• Title/Summary/Keyword: pN2

Search Result 18,682, Processing Time 0.059 seconds

Studies on the Factors Enhancing the Effects of Nitrogen Application of Rice Culture in Korea (수도작(水稻作)에서 시용질소효과 증대요인의 해석적(解析的) 연구)

  • Huh, Beom-Lyang
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.16 no.2
    • /
    • pp.131-155
    • /
    • 1983
  • Though it has been widely known the nitrogen effects are influenced by soils, varieties, and mineral nutrients in the rice culture, few analyses in relation to the factors increasing nitrogen effect have been studied in Korea. The effects of potassium and silica on the factors increasing nitrogen effects in paddy soils were investigated in accordance with soil improvement practices and nitrogen application methods for the cultivated varieties. The results obtained are as follows. 1. For 413 paddy fields, the yield from soils without nitrogen application ranged from 200 to 850kg/10a and that from nitrogen application did 350 to 1,051kg/10a. The yield increament by nitrogen application varied 50 to 650kg/10a depending on soils. 2. Soil chemical characteristics for high yield were different between with nitrogen and without nitrogen application. In the without nitrogen application, however, contents of organic matter, phosphorous, potassium and calcium of high yield soils were lower than those of low yield, while the available silica content was higher in the former. 3. The yield increased with nitrogen application up to 22.4kg/10a and thereafter it decreased. These phenomena were supposed to be not be decrease of nitrogen uptake but by lowered silica uptake. 4. Clay soil incorporation, deep plough, and inorganic constituents control such as Ca, Mg, and $Sio_2$ were effective as soil improvement praitices. It was appeared that increases of silica content and Ca/Mg ratio were important to increase nitrogen effects. 5. For the correlation between yield and yield components, it was high between yield and panicle in low nitrogen level and so was it between grain yield and ripening rate in high nitrogen. 6. In the urea and super granule urea application plot, recovery rate of nitrogen by plant and soil was high and yield was remarkable high. 7. Regardless of fertilizer types such as ammonium sulfate and urea, the residual nitrogen was about 4kg/10a in both plots of 5.8 and 11.6kg/10a. N applied. 8. The potassium application to soil enhanced the nitrogen efficiency. It was more effective in low potassium soil. 9. Optimum pH value for gel formation in the 4% sodium silicate solution was approximately 6.6. 10. It was suggested that silica could affect to rice plant growth as the inorganic and organic chemical components.

  • PDF

Changes of Seasonal and Vertical Water Quality in Soyang and Paldang River-reservoir System, Korea (소양호와 팔당호 수질의 수직 및 계절적 변화)

  • Kim, Jong-Min;Park, Jun-Dae;Noh, Hye-Ran;Han, Myung-Soo
    • Korean Journal of Ecology and Environment
    • /
    • v.35 no.1 s.97
    • /
    • pp.10-20
    • /
    • 2002
  • Changes of seasonal and vertical water quality was analyzed with physico-chemical data from Soyang and Paldang river-reservoir system in Korea during the 1996 to 1998. In Soyang river-reservoir system, the water column was well stratified, which narrow epilimnion layer of 5 to 10 m depth in spring to summer enlarged gradually about 40 m depth in fall as going to times. In contrast, metalimnion layer tended to be narrow during the same period. Water temperature of hypolimnion was maintained about $5^{\circ}C$ continuously throughout the year. DO of the epilimnion layer was supersaturated from spring to summer, however, it was decreased to 75% at the epilimnion layer and $45{\sim}50%$ at the hypolimnion layer at the late fall. The lowest conductivity of below $50\;{\mu}S/cm$ was observed at the metalimnion layer during thesummer to fall. In Paldang river-reservoir system, the water column wag well mixed layer throughout the year, although water temperature was changed seasonally from $5^{\circ}C$ in February to $28^{\circ}C$ in July. Water temperature between upper and lower layer was different about $5^{\circ}C$ from late spring (May) to early fall (September). DO was over and less saturated in upper and lower layer during the early summer to early fall, respectively. Conductivity was decreased to $90\;{\mu}S/cm$ in lower layer of below $4{\sim}5\;m$ depth during the late spring to early fall and that of upper layer of above 10 m depth decreased to about $100\;{\mu}S/cm$ during the late fall (November) and early spring (March). Retention time of Soyang river-reservoir system was much longer than that of Paldang river-reservoir system. Chlorophyll a, T-N and T-P concentration in Paldang river-reservoir system were higher than that of Soyang river-reservoir system by a factor of 2.7, 1.2 and 2.6, respectively. Algal blooming was deeply affected by the nutrients than the retention time.

