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On the critical radius in generalized Ostwald ripening
WANG Qin-bo, ROBERT Finsy, XU Hai-bo, LI Xi
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 1-.   https://doi.org/10.1631/jzus.2005.B0705
Abstract( 2387 )     PDF(0KB)( 965 )
The relation between the critical radius and the particle size distribution for generalized Ostwald type ripening processes whereby the mass transfer coefficient is modelled by a power law was derived. The critical radius is determined by the growth rate, the mass transfer coefficient and the mass balance, and is independent of whether the limiting stationary growth regime has been obtained.
Experimental approaches and analytical technique for determining heavy metals in fallen dust at ferrosilicon production factory in Edfu, Aswan, Egypt
SOLTAN M.E., RAGEH H.M., RAGEH N.M., AHMED M.E.
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 2-.   https://doi.org/10.1631/jzus.2005.B0708
Abstract( 2710 )     PDF(0KB)( 945 )
In this study aimed to evaluate the pollution extent of metals and nonmetals inside and outside the ferrosilicon production factory in Edfu, Aswan, Egypt, raw materials (quartz, cokes, iron oxides), ferrosilicon alloy, silica fume, dust and suspended dust (at different sites) samples were collected from the factory, and fallen dust samples were collected from outside the factory, horizontally (at different sites and different distance and directions) and vertically (at different floors in the selected buildings). Gravimetric methods, X-ray fluorescence (XRF), flame photometer, wide range carbon determinator and atomic absorption spectroscopy tools were used for elements determination. The results indicating that the fallen dust and its element contents on southern factory walls being higher than those on eastern factory walls may be due to the nature of the dusts and effects of wind force and wind direction. Fallen dust levels in different regions outside the factory were found to be affected by the distance, direction and floors. The nature of dust samples was affected by gravity and the suspended dust in different factory units depended on the work capacity and method of handling materials by personnel in different production units. Silica fume was a complicated problem, had dangerous effect against the workers’ health, and was characterized by high concentrations of SiO2 (90.6%~93.6%) and heavy metals (Mn, 420.6×10−6~520.3×10−6; Fe, 2354×10−6~2685×10−6; Co, 80.7×10−6~101.6×10−6 and Ni, 5.3×10−6~6.05×10−6). The TSP (Total Suspended Particulate) levels in all factory units were higher than the recommended air quality value (70 μg/m3) under Egyptian law. The effect of ferrosilicon factory fallen dust on the surrounding regions decreased with increasing distance between the factory and these regions. The suspended dust samples in the factory units and their components greatly exceeded national and international standards, so health and environmental criteria must be enforced on these units.
Chemical shift assignments of two oleanane triterpenes from Euonymus hederaceus
HU He-jiao, WANG Kui-wu, WU Bin, SUN Cui-rong, PAN Yuan-jiang
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 3-.   https://doi.org/10.1631/jzus.2005.B0719
Abstract( 2384 )     PDF(0KB)( 1061 )
1H-NMR and 13C-NMR assignments of 12-oleanene-3,11-dione (compound 1) were completely described for the first time through conventional 1D NMR and 2D shift-correlated NMR experiments using 1H-1HCOSY, HMQC, HMBC techniques. Based on its NMR data, the assignments of 28-hydroxyolean-12-ene-3,11-dione (compound 2) were partially revised.
