Identification of BLB resistant genes in some rice varieties for development of high yielding bacterial leaf blight tolerant types

Aim: To identify bacterial leaf blight resistant genes in some rice varieties so that these resistant varieties can be used as a good source of donor for BLB resistant genes in genetic enhancement program.Methodology: A total of sixty-one rice genotypes including resistant and susceptible checks were screened in field condition by artificial inoculation using IX020 strain of Xoo for two years (Kharif 2016 and 2017). These varieties were also genotyped for seven SSR markers tagged with major BLB resistant genes, i.e., Xa4, xa5, xa13 and Xa7. Results: In artificial screening, significant disease development was recorded and the varieties were categorized using disease scoring scale of IRRI, 1996 where seven cultivars exhibited resistance, while twenty-seven were found to be moderately resistant. In genotyping, there was distinct difference in banding position for resistant and susceptible genotypes. Genotypes having resistant disease reaction, carrying BLB resistant genes were identified. Interpretation: Genotypes IR-64, IR-68144-2b-2-2-3-1-127, Ratna, Surjamukhi, Kalinga-2, Azucena and Zheshan-2 expressed bands of RM markers closely linked to Xa4, xa5, xa13 and Xa7 BLB resistant genes and field testing also confirmed resistant host reaction against pathogens.

Screening of High-yield and High-oil Curcuma kwangsiensis / 中国药房

OBJECTIVE:To establish a method for analyzing the volatile oil of high-yield and high-oil Curcuma kwangsiensis, and to provide reference for its breeding. METHODS:GC-MS was performed on the column of HP-5MS quartz elastic capillary column,carrier gas was high purity helium(99.999%),flow rate was 1.0 ml/min,inlet temperature was 250 ℃,the initial tem-perature of column was 50 ℃(temperature programmed),split injection with split ratio of 10:1. Mass spectrometry conditions:ionization mode was the electron impact ion source,ionization energy was 70 eV,the ion source temperature was 230 ℃,the quadrupole temperature was 150 ℃, transmission line temperature was 280 ℃,the electron multiplier voltage was 1588 V,and mass scanning range was m/z 45 to 500. High-yield and high-oil germplasm of were screened from 100 different germplasms,the volatile oil composition of single plant and relative percentage contents of each composition were compared,SPSS 22.0 software was used for cluster analysis. RESULTS:Totally 10 high-yield and high-oil germplasm were screened,54 kinds of compounds were identified,the common compositions of 10 different germplasms were camphor,1-caryophyllene,γ-elemene,curcumene, gemma ketone and new curdione,most germplasms contained borneol,isoborneol,δ-elemene,germacrene and calamine. The C78,C104,purpose 2,volatile oil content and relative percentage contents of active compositions in volatile oil were high. The 10 high-yield and high-oil germplasms can be divided into 3 groups. CONCLUSIONS:The study basically clears the main chemicalcomposition of volatile oil of high-yield and high-oil C. kwangsiensis,C78,C104 and purpose 2 are the more excellent strains in high-yield and high-oil C. Kwangsiensis germplasm.

Strategies for producing high-yield viral vaccine antigens / 生物工程学报

Vaccination is an important strategy to prevent infectious diseases. However, low antigen yield of vaccine producing strains may lead to high cost of vaccines, low antigen production and vaccine failure. In recent years, many efforts have been made to improve the antigen yield of many vaccines. This mini-review summarizes various methods for increasing the antigen yield for vaccine production, including genetic modification of viruses, improvement of the adaptation of viruses to cells, and optimization of antigen expression systems and manufacturing procedures. Furthermore, we discuss the advantages and the problems of current strategies, as well as indicate the perspectives.

