Current Biotechnology

Research and Application of Gene Knockout Technology in Bacillus
XIAO Shui-hua1,2, HONG Qin-yang1,3, LIN Yan-zhen1,2, LI Jin-yu1,2*
2013, 3(2): 81-84. DOI: 10.3969/j.issn.2095-2341.2013.02.01
Abstract ( ) PDF (1087KB)( )

As a kind of probiotics, Bacillus was widely used in industrial, agriculture , medical treatment and public health fields. Gene knockout technology is an important mean for gene function research which is conductive to understand the biological control and regulation mechanisms in Bacillus. This paper reviews the principles and characteristics of two kinds of gene knockout technology methods which are homologous recombination and insertion mutation, and their application advance in Bacillu, discusses the limitation of gene knockout technology, finally prospects the research and development in the future.

Bioactive Components in Bacillus thuringiensis
HONG Qin-yang1,2, XIAO Shui-hua1,3, ZOU Qing-ya1,2, LIU Hong1,3, GUAN Xiong1*
2013, 3(2): 85-89. DOI: 10.3969/j.issn.2095-2341.2013.02.02
Abstract ( ) PDF (1109KB)( )

Bacillus thuringiensis is one of the most effective and widely used microbial insecticides. A variety of bioactive components have been identified from Bacillus thuringiensis continuously, such as insecticidal crystal proteins, vegetative insecticidal protein, chitinase, autoinducer inactivation protein, and immune Inhibitor A, etc. These bioactive factors have directly or indirectly influence on its insecticidal ability of Bacillus thuringiensis. Their properties and prospect applications are reviewed and discussed in this paper.

Extremely Radiation-resistant Bacterium Deinococcus radiodurans
WANG Jin-hui, ZHOU Zheng-fu, ZHANG Wei, LIN Min, CHEN Ming*
2013, 3(2): 90-95. DOI: 10.3969/j.issn.2095-2341.2013.02.03
Abstract ( ) PDF (1121KB)( )

Deinococcus radiodurans is Gram positive bacterium, possessing special cell structure. The genome comprises two chromosomes and two plastids, and the GC content is relatively high. Distincting from other Deinococcus bacteria, D. radiodurans is amenable to genetic manipulation owing to its natural transformability and the cells are competent throughout the exponential growth stage. Duing to unique structure and strong repair systems, D. radiodurans has strong ionizing radiation resistance, UV resistance, oxidation resistance, drought resistance and other characteristics, having great research and application value.

Stress Response and Signal Transduction System in Deinococcus Radiodurans
WANG Wen-tao， ZHOU Zheng-fu， CHEN Ming， LIN Min， ZHANG Wei*
2013, 3(2): 96-102. DOI: 10.3969/j.issn.2095-2341.2013.02.04
Abstract ( ) PDF (1145KB)( )

Deinococcus radiodurans is a robust bacterium which shows extreme radiation tolerance. This bacterium can survive under lots of stress conditions, such as desiccation, cold shock and vacuum. Several proteins and transcriptional factors are important for the various stress response in D. radiodurans. This view introduces the proteins, transcription regulators and signal transduction system involved in stress responses in D. radiodurans.

Research Progress on DNA Repair Mode and Functional Proteins Involved in the Extreme Radiation Resistant Deinococcus radiodurans
ZHANG Chen, ZHOU Zheng-fu, CHEN Ming, LIN Min, ZHANG Wei*
2013, 3(2): 103-108. DOI: 10.3969/j.issn.2095-2341.2013.02.05
Abstract ( ) PDF (1120KB)( )

Deinococcus radiodurans (DR) is one of the most ionizing-radiation resistant microorganisms. It has superior resistence to arefaction, ionizing radiation, UV-C, oxidant and other stresses. DR has many genes related to DNA repair system, which could repair DNA efficiently through metabolic pathways network control system. However, there is still very limited understanding of DR efficient and accurate damage DNA repair mechanisms under stresses. This paper mainly summarized the new development about the DNA repair systems and functional proteins of Deinococcus radiodurans.

