Tryptophan supplementation and pH adjustment for optimizing the sporulation of <Emphasis Type="Italic">Coniothyrium minitans</Emphasis>

To determine the effect of tryptophan and pH on sporulation of Coniothyrium minitans, the fungus was cultivated using a two-stage, agar plate method in which addition of tryptophan and pH were controlled at the sporulation stage. The spore yield was enhanced by 4 times with 0.1 g tryptophan/l addition after 72 h. The optimal pH values were 4 for mycelia growth and 5.8–6 for sporulation. Mycelia grown at pH 6 had a higher productivity of spore production than did those grown at pH 4.     

A new medium for spore production of <Emphasis Type="Italic">Blakeslea trispora</Emphasis> using response surface methodology

Optimization of the medium components which enhance sporulation of the two mating types of the fungus Blakeslea trispora ATCC 14271 and ATCC 14272 (a heterothallic Zygomycota producing carotene) was achieved with the aid of response surface methodology (RSM). Glucose, corn steep liquor, yeast extract, and ammonium sulfate were investigated as carbon and nitrogen sources in a basal medium. RSM was adopted to optimize the medium in order to obtain a good growth of the fungus as a prerequisite for enhanced sporulation. In the second step, the basal medium was supplemented with different trace elements which significantly affect sporulation (i.e. CuSO₄·5H₂O, FeCl₃·6H₂O, Co(NO₃)₂·6H₂O, and MnCl₂·4H₂O). Central composite design proved to be valuable in optimizing a chemically defined solid medium for spore production of B. trispora. The composition of the new solid medium to enhance spore production by B. trispora (ATCC 14271) is as follows (per liter): 7.5 g glucose, 3.2 g corn steep liquor, 1.7 g yeast extract, 4.1 g ammonium sulfate, 6 mg CuSO₄·5H₂O, 276 mg FeCl₃·6H₂O, 2 mg Co(NO₃)₂·6H₂O, and 20 g agar (pH 6.0). Practical validation of this optimum medium gave spore number of 1.2 × 10⁸ spores/dish which is 77% higher than that produced in Potato Dextrose Agar (PDA). In the case of B. trispora (ATCC 14272) the new solid substrate for enhanced sporulation consists of (per l) 6.4 g glucose, 3.3 g corn steep liquor, 1.4 g yeast extract, 4.3 g ammonium sulfate, 264 mg CuSO₄·5H₂O, 485 mg FeCl₃·6H₂O, 223 mg MnCl₂^.4H₂O, and 20 g agar (pH 6.0). Spore numbers of 2 × 10⁷ spores/dish were obtained on the new medium by B. trispora (ATCC 14272), which is 95% higher than that produced on PDA. The results corroborated the validity and the effectiveness of the models. The new media considerably improved sporulation of both strains of B. trispora compared to the production of spores on PDA, which is the medium usually used for sporulation of the fungus.     

Fluctuating water levels control water chemistry and metabolism of a charophyte‐dominated pond

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Mass balance and life cycle assessment of biodiesel from microalgae incorporated with nutrient recycling options and technology uncertainties