Eutrophication in the Downstream of Nakdong River (낙동강 하류역의 부영양화현상에 관한 연구)

  • CHOI Young-Chan;PARK Chung-Kil
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.19 no.4
    • /
    • pp.339-346
    • /
    • 1986
  • A study on eutrophication in the downstream of the Nakdong River was conducted from October 1983 to September 1984. Nutrients concentration of the samples in this area was usually high and the nitrogen ratio to the phosphorus was as very high as $63.5{\sim}119.6$. The concentration of nutrients was in the range of $0.22{\sim}173{\mu}g-at/l$ for ammonia nitrogen, $26.7{\sim}187{\mu}g-at/l$ for nitrate nitrogen, $1.07{\sim}8.22{\mu}g-at/l$ for nitrite nitrogen, $58.7{\sim}231{\mu}g-at/l$ for total inorganic nitrogen and $0.44{\sim}4.43{\mu}g-at/l$ for phosphate phosphorus. The concentration of chlorophyll-a was in the range of $1.8{\sim}75.2\;mg/m^3$. Correlationship between concentration of nutrients and chlorophyll-a was not found. The concentrations of total suspended solid were in the range of $10.7{\sim}45.9\;ppm$, and $16.2{\sim}35.2\%$ of the total suspended solid was consisted of volatile suspended solid. According to the state of lacustrine nutrition, the state of the downstream of Nakdong River was equivalent to the eutrophication state in term of chlorophyll-a and inorganic nitrogen, and mid-nutritional state in term of phosphate.

  • PDF

Total Spinal Block and Cortical Epidural Block for Whiplash Syndrome and Reflex Sympathetic Dystrophy (Report of Four Cases) (전척수(全脊髓) 및 경막외차단(硬膜外遮斷)으로 편타성(鞭打性) 손상(損傷)의 통증치험(痛症治驗) (4례(例) 보고(報告)))

  • Park, Wook;Ok, See-Young;Song, Hoo-Bin
    • The Korean Journal of Pain
    • /
    • v.1 no.1
    • /
    • pp.106-119
    • /
    • 1988
  • For the relief of pain in 3 cases of whiplash syndromes (case I, II and IV) and in one of reflex sympathetic dystrophy (case III), we have carried out six intentional. total spinal blocks (TSB) which attempted two times in case I, three in case II and one in carte III whoso various symptoms were chronically unresponsive to the usual conservative treatments, and a time of cervical epidural and right suprascapular nerve block in case W whose acute symptom lasted 4 drys following the cervical injury (see fables from 1 to 9). During the 753, we have observed clinically the sequential charges of respiration, lid and pupil reflexes, body motion and consciousness. And checked the blood pressure, pulse rate and arterial Pco2. The effectiveness of those blocks has been assessed by using the Visual Analog Scale which is designed to measure the patient$\acute{s}$ subjective intensity of pain and also we have found out the sequelae following those blocks. The methods of the blocks were as the following: 1. Under the N.P.O. for 8~10 hours, the preparations of immediate cardiopulmonary resuscitation and premedication with atropine 0.5mg at thirty minutes before the TSB, it was performed by injecting the mixture of 2% mepivacaine 10 or 15ml and normal saline 10 or 5ml through No. 23 G. spinal needle into the subarachnoid space of $C_7-T_1$ interspinous region with fully flexed neck on the lateral posture. Immediately after the injection of the local anesthetic in the lateral position, the patient$\acute{s}$ were hasten to change Trendelenburg$\acute{s}$ position in order to act the drugs cephalad and to make easy controlled respiration with oxygen. 2. The cervical epidural block was done by injecting the mixture of 0.5% bupivacaine 4ml, normal saline 4ml and triamcinolone 15mg through No. 18 G. Tuohy needle into the epidural space on the same region and posture as the above without premedication.7he suprascapular nerve block was done by injecting of 0.5% bupivacaine 3ml only into the right suprascapular fossa on the sitting posture. The results were as the following: 1. The cessation of respiration was seen within 5 minutes following the subarachnoidal injection of the above 20ml mixture in 2 to 3 minutes and then soon the consciousness began to disappear. The loss of Lid and pupil reflexes noted between 5 to 10 minutes and the size of the dilated pupils was equal between 5 to 20 minutes, but the pupil of the dependent side on tile lateral position was dilated 1 to 3 minutes earlier than that of the independent. The patients had r=ever responded to any stimulations during the TSB except their heart funtion. 2. The recovery of the TSB was as the following, firstly the ankle and lower limb of the independent side began to move slightly with in 34 to 75 minutes after the injection and then that of the dependent Secondly the neck and upper limb moved 6 to 15 minutes later than the lower limb. Thirdly the self respiration began to appear between 40 to 80 minutes from the block. The lid and pupil reacted to touch and light respectively between 40 to 80 minutes but the pupil of the independent side responded earlier than that of the depends. Lastly the consciousness recovered completely between 80 to 125 minutes from the block. 3. In the cardiopulmonary function during the TSB, the blood pressure were stable except the 210/130 tory at the and block of case I. There were bradycardias between 65 to 85 minutes in case I and II but no arrythmia on the EKG. The level of the arterial Pco2 was maintained to 43~45 torr during the TSB. 4. The effectiveness of the above blocks was no pain(0%) in case IV, and light (10~20%) in case I and II but no improvement in case III. 5. The right arm weakness has been complicated as to be Injected accidently the "COLD" local anesthetic at the End block of case I.

