Heat inactivation of cucumber mosaic virus in cultured tissues of Stellaria media

In vivo heat inactivation of cucumber mosaic virus (CMV) was studied in a low-temperature-tolerant species, Stellaria media. Infectivity remained high in infected 5. media cultures grown at 25 °C or less, but could not be detected in cultures incubated at 32 °C for 28 days. When infected tissues were grown at 12–32 °C for 24 days, virus was still detectable at a low level in cultures incubated at 30 °C. The highest level of infectivity was in cultures at 12 °C.     

Sporulation,storage and infectivity of obligate aphid pathogen Pandora nouryi grown on novel granules of broomcorn millet and polymer gel

Aims: Producing granular cultures of obligate aphid pathogen Pandora nouryi for improved sporulation and storage. Methods and Results: Small millet–gel granules were made of the mixtures of 80–95% millet powder with 5–20% polymer gel (polyacrylamide, polyacrylate or acrylate‐acrylamide copolymer) and inoculated with mycelia at 30 mg biomass g^?1 dry granules plus 87·5% water, followed by static incubation at 20°C for 4–12 days. The fungus grew well on 12 preparations but best on that including 10% copolymer. An 8‐day culture of this preparation discharged maximally 58·5 × 10⁴ conidia mg^?1 granule at 100% RH and was capable of ejecting conidia at the nonsaturated regimes of 86–97% RH. During storage at 6°C, granular cultures with >85% water content had twofold longevity (120 days) and half‐decline period (34–36 days) of those stored at room temperature. The steadily high water content preserved the cultures better than that decreasing at 6°C. However, conidia from 70‐day‐stored granules were less infective to Myzus persicae nymphs than those from fresh ones based on their LC₅₀s. Conclusions: The millet–gel granules had higher sporulation capacity than reported Pandora cultures and a capability of spore discharge at nonsaturated humidity. Significance and Impact of the Study: The granular cultures are more useful for aphid control.     

Effectiveness of different cleaning agents on the adherence of Candida albicans to acrylic denture base resin

doi: 10.1111/j.1741‐2358.2010.00379.x
Effectiveness of different cleaning agents on the adherence of Candida albicans to acrylic denture base resin Objective:  To evaluate the ability of three alkaline peroxide‐type (Polident, Efferdent, Fittydent) and two mouth rinse cleaning agents (CloSYSII and Corsodyl) to inhibit Candida albicans on acrylic denture base resin. Background:  Appropriate routine cleaning of dentures is necessary to prevent denture stomatitis and maintenance of healthy supporting tissues. Materials and methods:  A total of 180 acrylic resin specimens (10 × 10 × 2 mm) were prepared and divided into six groups. Candida albicans was incubated on Sabouraud dextrose agar (SDA) at 37°C for 48 h. After dilution, a final yeast suspension of approximately 10 6 C. albicans per millimetre was prepared. Ten acrylic resin specimens for each group were placed in a sterile Petri dish covered with 20 ml of fungal suspension and incubated at 37°C for 90 min. Then, the specimens were immersed in 40 ml of the test solution at 37°C for 15, 30 and 60 min. Fungal cells adhering to acrylic resin surfaces were fixed in formaldehyde and counted microscopically. Results:  Mouth rinses showed the highest removal activity for all the treatment times and completely eliminated the adherence of C. albicans. Conclusions:  The use of mouth rinse may be a suitable method for cleaning dentures.     

Effect of incubation temperature on muscle growth of barramundi Lates calcarifer at hatch and post-exogenous feeding