This article presents mass balances and a detailed life cycle assessment (LCA) for energy and greenhouse gases (GHGs) of a simulated microalgae biodiesel production system. Key parameters of the system include biomass productivity of 16 and 25 g m^?2 day^?1 and lipid content of algae of 40% and 25% for low and normal nitrogen conditions respectively. Based on an oil extraction efficiency from wet biomass of 73.6% and methane yields from anaerobically digested lipid‐extracted biomass of 0.31 to 0.34 l per gram of volatile solids, the mass balance shows that recycling growth media and recovering nutrients from residual biomass through anaerobic digestion can reduce the total demand for nitrogen by 66% and phosphorus by 90%. Freshwater requirements can be reduced by 89% by recirculating growth media, and carbon requirements reduced by 40% by recycling CO₂ from biogas combustion, for normal nitrogen conditions. A variety of technology options for each step of the production process and allocation methods for coproducts used outside the production system are evaluated using LCA. Extensive sensitivity and scenario analysis is also performed to provide better understanding of uncertainty associated with results. The best performing scenario consists of normal nitrogen cultivation conditions, bioflocculation and dissolved air flotation for harvesting, centrifugation for dewatering, wet extraction with hexane, transesterification for biodiesel production, and anaerobic digestion of biomass residual, which generates biogas used in a combined heat and power unit for energy recovery. This combination of technologies and operating conditions results in life cycle energy requirements and GHG emissions of 1.02 MJ and 71 g CO₂‐equivalent per MJ of biodiesel, with cultivation and oil extraction dominating energy use and emissions. Thus, even under optimistic conditions, the near‐term performance of this biofuel pathway does not achieve the significant reductions in life cycle GHG emissions hoped for from second‐generation biofuel feedstocks.     

Temperature response of photosynthetic light‐ and carbon‐use characteristics in the red seaweed Gracilariopsis lemaneiformis (Gracilariales,Rhodophyta)

The red seaweed Gracilariopsis is an important crop extensively cultivated in China for high‐quality raw agar. In the cultivation site at Nanao Island, Shantou, China, G. lemaneiformis experiences high variability in environmental conditions like seawater temperature. In this study, G. lemaneiformis was cultured at 12, 19, or 26°C for 3 weeks, to examine its photosynthetic acclimation to changing temperature. Growth rates were highest in G. lemaneiformis thalli grown at 19°C, and were reduced with either decreased or increased temperature. The irradiance‐saturated rate of photosynthesis (P_max) decreased with decreasing temperature, but increased significantly with prolonged cultivation at lower temperatures, indicating the potential for photosynthesis acclimation to lower temperature. Moreover, P_max increased with increasing temperature (~30 μmol O₂ · g^?1FW · h^?1 at 12°C to 70 μmol O₂ · g^?1FW · h^?1 at 26°C). The irradiance compensation point for photosynthesis (I_c) decreased significantly with increasing temperature (28 μmol photons · m^?2 · s^?1 at high temperature vs. 38 μmol photons · m^?2 · s^?1 at low temperature). Both the photosynthetic light‐ and carbon‐use efficiencies increased with increasing growth or temperatures (from 12°C to 26°C). The results suggested that the thermal acclimation of photosynthetic performance of G. lemaneiformis would have important ecophysiological implications in sea cultivation for improving photosynthesis at low temperature and maintaining high standing biomass during summer. Ongoing climate change (increasing atmospheric CO₂ and global warming) may enhance biomass production in G. lemaneiformis mariculture through the improved photosynthetic performances in response to increasing temperature.     

Regulation of phosphate uptake reveals cyanobacterial bloom resilience to shifting N:P ratios

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Comparative mycelial and spore yield by Trichoderma viride in batch and fed-batch cultures

The effects of cultural parameters such as carbon and nitrogen source and environmental factors including temperature and pH were investigated on spore and mycelial yield of Trichoderma viride, which has potential as a biocontrol agent against species of Fusarium in batch culture and fed-batch culture where there was limiting nutrient. The results obtained indicated that growth and sporulation of T. viride were greatly influenced by various carbon and nitrogen sources, and by environmental factors such as pH and temperature. Mannitol, wheat bran and rice bran as sole carbon sources appear to stimulate high mycelial growth and spore yield in fed-batch culture. Growth and sporulation were also favoured by NaNO₃, peptone and NH₄SO₄ as the nitrogen sources in fed-batch and batch cultures_. Maximum growth and sporulation was between pH 4.5 and 6.0. Temperatures between 30 and 37 °C were good for mycelium growth of T. viride while temperatures between 30 to 45 °C were good for sporulation. The amount of spore and mycelium produced and the time required for attainment of maximum spore yield increased with increasing carbon and nitrogen source in batch culture. The final spore yield obtained in fed-batch culture was two times higher than the apparent spore-carrying capacity of batch culture. These results show that T. viride is capable of growing and sporulating with varied nutritional and environmental conditions, and, therefore, this strain of T. viride may be useful as a biocontrol agent under diverse physiological and environmental conditions.     

