Search

Malted sorghum is used extensively as source of hydrolytic enzymes in brewing gluten-free beers. Malted barley is often used in combination with un-malted maize adjunct (flakes, grits, flours) to brew non-gluten-free beers. Sorghum and maize are similar in many ways. The potential of using malted maize in brewing gluten-free beers was studied. Sorghum and maize of similar total nitrogen content were malted under comparable conditions. Sorghum and maize grains followed some similar patterns in developing hydrolytic enzymes, measured as diastatic power (DP), when malted. Development of diastatic enzymes in both cereals increased with germination period. When mashed, the hot water extract (HWE) for malted sorghum was similar to malted maize when both had five days of germination. For malted sorghum, the HWE value was already reached after two days of germination. The total soluble nitrogen (TSN) for malted sorghum was, for the five germination times studied, half of the TSN values or less than those found for malted maize. Total soluble nitrogen, indicative of the proteolysis achieved during the malting of cereals, showed good proteolysis for the malted maize. The results suggest that like malted sorghum, malted maize could play a similar role in brewing gluten-free beers. [ABSTRACT FROM AUTHOR]

Copper (Cu) is a necessary trace element participated in many physiological processes in plants. But excessive Cu2+ is toxic, which can activate intracellular signals that lead to cellular damage. The mitogen-activated protein kinase (MAPK) cascade is at the center of cell signal transduction and has been reported to be involved in stress-related signaling pathways. ZmMPK3, a kind of MAPKs in maize cells, can be activated by diverse abiotic stresses. In the present study, we investigated the effects of Cu2+ on hydrogen peroxide (H2O2) level, ZmMPK3 activity as well as the activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and ascorbic acid peroxidase (APX) using maize leaf as an experimental model. The results demonstrated that acute Cu2+ exposure for 24 hours led to rapid increases of H2O2 level and the increase in ZmMPK3 activity as well as the total activities of antioxidant enzymes SOD, CAT and APX. H2O2 scavenger, dimethylthiourea (DMTU), effectively inhibited the Cu2+-increased H2O2 level and the activity of ZmMPK3 as well as the activities of the antioxidant enzymes SOD, CAT and APX. Pre-treatment with the MAPK inhibitor, PD98059, significantly blocked the Cu2+-increased activities of ZmMPK3, CAT, APX and SOD, but didn’t affect the accumulation of H2O2. Our results suggest that Cu2+ causes oxidative stress to the maize leaves which then activates defense antioxidant enzymes via MAPK pathway. Thus, the signaling pathway is Cu2+—H2O2—ZmMPK3—antioxidant enzymes. [ABSTRACT FROM AUTHOR]

The objective of this paper was to investigate the protective effect of three potential herbicide safeners (3-dichloroacetyl oxazolidine and its two optical isomers) on detoxifying to chloroacetanilide herbicide acetochlor in maize. In this study, physiological and biochemical tests were conducted under laboratory condition in 2015. All safeners increased the expression levels of herbicide detoxifying enzymes, including glutathione S-transferases (GST), catalase (CAT) and peroxidase (POD) to reduce chloroacetanilide herbicide phytotoxicity in maize seedlings. Our results suggest that the R-isomer of R-29148 can induce glutathione (GSH) expression, GST activity, and affinity for the 1-chloro-2,4-dinitrobenzene (CDNB) substrate in maize, which can protect maize from injury by chloroacetanilide herbicide acetochlor. Further information on the chiral safener role in antioxidative enzymes activation was obtained from CAT and POD activity to overcome oxidative stress caused by the herbicide. [ABSTRACT FROM AUTHOR]

A new strategy is described to optimize multiple closely related parameters that are involved in the degradation of lignocellulose. Exo-β-1,4- glucanase, endo-β-1,4-glucanase, and β-glucosidase contained in the broth of Trichoderma viride 3.3711 cultures were used as enzyme solution. Corn stover (CS) pretreated by a combination of H2O2 and lignin peroxidase was used as raw feedstock. A comprehensive hydrolysis index (CHI) of three enzymatic activities was constructed by principal component analysis (PCA). Corn stover (CS) was pretreated with a combination of H2O2 and lignin peroxidase. The accuracy of the CHI was demonstrated by a quadratic regression using the CHI as an independent variable and the yield of the total reducing sugar (Ytrs) as a dependent variable. The results showed that the CHI was closely post-correlated with Ytrs and could be used to optimize the fermentation medium components for T. viride cultures due to a highly significant correlation between CHI and Ytrs. Based on the CHI at 96 h, an optimal medium contained 0.6% fructose, 0.6% xylose, 0.3% bean pulp, 0.15% yeast extract, 0.12% KH2PO4, 0.004% CaCl2, 0.008% FeSO4, 0.006% ZnSO4, 0.012% glycine betaine, and 0.004% polyethylene glycol. The maximum actual Ytrs was very near to the theoretical Ytrs. [ABSTRACT FROM AUTHOR]