  • PDF

Change of Nutrients and Behaviour of Total Coliforms in the Natural Treatment of Wastewater by Subsurface Flow Wetland System (인공습지를 이용한 자연정화 오수처리시설에서 영양물질의 변화와 대장균군의 행동)

  • Yoon, Chun-Gyeong;Kwun, Soon-Kuk;Kim, Hyung-Joong
    • Korean Journal of Environmental Agriculture
    • /
    • v.16 no.3
    • /
    • pp.249-254
    • /
    • 1997
  • The constructed wetland system which is applicable to rural wastewater treatment was examined by pilot plant experiment. Removal rates of nutrients including nitrogen and phosphorus and total coliform were evaluated. The $NH_4\;^+$ concentration of the influent was in the range of 91.57 to 275.88mg/l and the effluent concentration was about 40% lower than the influent. The decreasing of the $NH_4\;^+$ concentration might be due to volatilization, plant uptake, adsorption onto soil particles, and mainly nitrification. However, generally concentrations of $NO_2\;^-$ and $NO_3\;^-$ were increased in the effluents compared to the influent concentrations, which implies that nitrogen components in the system were nitrified. Overall, the average removal rate of the nitrogen was about 5% which seems inadequate as a wastewater treatment system, and this system needs improvement on nitrogen removal mechamism. The removal rate of the phosphorus was quite high and effluent concentration was very low. Reason for high removal rate of the phosphorus might be mainly strong adsorption characteristic onto soil particles. The average removal rate of the total coliforms was about 83%, and main removal mechanisms are thought to be adsorption onto soil and inability to compete against the established soil microflora. From the results of the study, the constructed wetland system needs to be improved in nitrogen removal mechanism for field application.

  • PDF

Simultaneous Removal of Organic Pollutants, Nitrogen, and Phosphorus from Livestock Wastewater by Microbubble-Oxygen in a Single Reactor (단일반응기에서 마이크로버블-산소를 이용한 가축분뇨의 유기오염물질, 질소 및 인의 동시 제거)

