The effect of photo-irradiation on the growth and ingredient composition of young green barley (<i>Hordeum vulgare</i>)

We clarified that photo-irradiation of young green barley from three different light sources, natural light, 100% red light-emitting diodes (R-LEDs), and a mixture of 90% red-LEDs + 10% blue-LEDs (RB-LEDs), had significantly different results in growth degree (weight and height) and in components of young green barley. Barley that has sprouted for 15 days after germination did not show any apparent difference in height in response to irradiation by the three tested light sources, but by the 20th day of sprouting the height showed a positive effect by R-LEDs irradiation. By 15 days of sprouting the barley had achieved the heaviest weight by natural light irradiation, while the barley irradiated by R-LEDs had made remarkable progress at 20 days of sprouting. On the other hand, the irradiation by RB-LEDs showed a suppressive tendency after 15 days or more. The amino acid content, as indicated by dry weight conversion, was greatest in the barley irradiated by RB-LEDs, followed by R-LEDs, and natural light, which showed that LEDs irradiation is effective. In addition, four cyanogenic glucosides were isolated, identified, and quantified, as they are components frequently assessed in barley research. With regard to vitamin E, R-LEDs irradiation increased γ-tocopherol. Our results indicate that irradiation by LEDs would be effective for the enhancement of the functionality of young green barley.

Influence of the Environment on Cassava Quality Traits in Central Rift Valley of Kenya

Cassava (Manihot esculenta Cranzt) is an important food security crop for poor rural communities particularly in Africa. However, little is known about variability of critical root nutritional and quality traits of African cassava germplasm. Cassava roots contain low levels of important micronutrients and its quality can be influenced by the levels of cyanogenic glucosides. Roots from fourteen accessions comprising Kenyan local landraces and improved clones were screened for their nutritional traits including the contents of cyanogenic glycosides, protein and the micro nutrients iron and zinc. Trait stability and the effects of the environment on the expression of the nutritional traits were evaluated using various genotype (G) by environment (E) interaction study models. There were significant (p ≤ 0.05) differences for all the nutritional traits in the three test sites of Baringo, Kericho and Nakuru in Kenya. Contents of cyanogenic glycosides in both roots and leaves, total root proteins, root iron and zinc ranged from 31.8 ppm to 90.8 ppm;20.8 ppm to 154.4 ppm;1.15% to 3.47%;17.81 ppm to 59.69 ppm and 39.39 ppm to 118 ppm, respectively. The sites were also significantly (p ≤ 0.05) different from each other with the highest cyanogenic content in leaves and roots expressed at the Nakuru site. Regression analysis was used to assess genotype response to environments. Regression coefficients (bi) obtained ranged from 0.13 to 2.23 for all traits combined indicating wide variability in quality trait among the test germplasm. Analysis for sensitivity to environmental change SEi2 revealed that cassava genotypes differed in their level of sensitivity. The root cyanide trait had the highest mean SEi2 which indicated that it was the least stable quality trait in the cassava germplasm. This implies that the same cassava genotypes will give food of different quality depending on growing environment. The observed values for protein and mineral contents suggest the potential for improving the nutritive value of local cassava germplasm.

Expression Profiling of Genes Associated with Cyanogenesis in Three Cassava Cultivars Containing Varying Levels of Toxic Cyanogens

Cyanogenic glycosides, linamarin and lotaustralin, are presents in all tissues of Cassava (Manihot esculenta Crantz) except seeds and function as a deterrent for herbivores as well as the translocable form of reduced nitrogen. The genes involved in the cyanogenic pathway [CYP79D1/D2 (EC 1.14.13), linamarase (EC 3.2.1.21), α-hydroxynitrile lyase (HNL, acetone-cyanohydrin lyase. EC 4.1.2.37) and b-cyanoalanine synthase (β-CAS. EC 4.4.1.9] have been identified and partially characterized. Our objective was to identify the differential expression pattern of these genes in leaves and roots of three cassava cultivars with varying levels of cyanogenic glucosides. The results show that the differential ex- pression of the genes between leaves and roots is consistent with leaves being the primary site of synthesize of cyano- genic glucosides, which are then translocated to the roots. In addition, the varietal difference for cyanogenic glucoside levels could be explained in part by the combinatorial effort of the synthesis in the leaves and the linamarase catabolic step in the roots. Cluster analysis suggests a coordinated expression between CYP79D1/D2 and β-CAS genes as well as linamarase and HNL genes, which is in agreement with the spatial separation within a cell of the site of linamarin syn- thesis (vacuolar) and its breakdown to cyanide (cell wall). Furthermore, cluster analysis for cultivar classification using its gene expression profile match with the reported cyanide levels comparatively for the three cultivars. This is the first study that evaluates the transcriptional activities of the genes involved in the cyanogenic glycoside metabolism using a systematic approach.