Using CO2 to enhance carbon capture and biomass applications of freshwater macroalgae

A major limiting factor in the development of algae as a feedstock for the bioenergy industry is the consistent production and supply of biomass. This study is the first to access the suitability of the freshwater macroalgal genus Oedogonium to supply biomass for bioenergy applications. Specifically, we quantified the effect of CO₂ supplementation on the rate of biomass production, carbon capture, and feedstock quality of Oedogonium when cultured in large‐scale outdoor tanks. Oedogonium cultures maintained at a pH of 7.5 through the addition of CO₂ resulted in biomass productivities of 8.33 (±0.51) g DW m^?2 day^?1, which was 2.5 times higher than controls which had an average productivity of 3.37 (±0.75) g DW m^?2 day^?1. Under these productivities, Oedogonium had a carbon content of 41–45% and a higher heating value of 18.5 MJ kg^?1, making it an ideal biomass energy feedstock. The rate of carbon fixation was 1380 g C m^?2 yr^?1 and 1073.1 g C m^?2 yr^?1 for cultures maintained at a pH of 7.5 and 8.5, and 481 g C m^?2 yr^?1 for cultures not supplemented with CO₂. This study highlights the potential of integrating the large‐scale culture of freshwater macroalgae with existing carbon waste streams, for example coal‐fired power stations, both as a tool for carbon sequestration and as an enhanced and sustainable source of bioenergy.     

Are the benefits of yield responses to nitrogen fertilizer application in the bioenergy crop Miscanthus × giganteus offset by increased soil emissions of nitrous oxide?

A field trial was carried out on a 15 year old Miscanthus stand, subject to nitrogen fertilizer treatments of 0, 63 and 125 kg‐N ha^?1, measuring N₂O emissions, as well as annual crop yield over a full year. N₂O emission intensity (N₂O emissions calculated as a function of above‐ground biomass) was significantly affected by fertilizer application, with values of 52.2 and 59.4 g N₂O‐N t^?1 observed at 63 and 125 kg‐N ha^?1, respectively, compared to 31.3 g N₂O‐N t^?1 in the zero fertilizer control. A life cycle analyses approach was applied to calculate the increase in yield required to offset N₂O emissions from Miscanthus through fossil fuel substitution in the fuel chain. For the conditions observed during the field trial yield increases of 0.33 and 0.39 t ha^?1 were found to be required to offset N₂O emissions from the 63 kg‐N ha^?1 treatment, when replacing peat and coal, respectively, while increases of 0.71 and 0.83 t ha^?1 were required for the 125 kg‐N ha^?1 treatment, for each fuel. These values are considerably less than the mean above‐ground biomass yield increases observed here of 1.57 and 2.79 t ha^?1 at fertilization rates 63 and 125 kg‐N ha^?1 respectively. Extending this analysis to include a range of fertilizer application rates and N₂O emission factors found increases in yield necessary to offset soil N₂O emissions ranging from 0.26 to 2.54 t ha^?1. These relatively low yield increase requirements indicate that where nitrogen fertilizer application improves yield, the benefits of such a response will not be offset by soil N₂O emissions.     