  • Jang, Jae Kyung;Jin, Yu Jeong;Kang, Sukwon;Kim, Taeyoung;Paek, Yee;Sung, Je Hoon;Kim, Young Hwa
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.39 no.11
    • /
    • pp.599-606
    • /
    • 2017
  • The effects of microbubble-oxygen physicochemical method for the removal of organic pollutants, nitrogen, and phosphorus contained in animal manure were investigated using a laboratory scale single reactor. The characteristics of used livestock manure were $36,894{\pm}5,024mg\;TCOD/L$, $22,031{\pm}2,018mg\;SCOD/L$, $4,150{\pm}35mg\;NH_4-N/L$, and $659{\pm}113mg\;PO_4-P/L$. It was confirmed that the amount of organic pollutants, nitrogen, and phosphorus removal was increased by the use of oxygen rather than air as the gas supplied with the microbubble, and by input of larger oxygen amount. When the oxygen was fed with 600 mL flow rate per minute, TCOD and phosphorus removal were 2.5 times and 5.6 times higher than those of air supplied. As the microbubble-oxygen reaction time was longer, the removal rate of nutrients increased gradually. The removal rates of ammonium and phosphorus reach to $41.03{\pm}0.20%$ and $65.49{\pm}1.39%$, respectively, after 24 hours. When the coagulation treatment method was applied to increase phosphorus removal rate from the effluent of microbubble-oxygen treatment, the phosphorus was removed up to 92.7%. However, the removal rate of organic pollutants (TCOD) was as small as $28.7{\pm}0.2%$ within the first 6 hours, and then the negligible removal of TCOD was recorded. This study suggests that microbubble-oxygen can be applied not only livestock manure but also aeration tank of various wastewater treatment plant, which can reduce the load on the associated unit process and produce stable high-quality effluent.

Predictors of breast-feeding discontinuation in some followed-up hospital-delivered mothers (추적조사된 대구시내 일부 병원분만 산모에서 모유수유중단 예측변수)

  • Lee, Choong-Won;Lee, Moo-Sik;Park, Jong-Won;Lee, Mi-Young;Kang, Mi-Joung;Shin, Dong-Hoon;Lee, Se-Youp
    • Journal of Preventive Medicine and Public Health
    • /
    • v.28 no.4 s.51
    • /
    • pp.845-862
    • /
    • 1995
  • We followed prospectively some hospital-delivered mothers to identify characteristics of those not initiated breast-feeding and predictors of breast-feeding discontinuation in monthly telephone interviews. Recruits were composed of 482 mothers who delivered their babies at one university hospital and one OB/GYN clinic in September to November 1991. Breast-feeding discontinuation was defined as switch to 100% formula lasting more than one week regardless of solid foods. Average age of the study subjects was 27.3 years of age(standard deviation 3.2). Multiple logistic regression analysis indicated native place, occupation, method of delivery and method of feeding considered to be better for maternal health were statistically significant(p<0.1) between initiators and non-initiators of breast feeding. In starting cohort(N=242) of those initiated breast-feeding, that median of breast-feeding discontinuation were 5 months and 25th and 75th percentiles were 3 and 9 months respectively. In Cox's proportional hazard model, mothers with $10\sim13$ years of education were 2.63 times (95% confidence interval, CI $1.50\sim4.60$) more likely to discontinue than those with less than 9 years of education and those with more than 13 years of education were 3.55 time (95% CI $1.99\sim6.33$). Compared with house wife, mothers with part-time jobs were 1.99 times (95% CI $0.86\sim4.57$) more likely to discontinue and those with employed full-time were 1.55 times (95% CI $0.96\sim2.51$). These results suggest that the predictors of initiation and discontinuation of breast-feeding may be different and different target populations should be selected to promote initiation and to prevent discontinuation of breast-feeding according to the period after birth.

  • PDF

The Study of Dose Change by Field Effect on Atomic Number of Shielding Materals in 6 MeV Electron Beam (6 MeV 전자선의 차폐물질 원자번호와 조사야 크기에 따른 선량변화 연구)

