degrading petroleum hydrocarbons in oil sludge within a quasi-solid culture system under standard atmospheric conditions, a total degradation efficiency of 76.9% over 60 days was obtained, while 90.8% of saturated hydrocarbons and 69.2% of aromatics were degraded. Overall, the strain was capable of degrading petroleum hydrocarbons in both crude oil and oil sludge with high efficiencies This development demonstrated strong potential of Proteus mirabilis SB for oil sludge treatment and in situ bioremediation of crude oil contaminated soil/land.

사육수온이 강도다리 치어의 성장에 미치는 영향

This study aimed to investigate the optimal water temperature (low temperature; LT: 5, 8, 11 and 14℃, high temperature; HT: 17, 20, 23, 26 and 29℃) on growth of juvenile starry flounder. In the LT experiment, we used juvenile starry flounder averaging 19.3±0.1 g/fish (Mean ± SD) of body weight, in the HT experiment, the experimental fish averaging 15.8±2.7 g/fish (Mean ± SD) of body weight, and we reared the fish for 80 days. Survival of fish of LT group was >96.3%, and HT groups was >90.0% except for 29℃ (48.0%). Feed consumption, feed efficiency, weight gain and specific growth rate (SGR) in 5℃ was significantly lower than of fish reared at other temperature, and significantly higher weight gain was observed in 11 and 14℃ than other temperature of LT group. Highest weight gain and SGR was observed in 17℃ in HT group, and 29℃ was significantly lower than of fish reared at other temperature. Visceral somatic index and hepatosomatic index were not significantly difference among the temperature. Considering these results, the optimal rearing temperature range for normal growth and feed efficiency of juvenile starry flounder is 11-20℃.

Anaerotalea alkaliphila gen. nov., sp. nov., an alkaliphilic, anaerobic, fermentative bacterium isolated from a terrestrial mud volcano.

Diversity of extremophilic microorganisms in mud volcanoes is largely unexplored. Here, we report the isolation of a novel alkaliphilic, mesophilic, fermentative bacterium (strain F-3apT) from a terrestrial mud volcano located at the Taman peninsula, Russia. Cells of strain F-3apT are Gram-stain-positive non-motile rods. The formation of endospores is not observed. The temperature range for growth is 14-42°C, with an optimum at 37°C. The pH range for growth is 7.5-11.0, with an optimum at pH 9.0. The isolate utilizes various organic polymeric substances, organic acids, carbohydrates, and proteinaceous compounds. The end products of glucose fermentation are ethanol, CO2, and H2. The major cellular fatty acids of strain F-3apT are C16:0, C16:1, and C14:0. Phylogenetic analysis reveals that strain F-3apT belongs to the order Clostridiales, with less than 91% of 16S rRNA gene sequence similarity to any species with a validly published name. The total size of the genome of strain F-3apT is 2.98Mb, and a genomic DNA G + C content is 56.78mol%. The whole-genome phylogenetic analysis confirms that strain F-3apT forms a distinct lineage within Clostridia. We propose to assign strain F-3apT to a new species of a novel genus Anaerotalea alkaliphila gen. nov., sp. nov. The type strain is F-3apT (= KCTC 15917T = VKM B-3406T).

Growth temperature-dependent morphological, optical, and electrical study of SnO2 thin film by atomic layer deposition

Low temperature, high quality SnO2 thin film successfully deposited by the atomic layer deposition (ALD) method using tetrakis (dimethylamino)Sn (TDMASn) and O3-plasma. The influence of various growth temperatures having ranges between 115 °C to 250 °C on the film growth rate, morphology, composition, optical and electrical properties have been elucidated, and remarkable differences were noticed for possible electron transport layer (ETL). It was worth observing that the film growth rate steeply increased from 0.046 nm/cycle to 0.192 nm/cycle between the growth temperature range 115–250 °C because of the rapid dissociation of TDMASn precursor relative to temperature increase. The optical transmittances of films showed 81%–97% at the visible region for all growth temperatures; however, the optical bandgap energy of the SnO2 film was decreased from 3.4 eV to 3.1 eV while increasing deposition temperature. During lower deposition temperature of 115 °C, the film obtained high resistivity (7.3 × 102 Ω cm), while at a high growth temperature of 200 °C almost impurity-free low resistivity (8.9 × 10−4 Ω cm) film can be achieved apart from high carrier concentration (1.4 × 1021 cm−3) and 12.5 cm2 V−1s−1 mobility.

