African indigenous vegetables have many nutritional and health benefits that have not been well researched and fully exploited. The objective of this study was to determine iron and protein contents of seven priority ...African indigenous vegetables have many nutritional and health benefits that have not been well researched and fully exploited. The objective of this study was to determine iron and protein contents of seven priority African indigenous vegetables found in Eastern Africa. The vegetables were planted at two sites, Maseno University, Maseno in western Kenya and Jomo Kenyatta University of Agriculture and Technology （JKUAT）, Juja in Central Kenya between 2006 and 2008. These vegetables were organically grown and edible parts of each of the vegetable harvested during vegetative growth stages just before onset of flowering and analysed for iron and protein contents. Nightshade and cowpea had high levels of both iron and protein. Pumpkin leaves and amaranths had high iron content while spiderplant and slenderleaf had high protein levels. Both iron and protein levels differed significantly between the seven vegetables at both sites. Nightshade and cowpea contained iron and protein levels that would provide 100% of the recommended daily allowance （RDA） iron and 50% of recommended daily allowance protein for optimal human growth and health. These results help to demonstrate the nutritional value of African indigenous vegetables and their potential use in nutrition intervention programs.展开更多
Chromium(Cr) may cause losses in the yield of field plant, which is one of the favorite habitats of Bacillus thuringiensis(Bt). The purposes of our study were to assess the Cr(VI)-resistance and Cr(VI)-reducing abilit...Chromium(Cr) may cause losses in the yield of field plant, which is one of the favorite habitats of Bacillus thuringiensis(Bt). The purposes of our study were to assess the Cr(VI)-resistance and Cr(VI)-reducing abilities of an indigenous soil isolate of Bt and to determine the factors governing Cr(VI) reduction. Towards this end a novel dichromate-reducing Bt BRC-ZYR2, characterized with insecticidal crystal proteins(ICPs), was isolated from a uranium deposit. Minimum inhibitory concentrations(MICs) of Cr(VI) were determined by broth dilution method and the concentrations of Cr(VI) and total Cr in the supernatant were quantified colorimetrically using 1,5-diphenylcarbazide(DPC) reagent and a mixture of sulfuric-nitric acids, respectively. The isolate contained five ICP genes(cry1Ba, cry1 Bb, cry1Be/cry1 Bf, cry9 Ca and cry9Da) and exhibited a high level of Cr(VI) resistance with MICs of 150 mg L-1at pH 7.0 and 30?C, and 500 mg L-1under optimal conditions(pH 9.0 and 40?C). The total Cr concentration was similar to initial concentration of Cr(VI) under the optimal condition, suggesting that the essential removal of the Cr(VI) was dependent on Bt reduction. Under optimal conditions, the initial Cr(VI) concentrations from 25 to 75 mg L-1significantly decreased in 24 h after incubation. Addition of Mn2+, Co2+, Mo2+and Cu2+activated Bt-mediated Cr(VI) reduction, while Zn2+, Ni2+and glucose were found to inhibit the reduction. Our results indicated that this isolate could be a promising biopesticide with the potential for both insect biocontrol and Cr bioremediation in the field.展开更多
文摘African indigenous vegetables have many nutritional and health benefits that have not been well researched and fully exploited. The objective of this study was to determine iron and protein contents of seven priority African indigenous vegetables found in Eastern Africa. The vegetables were planted at two sites, Maseno University, Maseno in western Kenya and Jomo Kenyatta University of Agriculture and Technology （JKUAT）, Juja in Central Kenya between 2006 and 2008. These vegetables were organically grown and edible parts of each of the vegetable harvested during vegetative growth stages just before onset of flowering and analysed for iron and protein contents. Nightshade and cowpea had high levels of both iron and protein. Pumpkin leaves and amaranths had high iron content while spiderplant and slenderleaf had high protein levels. Both iron and protein levels differed significantly between the seven vegetables at both sites. Nightshade and cowpea contained iron and protein levels that would provide 100% of the recommended daily allowance （RDA） iron and 50% of recommended daily allowance protein for optimal human growth and health. These results help to demonstrate the nutritional value of African indigenous vegetables and their potential use in nutrition intervention programs.
基金Supported by the National Science and Technology Project in Rural Area during the"2th Five-Year Plan",China(Nos.2011AA10A203 and 2011BAD03B02-2)the National Natural Science Foundation of China(No.31201574)+3 种基金the Project of Fujian Provincial Department of Science and Technology,China(No.2011N5003)the State Key Laboratory for Biology of Plant Diseases and Insect Pests,Institute of Plant Protection,Chinese Academy of Agricultural Sciences(No.SKL2012OP05)the Talent Training Program for Distinguished Young Scholars in Universities of Fujian Province,China(No.JA12092)the Science Fund for Distinguished Young Scholars of Fujian Agriculture and Forestry University,China(No.xjq201203)
文摘Chromium(Cr) may cause losses in the yield of field plant, which is one of the favorite habitats of Bacillus thuringiensis(Bt). The purposes of our study were to assess the Cr(VI)-resistance and Cr(VI)-reducing abilities of an indigenous soil isolate of Bt and to determine the factors governing Cr(VI) reduction. Towards this end a novel dichromate-reducing Bt BRC-ZYR2, characterized with insecticidal crystal proteins(ICPs), was isolated from a uranium deposit. Minimum inhibitory concentrations(MICs) of Cr(VI) were determined by broth dilution method and the concentrations of Cr(VI) and total Cr in the supernatant were quantified colorimetrically using 1,5-diphenylcarbazide(DPC) reagent and a mixture of sulfuric-nitric acids, respectively. The isolate contained five ICP genes(cry1Ba, cry1 Bb, cry1Be/cry1 Bf, cry9 Ca and cry9Da) and exhibited a high level of Cr(VI) resistance with MICs of 150 mg L-1at pH 7.0 and 30?C, and 500 mg L-1under optimal conditions(pH 9.0 and 40?C). The total Cr concentration was similar to initial concentration of Cr(VI) under the optimal condition, suggesting that the essential removal of the Cr(VI) was dependent on Bt reduction. Under optimal conditions, the initial Cr(VI) concentrations from 25 to 75 mg L-1significantly decreased in 24 h after incubation. Addition of Mn2+, Co2+, Mo2+and Cu2+activated Bt-mediated Cr(VI) reduction, while Zn2+, Ni2+and glucose were found to inhibit the reduction. Our results indicated that this isolate could be a promising biopesticide with the potential for both insect biocontrol and Cr bioremediation in the field.