Magnetic properties and heavy metal contents of automobile emission particulates
LU Sheng-gao, BAI Shi-qiang, CAI Jing-bo, XU Chuang
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 6-.   https://doi.org/10.1631/jzus.2005.B0731
Abstract( 3028 )     PDF(0KB)( 1196 )
Measurements of the magnetic properties and total contents of Cu, Cd, Pb and Fe in 30 automobile emission particulate samples indicated the presence of magnetic particles in them. The values of frequency dependent susceptibility (cfd) showed the absence of superparamagnetic (SP) grains in the samples. The IRM20 mT (isothermal remanent magnetization at 20 mT) being linearly proportional to SIRM (saturation isothermal remanent magnetization) (R2=0.901), suggested that ferrimagnetic minerals were responsible for the magnetic properties of automobile emission particulates. The average contents of Cu, Cd, Pb and Fe in automobile emission particulates were 95.83, 22.14, 30.58 and 34727.31 mg/kg, respectively. Significant positive correlations exist between the magnetic parameters and the contents of Pb, Cu and Fe. The magnetic parameters of automobile emission particulates reflecting concentration of magnetic particles increased linearly with increase of Pb and Cu content, showed that the magnetic measurement could be used as a preliminary index for detection of Pb and Cu pollution.
Studies on the management of root-knot nematode, Meloidogyne incognita-wilt fungus, Fusarium oxysporum disease complex of green gram, Vigna radiata cv ML-1108
HASEEB Akhtar, SHARMA Anita, SHUKLA Prabhat Kumar
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 7-.   https://doi.org/10.1631/jzus.2005.B0736
Abstract( 3884 )     PDF(0KB)( 1073 )
Studies were conducted under pot conditions to determine the comparative efficacy of carbofuran at 1 mg a.i./kg soil, bavistin at 1 mg a.i./kg soil, neem (Azadirachta indica) seed powder at 50 mg/kg soil, green mould (Trichoderma harzianum) at 50.0 ml/kg soil, rhizobacteria (Pseudomonas fluorescens) at 50.0 ml/kg soil against root-knot nematode, Meloidogyne incognita–wilt fungus, Fusarium oxysporum disease complex on green gram, Vigna radiata cv ML-1108. All the treatments significantly improved the growth of the plants as compared to untreated inoculated plants. Analysis of data showed that carbofuran and A. indica seed powder increased plant growth and yield significantly more in comparison to bavistin and P. fluorescens. Carbofuran was highly effective against nematode, bavistin against fungus, A. indica seed powder against both the pathogens and both the bioagents were moderately effective against both the pathogens.
DNA sequence representation by trianders and determinative degree of nucleotides
DUPLIJ Diana, DUPLIJ Steven
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 8-.   https://doi.org/10.1631/jzus.2005.B0743
Abstract( 2316 )     PDF(0KB)( 1285 )
A new version of DNA walks, where nucleotides are regarded unequal in their contribution to a walk is introduced, which allows us to study thoroughly the “fine structure” of nucleotide sequences. The approach is based on the assumption that nucleotides have an inner abstract characteristic, the determinative degree, which reflects genetic code phenomenological properties and is adjusted to nucleotides physical properties. We consider each codon position independently, which gives three separate walks characterized by different angles and lengths, and that such an object is called triander which reflects the “strength” of branch. A general method for identifying DNA sequence “by triander” which can be treated as a unique “genogram” (or “gene passport”) is proposed. The two- and three-dimensional trianders are considered. The difference of sequences fine structure in genes and the intergenic space is shown. A clear triplet signal in coding sequences was found which is absent in the intergenic space and is independent from the sequence length. This paper presents the topological classification of trianders which can allow us to provide a detailed working out signatures of functionally different genomic regions.