Muscle morphology was investigated in newly hatched barramundi Lates calcarifer larvae incubated at set temperatures (26, 29 and 31° C) prior to hatching. Three days after hatching (the start of exogenous feeding), larvae from the 26 and 31° C treatments were each divided into two groups and reared at that temperature or transferred over the period of several hours to 29° C (control temperature). Incubation temperature significantly affected muscle cellularity in the developing embryo, with larvae incubated at 26° C (mean ±s .e . 223·3 ± 7·9) having on average 14·4% more inner muscle fibres than those incubated at 31° C (195·2 ± 8·8) and 4·8% more than those incubated at 29° C (213·5 ± 4·7). Conversely, inner muscle fibre cross‐sectional area significantly increased at the warm incubation temperature in L. calcarifer, so that the total cross‐sectional muscle area was not different between treatment groups. The total cross‐sectional area of superficial muscle fibres and the proportion of superficial to total fibre cross‐sectional area in just hatched L. calcarifer were also affected by incubation temperature, with incubation at the cool temperature (26° C) increasing both the total cross‐sectional area and proportion of superficial muscle fibres. By 9 days post‐hatch, the aforementioned differences were no longer significant. Similarly, there was no difference in total superficial fibre cross‐sectional area between any treatment groups of L. calcarifer, whereas incubation temperature still significantly affected the proportion of superficial to total muscle fibre cross‐sectional area. Larvae hatched and grown at 31° C had a significantly reduced percentage of superficial muscle cross‐sectional area (mean ±s .e . 5·11 ± 0·66%) compared with those incubated and grown at 29° C (8·04 ± 0·77%) and 26° C (9·32 ± 0·56%) and those incubated at 26° C and transferred to 29° C (7·52 ± 0·53%), and incubated at 31° C and transferred to 29° C (6·28 ± 0·69%). These results indicate that changes in muscle cellularity induced by raising or lowering the incubation temperature of L. calcarifer display varying degrees of persistence over developmental time. The significance of these findings to the culture of L. calcarifer is discussed.     

Regeneration of virus-free grapevines using in vitro apical culture

Fragmented shoot apex culture of grapevine has been demonstrated to regenerate plants free from the graft-transmissible diseases leafroll, yellow speckle, fleck and summer mottle. This technique in combination with heat therapy of the cultures has also produced vines free from fanleaf virus. Regenerated plants free of yellow speckle were consistently obtained if cultures were incubated at 27/20 °C but not if incubated at 35 °C. The possible ways that the in vitro elimination of these diseases was achieved are considered.     

Heart valve allograft decontamination with antibiotics: impact of the temperature of incubation on efficacy

Heart valve allografts are typically processed at 4°C in North America, including the step of antibiotic decontamination. In our own experience with heart valve banking, we often observe persistent positive cultures following decontamination at wet ice temperature. We hypothesized that warmer temperatures of incubation might increase the efficacy of the decontamination procedure. In a first series of experiments, 12 different bacterial species were grown overnight, frozen in standardized aliquots and used directly to inoculate antibiotic cocktail aliquots at 10⁵ colony-forming units (CFU)/ml. The antibiotic cocktail contains vancomycin (50 μg/ml), gentamicin (80 μg/ml) and cefoxitin (240 μg/ml) in Dulbecco’s Modified Eagle’s Medium. Inoculated aliquots were incubated at 4, 22 and 37°C and CFUs were determined at regular intervals up to 24 h post-inoculation. In a second set of experiments, 10 heart valves were spiked with 5000 CFU/ml and incubated with antibiotics at 4 and 37°C for 24 h. The final rinse solutions of these heart valves were filtered and tested for bacterial growth. After 24 h of incubation, CFUs of all 12 bacterial species were reduced by a factor of only one to two logs at 4°C whereas log reductions of 3.7 and 5.0 or higher were obtained at 22 and 37°C, respectively. Most microorganisms, including Staphylococcus epidermidis, Lactococcus lactis lactis and Propionibacterium acnes survived well the 24-h antibiotic treatment at 4°C (<1 Log reduction). All 10 heart valves that were spiked with microorganisms had positive final rinse solutions after antibiotic soaking at 4°C, whereas 8 out of 10 cultures were negative when antibiotic decontamination was done at 37°C. These experiments show that a wet ice temperature greatly reduces the efficacy of the allograft decontamination process as microorganisms survived well to a 24-h 4°C antibiotic treatment. This could explain the high rate of positive post-processing cultures obtained with our routine tissue decontamination procedure. Increasing the decontamination temperature from 4 to 37°C may significantly reduce the incidence of post-disinfection bacterial contamination of heart valves.     