A New Method for the Determination of Cyanide Ions and Their Quantification in Some Senegalese Cassava Varieties

Cassava (Manihot esculenta Crantz) is a starchy staple food that previous researches have showed to contain cyanogenic compounds, precursors of hydrocyanic acid, undoubtedly toxic for humans. With the aim to determine food security in cassava, this study developed a simple, fast and less expensive step for quantifying cyanide ions by using micro-diffusion with modified Conway cells. After an enzymatic degradation, the cyanide ions were quantified by electrochemical procedures. The validation of this method is estimated. The concentration of cyanide ions at different part of the samples was determined. The results showed high toxicity in some fresh Senegalese consumed cassava varieties (>100 mg HCN·kg﹣1). However, in the processed cassava products, less than 10 mg HCN·kg﹣1 was found in the different varieties studied except for the chips where the levels of CN﹣ contents were important (>49 mg HCN·kg﹣1).

Ground Flaxseed – How Safe is it for Companion Animals and for us?

EFSA released the 89-page Scientific Opinion“Evaluation of the health risks related to the presence of cyanogenic glycosides in foods other than raw apricot kernels”.This opinion,and the ensuring media coverage,has left uncertainty in the minds of consumers,feed and supplement manufacturers and flaxseed producers of how much ground flaxseed can safely be consumed without crossing the threshold of cyanide toxicity.This editorial updates the science and tries to bring clarity to the question“how much flaxseed can I safely feed my dog,cat,horse on a daily basis?”and“how much can I safely eat?”The great majority of ground flaxseed products have a cyanogenic glycoside content of less than 200 mg/kg seed.For people,consuming 30 grams of such flaxseed the average peak blood cyanide concentration will be about 5μmole/L,much less than the toxic threshold value of 20 to 40μmole/L favoured by EFSA.Thus,as much as 120 grams of crushed/ground flaxseed can be consumed by a 70 kg adult person before a toxic threshold of 40μmole/L is reached(up to 1.7 grams ground flaxseed/kg body weight).The toxic threshold of cyanide for dogs is 2 to 4-fold greater than for humans,and unknown for cats and horses.The daily serving amounts for dogs and cats are about 0.23 grams/kg body mass per day,which will result in blood cyanide well below the toxic threshold.The highest recommended daily serving amount for horses is 454 grams per day,or 0.8 to 2 grams per kg/body mass depending on mass of the horse.This amount for horses should not be exceeded.

Enhanced cyanogen chloride formation after UV/PS and UV/H_(2)O_(2) pre-oxidation and chlorination in natural river water

Ultraviolet/persulfate (UV/PS) and Ultraviolet/hydrogen peroxide (UV/H_(2)O_(2)) have attracted much attention in recent years as advanced oxidation processes for water treatment.However,it is not all clear how these two methods affect the formation of cyanogen chloride(CNCl) in the subsequent water chlorination process.In this study,it was found that both UV/H_(2)O_(2)and UV/PS pre-oxidation promoted the formation of CNCl in six actual water samples collected from urban rivers.Glycine,uric acid,arginine and histidine were investigated as the model compounds to explore the effects of different methods on the production of CNCl.The results showed that compared with chlorination alone,pre-oxidation by UV/H_(2)O_(2)and UV/PS can reduce the production of CNCl for glycine and uric acid by up to 95%during post-chlorination process.However,they can greatly promote the formation of CNCl for arginine and histidine by up to 120-fold.In a more detailed investigation,pre-oxidation of histidine formed highly reactive intermediates to chlorine,leading to increased CNCl formation and chlorine consumption.The results showed that the precursors of CNCl was altered after pre-oxidation,and need to be re-evaluated.

Cyano-and Nitro-containing Compounds from the Roots of Semiaquilegia adoxoides

Four cyano-containing compounds, (1E,4,5,6)-4,5,6-trihydroxy-2-cyclohexen-1-ylideneacetonitrile (1), lithospermoside (2), 4-hydroxy-2--D-glucopyranosyl oxyphenylacetonitrile (3) and 4-[-D-apiofuranosyl-(16)- O--D-glucopyranosyl oxy]phenylacetonitrile (4), and a nitro-containing one, 4-[-D-xylopyranosyl-(16)-O--D- glucopyranosyloxy]-1-(2-nitroethyl)benzene (5), as well as eleven other types of compounds, were isolated from the roots of Semiaquilegia adoxoides. Their structures were elucidated mainly by spectroscopic methods. Among them, 1 and 4 are new isolated compounds. The cyano- and nitro-containing compounds are very rare in plants and their isolation from one traditional Chinese medicine is really interesting.