Phototrophic cultivation of NaCl‐tolerant mutant of Spirulina platensis for enhanced C‐phycocyanin production under optimized culture conditions and its dynamic modeling

Commercial cultivation of Spirulina sp. is highly popular due to the presence of high amount of C‐phycocyanin (C‐PC ) and other valuable chemicals like carotenoids and γ‐linolenic acid. In this study, the pH and the concentrations of nitrogen and carbon source were manipulated to achieve improved cell growth and C‐PC production in NaCl‐tolerant mutant of Spirulina platensis . In this study, highest C‐PC (147 mg · L^?1) and biomass (2.83 g · L^?1) production was achieved when a NaCl‐tolerant mutant of S. platensis was cultivated in a nitrate and bicarbonate sufficient medium (40 and 60 mM, respectively) at pH 9.0 under phototrophic conditions. Kinetic study of wildtype S. platensis and its NaCl‐tolerant mutant was also done to determine optimum nitrate concentrations for maximum growth and C‐PC production. Kinetic parameter of inhibition (Haldane model) was fitted to the relationship between specific growth rate and substrate concentration obtained from the growth curves. Results showed that the maximum specific growth rate (μ_max) for NaCl‐tolerant mutant increased by 17.94% as compared to its wildtype counterpart, with a slight increase in half‐saturation constant (K_s), indicating that this strain could grow well at high concentration of NaNO₃. C‐PC production rate (C_max) in mutant cells increased by 12.2% at almost half the value of K_s as compared to its wildtype counterpart. Moreover, the inhibition constant (K_i) value was 207.85% higher in NaCl‐tolerant mutant as compared to its wildtype strain, suggesting its ability to produce C‐PC even at high concentrations of NaNO₃.     

Light History Influences the Response of Fluvial Biofilms to Zn Exposure

Fluvial biofilms are subject to multistress situations in natural ecosystems, such as the co‐occurrence of light intensity changes and metal toxicity. However, studies simultaneously addressing both factors are rare. This study evaluated in microcosm conditions the relationship between short‐term light intensity changes and Zn toxicity on fluvial biofilms with long‐term photoacclimation to different light conditions. Biofilms that had long‐term photoacclimation to 25 μmol photons · m^?2 · s^?1 (low light [LL] biofilms), 100 μmol photons · m^?2 · s^?1 (medium light [ML] biofilms), and 500 μmol photons · m^?2 · s^?1 (high light [HL] biofilms) were characterized by different structural (Chlorophyll‐a [Chl‐a], total biomass‐AFDW, EPS, algal groups, and diatom taxonomy) and physiological attributes (ETR‐I curves and photosynthetic pigments). HL biofilms showed higher light saturation intensity and a higher production of xanthophylls than LL biofilms. In contrast, LL biofilms had many structural differences; a higher proportion of diatoms and lower AFDW and EPS contents than ML and HL biofilms. A clear effect of light intensity changes on Zn toxicity was also demonstrated. Zn toxicity was enhanced when a sudden increase in light intensity also occurred, mainly with LL biofilms, causing higher inhibition of both the Φ′_PSII and the Φ_PSII. A decoupling of NPQ from de‐epoxidation reaction (DR) processes was also observed, indicating substantial damage to photoprotective mechanisms functioning in biofilms (i.e., xanthophyll cycle of diatoms) due to Zn toxicity. This study highlights the need to take into account environmental stress (e.g., light intensity changes) to better assess the environmental risks of chemicals (e.g., metals).     

Ammonia may play an important role in the succession of cyanobacterial blooms and the distribution of common algal species in shallow freshwater lakes