Lignification and changes in the enzymes involved in lignin biosynthesis were investigated in relation to the reduced tenderness occurring during the postharvest storage of fresh waxy corn at 20 °C. The firmness of the corn and its lignin and polyphenol contents increased as storage time increased. The lignin content was significantly correlated ( p < .05) with the polyphenol content and firmness. Phenylalanine ammonia-lyase was not the rate-limiting enzyme in polyphenol biosynthesis, whereas the cinnamate 4-hydroxylase activity was significantly correlated ( p < .05) with the polyphenol content. The activity of coenzyme A ligase (4CL) had a limited effect on the polyphenol content. Peroxidase was significantly correlated ( p < .05) with the lignin content, while no significant ( p > .05) effect of polyphenol oxidase or cinnamyl alcohol dehydrogenase (CAD) on the lignin content was observed. Practical applications Tenderness is a main factor in sensory quality of fresh waxy corn. Secondary cell wall lignifications induced by phenylpropanoid pathway is the main reason of tenderness decline for postharvest fresh waxy corn. But little information of lignin accumulation of fresh waxy corn is obtained from the present studies. Analyzing the changes of lignin and related precursor materials, enzyme activities will help to comprehensively understand the regulatory mechanism of postharvest lignification of fresh waxy corn, which can provide suitable methods to delay postharvest lignin accumulation, and maintain the eating quality of fresh waxy corn. [ABSTRACT FROM AUTHOR]

The su1-ref allele, the only mutant used in sweet maize (Zea mays L.) until the 1960s, continues to be used in sweet maize improvement programs. Wild-type Su1 encodes the starch debranching enzyme (DBE) isoamylase1 (ISA1) that is required for amylopectin production. Loss of Su1 function also leads to a reduction in activity of another DBE enzyme, pullulanase. Five naturally occurring su1 mutations have been identified and characterized as having different carbohydrate compositions. The alleles have not been evaluated for isoamylase and pullulanase DBE activity or for mature kernel composition of hybrid allele combinations. The five su1 alleles were backcrossed into two field corn lines, A619 and A632. The resulting inbreds were crossed in a factorial design. The hybrids were grown in 2015 and 2016 in Madison, WI, for an evaluation of mature kernel composition. In 2016, the su1 inbreds were grown and immature tissue was harvested 21 d after pollination for enzymatic analysis. Significant differences were identified among the su1 hybrids for starch and water-soluble polysaccharides (WSP). Hybrids containing the su1-p allele consistently accumulated the greatest amount of starch and the lowest amount of WSP and those with the su1-ne allele had the lowest amount of starch and greatest WSP content. No significant differences were observed among the su1 inbreds for isoamylase or pullulanase activity. Little to no isoamylase activity was observed, whereas pullulanase activity was reduced among the su1 mutants compared with the wild type, Ia453-Su1. Our data indicated that differences in starch and WSP observed among the su1 alleles was not due to isoamylase or pullulanase DBE activity. [ABSTRACT FROM AUTHOR]