The circadian rhythm regulator RpaA modulates photosynthetic electron transport and alters the preferable temperature range for growth in a cyanobacterium.

Cyanobacterial strains can grow within a specific temperature range that approximately corresponds to their natural habitat. However, how the preferable temperature range for growth (PTRG) is determined at the molecular level remains unclear. In this study, we detected a PTRG upshift in a mutant strain of Synechococcuselongatus PCC 7942 lacking the circadian rhythm regulator RpaA. Subsequent analyses revealed that RpaA decreases the electron transport from photosystem I to NADPH. The change in electron transport likely inhibits H2 O2 generation under high-temperature conditions and contributes to the observed PTRG upshift in rpaA-deficient cells. The importance of the effects of the circadian rhythm regulator on the PTRG is discussed.

Water temperature effects on growth performance, proximate body and tissue composition, morphometric characteristics and gastrointestinal evacuation processes of juvenile meagre, Argyrosomus regius (Asso 1801)

The effect of 4 temperature levels, 17, 20, 23 and 26 °C was investigated on growth performance, feed and nutrient utilization, body, fillet and liver composition and morphometric characteristics of meagre, of initial mean weight 36.46 g, after a 12-week trial, fed on a practical diet composed of 49% crude protein and 16% lipids (dry weight). Furthermore, the gastrointestinal evacuation processes of meagre were monitored by subjecting fish to 48-h fasting period, followed by force-feeding and collecting the stomach and intestinal contents at 1 h, 2 h, 4 h, 6 h, 8 h, 12 h and 24 h post-feeding. Meagre growth parameters significantly improved with the increase in temperature, resulting in double the thermal growth coefficient (TGC) at 23 and 26 °C compared to 17 °C. Maximum weight (122.5 g) was achieved at 26 °C. Daily feed intake (DFI) increased from 17 to 26 °C, whereas nutrient efficiency and utilization parameters were significantly lower only at 17 °C. A time effect was also evident on the growth-related parameters and feed conversion ratio (FCR), resulting in similar specific growth rate (SGR) and TGC values between 23 and 26 °C and lower FCR only in 17 °C by the 3rd month, despite the initial difference amongst the 4 treatments. Intestine length increased as fish grew bigger with temperature increase, but the relative intestine length to fish total length remained constant. No effect of temperature was found on condition index (CI), hepatosomatic index (HSI), body proximate composition, fillet lipids and liver glycogen content. Liver lipid content significantly increased from 17 °C to 26 °C. Temperature influenced gastric evacuation patterns, but not the digesta moisture in each gastrointestinal tract (GIT) segment. Hydration within the GIT was affected by temperature with lower content obtained at 17 °C. Stomach digesta moisture and hydration significantly elevated 4 h post-feeding in all treatments. Within the intestine, unlike in the stomach, digesta were mostly comprised of moisture. Gastric evacuation rate (GER) became faster with temperature increase. Meagre juveniles required 4.3–7.4 h to half-empty their stomachs depending on temperature and more than 24 h to completely evacuate their GIT. 23–27 °C was determined as the best water temperature range for growth of meagre of 36-123 g under the specific culture conditions. At 17 °C growth and feed efficiency were impaired, while gastric evacuation processes deviated from the rest.

Study on optical performance and 532 nm laser damage of rapidly grown KDP crystals

Type II samples were obtained from the adjacent positions of pyramidal sector and prismatic sector in the same potassium dihydrogen phosphate (KDP) single crystal grown by the “point seed” technique under different temperature range and supersaturation. Some samples were annealed at 160 °C for 24 h. The UV–Vis spectra, especially in the ultraviolet region, show the optimal transmitting ability for the KDP crystal which was grown under relative low temperature range. The structural analysis performed by means of Fourier transformed infrared spectroscopy (FTIR) suggests that the crystal lattice of the KDP grown under relative small supersaturation become compact at the molecular level. The results of photoluminescence (PL) emission spectra show that the PL intensity increases with the rise of supersaturation and growth temperature range, which indicates that the concentration of all the detected micro defects in the KDP is abundant. The damage threshold conducted using 532 nm ns laser pulses shows the same trend with the results of PL spectra. The laser-induced damage threshold (LIDT) has been improved with the decrease of growth temperature range and supersaturation, and its variation has the highest correlation with the concentration of hydrogen vacancy defect. In addition, thermal annealing can effectively reduce the concentration of all the detected micro defects in the sample, and LIDT of the samples can be enhanced further after laser sub-threshold annealing. • KDP single crystals were obtained using the “point seed” rapid growth technique. • The relationship between laser-induced damage threshold and the concentration of micro defects is established. • The synergistic effect of thermal annealing and laser sub-threshold annealing is confirmed. • Enhanced laser-induced damage competence and laser-induced damage mechanism of the samples has been discussed.