Growth rate of the carrageenophyte Kappaphycus alvarezii (Rhodophyta, Gigartinales) in vitro

Unialgal cultures were established trom a 2.5 g branch ot a brown variant ot Kappaphycus alvarezii (Doty) Doty ex P. Silva, with the main objective to produce branches for monthly outplanting in the sea. Ditterent conditions were tested to optimize production ot branches in the laboratory. The best growth was obtained under culture conditions of 25 ± 2°C, 170–210 μmol photons m² s^?1, 14:10 LD photoperiod and salinity 32–35‰. Three culture media (Provasoli,‘F/2’and von Stosch) were tested. Deleterious ettects were observed in branches incubated continuously in full‐ or halt‐strength Provasoli's enriched seawater medium (PES). Exponential growth rates ot about 3% day^?1 were obtained using PES, pulse‐fed 24 h per week, or other diluted media used continuously (one‐quarter strength ‘F/2’and half‐strength von Stosch). Laboratory‐grown branches with mean weights from 2.97 to 4.25 g were successfully introduced into the sea at Ubatuba, SP, Brazil (23°26.9′S, 45°0.3′W) an area with mean monthly seawater temperature from 20.3 to 28.5°C (extremes: 17.0–31.0°C). Transplantation of branches produced in unialgal culture, as done in the present study, avoids the risk of introduction of unwanted species into new areas.     

Activation of an Aquareovirus,Chum Salmon Reovirus (CSV), by the Ciliates Tetrahymena thermophila and T. canadensis

For the first time, ciliates have been found to activate rather than inactivate a virus, chum salmon reovirus (CSV). Activation was seen as an increase in viral titre upon incubation of CSV at 22 °C with Tetrahymena canadenesis and two strains of T. thermophila: wild type (B1975) and a temperature conditional mutant for phagocytosis (NP1). The titre increase was not likely due to replication because CSV had no visible effects on the ciliates and no vertebrate virus has ever been shown unequivocally to replicate in ciliates. When incubated with B1975 and NP1 at 30 °C, CSV was activated only by B1975. Therefore, activation required CSV internalization because at 30 °C only B1975 exhibited phagocytosis. CSV replicated in fish cells at 18 to 26 °C but not at 30 °C. Collectively, these observations point to CSV activation being distinct from replication. Activation is attributed to the CSV capsid being modified in the ciliate phagosomal‐lysosomal system and released in a more infectious form. When allowed to swim in CSV‐infected fish cell cultures, collected, washed, and transferred to uninfected cultures, T. canadensis caused a CSV infection. Overall the results suggest that ciliates could have roles in the environmental dissemination of some fish viral diseases.     

Cutinase promotes dry esterification of cotton cellulose

Cutinase from Thermobifida fusca was used to esterify the hydroxyl groups of cellulose with the fatty acids from triolein. Cutinase and triolein were pre‐adsorbed on cotton and the reaction proceeded in a dry state during 48 h at 35°C. The cutinase‐catalyzed esterification of the surface of cotton fabric resulted in the linkage of the oleate groups to the glycoside units of cotton cellulose. The superficial modification was confirmed by performing ATR‐FTIR on treated cotton samples and by MALDI‐TOF analysis of the liquors from the treatment of the esterified cotton with a crude cellulase mixture. Modified cotton fabric also showed a significant increase of hydrophobicity. This work proposes a novel bio‐based approach to obtain hydrophobic cotton. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 32:60–65, 2016     

Investigation of critical inter‐related factors affecting the efficacy of pulsed light for inactivating clinically relevant bacterial pathogens