Research Progress on Resistance and Tolerance Mechanisms Against Oxidative Stress of Deinococcus radiodurans
ZHAO Zhong-chao1,2, ZHANG Yu-xiu2, ZHOU Zheng-fu2, ZHANG Wei2, CHEN Ming2*
2013, 3(2): 109-114. DOI: 10.3969/j.issn.2095-2341.2013.02.06
Abstract ( ) PDF (1708KB)( )

Deinococcus radiodurans has strong resistance and tolerance mechanisms for oxidative stress, which protect proteins against oxidative damage and sanitize the cells against toxic oxidized products. The defence system against oxidative stress of D. radiodurans has nonenzymatic and enzymatic scavengers. The manganesecomplexes is a member of nonenzymatic scavengers, which is identified as the most powerful ROS scavengers. D. radiodurans has conserved proteins for cellular cleansing and anti-oxidation protection, which enhance the capacities of D. radiodurans for prevention and repair of damage to DNA, RNA and proteins. This paper mainly summarized the defence system against oxidative stress in D. radiodurans, so as to provide references for the application of tolerance mechanisms for oxidative stress in medicine and public health.

Current Status of Whitefly Control Using Integrated Pest Management
SONG Fei-fei1,2, SU De-wei2
2013, 3(2): 115-119. DOI: 10.3969/j.issn.2095-2341.2013.02.07
Abstract ( ) PDF (1107KB)( )

Whiteflies is one of major economic pests in China, which have wide host ranges and mainly do harm to vegetables and citrus etc. This paper reviewed on integrated pest managements of whiteflies including agricultural, physical and biological control, especially focused on biocontrol of whitefly using entomopathogenic fungi, so as to provide a base for better control of whiteflies.

Green Prevention and Control Measures Used in Organic Vegetable Cultivation
WANG Pin-shu1, QIAO Yan1, GE Xian-e2, YUE Jin1, DONG Jie1, YANG Jian-guo1
2013, 3(2): 120-123. DOI: 10.3969/j.issn.2095-2341.2013.02.08
Abstract ( ) PDF (1055KB)( )

Green prevention and control measures can replace the chemical pesticides to be applied in the cultivation of organic vegetables, preventing the occurrence of pests and diseases and improving the quality of organic vegetables. Using the application of green prevention and control measures in Beijing Green Vegetable Garden Vegetable Professional Cooperatives as a case, this paper explored the application of green prevention and control measures from three aspects of agricultural measures, physical and chemical control measures, biological measures. This paper also analyzed the problems and proposed the way of promotion and application of green prevention and control measures in vegetable cultivation.

Biological Characteristics of Bacillus thuringiensis Strain BRC-PC6 and Cloning, Bioinformatics Analysis of its aiiA Gene
YAO Zu-jie1, WU Song-qing1, PENG Yan1, YANG Mei2*
2013, 3(2): 124-131. DOI: 10.3969/j.issn.2095-2341.2013.02.09
Abstract ( ) PDF (2978KB)( )

In the QS system, the AiiA enzyme can decide the expression of pathogenic genes in several plant and human pathogenic bacteria, which is encoded by aiiA gene from Bacillus thuringiensis, involving in the degradation of N-acyl-homoserine lactones (AHLs). BRC-PC6 was isolated from the samples collected from the surroundings of a pesticide factory, and it can produce several insecticidal crystal proteins (ICPs) during the fermentation. Comparing with Bt subsp. kurstaki (HD-1), strain BRC-PC6 was characterized with biochemical characteristics, ICPs gene, ICPs, etc. The PC6-aiiA gene from the strain BRC-PC6 was identified, cloned and sequenced in this study. It was shown that cry1Aa and cry1Ac were detected in this novel strain. Basing on the bioassay, BRC-PC6 was toxic to the larva of Lepidoptera. Sequencing analysis was shown that the gene of aiiA was 753 bp, and it was 88%~97% homology with other known aiiA genes. For further research of this novel aiiA gene, bioinformatic analysis was carried out. An instability hydrophobic protein with one structural domain was predicted for Bt BRC-PC6 strain predicted, and AiiA had the signal predicted peptide.