Hydrogen-induced marginal growth model for the synthesis of graphene by arc discharge

High-quality graphene is prepared by arc discharge with low cost under hydrogen atmosphere. However, the growth mechanism of graphene synthesis by arc discharge remains unclear. In this paper, the hydrogen-induced marginal growth (HIMG) model is deduced to study the growth mechanism of graphene by combining experiment with numerical simulation results. First, the characteristics of thick edges and thin middle and containing hydrogen are verified by transmission electron microscopy and Raman spectroscopy, respectively. In addition, numerical simulation provides the chemical species and temperature range of graphene growth. Second, the marginal growth pattern of hydrogen transfer and carbon addition is introduced because the C-H and C-C reduce configuration energy and island energy, respectively. Meanwhile, the stacking growth at the margin of the graphene island leads to the longitudinal growth of graphene because of the Van der Waals force and the effect of self-assembly, increasing the number of graphene layers. Finally, graphene sheets with a small amount of hydrogen are deposited on the inner wall after annealing. The investigation of the growth mechanism of graphene under hydrogen atmosphere lays a foundation for the large-scale preparation of graphene by arc discharge.

Crystallinity, order, the thin-film silicon continuum, and the spectral dependence of the refractive index in thin silicon films grown through ultra-high-vacuum evaporation for a range of growth temperatures

Using ultra-high-vacuum evaporation, thin-films of silicon were grown. This paper starts with a placement of our thin-films into the overall thin-film silicon continuum. Then, our thin-film’s Raman spectra are examined. In particular, two short-range order Raman related measures, namely the breadth and position of the Raman spectrum’s transverse-optic-peak, and an intermediate-range order Raman related measure, namely the ratio of the integrated transverse-acoustic and transverse-optic-peak intensities, are plotted as functions of the growth temperature. We then correlate these changes found in the nature of the order found within our thin-films of silicon with the changes observed in the spectral dependence of the refractive index, focusing on the maximum of the refractive index over the spectral range under consideration in this analysis. We find that the maximum of the refractive index increases in response to increased ordering. Finally, the potential device implications of these results are explored.

Narrow range of temperature and irradiance supports optimal development of Lessonia corrugata (Ochrophyta) gametophytes: implications for kelp aquaculture and responses to climate change

The kelp Lessonia corrugata (Ochrophyta, Laminariales) is being developed for integrated multi-trophic aquaculture (IMTA) trials in the vicinity of salmon cages in Tasmania, Australia. Gametophytes are vegetally maintained before seeding on hatchery twine; however, the optimal temperature and light conditions for growth and sexual development are unknown. We measured vegetative size of female and male gametophytes and sexual development of females over a range of temperatures and irradiances using a temperature gradient table and neutral density light filters. Over a 4-week experiment, gametophytes were exposed to a combination of thermal (5.7–24.9 °C) and irradiance (10–100 μmol photons m−2 s−1) gradients, to assess biological performance. At the temperature extremes (hottest = 24.9 °C, coldest = 5.7 °C), we observed the critical thermal limits for this species and the results reveal a narrow optimal temperature range for growth and sexual development between 15.7 and 17.9 °C, with irradiances between 40 and 100 μmol photons m−2 s−1 resulting in fertile female gametophytes. Lessonia corrugata inhabits a small geographic range, found only around Tasmania, south of the Australian mainland, hence oceanic changes such as ongoing increases in sea surface temperatures (SSTs), and altered irradiance regimes may limit recruitment of the early microscopic life stages in the future. Our findings provide optimised culture conditions for aquaculture and information to predict the future geographic range of L. corrugata under ocean global change.