Tea saponins affect in vitro fermentation and methanogenesis in faunated and defaunated rumen fluid
HU Wei-lian, WU Yue-ming, LIU Jian-xin, GUO Yan-qiu, YE Jun-an
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 13-.   https://doi.org/10.1631/jzus.2005.B0787
Abstract( 3048 )     PDF(0KB)( 1141 )
The effect of tea saponins (TS) on rumen fermentation and methane emission was examined using an in vitro gas production technique named Reading Pressure Technique. Three levels of TS addition (0, 0.2, 0.4 mg/ml) were evaluated in the faunated and defaunated rumen fluid. Compared to the control, TS addition decreased the 24 h gas production in the faunated rumen fluid, but had a minor effect on gas yield in the defaunated rumen fluid. The TS significantly reduced methane production in vitro. In the faunated rumen fluid, 0.2 or 0.4 mg/ml TS decreased the 24 h methane emission by 12.7% or 14.0%, respectively. Rumen fluid pH value was affected neither by TS addition nor by defaunation. The TS addition had only minor effects on volatile fatty acids, but the yield and pattern of volatile fatty acids were greatly affected by defaunation. While the molar proportion of acetate was not affected by defaunation, the propionate was significantly increased and the butyrate significantly decreased. Ammonia-N concentration and microbial protein yield were influenced by TS inclusion and defaunation. Inclusion of 0.4 mg/ml TS increased the microbial protein mass by 18.4% and 13.8% and decreased the ammonia-N concentration by 8.3% and 19.6% in the faunated and defaunated rumen fluid, respectively. Protozoa counts were significantly reduced by TS inclusion. The current study demonstrated the beneficial effect of TS on methane production and rumen fermentation, and indicated that this may be due to the effect of the associated depression on protozoa counts.
Effects of supplementary urea‑minerals lick block on the kinetics of fibre digestion, nutrient digestibility and nitrogen utilization of low quality roughages
WU Yue-ming, HU Wei-lian, LIU Jian-xin
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 14-.   https://doi.org/10.1631/jzus.2005.B0793
Abstract( 2750 )     PDF(0KB)( 1017 )
Three yearling lambs with a rumen cannula were used to investigate the effects of supplementation with an urea-minerals lick block (ULB) on the kinetics of ruminal fibre digestion, nutrient digestibility and nitrogen (N) utilization of rice straw (RS), ammonia bicarbonate (AB)‑treated RS (ABRS) and hay prepared from natural pasture. The digestibility of dry matter and organic matter of RS increased by 13.1% and 12.7% (P<0.05) when the diet was supplemented with ULB, and approached to that of ABRS, indicating that the effect of ULB on digestibility of RS is similar to that of AB treatment. The digestibility of ABRS was slightly improved by the ULB feeding. Nitrogen retention was highest in lambs fed on ABRS alone, followed by hay with ULB, and was lowest in animals fed on RS with ULB. However, both the amount and proportion of N retention to N intake were enhanced by ULB supplementation to lambs fed on hay. The proportion of N retained to N digested decreased due to ULB supplementation to lambs fed on RS or ABRS. Supplementing ULB did not greatly influence the rumen degradation of either dry matter or crude protein in each of the three diets. RS and hay had similar values in the potential extent of digestion (PED) and digestion rate of PED (kd) of fibrous materials, but the discrete lag time for RS was lower than that for hay. The AB treatment significantly increased the PED (P<0.05) and kd (P<0.05) of RS. Neither the PED nor kd for RS and ABRS was influenced by ULB supplementation, but the kd for hay significantly increased due to ULB. The lag time for hay was also shortened by the ULB feeding. The ULB improved the digestion of fibre in the rumen of lambs fed on low quality roughage. It is inferred that while ULB is effective in increasing nutrient digestibility of low quality roughages by improving ruminal fibre digestion. A synchronized supply of N and energy to rumen microbes should be considered to improve the efficiency of N utilization when the basal diet is ammoniated straw.
Isolation and physiological characteristics of a premature senescence mutant in rice (Oryza sativa L.)
