1.Mechanism and Applications of Bio-mineralization Induced by Sporosarcina pasteurii and Related Microorganisms
Yang WU ; Jijian LIAN ; Yue YAN ; Hao QI
China Biotechnology 2017;37(8):96-103
As known so far,Sporosarcina pasteurii,or formally termed as Bacillus pasteurii,was considered as one of the most efficient biosystem which is capable of inducing biological mineralization through breaking down urea.Taking advantage of the ‘super power’ of bio-mineralization,Sporosarcina pasteurii has been successfully utilized in application of solidifying sand as a novel biological construction technology,termed as ‘bio-cementation’ Due to the nature of Sporosarcina pasteurii isolated from soil,non-pathogenicity has been observed,it was considered as a very environmentally friendly method.Recently,Sporosarcina pasteurii has been further applied into fields including environmental improvement and biomedicine.However,the mechanism under the strong Sporosarcina pasteurii mediated bio-mineralization is still not well understood.Here,the knowledge and the up-to-date studies about the biological mechanism of Sporosarcina pasteurii mediated bio-mineralization,and the utilization in construction,environment,and biomedicine are reviewed.
2.Comparison of Regulation on GM Crops Cultivation Management in USA and China
China Biotechnology 2017;37(8):119-127
The proposal to promote the commercialization of new insect-resistant GM cotton,GM corn and other major products in 13th Five Year Plan on National Science and Technology Innovation ,has put forward a test to the government's ability to manage GM crops cultivation.Only a few species of GM crops,not including food crops,have been commercialized in China,we lack experience in GM crops cultivation management.Taking USA,where the farmers cultivate huge areas of GM crops,as a comparison object,the examination and approval procedures before cultivation,GM crop growers' obligation of the management,the methods to reduce mingling of GM crops and non-GM crops are compared.And concludes that the differences in legal status of GM crops,the intellectual property regime and labeling regulation,the ability of relative stakeholders to implement segregation measures and bear loss lead to different regulation on GM crops cultivation management in USA and China.The government combine the domestic current situation of the agricultural environment in our country,and focus on substantial risk in the safety management of GM crops in cultivation management is advised.The competent department of agriculture,researchers and seed traders should work together to help guide growers to avoid the economic disputes due to mingling and reduce the impact on the ecological environment.
3.Revision of the General Policies of Nomenclature for Biological Products in China
China Biotechnology 2017;37(8):110-118
General Policies of Nomenclature for Biological Products in China were studied,aimed at establishing and perfecting the system of Chinese approved biologic name.By means of analysis of the current situation and existing problems of nomenclature for biological products and the development trend of new biotherapeutics.It is sufficiently studied on the existing leading international drug generic naming system,and the specific suggestions on revision of the General Policies of Nomenclature for Biological Products in China based on the naming principles of WHO INN and Chinese language recognition were put forward.
4.Progress on Function and Biosynthesis of Benzoxazinoids
Hongjiang GAO ; Shengyan LI ; Hai WANG ; Feng LIN ; Chunyu ZHANG ; Zhihong LANG
China Biotechnology 2017;37(8):104-109
Benzoxazinoids (BXs) are important secondary metabolites in plants.There has been a wide range of attention and research of them because of their role in defensive and allelopathy.With the development of genomics and molecular biology,the BXs biosynthesis and other molecular areas research has made great progress.The BXs profile,the function of BXs,the genetic basis of BXs biosynthesis and expression regulation were briefly introduced.
5.Heterologous Expression of Nanobodies: a Recent Progress
China Biotechnology 2017;37(8):84-95
Heavy chain antibodies (HcAb) without light chains are naturally produced by camelids.The single domain antigen-binding fragment of HcAb is referred to as VHH or nanobody (Nb),which is the smallest antigen-binding entity at present.Several characteristics such as low molecular weight,high stability,and low immunogenicity make the use of nanobodies superior to the conventional antibodies.Currently,nanobodies are highly valuable antibodies for various applications,including fundamental research,diagnostics,and therapeutics.A variety of nanobodies are investigated in clinical researches.The recent progresses of heterologous expression of nanobodies in seven expression systems,including Gram-negative and positive bacteria,yeasts,filamentous fungi,insect cells,mammalian cells and plant cells were focused on,and the expression systems,hosts,characteristics of vectors,construction of vectors and yield of nanobodies were summarized.The strategies to increase the yield of nanobodies are discussed from molecular level,expression level and rational design.
