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《东北农业大学学报(英文版)》2016,(4):47-54
The probiotic Bacillus subtilis(B. subtilis) was widely applied in animal production as feed additive. Lysine(Lys) and methionine(Met) were the two most important limiting amino acids in livestock animal feed. Raising Lys and Met contents in B. subtilis would provide better effects for animal production and save Lys and Met supplements. We still didn't know whether Lysrich and Met-rich protein genes from plants could be transfected into B. subtilis and expressed at a high level so as to improve animal production, such as milk production as an additional diet. The Lys-rich protein gene(Cflr) and Met-rich 10 ku-δ Zein were cloned from pepper anther and maize endosperm, respectively. Then they were constructed into plasmids individually and successfully cotransfected into B. subtilis. Upon IPTG induction, m RNAs and protein expressions could be observed. Lys and Met contents in the fermentation broth were raised by 65.92% and 46.39%, respectively. After feeding 200 g and 400 g · cow~(-1) · d~(-1), transgenic B. subtilis fermentation broth, the milk yield, milk protein and milk fat contents all significantly increased. The Lys-rich protein gene(Cflr) and Met-rich 10 ku-δ Zein were successfully transfected into B. subtilis. Contents of Lys and Met in the transgenic B. subtilis obviously raised and the fermentation broth of the transgenic bacteria could effectively improve milk yield and quality. 相似文献
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益生地衣芽孢杆菌天门冬氨酸激酶Ⅱ基因的PCR扩增及序列分析 总被引：2，自引：0，他引：2
通过聚合酶链反应（ＰＣＲ） 扩增得到了益生地衣芽孢杆菌Ｈ８８ － ３ 株天门冬氨酸激酶（Ａｓｐａｒ ｔｏｋｉｎａｓｅ,ＡＫ） Ⅱ基因,并用ＡＢＩＰＲＩＳＭＴＭ ３７７ ＤＮＡＳｅｑｕｅｎｃｅｒ 进行序列测定,所得核苷酸序列及推导的氨基酸序列与枯草芽孢杆菌ＶＢ２１７ 株进行了比较,结果它们的同源性非常高。 相似文献
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在田间条件下,对同一植株接穗红■(Loropetalum chinense var.rubrumYieh)和其砧木■(Loropetalum chinense Oliver.)上发出的叶片光合特性进行了研究。结果表明:①在8月中旬,天气晴朗的条件下,2种植物净光合速率(Pn)和蒸腾速率(Tr)均呈双峰曲线;气孔导度(Cond)均呈单峰曲线;胞间CO2浓度(Ci)均呈单谷曲线;Pn日均值■木大于红■木。②红■木的光饱和点(LSP)、光补偿点(LCP)、CO2饱和点(CSP)均低于■木,CO2补偿点(CCP)高于■木;③红■木的表观量子效率(AQY)、羧化效率(CE)均低于■木,故红■木的光合能力低于■木。④2种植物固碳释氧能力相比较,红■木低于■木,故而建议在居民小区和人群聚集地进行绿化时,宜适当减少红■木的使用。 相似文献
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[目的]对枯草芽孢杆菌subtilis str.168双精氨酸转运途径(Tat)分泌蛋白进行预测和功能分析。[方法]从NCBI中选取枯草芽孢杆菌subtilis str.168基因组注释的蛋白质氨基酸序列,然后用Signal P 4.0、Lipo P、Tat P、TMHMM 2.0软件分析该基因组中双精氨酸途径的分泌蛋白,同时采用COG功能数据库对预测的分泌蛋白进行功能注释和聚类分析。[结果]通过分析发现108个有motif没有酶切位点的Tat信号肽蛋白、25个有酶切位点没有motif的Tat信号肽蛋白、124个既有酶切位点也有motif的Tat信号肽蛋白,其中105个蛋白归为Tat途径的分泌蛋白。[结论]对枯草芽孢杆菌Tat途径分泌蛋白的基因组预测和功能分析,将为分析该菌胞外蛋白的分泌机制打下基础。 相似文献
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豆科植物普遍缺乏蛋氨酸和半胱氨酸这类含硫氨基酸,影响了其营养品质。采用基因工程手段改造内源蛋白基因,克隆异源高蛋氨酸蛋白基因,人工合成氨基酸平衡的蛋白基因,以及改造或过表达氨基酸代谢通路中的关键酶基因,然后通过转基因手段转化豆科植物,会使蛋氨酸含量均有不同程度提高。另外,利用高蛋氨酸的近缘种质资源进行有性杂交育种,通过化学诱变培育高蛋氨酸突变株,也可获得一些高蛋氨酸新品系。通过对这些方法的比较分析,提出了提高蛋氨酸丰富蛋白表达量和蛋氨酸合成量两方面相结合的研究思路,为豆科植物品质改良研究提供参考。 相似文献
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Improving Geese Production Performance in “Goose-Fish” Production System by Competitive Reduction of Pathogenic Bacteria in Pond Water 
