Big data-driven water research towards metaverse

Although big data is publicly available on water quality parameters,virtual simulation has not yet been adequately adapted in environmental chemistry research.Digital twin is different from conventional geospatial modeling approaches and is particularly useful when systematic laboratory/field experiment is not realistic(e.g.,climate impact and water-related environmental catastrophe)or difficult to design and monitor in a real time(e.g.,pollutant and nutrient cycles in estuaries,soils,and sediments).Data-driven water research could realize early warning and disaster readiness simulations for diverse environmental scenarios,including drinking water contamination.

Changes on Anuran Tadpole Functional Diversity along an Environmental Gradient at the Southernmost Atlantic Rainforest Remnant

For decades the ecologists are using the same methods in order to determine the environmental health of a community,however,the crescent need on defining how these processes act,triggered the development of new methods that could classify the organisms and their function at the habitats.Here we used the anuran larvae to understand the effects of an environmental gradient on the structure and organization of the anuran assemblages along it,and to access in a realistic form,the actual state of preservation of the la rgest remnant of Atlantic Rainforest on the Southernmost portion of Brazil.We found that despite the higher diversity of species and the conservation unit status of the place,the ecosystem itself is still in danger,given the low number of functional groups and thus a higher number of ecosystem services that can be lost.

Feasibility study of assessing cotton fiber maturity from near infrared hyperspectral imaging technique

Background Fiber maturity is a key cotton quality property,and its variability in a sample impacts fiber processing and dyeing performance.Currently,the maturity is determined by using established protocols in laboratories under a controlled environment.There is an increasing need to measure fiber maturity using low-cost(in general less than $20000)and small portable systems.In this study,a laboratory feasibility was performed to assess the ability of the shortwave infrared hyperspectral imaging(SWIR HSI)technique for determining the conditioned fiber maturity,and as a comparison,a bench-top commercial and expensive(in general greater than $60000)near infrared(NIR)instrument was used.Results Although SWIR HSI and NIR represent different measurement technologies,consistent spectral characteristics were observed between the two instruments when they were used to measure the maturity of the locule fiber samples in seed cotton and of the well-defined fiber samples,respectively.Partial least squares(PLS)models were established using different spectral preprocessing parameters to predict fiber maturity.The high prediction precision was observed by a lower root mean square error of prediction(RMSEP)(<0.046),higher R_(p)^(2)(>0.518),and greater percentage(97.0%)of samples within the 95% agreement range in the entire NIR region(1000-2500 nm)without the moisture band at 1940 nm.Conclusion SWIR HSI has a good potential for assessing cotton fiber maturity in a laboratory environment.

Phosphatase Hydrolysis of Organic Phosphorus Compounds

Phosphatases are diverse groups of enzymes that deserve special attention because of their significant roles in organic phosphorus (OP) mineralization to inorganic available forms (Pi). This work 1) compared the catalytic potentials of commercially acid phosphatase from wheat germ, sweet potato, and potato, and alkaline phosphatase from E. coli;2) demonstrated that the rate of hydrolysis, catalytic efficiency, thermal stability, and optimal pH of these enzymes depended on enzyme sources and the stereochemical or stereoisomeric structures of the substrates;3) revealed that both acid and alkaline phosphatases exhibited broad range of substrate hydrolysis with high affinity for p-nitrophenyl phosphate bis (cyclohexylammonium) than the widely used p-nitrophenyl phosphate disodium hexahydrate for phosphatase assay. Sweet potato had relatively higher reaction kinetics (Vmax, Km, Kcat, Kcat/Km) values with most substrates tested. The order of catalytic activity was in the order: sweet potato > wheat germ > potato, while the order of substrate hydrolyzed was: PNPBC > PNP > PNP2A2E > DG6P2Na > DG6PNa > Bis-PNP > phytate. The optimum pH for the acid phosphatase was observed to be 5.0. Generally, the activity of alkaline phosphatase was similar to that of acid phosphatase with optimal pH between 10 and 13, depending on the substrates. Knowledge derived from this work would be helpful in enzyme catalysis in soils and water environments.