The efficacy of micronization of maize (Arjun, EH-434042) in inactivating enzymes responsible for lipid degradation and extending the shelf-life of whole maize flour was evaluated. Micronization at 200°C for 4 min resulted in complete inactivation of peroxidase enzyme and reduction in lipase activity by 84%. Maize flour packaged in low density polyethylene pouches were exposed to accelerated (90% RH/38°C) and ambient (65% RH/27°C) storage conditions. The results indicated no significant change in free fatty acid content in micronized flour whereas a significant increase was observed in raw flour under both the storage conditions. The color and carotenoid content did not vary much during storage in both the maize flours. While micronized maize flour was stored for 60 and 120 days under accelerated and ambient conditions, respectively, without significantly affecting quality, the storage duration was only 15 and 30 days for raw maize flour under similar conditions. Practical applications Most of the thermal processing methods employed for enzyme inactivation to extend the shelf-life of whole grain flour often involve longer processing time and in cases such as wet heating require additional drying to keep the moisture content at safe levels. Infrared-based micronization of grains is one novel method that combines benefits like improved starch digestibility and enhanced shelf-life. The present study on micronization of maize grain was effective in inactivating peroxidase and lipase activity and significantly reducing the formation of free fatty acids during storage. Micronization enhanced the shelf-life of whole maize flour packed in low density polyethylene pouches by fourfold when stored under ambient conditions. The outcome of this study indicates that micronization of maize grain can be effectively employed to extended the 'shelf-life whole maize flour,' which otherwise is very less. [ABSTRACT FROM AUTHOR]

Corn ( Zea mays L.) and common beans ( Phaseolus vulgaris L.) are alternative suitable ingredients for snacks, because of their content of bioactive compounds such as phenolic compounds (PC) and oligosaccharides (OS). However, there is no information about the transformation of these compounds associated with food matrix during gastrointestinal digestion. Therefore, the objective of this work was to simulate the whole digestion process (mouth to colon) to estimate bioaccessibility and small intestine permeability of free PC and OS, and the antioxidant capacity of free PC. Digested nixtamalized corn-cooked common bean chips exhibited significant different quantities of free PC and OS, and higher antioxidant activity compared to methanolic extract. The free PC showed high values of apparent permeability coefficients (0.023–0.729 × 10 − 3 ), related with their absorption in the small intestine. Both free PC and OS were retained in the non-digestible fraction of chips (10.24–64.4%) and were able to reach the colon. Our results suggest the digestion potential to increase chip bioactive compounds and antioxidant activity. Additional studies are required to evaluate their in vivo effects. [ABSTRACT FROM AUTHOR]

In the present study, we report the effect of four different soluble additives (sucrose, lactitol, superfloc c577, and dextran sulfate) on the stability of glutathione transferase 1 enzyme from Zea mays ( ZmGSTF1-1) under free and tethered conditions at 4 and 25 °C. Among all additives, the best stabilizing effects were observed in the case of superfloc c577 and sucrose at both tested temperatures, yet at distinct concentrations at each condition. Those two stabilizing agents were further combined and potential positive synergistic effects were investigated. In addition, we assessed the long-term storage and operational stability of ZmGSTF1-1 under tethered conditions in the presence of additives, which provided the most conducive effects on its stability under free conditions. Our results strongly suggest that the presence of additives may be beneficial to the stability of the enzyme under both free and tethered conditions. Thermodynamic analysis of the free enzyme in the presence of sucrose, which exhibited the best stabilizing effect at both temperatures, shed light on the possible mechanism of action. Given the considerable importance of the development of GST-based biosensors with prolonged stability, the present work may be of general interest to researchers in the field of applied enzymology. [ABSTRACT FROM AUTHOR]

Isoxadifen-ethyl can effectively alleviate nicosulfuron injury in the maize. However, the effects of safener isoxadifen-ethyl on detoxifying enzymes in maize is unknown. The individual and combined effects of the sulfonylurea herbicide nicosulfuron and the safener isoxadifen-ethyl on the growth and selected physiological processes of maize were evaluated. Bioassays showed that the EC50 values of nicosulfuron and nicosulfuron plus isoxadifen-ethyl for maize cultivar Zhengdan958 were 18.87 and 249.28 mg kg-1, respectively, and were 24.8 and 275.51 mg kg-1, respectively, for Zhenghuangnuo No. 2 cultivar. Evaluations of the target enzyme of acetolactate synthase showed that the I50 values of nicosulfuron and nicosulfuron plus isoxadifen-ethyl for the ALS of Zhengdan958 were 15.46 and 28.56 μmol L-1, respectively, and were 0.57 and 2.17 μmol L-1, respectively, for the acetolactate synthase of Zhenghuangnuo No. 2. The safener isoxadifen-ethyl significantly enhanced tolerance of maize to nicosulfuron. The enhanced tolerance of maize to nicosulfuron in the presence of the safener, coupled with the enhanced injury observed in the presence of piperonyl butoxide, 1-aminobenzotriazole, and malathion, suggested cytochrome P450 monooxygenases may be involved in metabolism of nicosulfuron. We proposed that isoxadifen-ethyl increases plant metabolism of nicosulfuron through non-P450-catalyzed routes or through P450 monooxygenases not inhibited by piperonyl butoxide, 1-aminobenzotriazole, and malathion. Isoxadifen-ethyl, at a rate of 33 mg kg-1, completely reversed the effects of all doses (37.5–300 mg kg-1) of nicosulfuron on both of the maize cultivars. When the two compounds were given simultaneously, isoxadifen-ethyl enhanced activity of glutathione S-transferases (GSTs) and acetolactate synthase activity in maize. The free acid 4,5-dihydro-5,5-diphenyl-1,2-oxazole-3-carboxylic was equally effective at inducing GSTs as the parent ester and appeared to be the active safener. GST induction in the maize Zhenghuangnuo No. 2 was faster than in Zhengdan 958. [ABSTRACT FROM AUTHOR]