LI Fu-zhen, JIN Song-heng, HU Guo-cheng, FU Ya-ping, SI Hua-min, JIANG De-an, SUN Zong-xiu
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 16-.   https://doi.org/10.1631/jzus.2005.B0803
Abstract( 2681 )     PDF(0KB)( 932 )
A rice pse(t) (premature senescence, tentatively) mutant line, was isolated from 4 500 independent T-DNA inserted transgenic lines. The symptoms of premature senescence appeared more severely than those of the control plants (Zhonghua 11, japonica) at the last development stage. To characterize the mutant and provide basic information on the candidate genes by mapping to a physical region of 220-kb, experiments were carried out in two phytotrons under controlled temperature of 24 °C and 28 °C, respectively. The content of chlorophyll, soluble protein and MDA (malondialdehyde), net photosynthesis, the antioxidant enzyme activities of SOD (superoxide dismuase) (EC 1.15.1.1) and POD (peroxidase) (EC 1.11.1.7) and the peptidase activities of leaves were measured from top to bottom according to the leaf positions at the flowering stage. Compared with the control plant, the mutant showed the following characteristics: (1) Higher net photosynthesis rate (Pn) appeared in the 1st and 2nd leaves, contents of chlorophyll and soluble protein were also higher in the 1st leaf; (2) The activities of SOD, POD and peptidase were higher according to the leaf position from top to bottom; (3) The symptom of premature senescence was accelerated in the mutant at 28 °C treatment. The MDA content and the SOD and POD activities between the 24 °C and 28 °C treatment mutants were not significantly different. Content of chlorophyll and soluble protein of leaves mutant decreased rapidly at 28 °C treatment. The results show that pse(t) is sensitive to high temperature. The probable function of PSE(T) is discussed.
Behavioral response of tilapia (Oreochromis niloticus) to acute ammonia stress monitored by computer vision
XU Jian-yu, MIAO Xiang-wen, LIU Ying, CUI Shao-rong
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 17-.   https://doi.org/10.1631/jzus.2005.B0812
Abstract( 2842 )     PDF(0KB)( 1367 )
The behavioral responses of a tilapia (Oreochromis niloticus) school to low (0.13 mg/L), moderate (0.79 mg/L) and high (2.65 mg/L) levels of unionized ammonia (UIA) concentration were monitored using a computer vision system. The swimming activity and geometrical parameters such as location of the gravity center and distribution of the fish school were calculated continuously. These behavioral parameters of tilapia school responded sensitively to moderate and high UIA concentration. Under high UIA concentration the fish activity showed a significant increase (P<0.05), exhibiting an avoidance reaction to high ammonia condition, and then decreased gradually. Under moderate and high UIA concentration the school’s vertical location had significantly large fluctuation (P<0.05) with the school moving up to the water surface then down to the bottom of the aquarium alternately and tending to crowd together. After several hours’ exposure to high UIA level, the school finally stayed at the aquarium bottom. These observations indicate that alterations in fish behavior under acute stress can provide important information useful in predicting the stress.
Sequence analysis and expression pattern of MGTA1 gene in rice blast pathogen Magnaporthe grisea
WANG Jiao-yu, LIU Xiao-hong, LU Jian-ping, LIN Fu-cheng
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 18-.   https://doi.org/10.1631/jzus.2005.B0817
Abstract( 2562 )     PDF(0KB)( 1051 )
MGTA1, a putative fungal Zn(II)2Cys6 transcriptional activator-encoding gene, was isolated from rice blast pathogen Magnaporthe grisea, which is homologous to CLTA1 from Colletotrichum lindemuthianum with 51% identity at protein level. MGTA1 cassette contains a 2370 bp open reading frame, consisting of 6 exons, coding a 790 amino acid peptide. MGTA1 gene exists as a single copy in genomes of 7 strains of M. grisea, and is expressed in tip hyphae, conidia, and mature appressoria of strain Guy11.