Measuring phosphatidic acid phosphohydrolase (EC 3.1.3.4) activity using two phosphomolybdate-based colorimetric methods

Phosphatidic acid phosphohydrolase (3-sn-phosphatidate phosphohydrolase, EC 3.1.3.4), also known as PAP, catalyzes the dephosphorylation of phosphatidic acid (PtdOH) to form diacylglycerol (DAG) and inorganic orthophosphate. In eukaryotes, the PAP driven reaction is the committed step in the synthesis of triacylglycerol (TAG). Existing methods for measuring PAP activity rely on the use of radioactive PtdOH. These methods are costly and cumbersome. In this report, we describe a simple assay procedure to measure released inorganic orthophosphate, which is a coproduct of the PAP reaction. Each molecule of PtdOH would release one molecule of DAG and one molecule of inorganic orthophosphate (Pi) when subjected to enzymatic breakdown under optimal conditions. Given the published rates of in vitro PAP enzymatic activity from various sources, we proposed that colorimetric determination of released Pi is possible. With this view, we performed in vitro PAP activity assays using freshly isolated enzyme from bitter gourd, Momordica charantia, and measured the released Pi using two spectrophotometric methods. Both methods gave about 2.0 to 2.25 ηkat per mg of protein. Thus, it is now possible to perform PAP activity using a simple procedure that uses nonradioactive substrates, provided the sample is dialyzed extensively to lower the intrinsic concentration of free phosphate. The kinetics data presented in this study is comparable to that of other PAP enzymes reported elsewhere, which gives credence to the notion that non-radioactive methods can be used to perform PAP activity.

Impact of Management Practices on Water Extractable Organic Carbon and Nitrogen from 12-Year Poultry Litter Amended Soils

Water extractable organic carbon (WEOC) and nitrogen (WEON) are two key parameters of soil water extractable organic matter (WEOM). Proper management of manure application rate in combination with tillage and cropping management could maintain appropriate WEOC and WEON concentrations in soils while decreasing the risk of their runoff from cropland and pastures. The objective of this research was to determine the effect of poultry litter (PL) application on WEOC and WEON in soils under different crops, tillage regimes, and grazing strategies. From 2001 to 2012, PL was applied at multiple rates to cultivated fields in a corn-oat/wheat-hay rotation or to pastures grazed by cattle or ungrazed. Soil samples (0 - 15 cm) were analyzed for KCl-extractable mineral N, and WEOC, and WEON contents. In addition, Ultraviolet-visible (UV-vis) and fluorescence spectroscopies were used to characterize WEOC stability. Organic N levels were higher at the high PL application rates. The soil C:N ratio narrowed as the PL application rate increased. However, the soil from pastures which received PL tended to have a wider range of C:N ratios than soil from the cultivated fields, despite identical PL application rates. The spectral analyses indicated that WEOC properties were responsive to management and PL application rate;therefore, this parameter may be used as a guide to provide best management strategy for manure application.

Purification, characterization, and bioinformatics studies of phosphatidic acid phosphohydrolase from <i>Lagenaria siceraria</i>

