Current Biotechnology

Progress on Vitamins Fortification in Plants
JIANG Ling, ZHANG Chun-yi*
2016, 6(6): 381-388. DOI: 10.3969/j.issn.2095-2341.2016.06.01
Abstract ( ) PDF (1299KB)( )

Vitamins are vital nutrients that plants and animals require in limited amounts, including A, B1, B2, B3, B5, B6, B7, B9, B12, C, D, E and K. Human cannot synthesize the compounds in sufficient quantities, and they must be obtained from the diet, especially from plant foods. Vitamin deficiency is still prevalent in large population across the world, and closely associated with increasing risks of diseases. Scientists have made great efforts on the enhancement of vitamins in plants through biofortification to tackle this global problem. This review summarized the progress of vitamin metabolism and fortification in plants, and sheds light on the trends in breeding by molecular design for vitamin-enriched crops.

Progress on Biological Function of Vitamin E in Plants
ZHANG Lan, WANG Lei*
2016, 6(6): 389-395. DOI: 10.3969/j.issn.2095-2341.2016.06.02
Abstract ( ) PDF (1335KB)( )

Vitamin E, known as tocochromanol, is a lipid soluble vitamin which is essential for human and animal health. Vitamin E is synthesized only in plants and photosynthetic bacteria, thereof humans and animals intake vitamin E only from plant foods or supplements. Vitamin E function in humans and animals has been clearly illustrated, however, the biological function of vitamin E in plants makes tardy progress. In recent years, with generation of transgenic plants and obtaining of various vitamin E mutant, the biological role of vitamin E in plants has been made important progress. This paper reviewed the recent progress of vitamin E in seed germination, plant growth, transport of photoassimilates, leaf senescence, signal transduction and response to abiotic stresses, and prospected the research direction in the future, which was expected to provide reference for the basic research and application of vitamin E.

Physiological Function, Deficiency and its Solutions on Selenium: A review
YUAN Li-jun1,2,3, YUAN Lin-xi1,2,3*, YIN Xue-bin1,2,3*,QIN Li-qiang3,4
2016, 6(6): 396-405. DOI: 10.3969/j.issn.2095-2341.2016.06.03
Abstract ( ) PDF (1297KB)( )

Selenoproteins was identified up to 25 species in human body (eg. GPx, Dio, Sel K, Sel W), which closely associated with antioxidant, hormone regulation and minerals metabolism.This review focused on the research progress of physiological functions, dietary reference intakes (DRIs), dietary intake deficiency (so-called “hidden hunger”) and its solutions on the trace element selenium (Se) in recent 10 years, which was expected to provide reference for Se biofortification research.

Current Status and Discussion of Standard System for Elemental Analysis in Food of China
ZHANG Zhi-yang1, ZHANG Zhi-wei1,2, WANG Zhong3, WANG Bo1,4, MAO Xue-fei1*, LIU Ji-xin1*, WANG Min1
2016, 6(6): 406-413. DOI: 10.3969/j.issn.2095-2341.2016.06.04
Abstract ( ) PDF (1272KB)( )

China's national and industrial standard system for elemental analysis in food were collected, and their standard types, source, time and technical characteristics were also analyzed in this paper. Some critical problems about standard management, establishment and techniques were discussed, furthermore the suggestions were given to solve these problems mentioned above, in order to support the further reform of food standard system for elemental analysis.

The Cost-benefit and Cost-effectiveness of HarvestPlus-China Program——an Ex-ante Analysis of Biofortified Iron-rich Wheat in China
LI Lu-ping1, ZHANG Jin-lei1,2,3
2016, 6(6): 414-421. DOI: 10.3969/j.issn.2095-2341.2016.06.05
Abstract ( ) PDF (1366KB)( )

