Table of Content

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• Current Biotechnology
  Volume 5 Issue 1 25 January 2015
• CRISPR-Cas9-based Genome Engineering
• ZHENG Xiao-mei1,2, ZHANG Xiao-li1,3, YU Jian-dong 1,2, ZHENG Ping1,2,SUN Ji-bin1,2*
• 2015, 5(1):  1-9.  DOI: 10.3969/j.issn.2095-2341.2015.01.01
• Abstract ( ) PDF (5388KB)( )
CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated proteins) systems are the adaptive immune system in bacteria and archaea that defends against infectious viruses and plasmids. Immunity is mediated by Cas nucleases, which use small RNA guides (the crRNAs) to specify a cleavage site within the genome of invading nucleic acids. In type Ⅱ CRISPR-Cas systems, the DNA-cleaving activity is performed by a single enzyme Cas9 guided by an RNA duplex. Using synthetic single RNA guides, Cas9 can be reprogrammed to create specific double-stranded DNA breaks in the genomes of a variety of organisms, ranging from human cells to bacteria, and thus constitutes a powerful tool for genetic engineering. In this review, we described the development and applications of CRISPR-Cas9 system with highlighting the practical considerations for implementing CRISPR-Cas9 technology.
• Zero-Mode Waveguides: the Principle, Fabrication and Application in Detection of Single Fluorescent Molecules  
• WEI Qing-quan1,3, LI Yun-tao1,3, REN Lu-feng2,3, ZHOU Xiao-guang1,3, YU Yu-de1,3
• 2015, 5(1):  10-21.  DOI: 10.3969/j.issn.2095-2341.2015.01.02
• Abstract ( ) PDF (5538KB)( )
Techniques for single fluorescent molecules detection have garnered a great amount of interests from science community in recent years largely due to their ability to reveal the individual molecular properties and behaviors which were often obscured by techniques based on ensemble  average. In order to overcome diffraction-limit of optical observation, fluorescent molecules must be diluted to a very low concentration-way below normal physiological concentration. However, this may adversely impact the kinetics for the chemical or biochemical reaction under study. Zero-mode waveguides（ZMWs）, as a new kind of single fluorescent molecule detection device, effectively reduce the observation volume to the level of zeptoliter (10-21L), which is much lower than optical diffraction-limited volume, by utilizing of a nanoaperture structure. The zeptoliter-observation volume provides an environment where a single fluorescent molecule can be observed at normal physiological concentration. The ZMWs have been extensively used in the field of single fluorescent molecule detection due to its outstanding performance than diffraction-limited optics.Therefore we provided an overview of ZMWs, including discussions on its principle, fabrication techniques, and applications in DNA sequencing, biomembrane structure elucidation,  biomacromolecule interaction studies and kinetics study of single-molecule reaction.
• Progress on Glycoprotein Hormones
• CHANG Liang, LI Chen-hui, MA Zhi-jun, ZHAO Jing, GAO Jian*
• 2015, 5(1):  22-28.  DOI: 10.3969/j.issn.2095-2341.2015.01.03
• Abstract ( ) PDF (1281KB)( )
Glycoprotein hormone (GPH) is a kind of important human hormones family, which consist of four members of—FSH, LH, CG and TSH. The structures of these GPHs are similar, but the functions are different. This paper mainly reviewed on  the structure,  subunits assembly, receptors recognition, and long-acting engineering of glycoprotein hormones.
• Recent Advances and Application Prospects in Keratinases
• YANG Lian1, CAO Yong-hong2, YANG Pei-long1, HUANG Huo-qing1*
• 2015, 5(1):  29-34.  DOI: 10.3969/j.issn.2095-2341.2015.01.04
• Abstract ( ) PDF (1156KB)( )
Keratinase is kind of specific enzyme that can degrade keratin.It derives from a wealth of sources. A variety of microorganisms can produce keratinase in the process of feather degradation. Keratinases from different strains are different in structure, physical and chemical properties, activity and also substrate. Keratinase has broad application prospects in feed industry,  leather industry, and environmental waste disposal, etc., which bring enormous social and economic benefits. This paper summarizes research progress on keratinase in physicochemical properties, enzymatic mechanisms, sources and classification, as well as genetic engineering, introduces the status of keratinase application and finally proposes the application prospects.
• Advancement on Elucidating Geographical Segregation in Photosynthetic Carbon Assimilation Pathway within Genus Dendrobium
• REN Jian-wu1, BAI Wei-lan2
• 2015, 5(1):  35-40.  DOI: 10.3969/j.issn.2095-2341.2015.01.05
• Abstract ( ) PDF (1173KB)( )
Status quo of research on photosynthesis in Dendrobia was reviewed. The paper summarized the characters of photosynthetic carbon assimilation pathway in the plants with crassulacean acid metabolism，and emphasis was placed on genus Dendrobium. The relation between expression of crassulacean acid metabolism and ecological environment was analyzed，furthermore，it was concluded that there was geographical segregation in terms of photosynthetic carbon assimilation pathway within genus Dendrobium. The problems existed in current study on phylogeny in genus Dendrobium were estimated and the priority for future research were suggested，which meant that the biological mechanism of geographical segregation considering photosynthetic carbon assimilation pathway within genus Dendrobium would be decoded by the means of molecular phylogeny.