Phosphatidic acid phosphohydrolase (PAP), EC 3.1.3.4, is the penultimate step in the Kennedy pathway of triacyl glycerol (TAG) synthesis leading to the formation of diacylglycerol (DAG), which is a key intermediate in TAG synthesis. We partially purified a soluble PAP from mid maturing seeds of bottle gourd, Lagenaria siceraria. The steps include both anionic and cationic ion exchanger columns. Catalytic characterization of the partially purified PAP revealed that the optimum pH and temperature for activity were at 5.5?C and 45?C. Under optimum assay condition using dioleoyl phosphatidic acid (DPA) as the substrate, the Vmax and Km were 0.36 ηkat/mg of protein and 200 μM, respectively. For the synthetic substrate, ρ-nitrophenylphosphate, ρ-NPP, the Vmax and Km were 33.0 nkat/mg of protein and 140 μM, respectively. The activity was neither inhibited nor enhanced by the presence of Mg2+ at a concentration range of 0 to 10 mM. Two major protein bands at 42-kDa and 27-kDa were visible in SDS-PAGE after partial purification. Bioinformatics analysis of tryp-sinized protein fractions containing PAP activity showed peptide sequences with sequence homology to various phosphate metabolizing enzymes including cucumber and castor bean purple acid phosphatase, polyphosphate kinase, fructose biphosphate aldolase, and enolase from various dicotyledonous plants including rice, corn, grape, and Arabidopsis lyrata.

Nanocellulose-Based Biosensors: Design, Preparation, and Activity of Peptide-Linked Cotton Cellulose Nanocrystals Having Fluorimetric and Colorimetric Elastase Detection Sensitivity

Nanocrystalline cellulose is an amphiphilic, high surface area material that can be easily functionalized and is biocompatible and eco-friendly. It has been used singularly and in combination with other nanomaterials to optimize biosensor design. The attachment of peptides and proteins to nanocrystalline cellulose and their proven retention of activity provide a route to bioactive conjugates useful in designs for point of care biosensors. Elastase is a biomarker for a number of inflammatory diseases including chronic wounds, and its rapid sensitive detection with a facile approach to sensing is of interest. An increased interest in the use of elastase sensors for point of care diagnosis is resulting in a variety of approaches to elsastase sensors utilizing different detection technologies. Here elastase substrate peptide-celluose conjugates synthesized as colorimetric and fluorescent sensors on cotton cellulose nanocrystals are compared. The structure of the sensor peptide-nanocellulose crystals when modeled with computational crystal structure parameters demonstrates the spatio-stoichiometric features of the nanocrystalline surface that allows ligand to active site protease interacttion. An understanding of the structure/function relations of enzyme and conjugate substrate of the peptides covalently attached to nancellulose has implications for enhancing the biomolecular transducer. The potential applications of both fluorescent and colorimetric detection to markers like elastase using peptide cotton cellulose nanocrystals as a transducer surface to model point of care biosensors for protease detection are discussed.

A Single Mutation in the Hepta-Peptide Active Site of <i>Aspergillus niger</i>PhyA Phytase Leads to Myriad Biochemical Changes

The active site motif of proteins belonging to "Histidine Acid Phosphatase" (HAP) contains a hepta-peptide region, RHGXRXP. A close comparison among fungal and yeast HAPs revealed the fourth residue of the hepta-peptide to be E instead of A, which is the case with A. niger PhyA phytase. However, another phytase, PhyB, from the same microorganism has a higher turnover number and it shows E in this position. We mutated A69 residue to E in the fungal PhyA phytase. The mutant phytase shows a myriad of new kinetic properties. The pH profile shifted 0.5 pH unit in both 5.0 and 2.5 bi-hump peaks. The optimum temperature shifted down from 58℃ to 55℃. However, the greatest difference was observed in the mutant protein's reaction to GuCl at a concentration of 0.1 to 0.2 M. The activity of the mutant phytase jumped 100% while the wild type protein showed no activity enhancement in the same concentration range of GuCl. The kinetics performed at higher concentration of GuCl also contrasted the difference between the wild type and mutant phytase. While Km was least affected, the Vmax increased for the mutant and decreased for the wild type. The sensitivity towards myo-inositol hexasulfate, a potent inhibitor, was decreased by the mutation. All in all, A69E mutation has affected a multitude of enzymatic properties of the protein even though the residue was thought to be non-critical for phytase's catalytic function notwithstanding its location in the conserved hepta-peptide region of the biocatalyst.