6.The Application of Graphene and Derivatives in Orthopedics
Yang JIAO ; Heng LIU ; Maimaitijuma TALATIBAIKE ; Yongping CAO
China Biotechnology 2017;37(8):78-83
Graphene and its derivatives have unique physical,chemical and biological properties,such as antibacterial property,promoting osteogenesis,increasing the wear resistance of composite materials,etc.It has broad application prospects in biomedicine and tissue engineering.The application and research progress of graphene and its derivatives in orthopedics were introduced,in order to provide theoretical basis for the future clinical and fundamental research.
7.Advances in Optimization of Hyaluronic Acid Production by Genetic Engineering Technology
China Biotechnology 2017;37(8):72-77
Hyaluronic acid is a linear acid mucopolysaccharide composed of repeating disaccharide glucuronic acid and N-acetyl-glucosamine units,which is widely used in medicine,cosmetics,food and other fields.Traditional studies have made significant achievements in improving the production of hyaluronic acid by optimizing the fermentation parameters,but have reached the upper limit,and the natural strains have the increasing disadvantages of high cost of fermentation medium and pathogenicity.With the rapid development of molecular biology technology and the continuous research on the genes related to hyaluronic acid synthesis,the research focus has gradually shifted to the use of genetic engineering technology to construct high yield,safe and specific molecular weight hyaluronan genetically engineered strains.Here the strategies and research progress of genetic engineering for the production of hyaluronic acid were reviewed.
8.Research Progress of Bacterial Lux Bioluminescence Reporter System
Qingyu CUI ; Mingyu WANG ; Hai XU
China Biotechnology 2017;37(8):66-71
Lux reporter plays an important role in molecular biology,clinical microbiology and biochemical detection,owing to its high sensitivity,fast reaction and convenience.Here the component,types and characteristics of lux reporter system were introduced.Moreover,the recent advance of its application in environment detection,food safety,new drug discovery and tumor locating were reviewed.
9.High Throughput Screening Method and Application for L-glutamate Specific Aminotransferase
Linwei HE ; Zhangmin LIU ; Yan FENG ; Li CUI
China Biotechnology 2017;37(8):59-65
Objective:The aim is to establish L-glutamate specific aminotransferase-L-glutamate dehydrogenase coupling 96-well high throughput screening method,which is applied to molecular evolution of aminotransferase WecE from E.coli.Methods:An optical assay for aminotransferase catalytic activity based on aminotransferase-glutamate dehydrogenase coupling system is established by optimization of coupling enzyme loading,signal molecule NADH concentration and coupling time.Mutants library of WecE is obtained by sitedirected saturation mutagenesis.Positive mutants can be screened out through 96-well preliminary screening and flask second screening.Results:The target transamination reaction is coupled with L-glutamate dehydrogenase indicative reaction system which consists of 0.5 U/ml enzyme loading and 0.4 mmol/L NADH.A positive mutant Y321F whose catalytic activity increases 3.4 fold compared to that of wild type is screened out in Tyr 321 saturation mutagenesis library of WecE.Conclusion:An accurate high throughput screening method with weak background interference is established.It offers feasible solution for molecular evolution of L-glutamate specific aminotransferase.
10.Production of Restriction Endonuclease Not Ⅰ Utilizing CpG DNA Methylase M.Sss Ⅰ Co-expression Vector
Pei WANG ; Kai CHEN ; Song GAO
China Biotechnology 2017;37(8):51-58
Restriction endonucleases are important molecular biology tools for DNA recombination.Because of the cleavage of DNA,their recombinant expression is difficult with low yields and complicated purification processes.In commercial productions,the technology that uses specific methylases to protect host DNA from digestion of the expressed restriction enzymes was cumbersome and practically limited.For solving this problem the expression of restriction enzyme Not Ⅰ was performed by using the DNA methylase M.Sss Ⅰ derived from Spiroplasma sp.MQ1 which specifically kept CpG sequence methylated.The methylated DNA was protected from the cutting of Not Ⅰ whose recognition sequence contained CpG.The gene of methylase M.Sss Ⅰ was introduced into Escherichia coli ER2566 and constitutively expressed,resulting in the CpG methylation pattern of the host DNA.Restriction enzyme Not Ⅰ was successfully expressed in this E.coli strain.Furthermore,by adding a purification tag to one terminus of the enzyme,recombinant Not Ⅰ was prepared as a highly purified and active product through two simple Ni-affinity and anion exchange chromatography steps.This expression system can be applied for the preparation of a series of restriction enzymes with CpG in their recognition sequences.