Partitioning and purification of extracellular β-1,3-1,4-glucanase in aqueous two-phase systems
HE Guo-qing, ZHANG Xiu-yan, TANG Xing-jun, CHEN Qi-he, RUAN Hui
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 19-.   https://doi.org/10.1631/jzus.2005.B0825
Abstract( 2737 )     PDF(0KB)( 1063 )
The partition behaviors of β-1,3-1,4-glucanase, α-amylase and neutral proteases from clarified and whole fermentation broths of Bacillus subtilis ZJF-1A5 were investigated. An aqueous two-phase system (polyethylene glycol (PEG)/MgSO4) was examined with regard to the effects of PEG molecular weight (MW) and concentration, MgSO4 concentration, pH and NaCl concentration on enzyme partition and extraction. The MW and concentration of PEG were found to have significant effects on enzyme partition and extraction with low MW PEG showing the greatest benefit in the partition and extraction of β-glucanase with the PEG/MgSO4 system. MgSO4 concentration influenced the partition and extraction of β-glucanase significantly. pH had little effect on β-glucanase or proteases partition but affected α-amylase partition when pH was over 7.0. The addition of NaCl had little effect on the partition behavior of β-glucanase but had very significant effects on the partitioning of α-amylase and on the neutral proteases. The partition behaviors of β-glucanase, α-amylase and proteases in whole broth were also investigated and results were similar to those obtained with clarified fermentation broth. A two-step process for purifying β-glucanase was developed, which achieved β-glucanase recovery of 65.3% and specific activity of 14027 U/mg, 6.6 times improvement over the whole broth.
Classification of surface EMG signal with fractal dimension
HU Xiao, WANG Zhi-zhong, REN Xiao-mei
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 22-.   https://doi.org/10.1631/jzus.2005.B0844
Abstract( 3297 )     PDF(0KB)( 1191 )
Surface EMG (electromyography) signal is a complex nonlinear signal with low signal to noise ratio (SNR). This paper is aimed at identifying different patterns of surface EMG signals according to fractal dimension. Two patterns of surface EMG signals are respectively acquired from the right forearm flexor of 30 healthy volunteers during right forearm supination (FS) or forearm pronation (FP). After the high frequency noise is filtered from surface EMG signal by a low-pass filter, fractal dimension is calculated from the filtered surface EMG signal. The results showed that the fractal dimensions of filtered FS surface EMG signals and those of filtered FP surface EMG signals distribute in two different regions, so the fractal dimensions can represent different patterns of surface EMG signals.
Rapid in vitro propagation of medicinally important Aquilaria agallocha
HE Meng-ling, QI Shu-yuan, HU Lan-juan
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 23-.   https://doi.org/10.1631/jzus.2005.B0849
Abstract( 3373 )     PDF(0KB)( 1097 )
Aquilaria agallocha can produce fragrant agarwood used for incense, traditional medicine and other products. An efficient plant regeneration system was established via organogenesis from shoots developed from seedlings of Aquilaria agallocha. Shoots generated many buds on MS medium supplemented with 1.3 μmol/L BA (6-benzylaminopurine) in the first 7 weeks, and the buds elongated on MS medium with 1.3 μmol/L BA+0.5 μmol/L NAA (naphthaleneacetic acid) in another 7 weeks, 2.3 shoots 2 cm in length per explant were obtained within 14 weeks. Plantlets were rooted on 1/2 MS medium after being immersed in 5 μmol/L NAA for 48 h, 96.7% of the roots grew up two weeks later. All plantlets that survived acclimatization grew well in the pots.
Chemical and Environmental Engineering
Photochemical reactions of poly(3-butoxythiophene-2,5-diyl) with chloroform
IMIT Mokhtar, YAMAMOTO Takakazu, IMIN Patigul
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 722-724.   https://doi.org/10.1631/jzus.2005.B0722
Abstract( 2571 )     PDF(0KB)( 951 )
Photochemical reactions of poly(3-butoxythiophene-2,5-diyl) with chloroform under irradiation with light were studied. The reactions were separately carried out under air, oxygen, and nitrogen. The obtained results showed that this reaction belongs to the pseudo-first-order reaction with a rate constant kobs of 1.4×10−5 s−1 at room temperature. The presence or absence of air, oxygen, and nitrogen did not have obvious effects on the reaction rate under irradiation with light.