Elimination of a disulfide bridge in <i>Aspergillus niger</i>NRRL 3135 Phytase (PhyA) enhances heat tolerance and optimizes its temperature versus activity profile

In this study, the optimum temperature was lowered while the residual phytase activity after heating to 70℃ was raised in a widely utilized phytase, Aspergillus niger NRRL 3135 PhyA. This was accomplished by site-directed mutagenesis of the cysteines that are involved in the formation of a single disulfide bridge (DB). When compared to wild type (WT), three of the four mutant phytases displayed a lower optimum temperature, 42℃, and up to a four-fold increase in activity after heating. These findings have a potentially broad application to be incorporated along with other desirable features to engineer a phytase with superior physical and chem-ical attributes for animal feed applications.

Fire Self-Extinguishing Cotton Fabric: Development of Piperazine Derivatives Containing Phosphorous-Sulfur-Nitrogen and Their Flame Retardant and Thermal Behaviors

Recent studies have shown interest in flame retardants containing phosphorus, nitrogen and sulfur a combination small molecule with a promising new approach in preparing an important class of flame retardant materials. Tetraethyl piperazine-1,4-diyldiphosphonate (TEPP) and O,O,O’,O’- tetramethyl piperazine-1,4-diyldiphosphonothioate (TMPT), based on Piperazine derivatives, were prepared successfully and their structures were proved by means of 1H, 13C and 31P NMR. Cotton twill fabric was treated with both compounds to provide different add-on levels. Thermogravimetric Analysis (TGA), microscale combustion calorimeter (MCC), vertical and 45° flame test and limiting oxygen index (LOI) were performed on the treated cotton fabrics and showed promising results. When the treated twill fabrics (5 wt% - 7 wt% add-ons) were tested using the vertical flammability test (ASTMD6413-11), we observed that the ignited fabrics self extinguished and left behind a streak of char. Limiting oxygen index (LOI, ASTM 2863-09) was utilized to determine the effectiveness of the flame retardant on the treated fabrics. LOI values increased from 18 vol% oxygen in nitrogen for untreated twill fabric to a maximum of 30 vol% for the highest add-on of twill. Furthermore, Scanning Electron Microscope (SEM), Attenuated Total Reflection-Infrared (ATR-IR), and Thermogravimetric Analysis-Fourier Transform Infrared (TGA-FTIR) spectroscopy were employed to characterize the chemical structure on the treated fabrics, as well as, the surface morphology of char areas of treated and untreated fabrics. Additionally, analysis of the release gas products by TGA-FTIR shows some distinctive detail in the degradation of the treated fabrics during the burning process.

Feasibility assessment of phenotyping cotton fiber maturity using infrared spectroscopy and algorithms for genotyping analyses

Background:Cotton fiber maturity is an important property that partially determines the processing and performance of cotton.Due to difficulties of obtaining fiber maturity values accurately from every plant of a genetic population,cotton geneticists often use micronaire(MIC) and/or lint percentage for classifying immature phenotypes from mature fiber phenotyp es although they are complex fiber traits.The recent development of an algorithm for determining cotton fiber maturity(MIR)from Fourier transform infrared(FT-IR)spectra explores a novel way to measure fiber maturity efficiently and accurately.However,the algorithm has not been tested with a genetic population consisting of a large number of progeny pla,nts.Results:The merits and limits of the MIC-or lint percentage-bas ed phenotyping method were demonstrated by comparing the observed phenotypes with the predicted phenotypes based on their DNA marker genotypes in a genetic population consisting of 708 F2 plants with various fiber maturity.The observed MIC-based fiber phenotypes matched to the predicted phenotypes better than the observed lint percenta ge-based fiber phenotypes.The lint percentage was obtained from each of F2 plants,whereas the MIC values were unable to be obtained from the entire population since certain F2 plants produced insufficient fiber mass for their measurements.To test the feasibiility of cotton fiber infrared maturity(MIR)as a viable phenotyping tool for genetic analyses,we me asured FT-IR spectra from the second population composed of 80 F2 plants with various fiber maturities,determined MIR values using the algorithms,and compared them with their genotypes in addition to other fiber phenotypes.The results showed that MIR values were successfully obtained from each of the F2 plants,and the observed MIR-based phenotypes fit well to the predicted phenotypes based on their DNA marker genotypes as well as the observed phenotypes based on a combination of MIC and lint percentage.Conclusions:The M,R value obtained from FT-IR spectra of cotton fibers is able to accurately assess fiber maturity of all plants of a population in a quantitative way.The technique provides an option for cotton geneticists to determine fiber maturity rapidly and efficiently.