  • Lee, Seung Hoon;Kwak, Keun Tak;Park, Ju Kyeong;Gim, Yang Soo;Cha, Seok Yong
    • The Journal of Korean Society for Radiation Therapy
    • /
    • v.25 no.2
    • /
    • pp.145-151
    • /
    • 2013
  • Purpose: In this study, we analyzed how the dose change by field size effects on atomic number of shielding materials while using 6 MeV election beam. Materials and Methods: The parallel plate chamber is mounted in $25{\times}25cm^2$ the phantom such that the entrance window of the detector is flush with the phantom surface. phantom was covered laterally with aluminum, copper and lead which thickness have 5% of allowable transmission and then the doses were measured in field size $6{\times}6$, $10{\times}10$ and $20{\times}20cm^2$ respectively. 100 cGy was irradiated using 6 MeV electron beam and SSD (Source Surface Distance) was 100 cm with $10{\times}10cm^2$ field size. To calculate the photon flux, electron flux and Energy deposition produced after pass materals respectively, MCNPX code was used. Results: The results according to the various shielding materials which have 5% of allowable transmission are as in the following. Thickness change rate with field size of $6{\times}6cm^2$ and $20{\times}20cm^2$ that compared to the field size of $10{\times}10cm^2$ found to be +0.06% and -0.06% with aluminum, +0.13% and -0.1% with copper, -1.53% and +1.92% with lead respectively. Compare to the field size $10{\times}10cm^2$, energy deposition for $6{\times}6cm^2$ and $20{\times}20cm^2$ had -4.3% and +4.85% respectively without shielding material. With aluminum it had -0.87% and +6.93% respectively and with lead it had -4.16% and +5.57% respectively. When it comes to photon flux with $6{\times}6cm^2$ and $20{\times}20cm^2$ of field sizes the chance -8.95% and +15.92% without shielding material respectively, with aluminum the number -15.56% and +16.06% respectively and with copper the chance -12.27% and +15.53% respectively, with lead the number +12.36% and -19.81% respectively. In case of electron flux in the same condition, the number -3.92% and +4.55% respectively without shielding material respectively, with aluminum the number +0.59% and +6.87% respectively, with copper the number -1.59% and +3.86% respectively, with lead the chance -5.15% and +4.00% respectively. Conclusion: In this study, we found that the required thickness of the shielding materials got thinner with low atomic number substance as the irradiation field is increasing. On the other hand, with high atomic number substance the required thickness had increased. In addition, bremsstrahlung radiation have an influence on low atomic number materials and high atomic number materials are effected by scattered electrons.

  • PDF

Motives for Writing After-Purchase Consumer Reviews in Online Stores and Classification of Online Store Shoppers (인터넷 점포에서의 구매후기 작성 동기 및 점포 고객 유형화)

  • Hong, Hee-Sook;Ryu, Sung-Min
    • Journal of Distribution Research
    • /
    • v.17 no.3
    • /
    • pp.25-57
    • /
    • 2012
  • This study identified motives for writing apparel product reviews in online stores, and determined what motives increase the behavior of writing reviews. It also classified store customers based on the type of writing motives, and clarified the characteristics of internet purchase behavior and of a demographic profile. Data were collected from 252 females aged 20s' and 30s' who have experience of reading and writing reviews on online shopping. The five types of writing motives were altruistic information sharing, remedying of a grievance and vengeance, economic incentives, helping new product development, and the expression of satisfaction feelings. Among five motives, altruistic information sharing, economic incentives, and helping new product development stimulate writing reviews. Store customers who write reviews were classified into three groups based on their writing motive types: Other consumer advocates(29.8%), self-interested shoppers(40.5%) and shoppers with moderate motives(29.8%). There were significant differences among three groups in writing