A novel M2e-multiple antigenic peptide providing heterologous protection in mice

Swine influenza viruses (SwIVs) cause considerable morbidity and mortality in domestic pigs, resulting in a significant economic burden. Moreover, pigs have been considered to be a possible mixing vessel in which novel strains loom. Here, we developed and evaluated a novel M2e-multiple antigenic peptide (M2e-MAP) as a supplemental antigen for inactivated H3N2 vaccine to provide cross-protection against two main subtypes of SwIVs, H1N1 and H3N2. The novel tetra-branched MAP was constructed by fusing four copies of M2e to one copy of foreign T helper cell epitopes. A high-yield reassortant H3N2 virus was generated by plasmid based reverse genetics. The efficacy of the novel H3N2 inactivated vaccines with or without M2e-MAP supplementation was evaluated in a mouse model. M2e-MAP conjugated vaccine induced strong antibody responses in mice. Complete protection against the heterologous swine H1N1 virus was observed in mice vaccinated with M2e-MAP combined vaccine. Moreover, this novel peptide confers protection against lethal challenge of A/Puerto Rico/8/34 (H1N1). Taken together, our results suggest the combined immunization of reassortant inactivated H3N2 vaccine and the novel M2e-MAP provided cross-protection against swine and human viruses and may serve as a promising approach for influenza vaccine development.

High level secretory expression of recombinant human tissue factor in Pichia pastoris / 中国生化药物杂志

Objective To construct a eukaryotic expression vector in Pichia pastoris containing human tissue factor( hTF) gene,in order to achieve high level secretory expression in extracellular.Methods Expression plasmid, pGAPZaA-hTF, was constructed by inserting the synthesized sequence encoding human extracellular tissue factor into yeast expression vector pGAPZaA and transformed into Pichia pastoris SMD1168H with electroporation.Having been selected by Zeocin, transformants containing hTF cDNA were expressed in YPD, extracellular proteins were detected by SDS-PAGE and confirmed by Western bolt.Results Successfully constructed the recombinant pGAPZaA-hTF expression system in Pichia pastoris.SDS-PAGE showed that the molecular weight of the expression product was about 37 -40 kDa.Western-blot indicated that it was human extracellular tissue factor.The crude yield of total protein in medium was up to 1 g/L, more than 80% of which was hTF.Conclusion Truncated rTF gene is expressed in Pichia pastoris and the active products are secreted into the medium which have the same activation as the native TF.

Construction of a Vero cell-based high-yield H7N9 influenza vaccine candidate strain / 中华微生物学和免疫学杂志

Objective To construct an H7N9 vaccine strain by using a previously obtained Vero cell-based high-yield influenza A virus as the donor strain.Methods The recombinant virus strains, 4mut-H7N9 and PR8-H7N9, were respectively rescued with reverse genetics technique by combining the genes en-coding hemagglutinin (HA) and neuraminidase (NA) of H7N9 virus with the 6 internal genes of PR8-4mut or PR8 virus strains.The growth feature of 4mut-H7N9 virus strain was compared with that of PR8-H7N9 vi-rus strain with growth curves and plaque assays.The viral proteins produced by 4mut-H7N9 and PR8-H7N9 virus strains were measured by Western blot and Coomassie blue staining.Results The PR8-H7N9 and 4mut-H7N9 virus strains were successfully rescued.The virus titer of 4mut-H7N9 strain was about 3000 times higher than that of PR8-H7N9 strain at 72 hours after infecting Vero cells.The 4mut-H7N9 virus strain formed plaques of about 1 mm in diameter on Vero cells, while the PR8-H7N9 virus strain only formed pin-point plaques on Vero cells.The levels of viral proteins encoded by purified 4mut-H7N9 virus strain were significantly higher than that of the PR8-H7N9 virus strain as indicated by both Western blot and Coomassie blue staining.Moreover, the 4mut-H7N9 virus strain was less pathogenic than PR8-H7N9 strain in mice, and retained the trypsin dependence for infecting cells.Conclusion The reassortant 4mut-H7N9 vaccine strain as established by reverse genetics technique grew faster and better in Vero cells, suggesting the possi-bility of using it as a candidate vaccine strain whenever facing a potential epidemic of H7N9 virus.

Research progress on Nisin biosynthesis and breeding of high-yield strains / 中国生化药物杂志

Nisin, produced by several strains in the growth process of Lactococcus lactis, is a natural antimicrobial polypeptide.Now, Nisin has served as an effective and safe food additive extensively used in food industry in many countries and regions because of its excellent antimicrobial activity.However, the current production of Nisin is largely fermented by lactobacillus and its industrialized production still can not meet enormous market needs, therefore establishing reasonably high-yield Nisin strains is of great significance.This review mainly summarizes the development pathway of molecule based on the functional expression of Nisin biosynthetic genes and regulation of gene expression, and also the study status on high Nisin-producing strains which provides practical foundation for further study on expected strains as well as some useful guidance for large-scale industrialized production of Nisin.