Differences in Modified Morgan Phosphorus Levels Determined by Colorimetric and Inductively Coupled Plasma Methods

Phosphorus (P) fertilization is frequently needed for profitable crop production. Modified Morgan P (MMP) is a soil test P used to estimate plant available P in soils. The critical values of MMP for P fertilization and maintenance recommendations are based on the P concentrations measured by a common colorimetric molybdenum blue method although other P quantification methods have also been used for MMP measurements. In this study, we collected 120 surface soil samples of Caribou Sandy loam under potato cultivation or its rotation crops from Maine, USA, and 72 soil samples of Cecil sandy loam with cotton/corn crops under conventional tillage and no-till management with chemical and poultry litter fertilization in Georgia, USA. The MMP levels in all 192 dry samples were greater when they were measured by an inductively coupled plasma (ICP)-based method, compared to the corresponding data produced from colorimetry. Our results show the two sets of data were positively and significantly correlated (r = 0.93, P –1 with standard deviation of 12.9, compared to the average of colorimetric MMP level of 14.9 mg P kg–1 with standard deviation of 8.8. Based on the observations in this work, both colorimetric and ICP-based methods can be used for P fertilizer recommendation, but a conversion factor should be applied for ICP data as the current recommendation systems are based on colorimetric M&R data.

Fourier transform infrared spectral features of plant biomass components during cotton organ development and their biological implications

Background:The majority of attenuated total reflection Fourier transform infrared(ATR FT-IR)investigations of cotton are focused on the fiber tissue for biological mechanisms and understanding of fiber development and maturity,but rarely on other cotton biomass comp on ents.This work examined in detail the ATR FT-IR spectral features of various cott on tissues/organs at reproductive and maturation stages,an a lyzed and discussed their biological implications.Results:The ATR FT-IR spectra of these tissues/organs were an a lyzed and compared with the focus on the lower wavenumber fingerprinting range.Six outstanding FT-IR bands at 1730,1620,1525,1235,1050 and 895 cm^(-1) represented the major C=O stretching,protein Amide I,Amide II,the O-H/N-H deformation,the total C-O-C stretching and the β-glycosidic linkage in celluloses,respectively,and impacted differently between these organs with the two growth stages.Furthermore,the band intensity at 1620,1525,1235,and 1050 cm^(-1) were exclusively and significantly correlated to the levels of protein(Amide I bond),protein(Amide II bond),cellulose,and hemicellulose,respectively,whereas the band at 1730 cm^(-1) was negatively correlated with ash content.Conclusions:The resulting observations indicated the capability of ATR FT-IR spectroscopy for monitoring changes,transportation,and accumulation of the major chemical components in these tissues over the cotton growth period.In other words,this spectral technology could be an effective tool for physiological,biochemical,and morphological research related to cotton biology and development.