behavior (the frequency of writing reviews, writing intent of reviews, duration of writing reviews, and frequency of online shopping) and age. Based on results, managerial implications were suggested. Long Abstract : The purpose of present study is to identify the types of writing motives on online shopping, and to clarify the motives affecting the behavior of writing reviews. This study also classifies online shoppers based on the motive types, and identifies the characteristics of the classified groups in terms of writing behavior, frequency of online shopping, and demographics. Use and Gratification Theory was adopted in this study. Qualitative research (focus group interview) and quantitative research were used. Korean women(20 to 39 years old) who reported experience with purchasing clothing online, and reading and writing reviews were selected as samples(n=252). Most of the respondents were relatively young (20-34yrs., 86.1%,), single (61.1%), employed(61.1%) and residents living in big cities(50.9%). About 69.8% of respondents read and 40.5% write apparel reviews frequently or very frequently. 24.6% of the respondents indicated an "average" in their writing frequency. Based on the qualitative result of focus group interviews and previous studies on motives for online community activities, measurement items of motives for writing after-purchase reviews were developed. All items were used a five-point Likert scale with endpoints 1 (strongly disagree) and 5 (strongly agree). The degree of writing behavior was measured by items concerning experience of writing reviews, frequency of writing reviews, amount of writing reviews, and intention of writing reviews. A five-point scale(strongly disagree-strongly agree) was employed. SPSS 18.0 was used for exploratory factor analysis, K-means cluster analysis, one-way ANOVA(Scheffe test) and ${\chi}^2$-test. Confirmatory factor analysis and path model analysis were conducted by AMOS 18.0. By conducting principal components factor analysis (varimax rotation, extracting factors with eigenvalues above 1.0) on the measurement items, five factors were identified: Altruistic information sharing, remedying of a grievance and vengeance, economic incentives, helping new product development, and expression of satisfaction feelings(see Table 1). The measurement model including these final items was analyzed by confirmatory factor analysis. The measurement model had good fit indices(GFI=.918, AGFI=.884, RMR=.070, RMSEA=.054, TLI=.941) except for the probability value associated with the ${\chi}^2$ test(${\chi}^2$=189.078, df=109, p=.00). Convergent validities of all variables were confirmed using composite reliability. All SMC values were found to be lower than AVEs confirming discriminant validity. The path model's goodness-of-fit was greater than the recommended limits based on several indices(GFI=.905, AGFI=.872, RMR=.070, RMSEA=.052, TLI=.935; ${\chi}^2$=260.433, df=155, p=.00). Table 2 shows that motives of altruistic information sharing, economic incentives and helping new product development significantly increased the degree of writing product reviews of online shopping. In particular, the effect of altruistic information sharing and pursuit of economic incentives on the behavior of writing reviews were larger than the effect of helping new product development. As shown in table 3, online store shoppers were classified into three groups: Other consumer advocates (29.8%), self-interested shoppers (40.5%), and moderate shoppers (29.8%). There were significant differences among the three groups in the degree of writing reviews (experience of writing reviews, frequency of writing reviews, amount of writing reviews, intention of writing reviews, and duration of writing reviews, frequency of online shopping) and age. For five aspects of writing behavior, the group of other consumer advocates who is mainly comprised of 20s had higher scores than the other two groups. There were not any significant differences between self-interested group and moderate group regarding writing behavior and demographics.