Biodegradation of crude oil by Pseudomonas aeruginosa in the presence of rhamnolipids
ZHANG Guo-liang, WU Yue-ting, QIAN Xin-ping, MENG Qin
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 725-730.   https://doi.org/10.1631/jzus.2005.B0725
Abstract( 4228 )     PDF(0KB)( 1591 )
The potential biodegradation of crude oil was assessed based on the development of a fermentative process with a strain of Pseudomonas aeruginosa which produced 15.4 g/L rhamnolipids when cultured in a basal mineral medium using glycerol as a sole carbon source. However, neither cell growth nor rhamnolipid production was observed in the comparative culture system using crude oil as the sole carbon source instead. As rhamnolipid, an effective biosurfactant, has been reported to stimulate the biodegradation of hydrocarbons, 1 g/L glycerol or 0.22 g/L rhamnolipid was initially added into the medium to facilitate the biodegradation of crude oil. In both situations, more than 58% of crude oil was degraded and further converted into accumulated cell biomass and rhamnolipids. These results suggest that Pseudomonas aeruginosa could degrade most of crude oil with direct or indirect addition of rhamnolipid. And this conclusion was further supported by another adsorption experiment, where the adsorption capacity of crude oil by killed cell biomass was negligible in comparison with the biologic activities of live cell biomass.
Plant & Animal Sciences and Biotechnology
Dissipation of pencycuron in rice plant
PAL R., CHAKRABARTI K., CHAKRABORTY A., CHOWDHURY A.
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 756-758.   https://doi.org/10.1631/jzus.2005.B0756
Abstract( 2302 )     PDF(0KB)( 940 )
Pencycuron is a non-systemic protective fungicide for controlling sheath blight of rice. However, information on the fate of pencycuron in rice plant is lacking. The degradation of pencycuron in waterlogged tropic rice field was investigated. Pencycuron was applied at recommended field dose (187.5 g a.i./ha) and double recommended dose to cropped plots for three consecutive years. Pencycuron was rapidly degraded in rice plant at all doses of pencycuron application with first order half-lives of 1.57~2.77 d. The study revealed that pencycuron is safe from the human and environmental contamination point of view.
Comparative study on glutathione transferases of rat brain and testis under the stress of phenobarbitol and β-methylcholanthrene
THYAGARAJU K., HEMAVATHI B., VASUNDHARA K., RAO A.D., DEVI K.N.
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 759-769.   https://doi.org/10.1631/jzus.2005.B0759
Abstract( 2482 )     PDF(0KB)( 1201 )
A comparative study was made on the tissue specific expression of glutathione transferases (GST) in brain and testis after exposure of rat to phenobarbitol (PB) and b-methylcholanthrene (MC). Glutathione transferases, a family of multifunctional proteins are involved in intracellular transport processes and in detoxication of electrophilic xenobiotics by catalyzing reactions such as conjugation, isomerization, reduction and thiolysis. On purification, the yield of GST proteins by affinity chromatography was 39% in testis and 32% in brain. The affinity purified testis GSTs were resolved by chromatofocusing into six anionic and four cationic isozymes, and in brain glutathione transferases were resolved into four anionic and three cationic isozymes, suggesting the presence of multiple isozymes with Yc, Yb, Yβ and Yδ in both of them. In testis and brain, these isozymes at identical pI values showed variable functions with a battery of substrates and the cationic isozymes of brain and testis showed identical properties in CHP (cumene hydroperoxide) at pH values of above 7.0. Substrate specificity studies and immunoblot analysis of testis and brain proteins revealed that they play a predominant role in the detoxication of phenobarbitol or β-methylcholanthrene. Expression of the isozymes in testis and brain on exposure to PB and MC indicated elevated subunit variation. In both testis and brain, Yδ of π class was expressed on PB treatment and Yc of α class and Yβ of μ class was expressed in MC treated testis and only Yc was predominantly expressed in MC treated brain. Thus these subunits expression is considered as markers for carcinogenesis and specific to chemical toxicity under phenobarbitol and β-methylcholanthrene stress.
