Maximum Growth Temperature Research Articles

Unveiling species diversity within early-diverging fungi from China II: Three new species of Absidia (Cunninghamellaceae, Mucoromycota) from Hainan Province.

Absidia is distributed worldwide and primarily isolated from soil, feces, and decaying plants. The genus was initially classified into Absidiaceae and then Mucoraceae, and currently belongs to Cunninghamellaceae and is further divided into Absidia s.s., Lichtheimia, and Lentamyces. Three new species of Absidia s.s. are identified and described from soil in Hainan Province of China based on morphological characteristics, molecular data, and maximum growth temperatures as well. They are named based on distinct shapes of projections on columellae: A.crystalloides sp. nov. (crystal-like), A.pacifica sp. nov. (pacifier-like), A.pateriformis sp. nov. (bowling-like). In SSU-ITS-LSU-TEF-Act phylogram, the A.crystalloides is closely related to A.oblongispora and A.heterospora, the A.pacifica is a sister group with A.edaphica, and the A.pateriformis has a close relationship with A.jiangxiensis. This study enriches the species diversity of Absidia in China.

Evidence for widespread thermal acclimation of canopy photosynthesis.

Plants acclimate to temperature by adjusting their photosynthetic capacity over weeks to months. However, most evidence for photosynthetic acclimation derives from leaf-scale experiments. Here we address the scarcity of evidence for canopy-scale photosynthetic acclimation by examining the correlation between maximum photosynthetic rates (Amax,2,000) and growth temperature ( ) across a range of concurrent temperatures and canopy foliage quantity, using data from >200 eddy covariance sites. We detect widespread thermal acclimation of canopy-scale photosynthesis, demonstrated by enhanced Amax,2,000 under higher , across flux sites with adequate water availability. A 14-day period is identified as the most relevant timescale for acclimation across all sites, with a range of 12-25 days for different plant functional types. The mean apparent thermal acclimation rate across all ecosystems is 0.41 (-0.38-1.04 for 5th-95th percentile range) µmol m-2 s-1 °C-1, with croplands showing the largest acclimation rates and grasslands the lowest. Incorporating an optimality-based prediction of leaf photosynthetic capacities into a biochemical photosynthesis model is shown to improve the representation of thermal acclimation. Our results underscore the critical need for enhanced understanding and modelling of canopy-scale photosynthetic capacity to accurately predict plant responses to warmer growing seasons.

Первая находка для России Cadophora qinghaitibetana (Ascomycota) с Кавказа

Cadophora qinghaitibetana is isolated from soil near glacier at the mountains of the Caucasus (Tsei Gorge, the Main Caucasus Range, Republic of North Ossetia – Alania). Macro- and micromorphology of the isolate along with partial sequences of the internal transcribed spacer of rDNA (ITS1-5.8S-ITS2) are studied. The observed micro- and macromorphology of isolate NN-22 from Tsei Gorge corresponds to the micro- and macromorphology of C. qinghaitibetana from soils and melt water from the Yulong and Baima Mountains located on the Qinghai-Tibet Plateau, i. e., Tibetan Plateau (China), but the maximum growth temperature is higher. As a result of our study, we detected C. qinghaitibetana in the Caucasus and Russia for the first time. Our study shows that C. qinghaitibetana is a species found in both the Tibetan Plateau and the Caucasian mountains.

Unveiling species diversity within early-diverging fungi from China I: three new species of Backusella (Backusellaceae, Mucoromycota).

The species diversity of early-diverging fungi has long lagged behind that of higher fungi, posing a significant obstacle to our comprehensive understanding of the fungal kingdom. Our ongoing research endeavors aim to address this gap by exploring the species diversity of early-diverging fungi in China. In this study, we describe three novel species within the Backusella, namely B.elliptica sp. nov., B.fujianensis sp. nov., and B.variispora sp. nov., based on phylogenetic and morphological analyses. In the phylogenetic analysis of the ITS (internal transcribed spacer), LSU (large subunit of ribosomal RNA gene), and RPB1 (RNA polymerase II largest subunit gene) regions, the B.elliptica and B.fujianensis cluster closely with B.gigacellularis, B.ovalispora, and B.solicola, and the B.variispora is closely related to B.locustae and B.pernambucensis. Morphologically, B.elliptica is distinguished by elliptical sporangiospores, as well as cylindrical and hemispherical columellae. The B.fujianensis is characterized by elliptical sporangiospores, and various types of columellae such as hemispherical, subglobose, depressed globose and conical. The B.variispora is characterized by subglobose to globose sporangiospores, as well as hemispherical, subglobose to globose columellae. Additionally, the sporangiophores are long and monopodially branched in B.elliptica and B.fujianensis, while short and simple or sympodially branched in B.variispora. Physiologically, the maximum growth temperatures of B.elliptica (32 °C), B.fujianensis (35 °C), and B.variispora were (35 °C) were determined. With the inclusion of these newly described taxa, the total number of Backusella species known from China now stands at 12. Finally, we provide a key to facilitate the morphological identification of Backusella species from Asia.