Chinese steamed bread (CSB) is a staple food item produced through steaming fermented dough. High-amylose maize starch (HAMS) is a natural source of resistant starch and dietary fiber. The feasibility of using HAMS with 80% amylose content to formulate northern style CSB was reported. Adding HAMS (up to 10%) had minimal influences on the color and texture of CSB. Specific volume and spread ratio of CSB were reduced by 10 − 20% and 10 − 13%, respectively. Increasing HAMS concentration from 2 to 10% decreased the staling rate of CSB by 8 − 48%. CSB with and without HAMS had a 3-day mould-free shelf-life. Sensory evaluation showed that the overall acceptability of CSB containing HAMS (up to 6%) were comparable with control. Organoleptic, textural, and shelf life properties of CSB with 2% HAMS substitution were similar to the control. Practical Applications Adding HAMS could improve the shelf life of CSB without negatively affecting the sensory acceptability. The results of this study suggest the possibility of expanding the HAMS application and CSB in functional food market. The findings provide some insights for industrial research and development using resistant starch for healthy steamed cereal products. [ABSTRACT FROM AUTHOR]

Background: As metabolic pathway resources become more commonly available, researchers have unprecedented access to information about their organism of interest. Despite efforts to ensure consistency between various resources, information content and quality can vary widely. Two maize metabolic pathway resources for the B73 inbred line, CornCyc 4.0 and MaizeCyc 2.2, are based on the same gene model set and were developed using Pathway Tools software. These resources differ in their initial enzymatic function assignments and in the extent of manual curation. We present an in-depth comparison between CornCyc and MaizeCyc to demonstrate the effect of initial computational enzymatic function assignments on the quality and content of metabolic pathway resources. Results: These two resources are different in their content. MaizeCyc contains GO annotations for over 21,000 genes that CornCyc is missing. CornCyc contains on average 1.6 transcripts per gene, while MaizeCyc contains almost no alternate splicing. MaizeCyc also does not match CornCyc's breadth in representing the metabolic domain; MaizeCyc has fewer compounds, reactions, and pathways than CornCyc. CornCyc's computational predictions are more accurate than those in MaizeCyc when compared to experimentally determined function assignments, demonstrating the relative strength of the enzymatic function assignment pipeline used to generate CornCyc. Conclusions: Our results show that the quality of initial enzymatic function assignments primarily determines the quality of the final metabolic pathway resource. Therefore, biologists should pay close attention to the methods and information sources used to develop a metabolic pathway resource to gauge the utility of using such functional assignments to construct hypotheses for experimental studies. [ABSTRACT FROM AUTHOR]