Aims: To investigate critical electrical and biological factors governing the efficacy of pulsed light (PL) for the in vitro inactivation of bacteria isolated from the clinical environment. Development of this alternative PL decontamination approach is timely, as the incidence of health care–related infections remains unacceptably high. Methods and Results: Predetermined cell numbers of clinically relevant Gram‐positive and Gram‐negative bacteria were inoculated separately on agar plates and were flashed with ≤60 pulses of broad‐spectrum light under varying operating conditions, and their inactivation measured. Significant differences in inactivation largely occurred depending on the level of the applied lamp discharge energy (range 3·2–20 J per pulse), the amount of pulsing applied (range 0–60 pulses) and the distance between light source and treatment surface (range 8–20 cm) used. Greater decontamination levels were achieved using a combination of higher lamp discharge energies, increased number of pulses and shorter distances between treatment surface and the xenon light source. Levels of microbial sensitivity also varied depending on the population type, size and age of cultures treated. Production of pigment pyocynanin and alginate slime in mucoid strains of Pseudomonas aeruginosa afforded some protection against lethal action of PL; however, this was evident only by using a combination of reduced amount of pulsing at the lower lamp discharge energies tested. A clear pattern was observed where Gram‐positive bacterial pathogens were more resistant to cidal effects of PL compared to Gram negatives. While negligible photoreactivation of PL‐treated bacterial strains occurred after full pulsing regimes at the different lamp discharge energies tested, some repair was evident when using a combination of reduced pulsing at the lower lamp discharge energies. Strains harbouring genes for multiple resistances to antibiotics were not significantly more resistant to PL treatments. Slight temperature rises (≤4·2°C) were measured on agar surfaces after extended pulsing at higher lamp discharge energies. Presence of organic matter on treatment surface did not significantly affect PL decontamination efficacy, nor did growth of PL‐treated bacteria on selective agar diminish survival compared to similarly treated bacteria inoculated and enumerated on nonselective agar plates. Conclusions: Critical inter‐related factors affecting the effective and repeatable in vitro decontamination performance of PL were identified during this study that will aid further development of this athermal process technology for applications in health care and in industry. Very rapid reductions (c. 7 log₁₀ CFU cm^?2 within ≤10 pulses) occurred using discharge energy of 20 J for all tested clinically relevant bacteria under study when treated at 8 cm distance from xenon light source. While no resistant flora is expected to develop for treatment of microbial pathogens on two‐dimensional surfaces, careful consideration of scale up factors such as design and operational usage of this PL technique will be required to assure operator safety. Significance and Impact of the Study: Findings and conclusions derived from this study will enable further development and optimization of this decontamination technique in health care and in food preparation settings, and will advance the field of nonthermal processing technologies.     

Interactions between Escherichia coli and the plant‐parasitic nematode Meloidogyne javanica

Aims: To determine the potential of the plant‐parasitic nematode Meloidogyne javanica to serve as a temporary reservoir for Escherichia coli. Methods and Results: The adhesion to and persistence of E. coli on the surface of M. javanica were evaluated at different times and temperatures. A pure culture of green fluorescent protein (GFP) tagged E. coli was mixed with ca. 1000 J2 M. javanica for 2 h at 25°C. The nematodes were then washed and the rate of the adhesion of the bacteria to the nematodes was determined by counting the viable nematode‐associated E. coli, and by fluorescence microscopy. A dose‐dependent adhesion rate was observed only at a bacterium to nematode ratio of 10⁴–10⁶ : 1. The adhesion of E. coli to the nematodes was also tested over a 24 h‐period at 4°C, 25°C and 37°C. At 4°C and 37°C, maximal adhesion was observed at 5 h; whereas at 25°C, maximal adherence was observed at 8 h. Survival experiments showed that the bacteria could be detected on the nematodes for up to 2 weeks when incubated at 4°C and 25°C, but not at 37°C. Conclusions: Under laboratory conditions, at 4°C and 25°C, M. javanica could serve as a temporary vector for E. coli for up to 2 weeks. Significance and Impact of the Study: These findings support the hypothesis that, in the presence of high concentrations of E. coli, M. javanica might serve as a potential vehicle for the transmission of food‐borne pathogens.     

Effects of incubation temperature on the organic amendment‐mediated control of Fusarium wilt of tomato

Organic soil amendments play important roles in the reduction of plant diseases caused by soil‐borne plant pathogens. This study examined the combined effects of concentrations of organic amendments, temperature and period of incubation in soil on the management of Fusarium wilt of tomato caused by Fusarium oxysporum f. sp. lycopersici (Fol). In an experiment with substrate mixture, Fol reduction was higher when the soils were incubated at 35°C than at 30°C. Disease severity was proportionally reduced as the volume of amendment added increased. Furthermore, disease was significantly lower in substrates incubated for 30 days at both temperatures, as compared to substrates incubated for only 15 days. The most effective control was achieved with pelletised poultry manure (PPM). In experiments with natural sandy soil, the effects of amendments on Fol populations, measured by real‐time quantitative PCR with TaqMan probes, were significant. The highest decreases in Fol DNA resulted when the soil was amended with 2% PPM and incubated at 35°C. The reductions in DNA concentrations was most likely related to the accumulations of high concentrations of NH₃ (27.3 mM) in soils treated with 2% PPM and incubated at room temperature (RT; 23 ± 2°C), or at 35°C. Severity of plants grown in soils incubated at RT decreased by over 40%, and more than 73% when incubated at 35°C, regardless of the rate of PPM. The results indicate that the management with PPM, when combined with heating or solarisation, is an effective control measure against Fusarium wilt of tomato.     