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下载免费PDF全文 This study investigated whether competitive reduction of pathogenic bacteria growth in pond water alleviates lipopolysaccharide (LPS) contamination and improves geese production performances in the “goose-fish” production system, thereby providing the potential for an improved technique for ecological water fowl production. In the first experiment, 240 Magang goslings of 15-d age were randomly and equally allocated into 16 “yard and pond” pens using a 2×2 factorial design with 4 replications per treatment. In the 55-d experimental period, the goslings received 2 main treatments: supplementation of Bacillus subtilis spores in the feed and addition of photosynthetic bacteria (PSB) to the pond water. Both B. subtilis spores and PSB treatments significantly suppressed water counts of Gram-negative bacteria Escherichia coli, Salmonella and Shigella, and LPS concentrations in pond water and in gosling blood (P<0.05). As the result, the two treatments significantly improved gosling weight gain and carcass quality, marked by enhanced breast and leg muscle percentages and reduced subcutaneous fat proportions (P<0.05). Moreover, the improved effects of B. subtilis spores and PSB treatments were additive. In the second experiment, 1 160 adult geese were induced to start egg laying from May throughout the summer months. The geese were separated equally into control and experimental flocks to fit into 2 integration production units, with a density of 1 bird m-2 meter on pond water. Experimental flock geese were treated with B. subtilis spores in feed and PSB in the pond water for the duration of the study. Such treatment combination significantly depressed the growth of E. coli, Salmonella and Shigella in the pond water and reduced LPS concentrations both in pond water and in geese blood (P<0.01). As a result, egg fertility, fertile and set egg hatchabilities were all improved in the treated flock. Results from both growing goslings and breeding geese demonstrated that water bacteria pollution can be competitively reduced by supplementation with B. subtilis spores via the feed and addition of PSB in pond water, each of which reduces LPS contamination to geese and improves production performances. Microecological agents such as B. subtilis spores and PSB improve water quality and provide a simple ecological technique for the “water fowl-fish” integrative production system. 相似文献
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采用土壤盆栽试验,研究了土壤中Pb2+、Cd2+胁迫对红花檵木光合特性及叶片色素含量的影响。结果表明:(1)Pb2+浓度为100 mg/kg时,红花檵木叶片的光合特性指标和色素含量与对照相比均明显上升,当Pb2+浓度为500 mg/kg以上时,净光合速率(Pn)、气孔导度(Gs)和蒸腾速率(Tr)随Pb2+浓度的增加而下降,而叶绿素含量则在Pb2+浓度为1000 mg/kg以上时才出现显著下降趋势;(2)Cd2+处理降低了红花檵木叶片Pn、Tr和Gs,叶绿素含量在Cd2+浓度为100 mg/kg以上时显著下降;(3)Pb2+浓度为100mg/kg,Cd2+浓度为100 mg/kg时,红花檵木叶片中的花色素苷、可溶性糖含量和苯丙氨酸解氨酶(PAL)活性均明显高于对照,即促进了红花檵木叶片的着色。 相似文献
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Brown NJ Newell CA Stanley S Chen JE Perrin AJ Kajala K Hibberd JM 《Science (New York, N.Y.)》2011,331(6023):1436-1439