In roots of gramineous plants, lysigenous aerenchyma is created by the death and lysis of cortical cells. Rice ( Oryza sativa) constitutively forms aerenchyma under aerobic conditions, and its formation is further induced under oxygen-deficient conditions. However, maize ( Zea mays) develops aerenchyma only under oxygen-deficient conditions. Ethylene is involved in lysigenous aerenchyma formation. Here, we investigated how ethylene-dependent aerenchyma formation is differently regulated between rice and maize. For this purpose, in rice, we used the reduced culm number1 ( rcn1) mutant, in which ethylene biosynthesis is suppressed. Ethylene is converted from 1-aminocyclopropane-1-carboxylic acid (ACC) by the action of ACC oxidase (ACO). We found that OsACO5 was highly expressed in the wild type, but not in rcn1, under aerobic conditions, suggesting that OsACO5 contributes to aerenchyma formation in aerated rice roots. By contrast, the ACO genes in maize roots were weakly expressed under aerobic conditions, and thus ACC treatment did not effectively induce ethylene production or aerenchyma formation, unlike in rice. Aerenchyma formation in rice roots after the initiation of oxygen-deficient conditions was faster and greater than that in maize. These results suggest that the difference in aerenchyma formation in rice and maize is due to their different mechanisms for regulating ethylene biosynthesis. [ABSTRACT FROM AUTHOR]

We studied how the Lo5 and T250 maize lines, characterized by high and low nitrogen use efficiency (NUE), respectively, modified the microbial biomass, enzymatic activities and microbial community structure in the rhizosphere after exposure to different N forms. The two maize lines were grown for 4 weeks in rhizoboxes allowing precise sampling of rhizosphere and bulk soil with no nutrient additions, and then exposed to with nitric-, ammonium- and urea-N. After N exposure, the plants were inserted back into their original rhizoboxes to allow the root exudates diffusion into the rhizosphere. After 24 h rhizosphere soil were sampled and analyzed. Microbial biomass and soil enzymatic activities were increased after the exposure to different N forms of both maize lines. The plant exposure to different N forms also induced changes in the rhizosphere bacterial and fungal communities composition. Plant responses to the availability of different N forms was a dominant factor regulating activity and composition of the rhizosphere microbial communities, likely due to changes in the rhizodepositions. Therefore different N forms used for fertilization of agriculturally relevant plants such as maize can result in different plant mediated effects on the microbial activity and community structure in the rhizosphere. [ABSTRACT FROM AUTHOR]

We investigated changes in the antioxidant and enzyme activities of cooked, mini, super-sweet corn ( Zea mays L. saccharata ‘Naulthong’). After steaming, samples of whole-ear and cut mini corncobs were vacuum- or atmospheric-packaged then frozen for 6 months. Lutein, zeaxanthin, ferulic acid, total phenolics, 2,2′-azinobis-3-[ethylbenzothiazoline-6-sulfonic acid] (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) generally decreased in relation to storage time, which differed significantly depending on the serving pattern and type of packaging. Cut pieces with atmospheric packaging had the highest peroxidase (POD) and lipoxygenase (LOX) activity. For all storage periods, whole ears had higher levels of bioactive compounds and antioxidant activity than cut-pieces. Vacuum-packaging provided greater quality maintenance than atmospheric-packaging of frozen, cooked, mini, super-sweet ears. Preparation style and packaging during frozen storage affect nutritional quality and guide consumer choices. [ABSTRACT FROM AUTHOR]

Maize ALKALINE ALPHA GALACTOSIDASE (ZmAGA) is a key enzyme in the raffinose metabolism pathway. We have previously characterized the ZmAGA1 gene as heat shock induced in germinating maize seeds. Here, we report that ZmAGA1 is induced in maize leaves by heat shock, dehydration, NaCl, abscisic acid (ABA), and salicylic acid. The 1622 bp of the 5′-regulatory region of the ZmAGA1 gene was isolated and characterized for promoter activity. The 5′-deletion assay of the regulatory region indicated that the region from −629 to −1 (relative to the start codon AUG) showed the greatest promoter activity, and the sequences upstream of this fragment act to inhibit transcription. The cis-acting element ABRE (ABA - responsive element) was identified to be functional. Increasingly, more refined 3′-deletion constructs of the regulatory region demonstrated that a 6-nucleotide (nt) RNA motif in the 5′-untranslated region (UTR) of the ZmAGA1 gene stimulates the translation of the downstream open reading frame (ORF). Deletion or triplication of this motif decreased or enhanced downstream ORF translation, respectively, while the mRNA abundance remained the same. RNA-EMSA (electrophoretic mobility shift assay) confirmed that some cytosolic protein(s) was (were) able to bind to this 6-nt RNA motif. This work contributes to our understanding of the ZmAGA1 gene regulatory mechanism and the metabolism of raffinose in maize cells. [ABSTRACT FROM AUTHOR]