• Research Advances in Integrated Management of Tobacco Black Shank
• XIE Yong-hui1, ZHANG Yong-gui1, ZHU Li-quan1, YOU Dao-gui1, LU Yao2*
• 2015, 5(1):  41-46.  DOI: 10.3969/j.issn.2095-2341.2015.01.06
• Abstract ( ) PDF (1155KB)( )
Tobacco black shank, derived from Phytophthora parasitica var. nicotianae，is one of the most serious diseases of tobacco. In recent years, due to wide spreading in the tobacco-growing areas of China，this disease has caused serious losses, and has posed a severe threat to the sustainable development of flue-cured tobacco production. Considering agricultural control，chemical control and biological control，the characters of tobacco black shank and its integrated management strategies were  expounded，in order to lay a theoretical foundation for  better prevention and treatment of the disease.
• Comprehensive Utilization and Research of Functional Components of Purple Black Rice Germplasm
• YANG Jia-zhen1,2, ZENG Ya-wen1*, DU Juan1, YANG Xiao-meng1, TAO Xiang1, YANG Shu-ming1, PU Xiao-ying1, YANG Tao1
• 2015, 5(1):  47-53.  DOI: 10.3969/j.issn.2095-2341.2015.01.07
• Abstract ( ) PDF (1197KB)( )
Black and purple rice is rich in functional ingredients，such as anthocyanins，flavonoids，polyphenols and so on. The paper reviewed the research progress of composition differences in functional ingredients and the factors，especially anthocyanin，functional studies，functional components strengthening studies based on the metabolic mechanism， breeding and food processing. According to the progress of comprehensive research and utilization of functional components in purple black rice at home and abroad，we put forward to countermeasures of breeding utilization，health food，pharmaceutical research，molecular mechanism， new functional food development and industrialization for purple black rice, which were expected to provide reference for related research.
• Combinatorial Biosynthesis of Benzenediol Lactones with Domain Swaps
• BAI Jing, LU Wei, XU Yu-quan, CHEN Ming*
• 2015, 5(1):  54-59.  DOI: 10.3969/j.issn.2095-2341.2015.01.08
• Abstract ( ) PDF (1712KB)( )
Fungal benzenediol lactones, biosynthesized by a pair of highly reduced polyketide synthases and non-reduced polyketide synthases, have diverse structures and varied biological activities. Fungal polyketide synthases contain multiple functional domains which catalyze the specific structure of final products. We found that unnatural polyketides could be synthesized in the yeast Saccharomyces cerevisiae co-expressing different reduced fungal polyketide synthases and non-reduced polyketide synthases with functional domain swaps. Furthermore, identification pattern of acyltransferase domain was studied and discussed.
• Effects of Environmental Factors on Nitrogen and Phosphorus Removal by Chlorella vularis in Wastewater
• ZHOU Lian-ning1,2, WU Feng1, ZHAO Zhen-ye1,2, WANG Bo1*
• 2015, 5(1):  60-65.  DOI: 10.3969/j.issn.2095-2341.2015.01.09
• Abstract ( ) PDF (1583KB)( )
Chlorella vularis was employed to remove nitrogen and phosphorus from wastewater. The effects of initial NH+4-N and TP concentrations，N/P ratios，light/darkness ratios and pH on the removal of NH+4-N and TP were evaluated. The results showed that Chlorella vularis could almost 100% remove NH+4-N and TP，when initial concentrations of NH+4-N and TP were no more than 35 mg/L and 7 mg/L. Under the N/P ratios of 5∶1 and 10∶1， Chlorella vularis could completely remove NH+4-N within 4 d，while the N/P ratios almost has no effect on Chlorella vularis to removal of TP. At the same initial concentrations of NH+4-N or TP，the L/D ratios of 24 h∶0 h and 12 h∶12 h had no significantly effect on removal of NH+4-N and TP by Chlorella vularis. Along with the initial concentrations increasing，Chlorella vularis showed better removal effect of NH+4-N and TP under the L/D ratio of 24 h∶0 h. The optimal pH range for removal of NH+4-N and TP by Chlorella vularis were  pH 7～8 and pH 5~7, respectively.
• Research Methods for Antibacterial Mechanism of Traditional Chinese Medicine
• PENG Qi, XIE Li-ling*, XIE Jun
• 2015, 5(1):  66-69.  DOI: 10.3969/j.issn.2095-2341.2015.01.10
• Abstract ( ) PDF (1116KB)( )
As a result of antibiotics abuse, bacterial resistance and antibiotics residues in food have become growing problems. It is urgent to find new antibacterial drugs to deal with these problems. However, It takes long cycle and high cost to develop new antibiotics, besides, resistance and residues are inevitable when using antibiotics. Traditional Chinese medicine (TCM) has thousands years application history in our country, anti-bacterial anti-inflammatory effect of some TCM have been proved by modern science. In addition,  TCM has many merits, such as, cheap, non-toxic, non-residues, non-resistance and so on. However, current studies focused on separation and extraction of active ingredients, or preliminary antibacterial effect. This paper summarized the main principles, research methods and achievements of TCM antibacterial mechanisms from cell wall and cell membrane, protein and genetic material, and respiratory metabolism in order to provide a reference for conducting relative studies.