Latitudinal differences in temperature effects on the embryonic development and hatchling phenotypes of the Asian yellow pond turtle,Mauremys mutica

The effect of incubation temperature on embryonic development and offspring traits has been widely reported for many species. However, knowledge remains limited about how such effects vary across populations. Here, we investigated whether incubation temperature (26, 28, and 30 °C) differentially affects the embryonic development of Asian yellow pond turtle (Mauremys mutica) eggs originating from low‐latitude (Guangzhou, 23°06′N) and high‐latitude (Haining, 30°19′N) populations in China. At 26 °C, the duration of incubation was shorter in the high‐latitude population than in the low‐latitude population. However, this pattern was reversed at 30 °C. As the incubation temperature increased, hatching success increased in the low‐latitude population but slightly decreased in the high‐latitude population. Hatchlings incubated at 30 °C were larger and righted themselves more rapidly than those incubated at 26 °C in the low‐latitude population. In contrast, hatchling traits were not influenced by incubation temperature in the high‐latitude population. Overall, 30 °C was a suitable developmental temperature for embryos from the low‐latitude population, whereas 26 and 28 °C were suitable for those from the high‐latitude population. This interpopulation difference in suitable developmental temperatures is consistent with the difference in the thermal environment of the two localities. Therefore, similarly to posthatching individuals, reptile embryos from different populations might have evolved diverse physiological strategies to benefit from the thermal environment in which they develop. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 114 , 35–43.     

Electron transport is the functional limitation of photosynthesis in field-grown Pima cotton plants at high temperature

Restrictions to photosynthesis can limit plant growth at high temperature in a variety of ways. In addition to increasing photorespiration, moderately high temperatures (35–42 °C) can cause direct injury to the photosynthetic apparatus. Both carbon metabolism and thylakoid reactions have been suggested as the primary site of injury at these temperatures. In the present study this issue was addressed by first characterizing leaf temperature dynamics in Pima cotton (Gossypium barbadense) grown under irrigation in the US desert south‐west. It was found that cotton leaves repeatedly reached temperatures above 40 °C and could fluctuate as much as 8 or 10 °C in a matter of seconds. Laboratory studies revealed a maximum photosynthetic rate at 30–33 °C that declined by 22% at 45 °C. The majority of the inhibition persisted upon return to 30 °C. The mechanism of this limitation was assessed by measuring the response of photosynthesis to CO₂ in the laboratory. The first time a cotton leaf (grown at 30 °C) was exposed to 45 °C, photosynthetic electron transport was stimulated (at high CO₂) because of an increased flux through the photorespiratory pathway. However, upon cooling back to 30 °C, photosynthetic electron transport was inhibited and fell substantially below the level measured before the heat treatment. In the field, the response of assimilation (A) to various internal levels of CO₂ (C_i) revealed that photosynthesis was limited by ribulose‐1,5‐bisphosphate (RuBP) regeneration at normal levels of CO₂ (presumably because of limitations in thylakoid reactions needed to support RuBP regeneration). There was no evidence of a ribulose‐1,5‐bisphosphate carboxylase/oxygenase (Rubisco) limitation at air levels of CO₂ and at no point on any of 30 A–C_i curves measured on leaves at temperatures from 28 to 39 °C was RuBP regeneration capacity measured to be in substantial excess of the capacity of Rubisco to use RuBP. It is therefore concluded that photosynthesis in field‐grown Pima cotton leaves is functionally limited by photosynthetic electron transport and RuBP regeneration capacity, not Rubisco activity.     