Auxin is a major growth hormone in plants and the first plant hormone to be discovered and studied. Active research over >60 years has shed light on many of the molecular mechanisms of its action including transport, perception, signal transduction, and a variety of biosynthetic pathways in various species, tissues, and developmental stages. The complexity and redundancy of the auxin biosynthetic network and enzymes involved raises the question of how such a system, producing such a potent agent as auxin, can be appropriately controlled at all. Here it is shown that maize auxin biosynthesis takes place in microsomal as well as cytosolic cellular fractions from maize seedlings. Most interestingly, a set of enzymes shown to be involved in auxin biosynthesis via their activity and/or mutant phenotypes and catalysing adjacent steps in YUCCA-dependent biosynthesis are localized to the endoplasmic reticulum (ER). Positioning of auxin biosynthetic enzymes at the ER could be necessary to bring auxin biosynthesis in closer proximity to ER-localized factors for transport, conjugation, and signalling, and allow for an additional level of regulation by subcellular compartmentation of auxin action. Furthermore, it might provide a link to ethylene action and be a factor in hormonal cross-talk as all five ethylene receptors are ER localized. [ABSTRACT FROM AUTHOR]

Aconitase (EC 4.2.1.3) catalyzes the reversible interconversion of citrate, cis -aconitate, and d -isocitrate. It operates in mitochondria and cytosol. We investigated the expression of two aconitase genes ( Aco1 and Aco4 ) and activities of the mitochondrial and cytosolic forms in maize ( Zea mays L.) scutellum during germination. Both forms were isolated and purified. The cytosolic form had a higher pH optimum (8.0), twice higher affinity to citrate ( K m 9.5 mM), and slightly lower affinity to d , l -isocitrate ( K m 1.7 mM) as compared to the mitochondrial form (optimum pH 7.5, K m with citrate 21 mM, and K m with isocitrate 1.5 mM). The highest activity of both forms of aconitase was observed on the 4th day of germination; then the activity and expression of the cytosolic form sharply decreased, while the mitochondrial form decreased more slowly. The mitochondrial aconitase was more strongly inhibited by H 2 O 2 (half-inhibition at 35 μM) than the cytosolic form (60 μM). Aconitase activity was not detected in the glyoxysomal fraction beyond the cross-contamination level. It is suggested that the mitochondrial form operates in the tricarboxylic acid cycle, whereas the cytosolic form participates in the reactions of the glyoxylate cycle taking place outside the glyoxysome. [ABSTRACT FROM AUTHOR]

This study investigates how calcium modulates the properties of dual positional specific maize lipoxygenase-1, including its interaction with substrate, association with subcellular membrane and alteration of product distribution. Bioinformatic analyses identified Asp 38 , Glu 127 and Glu 201 as putative calcium binding residues and Leu 37 as a flanking hydrophobic residue also potentially involved in calcium-mediated binding of the enzyme to subcellular membranes. Asp 38 and Leu 37 were shown to be important but not essential for calcium-mediated association of maize lipoxygenase-1 to subcellular membranes in vitro . Kinetic studies demonstrate that catalytic efficiency ( V max / K m ) shows a bell-shaped dependence on log of the molar ratio of substrate to unbound calcium. Calcium also modulates product distribution of the maize lipoxygenase-1 reaction, favoring 13-positional specificity and increasing the relative amount of ( E,Z )-isomeric products. The results suggest that calcium regulates the maize lipoxygenase-1 reaction by binding to substrate, and by promoting binding of substrate to enzyme and association of maize lipoxygenase-1 to subcellular membranes. [ABSTRACT FROM AUTHOR]

The effects of eckol, a phenolic compound isolated from the seaweed Ecklonia maxima, on the growth of Zea mays cv. Border King were examined. Kernels were soaked in eckol solution (10 M) for 18 h prior to planting. Additional treatments were water control and 10 M phloroglucinol, a known phenolic plant growth regulator. Growth parameters, photosynthetic pigments, total proteins, α-amylase and malate dehydrogenase (MDH) activities, and secondary metabolite content such as total phenolics (TPC), total flavonoids, condensed tannins, and iridoid glycosides (IG) were determined in roots and shoots after 60 days. Generally, a considerable difference in growth, enzyme activities, and secondary metabolite content were observed between the treatments. The roots of eckol-soaked kernels yielded higher levels of proteins (124 ± 0 µg/g FW), TPC (7.0 ± 0.14 mg GAE/g DW), and IG (1.74 ± 0 mg HE/g DW) compared to the water control. The phloroglucinol treatment showed a significant ( P < 0.05) increase in TPC and IG of maize roots. Kernels soaked with eckol and phloroglucinol solutions showed enhanced α-amylase and MDH activities. In this study, eckol treatment enhanced both growth and biochemical physiology of the maize cultivar used, possibly through synergistic effects with other plant growth hormones. The mechanism of action needs further evaluation. [ABSTRACT FROM AUTHOR]