Engineering of Ogataea polymorpha strains with ability for high-temperature alcoholic fermentation of cellobiose.

Successful conversion of cellulosic biomass into biofuels requires organisms capable of efficiently utilizing xylose as well as cellodextrins and glucose. Ogataea (Hansenula) polymorpha is the natural xylose-metabolizing organism and is one of the most thermotolerant yeasts known, with a maximum growth temperature above 50°C. Cellobiose-fermenting strains, derivatives of an improved ethanol producer from xylose O.polymorpha BEP/cat8∆, were constructed in this work by the introduction of heterologous genes encoding cellodextrin transporters (CDTs) and intracellular enzymes (β-glucosidase or cellobiose phosphorylase) that hydrolyze cellobiose. For this purpose, the genes gh1-1 of β-glucosidase, CDT-1m and CDT-2m of cellodextrin transporters from Neurospora crassa and the CBP gene coding for cellobiose phosphorylase from Saccharophagus degradans, were successfully expressed in O. polymorpha. Through metabolic engineering and mutagenesis, strains BEP/cat8∆/gh1-1/CDT-1m and BEP/cat8∆/CBP-1/CDT-2mAM were developed, showing improved parameters for high-temperature alcoholic fermentation of cellobiose. The study highlights the need for further optimization to enhance ethanol yields and elucidate cellobiose metabolism intricacies in O. polymorpha yeast. This is the first report of the successful development of stable methylotrophic thermotolerant strains of O.polymorpha capable of coutilizing cellobiose, glucose, and xylose under high-temperature alcoholic fermentation conditions at 45°C.

Phytoplankton thermal trait parameterization alters community structure and biogeochemical processes in a modeled ocean.

Phytoplankton exhibit diverse physiological responses to temperature which influence their fitness in the environment and consequently alter their community structure. Here, we explored the sensitivity of phytoplankton community structure to thermal response parameterization in a modelled marine phytoplankton community. Using published empirical data, we evaluated the maximum thermal growth rates (μmax ) and temperature coefficients (Q10 ; the rate at which growth scales with temperature) of six key Phytoplankton Functional Types (PFTs): coccolithophores, cyanobacteria, diatoms, diazotrophs, dinoflagellates, and green algae. Following three well-documented methods, PFTs were either assumed to have (1) the same μmax and the same Q10 (as in to Eppley, 1972), (2) a unique μmax but the same Q10 (similar to Kremer etal., 2017), or (3) a unique μmax and a unique Q10 (following Anderson etal., 2021). These trait values were then implemented within the Massachusetts Institute of Technology biogeochemistry and ecosystem model (called Darwin) for each PFT under a control and climate change scenario. Our results suggest that applying a μmax and Q10 universally across PFTs (as in Eppley, 1972) leads to unrealistic phytoplankton communities, which lack diatoms globally. Additionally, we find that accounting for differences in the Q10 between PFTs can significantly impact each PFT's competitive ability, especially at high latitudes, leading to altered modeled phytoplankton community structures in our control and climate change simulations. This then impacts estimates of biogeochemical processes, with, for example, estimates of export production varying by ~10% in the Southern Ocean depending on the parameterization. Our results indicate that the diversity of thermal response traits in phytoplankton not only shape community composition in the historical and future, warmer ocean, but that these traits have significant feedbacks on global biogeochemical cycles.