Fast‐responding thermal‐death‐time tubes for the determination of thermal bacteria inactivation

The knowledge of thermal inactivation kinetics, usually expressed in terms of D‐ and z‐values, is of crucial importance for the design of sanitation and sterilization processes. In this study, we designed a simple, fast‐responding, and mechanically stable aluminum tube for inactivation measurements and compared these experiments with the successive‐sampling method at different temperatures. Up to 65°C, we determined a come‐up time of approximately 15 s for the tubes, which is lower than the corresponding values of other devices, presumably because of lower wall thickness, material properties, and a higher surface to volume ratio. D‐values of Escherichia coli calculated from tube inactivation experiments by first‐order kinetics were 370 s (56°C), 126 s (58°C), 53.2 s (60°C), 33.8 s (62°C), and 3.22 s (65°C), and the corresponding values determined with the successive‐sampling flask method were insignificantly different (417, 138, 48.6, and 29.1 s for 56, 58, 60, and 62°C, respectively). These data as well as those measured for Enterobacter cloacae, Pseudomonas putida, Serratia odorifera, and Yersinia rhodei were in close accordance with literature values.     

DNase test as a novel approach for the routine screening of Corynebacterium diphtheriae

Aims: To examine the value of the DNase test as an alternative procedure for differentiating Corynebacterium diphtheriae from Corynebacterium‐like colonies. Methods and Results: DNase test medium was inoculated by spotting a loopful of bacterial growth and incubated aerobically at 37°C. The DNase production was detectable following both 24 and 48 h incubation periods. The DNase activity was detected in all 91 C. diphtheriae (37 toxigenic and 54 nontoxigenic) strains examined, previously identified by both conventional biochemical methods and API Coryne System. Conversely, DNase test results were negative in 93·9% of the 564 nondiphtherial Gram‐positive rod clinical strains. Conclusions: The DNase test emerged as an easily interpretable and cost‐effective alternative screening procedure for C. diphtheriae laboratory identification. Significance and Impact of the Study: The method should facilitate routine laboratory diagnosis of toxigenic and nontoxigenic C. diphtheriae.     

Effect of egg‐phosphatidylcholine on the chilling sensitivity and lipid phase transition of Asian elephant (Elephas maximus) spermatozoa

This study was conducted in an effort to improve our understanding of the response of Asian elephant (Elephas maximus, Em) spermatozoa to chilling. Semen was collected from two elephant bulls by means of the manual rectal stimulation method. Five out of seven semen collections were deemed to be suitable for use based on motility (ranging from 20% to 60%) and membrane integrity. We evaluated the chilling sensitivity by incubating the sperm with a fluorescent dye (5‐carboxyfluorescein diacetate (cFDA)) at 16°C, 12°C, 4°C, and 22°C (control). Cells with an intact membrane retained the dye and were identified as viable. The membrane lipid phase transition (LPT) temperature curve was determined with a Fourier transform infrared (FTIR) spectrometer connected to an FTIR microscope. The LPT center, T_m, was determined by statistical analysis. The LPT and T_m were also assessed in fresh spermatozoa and spermatozoa incubated with egg yolk or egg‐phosphatidylcholine (EPC) liposomes at 16°C, 12°C, 4°C, and 26°C (control). The results show that the membrane integrity of spermatozoa incubated at 16°C, 12°C, and 4°C decreased by 39%, 62%, and 67%, respectively, compared to the control. The LPT temperatures were between room temperature (26°C) and 10°C, with T_m at 14–16°C. The T_m for sperm incubated with liposomes or egg‐yolk extender was below the measured range (2°C). Chilling sensitivity was found at a wide range of temperatures and transition temperatures, suggesting the presence of a wide variety of fatty acids (FAs) in the membrane with a high ratio of saturated‐to‐polyunsaturated FAs. Here we show that the protection afforded by the presence of egg yolk or liposomes in the extender is accomplished by shifting the T_m to below the 4°C point at which chilled semen is maintained for transport, or the point at which fast freezing begins to minimize cellular damage. Zoo Biol 0:1–13, 2005. © 2005 Wiley‐Liss, Inc.     