Survival of the biocontrol agents Brevibacillus brevis ZJY-1 and Bacillus subtilis ZJY-116 on the spikes of barley in the field
ZHANG Xin, ZHANG Bing-xin, ZHANG Zhen, SHEN Wei-feng, YANG Ching-hong, YU Jing-quan, ZHAO Yu-hua
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 770-777.   https://doi.org/10.1631/jzus.2005.B0770
Abstract( 2624 )     PDF(0KB)( 1038 )
Fusarium head blight (FHB) caused by Fusarium graminearum is a devastating disease that results in extensive yield losses to wheat and barley. A green fluorescent protein (GFP) expressing plasmid pRP22-GFP was constructed for monitoring the colonization of two biocontrol agents, Brevibacillus brevis ZJY-1 and Bacillus subtilis ZJY-116, on the spikes of barley and their effect on suppression of FHB. Survival and colonization of the Brevibacillus brevis ZJY-1 and Bacillus subtilis ZJY-116 strains on spikes of barley were observed by tracking the bacterial transformants with GFP expression. Our field study revealed that plasmid pRP22-GFP was stably maintained in the bacterial strains without selective pressure. The retrieved GFP-tagged strains showed that the bacterial population fluctuation accorded with that of the rain events. Furthermore, both biocontrol strains gave significant protection against FHB on spikes of barley in fields. The greater suppression of barley FHB disease was resulted from the treatment of barley spikes with biocontrol agents before inoculation with F. graminearum.
Active changes of lignification-related enzymes in pepper response to Glomus intraradices and/or Phytophthora capsici
ZHENG Hu-zhe, CUI Chun-lan, ZHANG Yu-ting, WANG Dan, JING Yu, KIM Kil Yong
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 778-786.   https://doi.org/10.1631/jzus.2005.B0778
Abstract( 2713 )     PDF(0KB)( 1055 )
The activities of enzymes responsible for lignification in pepper, pre-inoculation with arbuscular mycorrhizal (AM) fungus of Glomus intraradices and/or infection with pathogenic strain of Phytophthora capsici, and the biological control effect of G. intraradices on Phytophthora blight in pepper were investigated. The experiment was carried out with four treatments: (1) plants pre-inoculated with G. intraradices (Gi), (2) plants pre-inoculated with G. intraradices and then infected with P. capsici (Gi+Pc), (3) plants infected with P. capsici (Pc), and (4) plants without any of the two microorganisms (C). Mycorrhizal colonization rate was reduced by about 10% in pathogen challenged plants. Root mortality caused by infection of P. capsici was completely eliminated by pre-inoculation with antagonistic G. intraradices. On the ninth day after pathogen infection, Peroxidase (POD) activity increased by 116.9% in Pc-treated roots but by only 21.2% in Gi+Pc-treated roots, compared with the control, respectively. Polyphenol oxidase (PPO) and Phenylalanine ammonia-lyase (PAL) activities gradually increased during the first 3 d and dramatically decreased in Pc-treated roots but slightly decreased in Gi+Pc-treated roots, respectively. On the ninth day after pathogen infection, PPO and PAL decreased by 62.8% and 73.9% in Pc-treated roots but by only 19.8% and 19.5% in Gi+Pc-treated roots, compared with the control, respectively. Three major POD isozymes (45 000, 53 000 and 114 000) were present in Pc-treated roots, while two major bands (53 000 and 114 000) and one minor band (45 000) were present in spectra of Gi+Pc-treated roots, the 45 000 POD isozyme was significantly suppressed by G. intraradices, suggesting that the 45 000 POD isozyme was induced by the pathogen infection but not induced by the antagonistic G. intraradices. A 60 000 PPO isozyme was induced in Pc-treated roots but not induced in Gi+Pc-treated roots. All these results showed the inoculation of antagonistic G. intraradices alleviates root mortality, activates changes of lignification-related enzymes and induces some of the isozymes in pepper plants infected by P. capsici. The results suggested that G. intraradices is a potentially effective protection agent against P. capsici.