With the human intensification of agricultural and industrial activities, large amount of reduced nitrogen enter into the biosphere, which consequently results in the development of global eutrophication and cyanobacterial blooms. However, no research had reported the effect of ammonia toxicity on the algal succession. In this study, we investigated the ammonia toxicity to 19 algal species or strains to test the hypothesis that ammonia may regulate the succession of cyanobacterial blooms and the distribution of common algal species in freshwater lakes. The bloom‐forming cyanobacterium Microcystis aeruginosa PCC 7806 suffered from ammonia toxicity at high pH value and light intensity conditions. Low NH₄Cl concentration (0.06 mmol L^?1) resulted in the decrease of operational PSII quantum yield by 50% compared with the control exposed to 1000 μmol photons m^?2 s^?1 for 1 h at pH 9.0 ± 0.2, which can be reached in freshwater lakes. Furthermore, the tolerant abilities to NH₃ toxicity of 18 freshwater algal species or strains were as follows: hypertrophication species > eutrophication species > mesotrophication species > oligotrophication species. The different sensitivities of NH₃ toxicity in this study could well explain the distributing rule of common algal species in the freshwater lakes of different trophic states. Meanwhile, the cyanobacterial bloom (e.g. M. aeruginosa) always happened at the low concentration of ammonia in summer, and disappeared with the decrease of ammonia. This may be attributed to the toxic effect of ammonia to M. aeruginosa in spring (the average and maximum ammonia concentration were 0.08 and 0.72 mmol L^?1 in 33 Chinese lakes), and the low level of NH₃‐N in summer and fall in the lakes might be used as preferred nitrogen nutrition by M. aeruginosa, rather than with toxicity. Therefore, ammonia could be a key factor to determine the distribution of common algal species and cyanobacterial bloom in the freshwater systems.     

Nutritional study on <Emphasis Type="Italic">Embellisia astragali</Emphasis>, a fungal pathogen of milk vetch (<Emphasis Type="Italic">Astragalus adsurgens</Emphasis>)

Embellisia astragali is a strong, virulent pathogen that develops within milk vetch (Astragalus adsurgens). In order to determine nutrient requirements, the fungus was cultured on 9 carbon sources, 9 nitrogen sources, and 13 growth media in the dark at 25°C. Growth rates and sporulation capacity were measured after 4 and 12 weeks. All carbon sources supported growth, but only soluble starch, inulin, and dextrose supported sporulation. In general, better growth was obtained on disaccharides and polysaccharides than on monosaccharides. Compared with no growth on NH₄ ⁺-N and urea, the fungus grew little on all NO₃ ⁻-N, amino-N, and other organic-N such as peptone. There was no sporulation or very sparse conidia on almost all nitrogen sources with supplied dextrose or soluble starch as sole carbon source. The better growth and sporulation on most of the semidefined media than on defined media indicates that some components in plant or animal material may be vital to the fungus. Sporulation was positively correlated with growth rate in N source experiment at 12 weeks and in growth media experiment at 4 and 12 weeks. The fungus favors grow within agar with growth rate less than 1.18 mm day⁻¹.     

Environmental costs and benefits of growing Miscanthus for bioenergy in the UK

Planting the perennial biomass crop Miscanthus in the UK could offset 2–13 Mt oil eq. yr^?1, contributing up to 10% of current energy use. Policymakers need assurance that upscaling Miscanthus production can be performed sustainably without negatively impacting essential food production or the wider environment. This study reviews a large body of Miscanthus relevant literature into concise summary statements. Perennial Miscanthus has energy output/input ratios 10 times higher (47.3 ± 2.2) than annual crops used for energy (4.7 ± 0.2 to 5.5 ± 0.2), and the total carbon cost of energy production (1.12 g CO₂‐C eq. MJ^?1) is 20–30 times lower than fossil fuels. Planting on former arable land generally increases soil organic carbon (SOC) with Miscanthus sequestering 0.7–2.2 Mg C4‐C ha^?1 yr^?1. Cultivation on grassland can cause a disturbance loss of SOC which is likely to be recovered during the lifetime of the crop and is potentially mitigated by fossil fuel offset. N₂O emissions can be five times lower under unfertilized Miscanthus than annual crops and up to 100 times lower than intensive pasture. Nitrogen fertilizer is generally unnecessary except in low fertility soils. Herbicide is essential during the establishment years after which natural weed suppression by shading is sufficient. Pesticides are unnecessary. Water‐use efficiency is high (e.g. 5.5–9.2 g aerial DM (kg H₂O)^?1, but high biomass productivity means increased water demand compared to cereal crops. The perennial nature and belowground biomass improves soil structure, increases water‐holding capacity (up by 100–150 mm), and reduces run‐off and erosion. Overwinter ripening increases landscape structural resources for wildlife. Reduced management intensity promotes earthworm diversity and abundance although poor litter palatability may reduce individual biomass. Chemical leaching into field boundaries is lower than comparable agriculture, improving soil and water habitat quality.     