C? photosynthesis allows increased photosynthetic efficiency because carbon dioxide (CO?) is concentrated around the key enzyme RuBisCO. Leaves of C? plants exhibit modified biochemistry, cell biology, and leaf development, but despite this complexity, C? photosynthesis has evolved independently in at least 45 lineages of plants. We found that two independent lineages of C? plant, whose last common ancestor predates the divergence of monocotyledons and dicotyledons about 180 million years ago, show conserved mechanisms controlling the expression of genes important for release of CO(2) around RuBisCO in bundle sheath (BS) cells. Orthologous genes from monocotyledonous and dicotyledonous C? species also contained conserved regulatory elements that conferred BS specificity when placed into C? species. We conclude that these conserved functional genetic elements likely facilitated the repeated evolution of C? photosynthesis. 相似文献
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枯草芽孢杆菌信号肽筛选载体的构建及木聚糖酶基因的表达 总被引：1，自引：0，他引：1
构建枯草芽孢杆菌信号肽筛选载体并用菌体自身信号肽引导表达外源木聚糖酶基因,为枯草芽孢杆菌木聚糖酶高效分泌表达系统的建立奠定基础。利用基因工程的原理和方法,将壮观霉素抗性基因(spec)与短小芽孢杆菌的木聚糖酶基因(xynA)克隆到大肠杆菌-枯草芽孢杆菌穿梭表达载体GJ148上,构建枯草芽孢杆菌信号肽筛选载体pYG,将枯草芽孢杆菌信号肽Epr克隆到已构建载体上,以枯草芽孢杆菌WB700为表达宿主,引导木聚糖酶基因进行表达。最终成功构建枯草芽孢杆菌信号肽筛选载体pYG,将枯草芽孢杆菌信号肽Epr克隆到pYG上,在WB700中引导并表达木聚糖酶基因。试验证明信号肽筛选载体可以成功构建,在克隆入信号肽后可成功表达木聚糖酶基因,为信号肽的系统性筛选和木聚糖酶高效表达提供依据。 相似文献
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The type III ribulose-1,5-bisphosphate carboxylase-oxygenase (RuBisCO) present in the archaeon Thermococcus kodakaraensis was found to participate in adenosine 5'-monophosphate (AMP) metabolism, a role that is distinct from that of classical RuBisCOs of the Calvin-Benson-Bassham cycle. Genes annotated as thymidine phosphorylase (deoA) and eucaryal translation initiation factor 2B (e2b2) were found to encode AMP phosphorylase and ribose-1,5-bisphosphate isomerase, respectively. These enzymes supplied the RuBisCO substrate, ribulose-1,5-bisphosphate, from AMP and phosphate. Archaea with type III RuBisCOs all harbor both DeoA and the corresponding E2b2 homologs. In this pathway, adenine was released from AMP and the phosphoribose moiety entered central-carbon metabolism. 相似文献
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[目的]构建含不同信号肽编码序列的枯草芽孢杆菌分泌表达载体,并研究这些载体对脂肪酶A的分泌表达效率。[方法]克隆得到枯草芽孢杆菌168株的脂肪酶A编码基因,同时扩增得到蛋白质NprE、Bpr、YweA的信号肽编码序列,构建了脂肪酶A分泌表达载体pMA5-estA、pMA5-nprE-estA、pMA5-bpr-estA和pMA5-yweA-estA,并转化到枯草芽孢杆菌168株中得到相应的重组分泌表达菌株。[结果]对4株重组表达菌株进行摇瓶培养,所有菌株都实现了脂肪酶A的分泌,20 h后,168（pMA5-bpr-estA）的细胞外脂肪酶A的酶活力达到1.68 U/ml,约占该菌株脂肪酶A总表达量的86%。[结论]枯草芽孢杆菌Bpr信号肽对脂肪酶A具有较高的分泌效率。 相似文献
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A known inhibitor of pteridine utilization (4-phenoxy,2,6-diamino pyridine) blocks the synthesis of colored carotenoids in the photosynthetic bacterium Rhodospirillum rubrum. In many ways the effect is similar to the inhibition of the synthesis of colored carotenoids by diphenylamine. This inhibition is probably independent of other effects of pteridine on photosynthetic electron transport since it is not as readily reversible as the total inhibition of photosynthetic activity by pteridine analogs. 相似文献