One-step analysis of growth kinetics of mesophilic Bacillus cereus in liquid egg yolk during treatment with phospholipase A2: Model development and validation

Liquid egg yolk (LEY) is often treated with phospholipase A2 (PLA2) to improve its emulsifying capacity and thermal stability. However, this process may allow certain pathogens to grow. The objective of this study was to evaluate the growth kinetics of mesophilic Bacillus cereus in LEY during PLA2 treatment. Samples, inoculated with B. cereus vegetative cells, were incubated isothermally at different temperatures between 9 and 50 °C to observe the bacterial growth and survival.Under the observation conditions, bacterial growth occurred between 15 and 48 °C, but not at 9 and 50 °C. The growth curves were analyzed using the USDA IPMP-Global Fit, with the no-lag phase model as the primary model in combination with either the cardinal temperatures model (CTM) or the Huang square-root model (HSRM) as the secondary model. While similar maximum growth temperatures (Tmax) were determined (48.4 °C for HSRM and 48.1 °C for CTM), the minimum growth temperature (Tmin) of the HSRM more accurately described the lower limit (9.26 °C), in contrast to 6.51 °C for CTM, suggesting that the combination of the no-lag phase model and HSRM was more suitable to describe the growth of mesophilic B. cereus in LEY.The root mean square error (RMSE) of model validation and development was <0.5 log CFU/g, indicating the combination of the no-lag phase model and HSRM could predict the growth of mesophilic B. cereus in LEY during PLA2 treatment. The results of this study may allow the food industry to choose a suitable temperature for PLA2 treatment of LEY to prevent the growth of mesophilic B. cereus.

Dual thermal ecotypes coexist within a nearly genetically identical population of the unicellular marine cyanobacterium Synechococcus.

The extent and ecological significance of intraspecific functional diversity within marine microbial populations is still poorly understood, and it remains unclear if such strain-level microdiversity will affect fitness and persistence in a rapidly changing ocean environment. In this study, we cultured 11 sympatric strains of the ubiquitous marine picocyanobacterium Synechococcus isolated from a Narragansett Bay (RI) phytoplankton community thermal selection experiment. Thermal performance curves revealed selection at cool and warm temperatures had subdivided the initial population into thermotypes with pronounced differences in maximum growth temperatures. Curiously, the genomes of all 11 isolates were almost identical (average nucleotide identities of >99.99%, with >99% of the genome aligning) and no differences in gene content or single nucleotide variants were associated with either cool or warm temperature phenotypes. Despite a very high level of genomic similarity, sequenced epigenomes for two strains showed differences in methylation on genes associated with photosynthesis. These corresponded to measured differences in photophysiology, suggesting a potential pathway for future mechanistic research into thermal microdiversity. Our study demonstrates that present-day marine microbial populations can harbor cryptic but environmentally relevant thermotypes which may increase their resilience to future rising temperatures.

Divergence in the Saccharomyces Species' Heat Shock Response Is Indicative of Their Thermal Tolerance.

The Saccharomyces species have diverged in their thermal growth profile. Both Saccharomyces cerevisiae and Saccharomyces paradoxus grow at temperatures well above the maximum growth temperature of Saccharomyces kudriavzevii and Saccharomyces uvarum but grow more poorly at lower temperatures. In response to thermal shifts, organisms activate a stress response that includes heat shock proteins involved in protein homeostasis and acquisition of thermal tolerance. To determine whether Saccharomyces species have diverged in their response to temperature, we measured changes in gene expression in response to a 12 °C increase or decrease in temperature for four Saccharomyces species and their six pairwise hybrids. To ensure coverage of subtelomeric gene families, we sequenced, assembled, and annotated a complete S. uvarum genome. In response to heat, the cryophilic species showed a stronger stress response than the thermophilic species, and the hybrids showed a mixture of parental responses that depended on the time point. After an initial strong response indicative of high thermal stress, hybrids with a thermophilic parent resolved their heat shock response to become similar to their thermophilic parent. Within the hybrids, only a small number of temperature-responsive genes showed consistent differences between alleles from the thermophilic and cryophilic species. Our results show that divergence in the heat shock response is mainly a consequence of a strain's thermal tolerance, suggesting that cellular factors that signal heat stress or resolve heat-induced changes are relevant to thermal divergence in the Saccharomyces species.

Thermal adaptation of soil microbial growth traits in response to chronic warming.

Soils are the largest terrestrial carbon sink and the foundation of our food, fiber, and fuel systems. Healthy soils are carbon sinks, storing more carbon than they release. This reduces the amount of carbon dioxide released into the atmosphere and buffers against climate change. Soil microbes drive biogeochemical cycling and contribute to soil health through organic matter breakdown, plant growth promotion, and nutrient distribution. In this study, we determined how soil microbial growth traits respond to long-term soil warming. We found that bacterial isolates from warmed plots showed evidence of adaptation of optimum growth temperature. This suggests that increased microbial biomass and growth in a warming world could result in greater carbon storage. As temperatures increase, greater microbial activity may help reduce the soil carbon feedback loop. Our results provide insight on how atmospheric carbon cycling and soil health may respond in a warming world.