  • PDF

Brief Introduction of Research Progresses in Control and Biocontrol of Clubroot Disease in China

  • He, Yueqiu;Wu, Yixin;He, Pengfei;Li, Xinyu
    • 한국균학회소식:학술대회논문집
    • /
    • 2015.05a
    • /
    • pp.45-46
    • /
    • 2015
  • Clubroot disease of crucifers has occurred since 1957. It has spread to the whole China, especially in the southwest and nourtheast where it causes 30-80% loss in some fields. The disease has being expanded in the recent years as seeds are imported and the floating seedling system practices. For its effective control, the Ministry of Agriculture of China set up a program in 2010 and a research team led by Dr. Yueqiu HE, Yunnan Agricultural University. The team includes 20 main reseachers of 11 universities and 5 institutions. After 5 years, the team has made a lot of progresses in disease occurrence regulation, resources collection, resistance identification and breeding, biological agent exploration, formulation, chemicals evaluation, and control strategy. About 1200 collections of local and commercial crucifers were identified in the field and by artificiall inoculation in the laboratories, 10 resistant cultivars were breeded including 7 Chinese cabbages and 3 cabbages. More than 800 antagostic strains were isolated including bacteria, stretomyces and fungi. Around 100 chemicals were evaluated in the field and greenhouse based on its control effect, among them, 6 showed high control effect, especially fluazinam and cyazofamid could control about 80% the disease. However, fluzinam has negative effect on soil microbes. Clubroot disease could not be controlled by bioagents and chemicals once when the pathogen Plasmodiophora brassicae infected its hosts and set up the parasitic relationship. We found the earlier the pathogent infected its host, the severer the disease was. Therefore, early control was the most effective. For Chinese cabbage, all controlling measures should be taken in the early 30 days because the new infection could not cause severe symptom after 30 days of seeding. For example, a biocontrol agent, Bacillus subtilis Strain XF-1 could control the disease 70%-85% averagely when it mixed with seedling substrate and was drenching 3 times after transplanting, i.e. immediately, 7 days, 14 days. XF-1 has been deeply researched in control mechanisms, its genome, and development and application of biocontrol formulate. It could produce antagonistic protein, enzyme, antibiotics and IAA, which promoted rhizogenesis and growth. Its The genome was sequenced by Illumina/Solexa Genome Analyzer to assembled into 20 scaffolds then the gaps between scaffolds were filled by long fragment PCR amplification to obtain complet genmone with 4,061,186 bp in size. The whole genome was found to have 43.8% GC, 108 tandem repeats with an average of 2.65 copies and 84 transposons. The CDSs were predicted as 3,853 in which 112 CDSs were predicted to secondary metabolite biosynthesis, transport and catabolism. Among those, five NRPS/PKS giant gene clusters being responsible for the biosynthesis of polyketide (pksABCDEFHJLMNRS in size 72.9 kb), surfactin(srfABCD, 26.148 kb, bacilysin(bacABCDE 5.903 kb), bacillibactin(dhbABCEF, 11.774 kb) and fengycin(ppsABCDE, 37.799 kb) have high homolgous to fuction confirmed biosynthesis gene in other strain. Moreover, there are many of key regulatory genes for secondary metabolites from XF-1, such as comABPQKX Z, degQ, sfp, yczE, degU, ycxABCD and ywfG. were also predicted. Therefore, XF-1 has potential of biosynthesis for secondary metabolites surfactin, fengycin, bacillibactin, bacilysin and Bacillaene. Thirty two compounds were detected from cell extracts of XF-1 by MALDI-TOF-MS, including one Macrolactin (m/z 441.06), two fusaricidin (m/z 850.493 and 968.515), one circulocin (m/z 852.509), nine surfactin (m/z 1044.656~1102.652), five iturin (m/z 1096.631~1150.57) and forty fengycin (m/z 1449.79~1543.805). The top three compositions types (contening 56.67% of total extract) are surfactin, iturin and fengycin, in which the most abundant is the surfactin type composition 30.37% of total extract and in second place is the fengycin with 23.28% content with rich diversity of chemical structure, and the smallest one is the iturin with 3.02% content. Moreover, the same main compositions were detected in Bacillus sp.355 which is also a good effects biocontol bacterial for controlling the clubroot of crucifer. Wherefore those compounds surfactin, iturin and fengycin maybe the main active compositions of XF-1 against P. brassicae. Twenty one fengycin type compounds were evaluate by LC-ESI-MS/MS with antifungal activities, including fengycin A $C_{16{\sim}C19}$, fengycin B $C_{14{\sim}C17}$, fengycin C $C_{15{\sim}C18}$, fengycin D $C_{15{\sim}C18}$ and fengycin S $C_{15{\sim}C18}$. Furthermore, one novel compound was identified as Dehydroxyfengycin $C_{17}$ according its MS, 1D and 2D NMR spectral data, which molecular weight is 1488.8480 Da and formula $C_{75}H_{116}N_{12}O_{19}$. The fengycin type compounds (FTCPs $250{\mu}g/mL$) were used to treat the resting spores of P. brassicae ($10^7/mL$) by detecting leakage of the cytoplasm components and cell destruction. After 12 h treatment, the absorbencies at 260 nm (A260) and at 280 nm (A280) increased gradually to approaching the maximum of absorbance, accompanying the collapse of P. brassicae resting spores, and nearly no complete cells were observed at 24 h treatment. The results suggested that the cells could be lyzed by the FTCPs of XF-1, and the diversity of FTCPs was mainly attributed to a mechanism of clubroot disease biocontrol. In the five selected medium MOLP, PSA, LB, Landy and LD, the most suitable for growth of strain medium is MOLP, and the least for strains longevity is the Landy sucrose medium. However, the lipopeptide highest yield is in Landy sucrose medium. The lipopeptides in five medium were analyzed with HPLC, and the results showed that lipopeptides component were same, while their contents from B. subtilis XF-1 fermented in five medium were different. We found that it is the lipopeptides content but ingredients of XF-1 could be impacted by medium and lacking of nutrition seems promoting lipopeptides secretion from XF-1. The volatile components with inhibition fungal Cylindrocarpon spp. activity which were collect in sealed vesel were detected with metheds of HS-SPME-GC-MS in eight biocontrol Bacillus species and four positive mutant strains of XF-1 mutagenized with chemical mutagens, respectively. They have same main volatile components including pyrazine, aldehydes, oxazolidinone and sulfide which are composed of 91.62% in XF-1, in which, the most abundant is the pyrazine type composition with 47.03%, and in second place is the aldehydes with 23.84%, and the third place is oxazolidinone with 15.68%, and the smallest ones is the sulfide with 5.07%.

  • PDF