Rsearch progress on breeding of pullulan high-yield strain without melanin / 中国生化药物杂志

Pullulan is a linear glucosic polysaccharide produced by the polymorphic fungus Aureobasidium Pullulans, which has long been applied for various applications in medical and food industry due to its security, stability and low adhesive ability.At present, the two problems in restricting pullulan industrial production are the low polysaccharide production and melanin secreted which is hard to erase completely, giving the following process some problem.As a starting point, this review article collects and analyzes the progress on the breeding of pullulan high-yield strain without melanin in recent years, in order to find more efficient strains breeding methods, laying a foundation for further breeding of pullulan high-yield strain without melanin.

High-yield production of scutellaria radix flavonoids (baicalein, baicalin and wogonin) by liquid-culture of Scutellaria baicalensis root-derived cells

Production of baicalein, baicalin and wogonin by liquid culture of Scutellaria baicalensis cells derived from the plant root was studied. The maximum production obtained were 119 mg/L of baicalein at two week, 1372 mg/L of baicalin at eight week, and 14 mg/L of wogonin at two week. In addition, the production of baicalin was drastically increased to 1000 mg/L level at 3-week culture, and the extremely high production rate (339 mg/L•week) was obtained. In the comparison of total antioxidative activities among baicalein, baicalin and wogonin, evaluated by thiocyanate method, it was suggested that the location of hydroxyl groups both at 5- and 6-position contributed to enhancement of radical scavenging activity, and/or methoxylation at 8-position diminished the activity. The possibility of utilizing these flavonoids for natural antioxidants and medicine is also discussed.

Mass Production of Pinellia ternate by Tissue Culture and the Selection for High-yield Individuals / 中国生物工程杂志

Using the tissue culture technology to achieve the fast propagation of P.ternata and through the photosynthetic characters and yield comparison,two high-yield indivaduals were obtained. The result showed that the coefficent of propagation can get to 1∶6.23 per generation, through 3 month culture the average diameter of the in vitro tuber can get 0.88 cm. P.ternata was a typical shade-plant, of which LCP was only 700?mol?photons/s?m2. Photo-inhibition was observed among all the three leaf-types of P.ternata, and the willow leaf type showed the most obvious photo-inhibition. Both of the light response Pn curve and single tuber weight were significant different among leaf styles. Result for studying the chlorophyll fluorescence parameters showed that all the difference of NPQ, qP and qN among three leaf-types of P.ternata were significant and the difference of potential-photosynthetic productivity among them was significant. The willow leaf style had the strongest light-tolerance capacity.The individuals of T2(peach-leaf type) had the highest Pn and single tuber weight among 11 superior individuals and the individuals of L2(willow-leaf type) showed the strongest light-tolerance capacity. Through 6 month propagation ten thousands in virto tuber of T2 and L2 each were gotten. And after growing in Wenzhou experimental base for one year, the total gross weight of the high-yield individual tuber get to 100kg each.

Studies on Screening and Conditions of Strains Highly Producing Neutral Phytase / 微生物学通报

A highly phytase-producing strain B.licheniformis LL8 was obtained by several mutagenesis of UV with B.licheniformis as starting strain.The new strain produced about two folds of phytase activity as compared with the starting strain. The production performance of the strain was stable. The cultivation conditions were optimized by single factor and orthogonal experiment. When the mutant B.licheniformis LL8 was cultivated at 55℃, initial pH 7.5 with the inoculation size of 10% for 30h in WBE medUm, the phytase activity was up to 2268.4U/mL.

THE ISOLATION,SCREENING AND IDENTIFICATION OF BACILLUS SUBTILIS STRAINS PRODUCING HIGH-ACTIVITY FIBRONOLYSIN / 微生物学通报

The results of isolation,screening and identification of Bacillus subtilis strains which produced fibronolysion were reported in this paper.20 Bacillus subtilis strains were screened from different withered straw samples.Among them,FM-S1,FM-S2,FM-S6,FM-S8 and FM-S11 produce fibronolysin with higher activity.According to morphological,physiological and biochemical characters,the screened strains were confirmed to be Bacillus subtilis. For FM-S2,the production of fibronolysin type in solid fermentation was considered to be synchronous with growth.