Culture conditions for mycelial growth of eight Philippine wild strains of tiger sawgill mushroom, Lentinus tigrinus

Lentinus tigrinus is a wild edible and medicinal mushroom with potential culinary and pharmaceutical applications. In the present work, we evaluated the different culture media, pH and physical conditions such as aeration, illumination and temperature for maximum mycelial growth of eight L. tigrinus strains. Mycelial growth of the eight strains respond differently to the nutritional and physical factors. All strains showed maximum mycelial growth on coconut water gulaman (CWG), except TLLt 3, which favored potato dextrose agar (PDA) and malt extract agar (MEA). TLLt 1, 5, 6, 7 and 8 mycelia luxuriantly grew at pH 5.0-8.0 whereas TLLt 2 preferred pH 5.0-7.0, and TLLt 3 and 4 favored pH 5.0-6.5. Sealed condition was found to be more suitable for TLLt 1 mycelia while no significant difference was noted between the two aeration conditions for the mycelial growth of other seven strains. Both TLLt 1 and 2 mycelia favorably grew in lighted condition while the other six favorably grew in both lighted and dark conditions. Room temperature (30⁰C) recorded the fastest mycelial growth fo all strains, but found comparable to air-conditioned temperature (23⁰C) for the growth of TLLt 3, 6 and 8 mycelia. Therefore, mycelial growth of L. tigrinus on the different nutritional and physical parameters may vary depending on the strain type.

A New Method to Calibrate Cardinal Temperatures for Eucalyptus Plantation

Developing a good understanding of the interactions between forest plantation growth and climate is essential for predicting the impact of climate change on terrestrial ecosystems and for assessing the adaptation and vulnerability of tree species. One such interaction, the response in growth rate of a forest stand to changes in temperature, may be described mathematically. Some models that run on monthly time steps assume a yearly optimum, minimum, and maximum temperature for simplicity, which may not represent well to actual forest growth. Here, we developed a finer-resolution methodology that encompasses monthly growth rates and temperature limits to calibrate the parameters for an envelope curve in Eucalyptus plantations in South America. Several polynomial curves were tested to determine temperature patterns, and their yearly tree growth patterns demonstrated that responses to temperature differed by as much as 10 °C among seasons. The best curve was a second-degree polynomial curve, whose extreme values indicated the optimum temperature and whose real roots limited the minimum and maximum temperatures for growth. This polynomial was fitted every month to describe yearly changes in optimum, maximum, and minimum temperatures. When fitted to annual data, it determined 7 °C, 19 °C, and 31 °C as the minimum, optimum, and maximum temperatures for tree growth, respectively. The monthly model predictions indicated that the minimum, optimum, and maximum temperatures lay between 8 °C and 16 °C, 18 °C and 22 °C, and 27 °C and 30 °C, respectively. These monthly temperature ranges can improve the estimation of productivity in process-based models. Our results contribute to the understanding of tree growth dynamics and its relationship to changes in temperature. Accurate ranges of temperature can be used to improve productivity predictions in new expanding planting regions with no previous information or to suggest a regionalization for potential species.

First record of Bacillicladium lobatum (Chaetothyriales) in Caucasus (second finding in the world)

First record of Bacillicladium lobatum (Chaetothyriales) in Caucasus (second finding in the world)

Discovery and Functional Evaluation of Heat Tolerance Genes in the Nonconventional Yeast Yarrowia lipolytica

Yarrowia lipolytica, a GRAS (generally recognized as safe) nonconventional yeast, has been used widely in industrial fermentation to produce chemicals, fuels, and functional sugars such as erythritol and mannitol. Although Y. lipolytica is a promising organism for bioconversion and has substantial potential in industrial production, its utilization is restricted by the high cost of cooling during the fermentation process; the optimum growth or fermentation temperature of Y. lipolytica is 28–30 °C, which is lower than that of some fermenting species. Therefore, it is necessary to breed a thermoresistant Y. lipolytica for use in a fermentation system. Here, we report a new thermoduric Y. lipolytica strain (a thermoresistant clone, HRC) that can grow at 35 °C—higher than the starting strain Y. lipolytica CGMCC7326 (maximum growth temperature at 33 °C)—by laboratory adaptive evolution. Based on the transcriptome analysis of the mutant strain HRC and the parental strain Y. lipolytica CGMCC7326 at different temperatures, 22 genes with increased expression at high temperatures were identified and 10 of them were overexpressed in Y. lipolytica CGMCC7326. HRC1, HRC2, and HRC3 (with YALI0B21582g, YALI0C13750g, and YALI0B10626g overexpressed, respectively) were assessed for growth at higher temperatures. This revealed that these three genes were related to thermotolerance. This study provides insights into the metabolic landscape of Y. lipolytica under heat stress, enabling future metabolic engineering endeavors to improve both thermoresistance and sugar alcohol production in the yeast Y. lipolytica.