The damage and tolerance mechanisms of Phaffia rhodozyma mutant strain MK19 grown at 28\xa0\xb0C

BackgroundPhaffia rhodozyma has many desirable properties for astaxanthin production, including rapid heterotrophic metabolism and high cell densities in fermenter culture. The low optimal temperature range (17–21 °C) for cell growth and astaxanthin synthesis in this species presents an obstacle to efficient industrial-scale astaxanthin production. The inhibition mechanism of cell growth at > 21 °C in P. rhodozyma have not been investigated.ResultsMK19, a mutant P. rhodozyma strain grows well at moderate temperatures, its cell growth was also inhibited at 28 °C, but such inhibition was mitigated, and low biomass 6 g/L was obtained after 100 h culture. Transcriptome analysis indicated that low biomass at 28 °C resulted from strong suppression of DNA and RNA synthesis in MK19. Growth inhibition at 28 °C was due to cell membrane damage with a characteristic of low mRNA content of fatty acid (f.a.) pathway transcripts (acc, fas1, fas2), and consequent low f.a. content. Thinning of cell wall and low mannose content (leading to loss of cell wall integrity) also contributed to reduced cell growth at 28 °C in MK19. Levels of astaxanthin and ergosterol, two end-products of isoprenoid biosynthesis (a shunt pathway of f.a. biosynthesis), reached 2000 µg/g and 7500 µg/g respectively; ~2-fold higher than levels at 21 or 25 °C. Abundance of ergosterol, an important cell membrane component, compensated for lack of f.a., making possible the biomass production of 6 g/L for MK19 at 28 °C.ConclusionsInhibition of growth of P. rhodozyma at 28 °C results from blocking of DNA, RNA, f.a., and cell wall biosynthesis. In MK19, abundant ergosterol made possible biomass production 6 g/L at 28 °C. Significant accumulation of astaxanthin and ergosterol indicated an active MVA pathway in MK19 at 28 °C. Strengthening of the MVA pathway can be a feasible metabolic engineering approach for enhancement of astaxanthin synthesis in P. rhodozyma. The present findings provide useful mechanistic insights regarding adaptation of P. rhodozyma to 28 °C, and improved understanding of feasible metabolic engineering techniques for industrial scale astaxanthin production by this economically important yeast species.

Temperature dependence of Ga2O3 growth by halide vapor phase epitaxy on sapphire and β -Ga2O3 substrates

The influence of growth temperature on Ga2O3 growth by atmospheric-pressure halide vapor phase epitaxy was investigated on sapphire and β-Ga2O3 substrates. In the growth-temperature range of 700–1000 °C, the growth rate of Ga2O3 was in agreement with that estimated by thermodynamic analysis under the assumption of growth under thermal equilibrium. However, when the growth temperature was lower than 700 °C, the growth rate, which decreased as the growth temperature decreased, deviated from that estimated by thermodynamic analysis, reflecting growth behavior under nonthermal equilibrium. X-ray diffraction and optical absorption measurements of the grown layers revealed that the Ga2O3 growth under nonthermal equilibrium was constrained by the crystal structure of the substrate, i.e., the metastable phase α-Ga2O3(0001) grew on the sapphire (0001) substrate, whereas the stable phase β-Ga2O3 grew homoepitaxially on a β-Ga2O3(001) substrate. However, under thermal equilibrium, the growth of the stable phase β-Ga2O3 occurred irrespective of the substrate and the constraint from the crystal structure of the substrate was no longer observed. We also observed that in the β-Ga2O3 homoepitaxial layer grown under nonthermal equilibrium, crystal twinning occurred in the homoepitaxial layer, presumably due to an insufficient growth temperature.

Late Holocene seasonal temperature variability of the western Scottish shelf (St Kilda) recorded in fossil shells of the bivalve Glycymeris glycymeris

The North Atlantic Ocean and adjacent shelf seas play a crucial role in global climate. To better constrain long-term natural variability and marine-terrestrial linkages in this region, a network of highly resolved marine archives from the open ocean and continental shelves is needed. In recent decades, bivalve sclerochronology has emerged as a field providing such records from the mid- to high latitudes. In May 2014, dead valves and young live specimens of the bivalve Glycymeris glycymeris were collected at St Kilda, Scotland. A floating chronology spanning 187 years was constructed with fossil shells and radiocarbon dated to 3910–3340 cal yr before present (BP), with a probability density cluster at ca. 3700–3500 cal yr BP. Sub-annual δ18O data were obtained from five fossil and three modern specimens and showed a strong seasonal signal in both time intervals. The growth season of G. glycymeris at this location today lasts from May to October, with most growth occurring before the temperature peak in August. Thus, the modern specimens and the fossil chronology represent late-spring and summer sea surface temperatures (SST). The annual temperature range was 4.4 °C in the fossil shells, which is similar to the range observed today (3.8 °C). Average SSTs reconstructed from the fossil shells were 1 °C cooler than in 2003–2013 CE and similar to the early 20th century CE. The radiocarbon age of the floating chronology coincides with a climatic shift to wetter conditions on the British Isles and with a cold interval observed in palaeoceanographic records from south of Iceland. However, our data do not provide evidence of a cold interval on the Scottish shelf. The similarity in growth season and temperature range between the fossil and modern specimens are attributed to similar boundary conditions in the fourth millennium BP compared to today.