This paper set biofortified iron-rich wheat as an example, applied cost benefit analysis and cost effectiveness analysis methods, detailed analyzed health benefit, total R&D cost and its construction, cost benefit ratio and cost-effectiveness, and made international comparision. The results showed that the nutrition intervention of the biofortified iron-rich wheat project of HarvestPlus-China was high cost-effective. The health benefit gained was 112 706~291 753 DALYs saved per year, implying that the economic benefit was 2.353 billion~6.091 billion yuan in 1 year after monetization, and 70.586 billion~182.719 billion yuan economic benefit over 30 years; HarvestPlus-China program will put in total RMB 63.1492 million~94.1653 million yuan, in which the promoting cost accounted for almost 99%; the cost benefit ratio of biofortified iron-rich wheat project of HarvestPlus-China program was 1 117.76~1 940.41, implying that with RMB 1 yuan of investment, the iron-rich wheat project could gain benefit of RMB 1 117.76~1 940.41 yuan; according to the standards setting by World Bank and World Health Organization sepaerately, the biofortified iron-rich wheat project of HarvestPlus-China program was high cost-effectiveness on public nutrition intervention; the data from HarvestPlus program presented that in general the biofortification had an advantage of cost-effectiveness over food fortification and supplementation. In the end, a number of counter-measures proposed, such as increasing the investment in R&D to strengthen micronutrient content of biofortified crops, paying great attention to the biofortified crops' promotion and propaganda.

Change Research of Selenium in the Processing from Grain to Steamed Bread
WANG Pei1, ZHANG Xiao-cun1*, KONG Fan-mei2, SHI Yan-xi3, DONG Hai-zhou1
2016, 6(6): 422-427. DOI: 10.3969/j.issn.2095-2341.2016.06.06
Abstract ( ) PDF (1585KB)( )

In order to study selenium change and speciation in wheat processing, Tainong18, which was sprayed selenium fertilizer, was used as material to determinate the selenium levels of wheat grain, flour, bran and steamed bread, respectively. The results showed that Se existed mainly in organic form, accounting for 88.4%, 83.1%, 87.4% and 79.2% in gain, flour, wheat bran and steamed bread, respectively. The selenium of glutenin accounted for 16.32% in grain, which was the highest. The selenium of glutenin accounted for 9.68% of most total selenium in flour. The content of selenium of glutenin was highest, accounting for 8.94% in wheat bran. Among the proteins, glutenin owned the highest content of selenium, accounting for 8.39%. Total selenium and organic selenium had a certain degree of loss at the process of steamed bread. This study is of great significance to the human body for using steamed bread scientifically filling selenium.

Genetic Stability Analysis of Insect-resistant and Herbicide-tolerance Transgenic Maize HiII-NGc-1
LIU Yang1, LIU Xiang-guo1, WANG Yang-zhou2, ZHAO Fang-fang3, ZHANG Yan1, XIAO Guo-hong3, FENG Shu-dan3, HAN Si-ping1*, YIN Yue-jia1*
2016, 6(6): 428-434. DOI: 10.3969/j.issn.2095-2341.2016.06.07
Abstract ( ) PDF (6531KB)( )

The genetic stability of target genes is the premise for the breeding of transgenic plants. We analyzed the genetic stability of transgenic maize HiII-NGc-1, which approved environmental release in Jilin province, such as integration of the target gene, expression of the target gene, stability of the target traits. cryNGc and bar gene were demonstrated co-integrated into the maize genome DNA at T2~T4 generation by PCR method. RT-PCR and Immunostrip tests demonstrated that CryNGc and PAT proteins were expressed in transgenic maize HiII-NGc-1 at T2~T4 generation. Bioassay for insect resistance and herbicide-tolerance analysis in field showed that transgenic maize HiII-NGc-1 had 5 times glufosinate tolerance, and high resistance against Ostrinia furnacalis at whorl stage and heading stage. Genetic stability of transgenic maize HiII-NGc-1 is the basis for further research of its biological safety evaluation. The results of this study are important for the safety evaluation and industrialization of transgenic insect resistant maize.

BAC Clone Identification and Chromosomal Localization of Maize Transcription Factor ABP9#br#
PU Yan-jun1, YUAN Jing2, PANG Jun-ling1, HAN Fang-pu2, ZHAO Jun1*
2016, 6(6): 435-442. DOI: 10.3969/j.issn.2095-2341.2016.06.08
Abstract ( ) PDF (4221KB)( )

In order to obtain the accurate genomic sequence and its flanking genomic sequences of maize transcription factor ABP9, PCR method was used to screen the BAC library of maize inbred line Qi319 for identification of single BACs which contain ABP9. As a result, four positive single BACs were obtained from two randomly selected among 19 positive primary pools, namely BAC-103, BAC-159. By sequencing and sequence alignment of single clone BAC-103-C3 with Mo17 genome, ABP9 was mapped on chromosome 3 of Mo17. This result was confirmed by fluorescence in situ hybridization using green fluorescent-labeled ABP9 ORF as the probe with root tip chromosomes drops of germinating seeds of maize inbred lines Qi319 and Mo17. The knowledge of accurate genomic sequence and chromosomal localization of ABP9 will facilitate the development of molecular markers of this gene for use in molecular breeding.