Partial branching enzyme treatment was used to modulate the starch fine chain structure responsible for a high content of slowly digestible starch fraction. Normal maize starch modified using branching enzyme for 4 h showed a maximum slowly digestible starch content of 23.90%. The branching enzyme hydrolysis decreased the amylose content from 32.8% to 12.8%. The molecular weight distribution of enzyme-treated starches showed a larger proportion of low molecular weight fractions appeared in the enzyme treated starch sample compare to native starch. The number of shorter chains (DP < 13) increased from 18.71% to 28.23.1%, accompanied by a reduction of longer chains (DP > 30) from 20.11% to 11.95%. 1H NMR spectra showed an increase of α-1,6 branching ratio from 4.7% to 9.4% during enzyme treatment. The increase in the amount of shorter chains and more a-1,6 linkages likely contribute to their slow digestion property. These results suggest that starches treated with partial branching enzyme synthesis a novel branched structure with slowly digestible character. [ABSTRACT FROM AUTHOR]

Hydrolysis of corn leaf utilizing two treatment sequences was carried out in this study. The first treatment was chemical and involved subjecting the corn leaf to an alkaline pre-treatment and then to a smooth acid hydrolysis. The second consisted of biological delignification using the strain Trametes sp. 44 H88, followed by enzymatic hydrolysis using the enzymatic extract produced by Trichoderma sp. H88. The ligninolytic extract produced by Trametes sp. 44 H88 was used to detoxify the hydrolyzate. The results indicate that biological pre-treatment with delignification is more favorable and improves the subsequent hydrolysis, regardless of whether the hydrolysis is chemical or biological. The chemical treatment sequence obtained 80% conversion of monosaccharides, while the biological treatment sequence resulted in a 87% conversion rate. Finally, the use of the ligninolytic extract for the dephenolization of the hydrolyzate reduced the presence of compounds of phenolic origin by 23%. [ABSTRACT FROM AUTHOR]

BACKGROUND Transglutaminases catalyze post-translational modification of proteins by ε-( γ-glutamyl) links and covalent amide bonds. Research on properties and applications of plant transglutaminases is less developed than in animals and micro-organisms. In a previous study, optimized Zea mays transglutaminase was purified from recombinant Pichia pastoris strain. The main objective of the present study was to characterize this enzyme and assess its effect on the properties of yoghurt. RESULTS The purified recombinant transglutaminase presented a Km of 3.98 µmol L−1 and a Vmax of 2711 min−1 by the fluorometric method. The enzyme was stable after incubation for 30 min below 50 °C and over a broad pH range of 5-8 at −20 °C for 12 h. The results showed that the crosslinking reaction catalyzed by this enzyme could effectively improve the properties of full and non-fat yoghurts. Also, the properties of non-fat yoghurt could be improved similar to the full-fat product by recombinant transglutaminase. CONCLUSION The application of recombinant transglutaminase in yoghurt indicated that this enzyme could be used as a substitute for microbial transglutaminase in the production of yoghurt, thus providing experimental evidence for the future application of plant transglutaminases in the food industry. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Background The main problem encountered during processing of cereals in distilleries, in particular by pressureless methods, is the relatively high viscosity of mashes that in turn retards their fermentation. It is caused by the extraction (along with starch) of pentosans, ß-glucans, cellulose and hemicelluloses from cereal grains. Results Experiments carried out within this work centered on the determination of the effect of treatment of corn mashes with xylanase, pullulanase, cellulase enzyme complex and cellobiase on chemical composition, viscosity of these mashes and yield of fermentation. The treatment with xylanase caused the greatest decrease in viscosity of the corn mash, by c. 41% in relation to the reference mash (9.08 ± 0.45 mPa s). In the mash digested with pullulanase the ethanol yield was increased from 70.85 ± 0.71% (reference mash) to 76.09 ± 0.76% of theoretical. The most beneficial impact on the synthesis of ethanol was afforded by the treatment of mashes with cellulase enzyme complex preparation. The yield of ethanol reached 79.59 ± 0.8% of theoretical productivity and the intake of sugars was 92.85 ± 0.93%. Conclusion Under the optimal conditions found in these experiments, i.e. in corn mash supported with cellulase enzyme complex ( CeluStar XL preparation) 61.69 ± 0.62 L of absolute ethanol could be obtained from 100 kg of starch. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The article discusses a study regarding impact of cystein proteinases inhibitor Cystatin expressed in transgenic soybean on growth of the stink bug, Riptortus clavatus. The study compared inhibitory activity of cystatin obtained from cereals including corn, rice and Job's tear against R. clavatus cysteine proteinase. The study demonstrated that heterologous expression of corn cyatatin in soybean seeds inhibits cystein proteinases without affecting growth of R. Clavatus.