Environmental Regulation of the Distribution and Ecology of Bdellovibrio and Like Organisms.

The impact of key environmental factors, salinity, prey, and temperature, on the survival and ecology of Bdellovibrio and like bacteria (BALOs), including the freshwater/terrestrial, non-halotolerant group and the halophilic Halobacteriovorax strains, has been assessed based on a review of data in the literature. These topics have been studied by numerous investigators for nearly six decades now, and much valuable information has been amassed and reported. The collective data shows that salinity, prey, and temperature play a major role in, not only the growth and survival of BALOs, but also the structure and composition of BALO communities and the distribution of the predators. Salinity is a major determinant in the selection of BALO habitats, distribution, prey bacteria, and systematics. Halophilic BALOs require salt for cellular functions and are found only in saltwater habitats, and prey primarily on saltwater bacteria. To the contrary, freshwater/terrestrial BALOs are non-halotolerant and inhibited by salt concentrations greater than 0.5%, and are restricted to freshwater, soils, and other low salt environments. They prey preferentially on bacteria in the same habitats. The halophilic BALOs are further separated on the basis of their tolerance to various salt concentrations. Some strains are found in low salt environments and others in high salt regions. In situ studies have demonstrated that salinity gradients in estuarine systems govern the type of BALO communities that will persist within a specific gradient. Bacterial prey for BALOs functions more than just being a substrate for the predators and include the potential for different prey species to structure the BALO community at the phylotype level. The pattern of susceptibility or resistance of various bacteria species has been used almost universally to differentiate strains of new BALO isolates. However, the method suffers from a lack of uniformity among different laboratories. The use of molecular methods such as comparative analysis of the 16S rDNA gene and metagenomics have provided more specific approaches to distinguished between isolates. Differences in temperature growth range among different BALO groups and strains have been demonstrated in many laboratory experiments. The temperature optima and growth range for the saltwater BALOs is typically lower than that of the freshwater/terrestrial BALOs. The collective data shows not only that environmental factors have a great impact on BALO ecology, but also how the various factors affect BALO populations in nature.

The effect of concurrent elevation in CO2 and temperature on the growth, photosynthesis, and yield of potato crops.

Global climate change accompanied by continuous increases in atmospheric carbon dioxide (CO2) concentration and temperature affects the growth and yield of important crops. The present study investigated the effect of elevated temperature and CO2 concentrations on the growth, yield, and photosynthesis of potato (Solanum tuberosum L. cv. Superior) crops using Korean Soil-Plant-Atmosphere-Research chambers that allow the regulation of temperature and CO2 concentration under daylight conditions. Based on the average temperature from 1991 to 2010 in the Jeonju area, South Korea, potato plants were exposed to four different conditions: ambient weather (400 μmol mol-1, aCaT), elevated temperature (+4°C, aCeT), elevated CO2 concentration (800 μmol mol-1, eCaT), and concurrently elevated CO2 concentration and temperature (eCeT). Under aCeT conditions, the temperature exceeded the optimal growth temperature range towards the late growth phase that decreased stomatal conductance and canopy net photosynthetic rate and subsequently reduced biomass and tuber yield. Stomatal conductance and chlorophyll concentration were lower under eCaT conditions than under aCaT conditions, whereas late-growth phase biomass and tuber yield were greater. Compared to other conditions, eCeT yielded a distinct increase in growth and development and canopy net photosynthetic rate during tuber initiation and bulking. Consequently, biomass and canopy net photosynthesis increased, and tuber yield increased by 20.3%, which could be attributed to the increased tuber size, rather than increased tuber number. Elevated CO2 reduced chlorophyll, magnesium, and phosphorus concentrations; reducing nitrogen concentration (by approximately 39.7%) increased the C:N ratio. The data indicate that future climate conditions will likely change nutrient concentration and quality of crops. The present study shows that while elevated temperature may negatively influence the growth and yield of potato crops, especially towards the late-growth phase, the concurrent and appropriate elevation of CO2 and temperature could promote balanced development of source and sink organs and positively effect potato productivity and quality.