Interactive effects of nitrate concentrations and carbon dioxide on the stoichiometry,biomass allocation and growth rate of submerged aquatic plants

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Optimization of culture conditions and medium components for the production of mycelial biomass and exo-polysaccharides with Cordyceps militaris in liquid culture

Both crude exo-biopolymers and mycelial biomass, produced by liquid culture of Cordyceps species, are believed to possess several potential health benefits. As a result of its known biological activities, Cordyceps militaris has been extensively characterized in regards to potential medicinal applications. However, optimized liquid culture conditions for enhanced polysaccharide productivity have yet to be developed, which is a necessary step for industrial applications. Therefore, in this study, the liquid culture conditions were optimized for maximal production of mycelial biomass and exo-polysaccharide (EPS) by C. militaris. The effects of medium composition, environmental factors, and C/N ratio were investigated. Among these variables 80 g, glucose; 10 g, yeast extract; 0.5 g, MgSO₄·7H₂O; and 0.5 g, KH₂PO₄ in 1 L distilled water were found to be the most suitable carbon, nitrogen, and mineral sources, respectively. The optimal temperature, initial pH, agitation, and aeration were determined to be 24°C, uncontrolled pH, 200 rpm, and 1.5 vvm, respectively. Under these optimal conditions, mycelial growth in shake flask cultures and 5 L jar bioreactors was 29.43 and 40.60 g/L, respectively, and polysaccharide production in shake flask cultures and 5 L jar bioreactors was 2.53 and 6.74 g/L, respectively.     

Nitrogen fertilization increases diversity and productivity of prairie communities used for bioenergy

Using prairie biomass as a renewable source of energy may constitute an important opportunity to improve the environmental sustainability of managed land. To date, assessments of the feasibility of using prairies for bioenergy production have focused on marginal areas with low yield potential. Growing prairies on more fertile soil or with moderate levels of fertilization may be an effective means of increasing yields, but increased fertility often reduces plant community diversity. At a fertile site in central Iowa with high production potential, we tested the hypothesis that nitrogen fertilization would increase aboveground biomass production but would decrease diversity of prairies sown and managed for bioenergy production. Over a 3 year period (years 2–4 after seeding), we measured aboveground biomass after plant senescence and species and functional‐group diversity in June and August for multispecies mixtures of prairie plants that received no fertilizer or 84 kg N ha^?1 year^?1. We found that nitrogen fertilization increased aboveground biomass production, but with or without fertilization, the prairies produced a substantial amount of biomass: averaging (±SE) 12.2 ± 1.3 and 9.1 ± 1.0 Mg ha^?1 in fertilized and unfertilized prairies, respectively. Unfertilized prairies had higher species diversity in June, whereas fertilized prairies had higher species diversity in August at the end of the study period. Functional‐group diversity was almost always higher in fertilized prairies. Composition of unfertilized prairies was characterized by native C₄ grasses and legumes, whereas fertilized prairies were characterized by native C₃ grasses and forbs. Although most research has found that nitrogen fertilization reduces prairie diversity, our results indicate that early‐spring nitrogen fertilization, when used with a postsenescence annual harvest, may increase prairie diversity. Managing prairies for bioenergy production, including the judicious use of fertilization, may be an effective means of increasing the amount of saleable products from managed lands while potentially increasing plant diversity.     