Two experiments were conducted to determine the effects of dietary supplementation of exogenous enzymes on growth performance, apparent total tract digestibility (ATTD) of energy and nutrients, blood metabolites, fecal VFA, and fecal ammonia-N in growing pigs (Sus scrofa) fed a com (Zea mays L.)- and soybean [Glycine max (L.) Merr.] meal (SBM)-based diet. In Exp. 1, 240 growing barrows (initial BW: 55.6 ± 0.9 kg) were randomly allotted to 5 treatments on the basis of BW. There were 4 replicates in each treatment with 12 pigs per replicate. The 5 treatments consisted of a corn-SBM-based control diet and 4 additional diets were similar to the control diet, with the exception that 0.05% p-mannanase (M), a-amylase + P-mannanase (AM), P-mannanase + protease (MPr), or a-amylase + P-mannanase + protease (AMP) was added to the diets, which were fed for 28 d. Pigs fed the AM, MPr, or AMP diet had greater (P < 0.05) ADG than pigs fed the control diet. Pigs fed the AMP diet also had greater (P < 0.05) ADG than pigs fed the M, AM, or MPr diet. Pigs fed the AMP diet had greater (P < 0.05) G:F than pigs fed the control diet. The G:F of the pigs fed the M, AM, or MPr diet were not different (P> 0.05) from the G:F in pigs fed the AMP or control diet. The ADFI, ATTD of nutrients, blood metabolites, and fecal VFA and ammonia-N concentrations were not different among treatments. In Exp. 2, 192 growing barrows (initial BW: 56.9 ± 1.0 kg) were allotted to 4 treatments. There were 4 replicates in each treatment with 12 pigs per replicate. Pigs were fed a corn-SBM-based diet (CSD) or a complex diet (CD) that contained com, SBM, 3% rapeseed (Brassica napus L.) meal, 3% copra (Cocos nucifera L.) meal, and 3% palm {Elaeis guineensis Jacq.) kernel meal. Each diet was prepared without exogenous enzymes or with 0.05% AMP and all diets were fed for 28 d. The ADG and G:F of pigs fed the CSD were greater (P < 0.05) than pigs fed the CD. However, the type of diet had no effect on the ATTD of nutrients, blood metabolites, or fecal VFA and ammonia-N, and there was no diet x enzyme interaction for any of the measured variables. Supplementation of diets with exogenous enzymes resulted in greater CP < 0.05) ADG, G:F, ATTD of DM, GE, and CP, and blood urea nitrogen (BUN) concentration. These results indicate that supplementation of 0.05% of AMP enzymes to a corn-SBM diet or a complex diet may improve the performance of growing pigs. [ABSTRACT FROM AUTHOR]

Phenol is one of the greatest menaces among the industrial pollutants. A treatment method which utilizes agricultural wastes in a simple manner has become the need of the hour. In this investigation, details on the extraction, optimization of parameters and study of detoxification potential of the peroxidase enzyme obtained from baby corn waste have been elaborated. The enzyme has been extracted from both corn silk and husk, and studies have been conducted on both the samples. Estimation of amount of protein and enzyme activity has shown promising results, and the conditions optimized are easily attainable at larger scales, making this work feasible for scale-up. [ABSTRACT FROM AUTHOR]