Cloning and Activity Analysis of Promoter of Sericin1 Gene from Bombyx mori Yun 7A
ZHANG Yong-hong1, ZHU Feng1, TANG Fen-fen1, SHAO Yu-lan1, YU Bin2, BAI Xing-rong1*
2016, 6(6): 443-448. DOI: 10.3969/j.issn.2095-2341.2016.06.09
Abstract ( ) PDF (4760KB)( )

Sericin1 gene (Ser1) of silkworm (Bombyx mori) is specifically expressed in middle silkgland, its promoter plays an important role in silkworm bioreactor. In order to learn polymorphisms of upstream regulation sequence of Ser1 gene from silkworm breed Yun 7A, we obtained Ser1 promoter sequences that had driver activity, Ser1 promoter sequence was cloned and then analyzed, the expression vector of pBac [Ser1p-DsRed-SV40+A3-EGFP] contained DsRed (red fluorescent protein gene)was driven by Ser1 promoter, the vector was transferred to BmN cells to verify the promoter activity through transient transfection expression assay. Sequence alignment showed that cis element area had been highly conservative between upstream regulation sequence of reported Ser1 and Ser1 promoter sequence of Yun 7A, the other area showed absence of the genetic phenomenon of 422 bp bases; there were conservative sequences of TATA box and CAAT box located at position -24～-30 and -112～-115 respectively, the sequences of TATA box was TATAAAA; the promoter of Ser1 could drive DsRed gene, the transiently expression products could be observed successfully in the cultural BmN cells and middle silkgland. The polymorphism and driver activity of Ser1 upstream regulation sequence from Yunnan silkworm breed were analyzed in this study, so as to lay the foundation for understanding the ability difference of sericin synthetic in the different silkworm breeds and acquiring the efficient promoter.

Quantitative Analysis of Cronobacter sakazakii Biofilm Structure
YOU Xue-jiao, ZHAO Zhi-ying, MA Lian-ying, PENG Fei-yuan, LI Liang-qiu*
2016, 6(6): 449-454. DOI: 10.3969/j.issn.2095-2341.2016.06.10
Abstract ( ) PDF (4000KB)( )

To quantify the sequential development of Cronobacter sakazakii biofilm structure in biofilm process, with hyphened technique of the program confocal laser scanning microscopy (CLSM) and COMSTAT, C. sakazakii biofilm model in vitro was constructed on glass slice in cell culture plate and biofilm development was monitored at different time intervals (6 h, 12 h, 24 h, 36 h, 48 h, 60 h and 72 h). Meanwhile, the total biomass of biofilms was analyzed using the crystal violet (CV) staining method. The change of A570 value ascended before 60 h and then descended. With the elongation of culture time, total biomass, average thickness and average diffusion distance increased first and decreased afterwards, and reached the peak at 60 h, whereas live/dead ratio, roughness coefficient and surface to volume ratio rose after the first drop, and the minimum values occurred at 60 h, 48 h and 60 h, respectively. The biofilm extracellular polysaccharide (EPS) increased first and then decreased with the extension of culture time. The formation of C. sakazakii biofilm was divided into four steps: adhesion (0~12 h), development (12~48 h), maturation (48~60 h) and dispersal (>60 h). CLSM-COMSTAT method provides not only direct qualitative observation of biofilm spatial structure but also the respective quantitative structural parameters, and furthermore the change of total biomass measured by CLSM-COMSTAT method was in accordance with the CV staining method. CLSM-COMSTAT method can be used as a regular method for quantitative analysis of C. sakazakii biofilm structure, which is beneficial to study the formation mechanism and prevention techniques of C. sakazakii biofilm.