Endophyte species influence the biomass production of the native grass Achnatherum sibiricum (L.) Keng under high nitrogen availability

Research on the interaction of endophytes and native grasses normally takes infection status into account, but less often considers the species of endophyte involved in the interaction. Here, we examined the effect of endophyte infection, endophyte species, nitrogen availability, and plant maternal genotype on the performance of a wild grass, Achnatherum sibiricum. Six different Epichloë‐infected maternal lines of A. sibiricum were used in the study; three lines harbored Epichloë gansuensis (Eg), while three lines harbored Epichloë sibirica (Es). These endophytes are vertically transmitted, while Eg also occasionally produces stromata on host tillers. We experimentally removed the endophyte from some ramets of the six lines, with the infected (E+) and uninfected (E?) plants grown under varying levels of nitrogen availability. Eg hosts produced more aboveground biomass than Es hosts only under high nitrogen supply. Endophyte species did not show any influence on the maximum net photosynthetic rate (P_max), photosynthetic nitrogen use efficiency, or total phenolics of A. sibiricum under all nitrogen conditions. However, the plant maternal genotype did influence the P_max and shoot biomass of A. sibiricum. Our results show that endophyte species influenced the shoot biomass of A. sibiricum, and this effect was dependent on nitrogen supply. As with most coevolutionary interactions, A. sibiricum that harbored Eg and Es may show pronounced geographic variation in natural habitats with increased nitrogen deposition. In addition, stroma‐bearing endophyte (Eg) provides positive effects (e.g., higher biomass production) to A. sibiricum plants during the vegetative growth stage.     

Statistical optimization of growth media for Paecilomyces lilacinus 6029 using non-edible oil cakes

The development of biofriendly and economical alternatives to chemical pesticides is a globally important scientific challenge. In this work, Karanja-based media conditions were optimized for obtaining high production of biomass and spores of a biocontrol agent, the entomopathogenic fungus Paecilomyces lilacinus 6029, using a two-step statistical approach coupled with rigorous experimentation. In the first step, non-edible Karanja cake was screened out as a major substrate from other oil cakes. In the second step, biomass production was maximized by applying response surface methodology to experimental variations in key physico-chemical factors: carbon/nitrogen (C/N) ratio and pH. This approach eventually predicted a maximum biomass production of 10.559 g/l with a medium having a C/N ratio of 35.88 and pH 5.9. An experimental production of 10.529 g/l biomass was obtained. The remarkable agreement between the predicted and the experimentally obtained biomass confirm the validity of the approach utilized to maximize production of P. lilacinus.     

Can chilling tolerance of C4 photosynthesis in Miscanthus be transferred to sugarcane?

The goal of this study was to investigate whether chilling tolerance of C₄ photosynthesis in Miscanthus can be transferred to sugarcane by hybridization. Net leaf CO₂ uptake (A_sat) and the maximum operating efficiency of photosystem II (Ф_PSII) were measured in warm conditions (25 °C/20 °C), and then during and following a chilling treatment of 10 °C/5 °C for 11 day in controlled environment chambers. Two of three hybrids (miscanes), ‘US 84‐1058’ and ‘US 87‐1019’, did not differ significantly from the chilling tolerant M. ×giganteus ‘Illinois’ (Mxg), for A_sat, and Φ_PSII measured during chilling. For Mxg grown at 10 °C/5 °C for 11 days, A_sat was 4.4 μmol m^?2 s^?1, while for miscane ‘US 84‐1058’ and ‘US 87‐1019’, A_sat was 5.7 and 3.5 μmol m^?2 s^?1, respectively. Miscanes ‘US 84‐1058’ and ‘US 87‐1019’ and Mxg had significantly higher rates of A_sat during chilling than three tested sugarcanes. A third miscane showed lower rates than Mxg during chilling, but recovered to higher rates than sugarcane upon return to warm conditions. Chilling tolerance of ‘US 84‐1058’ was further confirmed under autumn field conditions in southern Illinois. The selected chilling tolerant miscanes have particular value for biomass feedstock and biofuel production and at the same time they can be a starting point for extending sugarcane's range to colder climates.