Cloning and Expression of cry1Ab Gene from Bacillus thuringiensis for Further Molecular Modification
CHEN Fan-bing1,3, SHAO En-si1,2, HUANG Zhi-peng1*
2013, 3(2): 132-136. DOI: 10.3969/j.issn.2095-2341.2013.02.10
Abstract ( ) PDF (2053KB)( )

The cry1Ab gene from Bacillus thuringiensis has been widely used in transgenic plants around the world. However, the Cry1Ab insecticidal protein shows no or little toxicity to the pests with piercing-suckling moutnparts. In this study, the cry1Ab gene was amplified from total DNA of Bt strains WB7 with a pair of primers designed on the full-length sequences of published cry1Ab genes. Then it was ligated with linearized pGEX-KG vector to construct recombinant expression vector pGEX-KG-cry1Ab. The soluble Cry1Ab-GST fusion protein was obtained after transferring pGEX-KG-cry1Ab into E. coli BL21(DE3) and then inducing by IPTG. The results provided a basis for further studies of directional modification of Cry1Ab in order that it can bind to the proper receptors in midgut of the pests with piercing-suckling moutnparts.

Using BP Neural Network and Genetic Algorithm to Optimize the Fermentation Medium of Bacillus thuringiensis
GUO Hui-hui
2013, 3(2): 137-139. DOI: 10.3969/j.issn.2095-2341.2013.02.11
Abstract ( ) PDF (1076KB)( )

BP neural network and genetic algorithms methods were used to optimize the fermentation medium of Bacillus thuringiensis. The best fermentation medium is 0.392 8% yeast extract, 0.492 8% corn meal, 2% defatted peanut flour, 0.035% MgSO4·7H2O, 0.025%KH2PO4, 0.049 6% CaCO3. The spore production was 6.3×108/mL under this condition,which was 7.7% higher than that by RSM method.

The Relationship Between Morphological Differentiation and Cyclosporin A Synthesis in Tolypocladium niveum
ZHENG Xiao-xian
2013, 3(2): 140-144. DOI: 10.3969/j.issn.2095-2341.2013.02.12
Abstract ( ) PDF (1076KB)( )

The relationship between morphological differentiation and cyclosporin A synthesis in fermentation process of Tolypocladium niveum CA411 was studied. The mycelium and spore morphology changes were observed while Tolypocladium niveum were inoculated in mycelium and sporulation media under the optical microscope. The cyclosporin A synthesis was highly related with morphological differentiation. It's more conducive to the synthesis of cyclosporin A during the process of filamentous hyphae into spore.

The Effect of Spinosad on Thrips Prevention in Color Sweet Pepper
GU Pei-yun, MA Yong-jun, JIAO Xue-xia, GUO Shu-chen, GUO Yang, GUO Ming-ge, TIAN Xue-wei
2013, 3(2): 145-147. DOI: 10.3969/j.issn.2095-2341.2013.02.13
Abstract ( ) PDF (1030KB)( )

To demonstrate the effect and method for thrips prevention in color sweet pepper, the trial of 25 g/L spinosad, 240 g/L spirotetramat+1.8%abamectin were compared in means of leaf-spray and both of leaf-spray and floor-spray. The result showed that 25 g/L spinosad achieved the best effect in both leaf-and floor-spray, the control effecacy reached 94.71% in 2-day and 77.77% in 8-day post-application respectively.

Control Effects of 30% Abamectim Dimilim SC on Pear Big Borer in Field
QIAO Yan1, GUO Xi-hong1, YIN Zhe1, DONG Jie1, YUE Jin1, SONG Yu-lin2, WANG Ze-min2
2013, 3(2): 148-150. DOI: 10.3969/j.issn.2095-2341.2013.02.14
Abstract ( ) PDF (1040KB)( )

Aqueous solution of 30% abamectim dimilim SC was used to control pear big borer in field. The results showed that the efficacies of the solution diluting 1 000 times and 2 000 times of 30% abamectim dimilim SC was equivalent to effecacy of the control and better than the 3 000 times dilutions. It was safe compared with CG and it could be recognized as the ideal pesticide against the pear big borer.

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