Isolation and characterization of a novel organic solvent-tolerant Anoxybacillus sp. PGDY12, a thermophilic Gram-positive bacterium

Aims: To isolate and characterize new bacteria capable of tolerating high concentrations of organic solvents at high temperature. Methods and Results: A solvent‐tolerant, thermophilic bacterium was isolated from hot spring samples at 55°C. The strain PGDY12 was characterized as a Gram‐positive bacterium. It was able to tolerate 100% solvents, such as toluene, benzene and p‐xylene on plate overlay and high concentrations of these solvents in liquid cultures. A comparison of growth showed that 0·2% (v/v) benzene and 0·15% (v/v) p‐xylene were capable of enhancing the final cell yields. Transmission electron micrographs showed the incrassation of electron‐transparent intracellular material and the distorted cytoplasm in case of the cells grown in toluene. A phylogenetic analysis based on 16S rRNA sequence data indicated that the strain PGDY12 was member of the genus Anoxybacillus. Conclusions: The thermophilic, Gram‐positive Anoxybacillus sp. PGDY12 exhibited a unique and remarkable ability to tolerate solvents at 55°C. Significance and Impact of the Study: The solvent tolerance properties are less known in thermophilic bacteria. The Anoxybacillus sp. PGDY12 is the first strictly thermophilic bacterium able to tolerate a broad range of solvents. This strain is a promising candidate for use as a high temperature biocatalyst in the biotechnological applications.     

Environmental cues for natural reproduction of the Chinese sturgeon,Acipenser sinensis Gray, 1835, in the Yangtze River,China

For effective conservation, it is important to explore the environmental cues initiating the spawning activities of a fish species. Based on monitoring data gathered between 1998 and 2011, the relationships between spawning activities of the Chinese sturgeon, Acipenser sinensis, and several environmental cues were analyzed using the rare events logistic regression ‘Relogit’ method, which indicated that water temperature, 1‐day ?‐discharge, and atmospheric pressure were among the key spawning cues for A. sinensis (P < 0.05). It is suggested that Chinese sturgeon might have an optimal environment window of 17–20°C water temperature, high day‐to‐day discharge increase, and low atmospheric pressure for spawning. In support of Chinese sturgeon reproduction, suggested modifications to the operational procedures for the Three Gorges Reservoir (TGR) to trigger spawning are: lowering the downstream water temperature to below 20°C before mid‐October and expanding the period with water temperatures of between 17 and 20°C; to create a day‐to‐day intermittent increase in the discharge to an optimal spawning water temperature; and to regulate flow at nights with a low atmospheric pressure.     

Effects of temperature on germination and hyphal growth from ascospores of A-group and B-group Leptosphaeria maculans (phoma stem canker of oilseed rape)

Ascospores of both A‐group and B‐group Leptosphaeria maculans germinated at temperatures from 5–20°C on distilled water agar or detached oilseed rape leaves. After 2 h of incubation on water agar, some A‐group ascospores had germinated at 10–20°C and some B‐group ascospores had germinated at 5–20°C. The percentages of both A‐group and B‐group ascospores that had germinated after 24 h of incubation increased with increasing temperature from 5–20°C. The observed time (Vo₅₀) which elapsed from inoculation until 50% of the spores had germinated was shorter for B‐group than for A‐group ascospores. Germ tube length increased with increasing temperature from 5–20°C for both ascospore groups. Germ tubes from B‐group ascospores were longer than germ tubes from A‐group ascospores at all temperatures tested, but the mean diameter of germ tubes from A‐group ascospores (1.8 μm) was greater than that of those from B‐group ascospores (1.2μm) at 15°C and 20°C. The average number of germ tubes produced from A‐group ascospores (3.8) was greater than that from B‐group ascospores (3.1) after 24 h of incubation at 20°C, on both water agar and leaf surfaces. Germ tubes originated predominantly from interstitial cells or terminal cells of A‐group or B‐group ascospores, respectively, on both water agar and leaf surfaces. Hyphae from A‐group ascospores grew tortuously with extensive branching, whilst those from B‐group ascospores were predominantly long and straight with little branching, whether the ascospores were produced from oilseed rape debris or from crosses between single ascospore isolates, and whether ascospores were germinating on water agar or leaf surfaces.