Effects of the dietary supplementation with fructooligosaccharides on the excretion of nitrogen and phosphorus in Miichthys miiuy fries
WU Tian-xing, SONG Zeng-fu, CAI Li-sheng, DING Xue-yan, YU Qing-sen
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 798-802.   https://doi.org/10.1631/jzus.2005.B0798
Abstract( 2567 )     PDF(0KB)( 921 )
Effects of dietary supplementation with fructooligosaccharides on the excretion of nitrogen and phosphorus in Miichthys miiuy fries were investigated. Nine hundred Miichthys miiuy fries were divided into 3 groups, each with triplicates. The basal diet and the basal diet supplemented with carnitine groups were considered as the negative and positive controls respectively. Results showed that the nitrogen concentration in excreted feces decreased significantly in fries fed the diet supplementation with 1000×10−6 fructooligosaccharides and 200×10−6 carnitine (P<0.05). The ammonic-nitrogen concentration decreased significantly in the carnitine group only (P<0.05), indicating the decreasing tendency caused by the supplementation with fructooligosaccharides. Supplementation with both did not have significant effects on the concentration of phosphorus in feces of Miichthys miiuy fries.
Cloning, expression, purification, and characterization of LC-1 ScFv with GFP tag
LU Min, GONG Xing-guo, YU Hong, LI Jian-yong
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 832-837.   https://doi.org/10.1631/jzus.2005.B0832
Abstract( 3002 )     PDF(0KB)( 1308 )
Total RNA was isolated from the hybridoma cell line (LC-1), which secretes anti-lung adenocarcinoma monoclonal antibody, and was transferred into cDNA. Based on the FR1 (framework region 1) and FR4 conserved regions of LC-1 gene, the variable regions of heavy chain (Vh) and light chain (Vl) were amplified, and the Vh and modified Vl were connected to single chain Fv (ScFv) by SOE-PCR (splice overlap extension PCR). The modified ScFv was fused with green fluorescent protein (GFP) and introduced into E. coli JM109. The fusion protein induced by IPTG (Isopropylthiogalactoside) was about 57000 on a 10% SDS-PAGE gel (10% Sds Polyacrylamide Gel Electrophoresis), and primarily manifested as inclusion bodies. The renatured protein purified by Ni-NTA Superflow resins showed ability to bind to antigen on SPC-A-1 lung adenocarcinoma. In addition, the induced host cells fluoresced bright green under 395 nm wavelength, which indicated that the expected protein with dual activity was expressed in the prokaryotic system. The ScFv with GFP tag used in this research can be applied as a new reagent to detect immunological dye, and provide a feasible way to detect adenocarcinoma in a clinical setting.
Background correction in near-infrared spectra of plant extracts by orthogonal signal correction
QU Hai-bin, OU Dan-lin, CHENG Yi-yu
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2005, 6(8): 838-843.   https://doi.org/10.1631/jzus.2005.B0838
Abstract( 2612 )     PDF(0KB)( 1115 )
In near-infrared (NIR) analysis of plant extracts, excessive background often exists in near-infrared spectra. The detection of active constituents is difficult because of excessive background, and correction of this problem remains difficult. In this work, the orthogonal signal correction (OSC) method was used to correct excessive background. The method was also compared with several classical background correction methods, such as offset correction, multiplicative scatter correction (MSC), standard normal variate (SNV) transformation, de-trending (DT), first derivative, second derivative and wavelet methods. A simulated dataset and a real NIR spectral dataset were used to test the efficiency of different background correction methods. The results showed that OSC is the only effective method for correcting excessive background.
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