A β-glucosidase-producing M-2 strain: Isolation from cow dung and fermentation parameter optimization for flaxseed cake

Flaxseed cake contains cyanogenic glucosides, which can be metabolized into hydrocyanic acid in an animal's body, leading to asphyxia poisoning in cells. Beta-glucosidase is highly efficient in degrading cyanogenic glucosides. The Cattle may have b-glucosidase-producing strains in the intestinal tract after eating small amounts of flaxseed cake for a long time. This study aimed to isolate of a strain from cow dung that produces b-glucosidase with high activity and can significantly reduce the amount of cyanogenic glucosides. We used cow dung as the microflora source and an esculin agar as the selective medium. After screening with 0.05% esculin and 0.01% ferric citrate, we isolated 5 strains producing high amounts of b-glucosidase. In vitro flaxseed cake fermentation was fermented by these 5 strains, in which the strain M-2 exerted the best effect(P < 0.05). The strain M-2 was identified as Lichtheimia ramosa and used as the fermentation strain to optimize the fermentation parameters by a single factor analysis and orthogonal experimental design. The optimum condition was as follows: inoculum size3%, water content 60%, time 144 h, and temperature 32℃. Under this condition, the removal rate of cyanogenic glucosides reached 89%, and crude protein increment reached 44%. These results provided a theoretical basis for the removal of cyanogenic glucosides in flaxseed and the comprehensive utilization of flaxseed cake.

Oximes： Unrecognized Chameleons in Genera and Specialized Plant Metabolism

Oximes （R1R2C=NOH） are nitrogen-containing chemical constituents that are formed in species representing all kingdoms of life. In plants, oximes are positioned at important metabolic bifurcation points between general and specialized metabolism. The majority of plant oximes are amino acid-derived metabolites formed by the action of a cytochrome P450 from the CYP79 family. Auxin, cyanogenic glucosides, glucosinolates, and a number of other bioactive specialized metabolites including volatiles are produced from oximes. Oximes with the E configuration have high biological activity compared with Z-oximes. Oximes or their derivatives have been demonstrated or proposed to play roles in growth regulation, plant defense, pollinator attraction, and plant communication with the surrounding environment. In addition, oxime-derived products may serve as quenchers of reactive oxygen species and storage compounds for reduced nitrogen that may be released on demand by the activation of endogenous turnover pathways. As highly bioactive molecules, chemically synthesized oximes have found versatile uses in many sectors of society, especially in the agro- and medical sectors. This review provides an update on the structural diversity, occurrence, and biosynthesis of oximes in plants and discusses their role as key players in plant general and specialized metabolism.

MICROBE-METAL-INTERACTIONS FOR THE BIOTECHNOLOGICAL TREATMENT OF METAL-CONTAINING SOLID WASTE

In nature, microbes are involved in weathering of rocks, in mobilization of metals from minerals, and in metal precipitation and deposition. These microbiological principles and processes can be adapted to treat particulate solid wastes. Especially the microbiological solubilization of metals from solid minerals （termed bioleaching） to obtain metal values is a well-known technique in the mining industry. We focus here on non-mining minerai wastes to demonstrate the applicability of mining-based technologies for the treatment of metal-containing solid wastes. In the case study presented, microbial metal mobilization from particulate fly ash （originating from municipal solid waste incineration） by Acidithiobacilli resulted in cadmium, copper, and zinc mobilization of 〉80%, whereas lead, chromium, and nickel were mobilized by 2, 11 and 32%, respectively. In addition, the potential of HCN-forming bacteria （Chromobacterium violaceum, Pseudornonas fluorescens） was investigated to mobilize metals when grown in the presence of solid materials （e.g.,copper-containing ores, electronic scrap, spent automobile catalytic converters）. C. violaceum was found capable of mobilizina nickel as tetracyanonickelate from fine-grained nickel powder. Gold was microbially solubJlized as dicyanoaurate from electronic waste. Additionally, cyanide-complexed copper was detected during biological treatment of shredded printed circuit-board scraps. Water-soluble copper and platinum cyanide were also detected during the treatment of spent automobile catalytic converters.