Identification of a soluble phosphatidate phosphohydrolase in the developing cotyledons of <i>Momordica</i><i>charantia</i>

Phosphatidate phosphatase (EC 3.1.3.4), PAP, catalyzes the dephosphorylation of phosphatidate (PtdOH) to form diacylglycerol. In eukaryotes, PAP driven reaction is the committed step in the synthesis of triacylglycerol. A Mg2+ independent PAP activity was identified in the soluble extract of Momordica charantia cotyledons undergoing maturation. While the microsomal fraction of the extract gave only 10% of the PAP activity, the remaining 90% of the activity was associated with the soluble fraction. At pH 3.0, the soluble PAP was bound to S column and eluted with glycine-HCl buffer containing high salt. The pH and temperature optima of the PAP activity were 6.0 and 53℃, respectively. Under optimum assay condition, the Vmax and Km for dioleoyl phosphatidic acid were 1.89 ηkat/mg of protein and 142 μM, respectively. For the synthetic substrate, ρ-nitrophenylphosphate, ρ- NPP, the Vmax and Km were 10.4 ηkat/mg of protein and 107 μM, respectively. The inclusion of Mg2+ and β-mercaptoethanol into the reaction mix did not change the enzyme activity nor did the addition of N-ethylmaleimide and phenylglyoxal, which indicates that cysteine and arginine are not involved in catalysis of PtdOH. The addition of Mg2+ up to 10 mM also did not change the level of PAP activity. Triton X-100, however, inhibited the activity. This is the first documented case of an in vitro PAP activity in the developing cotyledons of Momordica charantia. The PAP described here could serve as a model for lipin-1 or lipin-2 in humans. Mutations in these genes lead to acute myoglobinuria in human infants.

Degradation of Chitin and Chitosan by a Recombinant Chitinase Derived from a Virulent <i>Aeromonas hydrophila</i>Isolated from Diseased Channel Catfish

A chitinase was identified in extracellular products of a virulent?Aeromonas hydrophila?isolated from diseased channel catfish (Ictalurus punctatus). Recombinant chitinase (rChi-Ah) was produced in?Escherichia coli. Purified rChi-Ah had optimal activity at temperature of 42℃?and pH 6.5. The affinity (Km) for chitosan was 4.18 mg·ml-1?with?Vmax?of 202.5 mg·min-1·mg-1. With colloidal chitin as substrate, rChi-Ah generated N,N’-diacetyl-glucosamine predominantly. Conversion of chitosan (≥75% deacetylated) by rChi-Ah revealed five major products: 2 to 4 units of glucosamine, all of which had at least one acetyl group. It was determined that N-acetylated glucosamine was the recognition and cleavage site of rChi-Ah;the minimal and maximal cleavages were two and four glucosamine units, respectively. Functional analysis of rChi-Ah suggests that?A. hydrophilachitinase is a bioactive chitinolytic enzyme, which may benefit the pathogen for survival and/or infection.

Ethanol Tolerance in <i>Aspergillus niger</i>and <i>Escherichia coli</i>Phytase

Despite yeast having its own native phytase, the high levels of phytate found in DDGS, a byproduct of ethanol (ETOH) fermentation, suggest that its activity is diminished in the presence of ETOH. Ethanol, a product of grain fermentation, is known to inactivate several hydrolytic enzymes but its effect on phytases is relatively unknown. In this study, two phytases, Aspergillus niger (PhyA) and Escherichia coli (AppA2), were tested for ETOH tolerance. The E. coli phytase displayed greater ethanol tolerance over fungal phytase in the 5% to 10% range. However, ETOH inactivation was found to be reversible for both the enzymes. These differences in ETOH tolerance do suggest that there is a potential to achieve higher ETOH tolerance in phytases by 'structure-function' studies to lower phytic acid levels in DDGS and for other applications.