Are Bacillus thuringiensis strains like any other Bacillus cereus strains? Phenotypic-based tools to locate Bacillus thuringiensis in the diversity of the Bacillus cereus sensu lato group

Some Bacillus thuringiensis (Bt) strains are used as pesticide agent. This species belongs to Bacillus cereus (Bc) group which contains many species with a high phenotypic diversity, and could be pathogenic like B. cereus. The aim of this study was to characterize the phenotype of 90 strains belonging to Bc group, half of which were Bt. Knowing that Bt strains belong to different phylogenetic Bc groups, do Bt strains have the same phenotype than other Bc group strains?Five phenotypic parameters were estimated for 90 strains in the Bc group, of which 43 were Bt strains: minimal, maximal and optimal growth temperature, cytotoxicity on Caco-2 cells, heat resistance of spores. The dataset was processed by principal component analysis, showing that 53% of the variance of the profiles corresponded to factors linked to growth, heat resistance and cytotoxicity. The phenotype followed the phylogenetic groups based on panC. Bt strains showed similar behavior to other strains in the Bc group, in our experimental conditions. Commercial bio-insecticide strains were mesophilic with low heat resistance.

Synchrospora gen. nov., a New Peronosporaceae Genus with Aerial Lifestyle from a Natural Cloud Forest in Panama.

During a survey of Phytophthora diversity in Panama, fast-growing oomycete isolates were obtained from naturally fallen leaves of an unidentified tree species in a tropical cloud forest. Phylogenetic analyses of sequences from the nuclear ITS, LSU and ßtub loci and the mitochondrial cox1 and cox2 genes revealed that they belong to a new species of a new genus, officially described here as Synchrospora gen. nov., which resided as a basal genus within the Peronosporaceae. The type species S. medusiformis has unique morphological characteristics. The sporangiophores show determinate growth, multifurcating at the end, forming a stunted, candelabra-like apex from which multiple (8 to >100) long, curved pedicels are growing simultaneously in a medusa-like way. The caducous papillate sporangia mature and are shed synchronously. The breeding system is homothallic, hence more inbreeding than outcrossing, with smooth-walled oogonia, plerotic oospores and paragynous antheridia. Optimum and maximum temperatures for growth are 22.5 and 25-27.5 °C, consistent with its natural cloud forest habitat. It is concluded that S. medusiformis as adapted to a lifestyle as a canopy-dwelling leaf pathogen in tropical cloud forests. More oomycete explorations in the canopies of tropical rainforests and cloud forests are needed to elucidate the diversity, host associations and ecological roles of oomycetes and, in particular, S. medusiformis and possibly other Synchrospora taxa in this as yet under-explored habitat.

Diversity of the genus Cryobacterium and proposal of 19 novel species isolated from glaciers.

The bacterial genus Cryobacterium includes at present 14 species that live in cryospheric environments. In this study, we analyzed 101 genomes of Cryobacterium with pure cultures obtained from GenBank. They could be classified into 44 species based on average nucleotide identity (ANI) analysis, showing the diversity of Cryobacterium. Among these, 19 strains in our laboratory were isolated from the glacier samples in China. The pairwise ANI values of these 19 strains and known species were <95%, indicating that they represented 19 novel species. The comparative genomic analysis showed significant differences in gene content between the two groups with a maximum growth temperature (T max) of ≤ 20°C and a T max of >20°C. A comprehensive and robust phylogenetic tree, including 14 known species and 19 novel species, was constructed and showed five phylogenetic branches based on 265 concatenated single-copy gene sequences. The T max parameter had a strong phylogenetic signal, indicating that the temperature adaptation of Cryobacterium was largely through vertical transfer rather than horizontal gene transfer and was affected by selection. Furthermore, using polyphasic taxonomy combined with phylogenomic analysis, we proposed 19 novel species of the genus Cryobacterium by the following 19 names: Cryobacterium serini sp. nov., Cryobacterium lactosi sp. nov., Cryobacterium gelidum sp. nov., Cryobacterium suzukii sp. nov., Cryobacterium fucosi sp. nov., Cryobacterium frigoriphilum sp. nov., Cryobacterium cryoconiti sp. nov., Cryobacterium lyxosi sp. nov., Cryobacterium sinapicolor sp. nov., Cryobacterium sandaracinum sp. nov., Cryobacterium cheniae sp. nov., Cryobacterium shii sp. nov., Cryobacterium glucosi sp. nov., Cryobacterium algoritolerans sp. nov., Cryobacterium mannosilyticum sp. nov., Cryobacterium adonitolivorans sp. nov., Cryobacterium algoricola sp. nov., Cryobacterium tagatosivorans sp. nov., and Cryobacterium glaciale sp. nov. Overall, the taxonomy and genomic analysis can improve our knowledge of phenotypic diversity, genetic diversity, and evolutionary characteristics of Cryobacterium.