Research on the Effects of CIT2 Gene on Xylose Utilization of the Recombinant Saccharomyces cerevisiae
LI Wei-wei1,2, ZHANG Ji1, CHEN Chao-ru1, WANG Zhi1, QU Juan-juan2*, DUN Bao-qing1*, LI Gui-ying1, LU Ming1
2016, 6(6): 455-461. DOI: 10.3969/j.issn.2095-2341.2016.06.11
Abstract ( ) PDF (1451KB)( )

Xylose fermentation is one of the bottleneck of cellulosic ethanol industry. The transformation of Saccharomyces cerevisiae for xylose metabolism has become one of the research hotspot at present. In order to study the influence of CIT2 gene on xylose utilization of Saccharomyces cerevisiae strain C5D-P-M for glucose and xylose co-fermentation, the CIT2 gene disruption cassette produced by overlapping PCR technology, transformed into C5D-P-M for knockout of CIT2 by homologous recombination and mutant strain C5D-P-M-CIT2Δ was gained finally. In contrast with C5D-P-M, the growth rate, glucose utilization, xylose utilization, and ethanol production of C5D-P-M-CIT2Δ had improved to some extent. The result suggested CIT2 gene is one factor that can influence the xylose utilization and its knockout can improve xylose utilization of Saccharomyces cerevisiae.

Progress on Biodiversity of Taxol-producing Microorganisms
MA Li-li1,2, SONG Pei-yong1*
2016, 6(6): 462-468. DOI: 10.3969/j.issn.2095-2341.2016.06.12
Abstract ( ) PDF (1302KB)( )

Paclitaxel is a diterpenic polyoxygenated pseudoalkaloid, which has a widespread medicinal value and its anticancer mechanism is unique, so it is recognized as one of the best antitumor agents. Using the microorganism fermentation method to produce taxol maybe an ideal way to solve the drug resources shortage in the future. This paper introduced the medicinal value and antitumor mechanism, summarized recent advances in biodiversity and its source of taxol-producing microorganisms. At last the paper also made a forecast of the future prospects on taxol-producing microorganism, which was expected to provide reference for research and development of taxol drug.

The Improvement of Total Flavonoids Content of Gynura divaricata Callus by the Tissue Culture Technology
GAO Yuan, LIU Yu-feng*, SONG Shu-min, JI Yan-ru, YANG Qing-li, ZHANG Zheng-hai
2016, 6(6): 469-474. DOI: 10.3969/j.issn.2095-2341.2016.06.13
Abstract ( ) PDF (1759KB)( )

The test mainly aimed at the establishment of a tissue culture technology to improve the total flavonoids of Gynura divaricate callus. The tissue culture technology was used to change the MS medium with different hormone combination, carbon source, nitrogen source and trace element ratio. The orthogonal experiment results showed that the maximum total flavones content was increased by 15% when the NAA∶6-BA was 0.1 mg/L∶1.5 mg/L, carbon source was 30 g/L, Mn2+∶Zn2+ was 44.6 mg/L∶13.2 mg/L and nitrogen source KNO3∶NH4NO3 was 2 020 mg/L∶1 600 mg/L. A system of tissue culture was developed for the enhancing of the total flavonoid of the G. divaricata DC, which was helpful for the seeding cultivation technology of G. divaricata DC and provided essential principles and techniques of improving the secondary metabolism for further research.

HPLC Determination of Rutin, Quercetin and Resveratrol Content in Asparagus Stems
YAO Hong-juan1, ZHOU Chang-sheng2, LIU Xiu-he1*, WANG Jun1, SUN De-lin2, HAN Jiao-xia2
2016, 6(6): 475-480. DOI: 10.3969/j.issn.2095-2341.2016.06.14
Abstract ( ) PDF (1379KB)( )

In order to establish a HPLC method to determinate its content of rutin, quercetin and resveratrol. The study used different methods to extract rutin, quercetin and resveratrol from asparagus stems, the results showed that methanol, methanol-HCl and ethanol had the best extraction rate for rutin, quercetin and resveratrol extraction. And it chose the optimum chromatographic conditions of HPLC method: The mobile phases of rutin and quercetin were 0.2 mol/L sodium acetate-methanol (Me-OH∶H2O=35∶65) solution (pH 2.80 adjusted with phosphoric acid), anhydrous methanol-0.4% phosphoric acid solution (55∶45, V/V), isocratic elution, and resveratrol mobile phase was water and methanol, binary linear gradient elution, respectively. Their detection wavelength was 254 nm, 360 nm and 306 nm, and velocity of flow was 0.8 mL/min, 1.0 mL/min and 0.8 mL/min. The average recoveries of rutin, quercetin and resveratrol were 98%, 97% and 98%.

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