Peanut Allergens Attached with p-Aminobenzamidine Are More Resistant to Digestion than Native Allergens

Despite being known as resistant proteins, peanut allergens (Ara h 1 and Ara h 2) can be digested and cause allergic reactions. Making the allergens more resistant to digestion may aid in non-absorption and excretion of the allergens. Our objectives were to make Ara h 1 and Ara h 2 more resistant to digestion and test them in a model system using trypsin as the digestive enzyme. The resistant allergens were prepared by covalently attaching p-aminobenzamidine (pABA), a protease inhibitor, to peanut allergens in an extract or on a PVDF membrane using glutaraldehyde, and were then tested for resistance to trypsin digestion. SDS-PAGE and Western blot were performed to determine the allergenic capacity of the modified allergens. A control was prepared using glycine instead. Results showed that Ara h 2, when covalently attached with pABA, was more resistant to trypin digestion than the native allergen. Similarly, Ara h 1, prepared on a PVDF membrane and treated with pABA, displayed a resistance to trypsin digestion. Treatment of the allergens with glycine (a control) instead of pABA showed that the modified allergens were as digestible as native allergens. Blot assays showed that the pABA-treated allergens exhibited a lower allergenic capacity than native allergens. It was concluded that pABA, when attached to peanut allergen Ara h 1 or Ara h 2, inhibited digestion of the allergen by trypsin and reduced their allergenic capacity as well.

Identification of an Mg2+-Independent Soluble Phosphatidate Phosphatase in Cottonseed (Gossypium hirsutum L.)

Cotton (Gossypium hirsutum L.) provides a major source of oil for food and feed industries, but little was known about the enzymes in the oil biosynthesis pathway in cottonseed. We are interested in a better understanding of enzymatic components for oil accumulation in cottonseed. The objective of this study was to identify one key enzyme in oil biosynthesis pathway: phosphatidic acid phosphatase (PAP, 3-sn-phosphatidate phosphohydrolase, EC 3.1.3.4). PAP hydrolyzes the phosphomonoester bond in phosphatidate yielding diacylglycerol and Pi. PAPs are generally categorized into Mg2+-dependent soluble PAP and Mg2+-independent membrane-associated PAP. Cottonseed from 25 - 30 days post anthesis was used for the study. The results showed that an Mg2+-independent soluble PAP activity was identified from the cottonseed. While the microsomal fraction of the extract provided only 9% of the PAP activity, 69% of the PAP activity was associated with the cytosol. The PAP activity correlated well with enzyme concentration and incubation time. The pH and temperature optima of the enzyme were pH 5 and 55℃, respectively. Under optimized assay conditions, the Vmax and Km values of cottonseed PAP for dioleoyl phosphatidic acid as the substrate were 2.8 nkat/mg of protein and 539 μM, respectively. Inclusion of the detergent Triton X-100 (0% - 0.5%) or magnesium chloride (1 mM) in the reaction mix did not alter activity to a significant degree. This is the first report of a PAP activity in the seeds of Gossipium hirsutum. This study should provide a basis for purification and characterization of this important enzyme from cottonseed in the future.

Comparison of Stem Damage and Carbohydrate Composition in the Stem Juice between Sugarcane and Sweet Sorghum Harvested before and after Late Fall Frost

A late fall frost may significantly affect sugar crops’ stem sugar composition, yield and juice quality for biofuel and bioproduct manufacture. Research on the effects of late fall frost in sugarcane is well documented, but information is lacking for sweet sorghum. Three and six commercial cultivars of sugarcane and sweet sorghum, respectively, were selected and evaluated for exposure to a late fall frost (-2.8&degC) in Griffin, Georgia, USA. Under the same controlled environmental conditions in a screen house, the late fall frost induced more damage to sugarcane than sweet sorghum stems. The frost caused damage to sugarcane tissue and for juice to exude from stems, whereas similar behavior was not observed for sweet sorghum. In both sugarcane and sweet sorghum, the glucose/fructose ratio was significantly reduced, but this change may not be totally directly related to the frost effect. Overall, these initial results suggest that sweet sorghum may have a better tolerance to fall frost than sugarcane. Two sweet sorghum cultivars, Grassl and M81E, responded well to the late fall frost, and they can possibly be used as feedstocks for biofuel/bioproduct manufacture in areas susceptible to frosts including northern regions of the Southeastern US.