Discovery of a New Lichtheimia (Lichtheimiaceae, Mucorales) from Invertebrate Niche and Its Phylogenetic Status and Physiological Characteristics.

Species of Lichtheimia are important opportunistic fungal pathogens in the order Mucorales that are isolated from various sources such as soil, indoor air, food products, feces, and decaying vegetables. In recent years, species of Lichtheimia have become an emerging causative agent of invasive mucormycosis. In Europe and USA, Lichtheimia are the second and third most common causal fungus of mucormycosis, respectively. Thus, the aim of this study was to survey the diversity of species of Lichtheimia hidden in poorly studied hosts, such as invertebrates, in Korea. Eight Lichtheimia strains were isolated from invertebrate samples. Based on morphology, physiology, and phylogenetic analyses of ITS and LSU rDNA sequence data, the strains were identified as L. hyalospora, L. ornata, L. ramosa, and a novel species, L. koreana sp. nov. Lichtheimia koreana is characterized by a variable columellae, sporangiophores arising solitarily or up to three at one place from stolons, and slow growth on MEA and PDA at all temperatures tested. The new species grows best at 30 and 35 °C and has a maximum growth temperature of 40 °C. Detailed descriptions, illustrations, and a phylogenetic tree are provided.

Experimental evolution of Saccharomyces uvarum at high temperature yields elevation of maximal growth temperature and loss of the mitochondrial genome.

An organism's upper thermal tolerance is a major driver of its ecology and is a complex, polygenic trait. Given the wide variance in this critical phenotype across the tree of life, it is quite striking that this trait has not proven very evolutionarily labile in experimental evolution studies of microbes. In stark contrast to recent studies, William Henry Dallinger in the 1880s reported increasing the upper thermal limit of microbes he experimentally evolved by >40°C using a very gradual temperature ramping strategy. Using a selection scheme inspired by Dallinger, we sought to increase the upper thermal limit of Saccharomyces uvarum . This species has a maximum growth temperature of 34-35°C, considerably lower than S. cerevisiae . After 136 passages on solid plates at progressively higher temperatures, we recovered a clone that can grow at 36°C, a gain of ~1.5°C. Additionally, the evolved clone lost its mitochondrial genome and cannot respire. In contrast, an induced rho 0 derivative of the ancestor shows a decrease in thermotolerance. Also, incubation of the ancestor at 34°C for 5 days increased the frequency of petite mutants drastically compared to 22°C, supporting the notion that mutation pressure rather than selection drove loss of mtDNA in the evolved clone. These results demonstrate that S. uvarum 's upper thermal limit can be elevated slightly via experimental evolution and corroborate past observations in S. cerevisiae that high temperature selection schemes can inadvertently lead to production of the potentially undesirable respiratory incompetent phenotype in yeasts.

A new species of Neoconidiobolus (Entomophthorales, Ancylistaceae) from China based on morphological, molecular and physiological evidences

Neoconidiobolus pseudothromboides is proposed as a species new on the basis of morphological characteristics, physiological feature and molecular phylogeny. This new species is morphologically allied to N. thromboides. However, the maximum growth temperature of this new species is lower than that of N. thromboides and it grows slower than N. thromboides. The phylogenetic analysis of mitochondrial small subunit (mtSSU), nuclear large subunit (nucLSU) and translation elongation-factor-like (EFL) reveals that Neoconidiobolus is divided into three clades, and N. pseudothromboides sp. nov. is closely related to N. lachnodes rather than N. thromboides. Morphological comparisons between N. pseudothromboides sp. nov. and its affinities are provided herein.