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大豆GmRLP19基因克隆及胁迫应答模式分析 总被引：1，自引：1，他引：0
以大豆品种Williams82为试验材料,克隆GmRLP19基因,通过生物信息学分析qPCR检测探讨该基因不同生育期品种、不同组织、不同非生物胁迫下表达模式。结果表明,该基因编码区全长3 138 bp,编码1 045个氨基酸,编码蛋白具有胞外信号肽,LRRNT域,富含亮氨酸重复结构域,跨膜结构域和一段胞内短肽,属于受体类蛋白家族,定位于质膜。该基因在不同生育期品种间差异表达,在豆和豆荚中特异性表达,且在5种非生物胁迫中均有响应。研究为探究WRKY20基因功能及挖掘和完善基因调控通路奠定基础。 相似文献
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[目的]克隆生防菌芽孢形成关键基因spo0A启动子Pspo0A,并检测其特性.[方法]从生防菌B579 DNA中,经PCR扩增芽孢形成关键基因spo0A启动子Pspo0A,插入载体pGFP,构建重组表达质粒pGFP-Pspo0A.[结果]重组表达质粒经双酶切和PCR鉴定,证明构建正确,测序,结果与GenBank中的序列同源性为98％.[结论]该方法获得了含有绿色荧光蛋白基因和芽孢形成关键基因Spo0A的重组质粒,为进一步研究生防菌B579芽孢形成规律奠定了基础. 相似文献
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Spore formation by the bacterium Bacillus subtilis is an elaborate developmental process that is triggered by nutrient limitation. Here we report that cells that have entered the pathway to sporulate produce and export a killing factor and a signaling protein that act cooperatively to block sister cells from sporulating and to cause them to lyse. The sporulating cells feed on the nutrients thereby released, which allows them to keep growing rather than to complete morphogenesis. We propose that sporulation is a stress-response pathway of last resort and that B. subtilis delays a commitment to spore formation by cannibalizing its siblings. 相似文献
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Multiple principal sigma factor homologs in eubacteria: identification of the "rpoD box" 总被引：23，自引：0，他引：23
Genes for the principal sigma factor (rpoD genes) of various eubacteria were identified with a synthetic oligonucleotide probe corresponding to a conserved sequence in rpoD gene products of Escherichia coli and Bacillus subtilis. Multiple rpoD homologs were found in the strains of Micrococcus, Pseudomonas, and Streptomyces, whereas single genes were detected in E. coli, B. subtilis, and Staphylococcus aureus. The four rpoD homologs of Streptomyces coelicolor A3(2) were cloned and sequenced. A homologous portion with 13 amino acids was found in the rpoD genes of S. coelicolor A3(2), E. coli, and B. subtilis and was named the "rpoD box." 相似文献
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[目的]研究来源于苏云金芽孢杆菌的几丁质酶基因chiA在枯草芽孢杆菌中的表达情况。[方法]以苏云金芽孢杆菌染色体DNA为模板,PCR扩增获取几丁质酶基因chiA,将其与枯草芽孢杆菌表达载体pHSG连接,构建重组菌,经IPTG诱导后,检测培养液中的几丁质酶活性。[结果]扩增得到几丁质酶基因chiA大小为2.5 kb。构建的重组菌对底物[4-MU-(GlcNAc)3]显示出一定的水解活性,培养液酶活约为2.8 U/ml,而pHSG空质粒转化子在同样条件下其培养液没有明显酶活。该重组酶的最适pH值为6.5,最适反应温度为50℃,与苏云金芽孢杆菌自身产生的几丁质酶性质一致。[结论]几丁质酶基因chiA能在枯草芽孢杆菌中成功表达,表达产物可成功分泌到细胞外。 相似文献
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构建了β-葡聚糖酶表达载体 P~(SGI)。转化枯草杆菌 SO113后,可高效表达β-葡聚糖酶,并分泌到培养基中。其酶活性约为无表达质粒的枯草杆菌的十倍。 相似文献
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玉米生育后期光合特性的遗传分析 总被引：6，自引：0，他引：6
【目的】了解玉米生育后期光合生理性状的遗传规律。【方法】选用8个光合速率差异较大的玉米自交系,按n(n+1)/2双列杂交法配制36个组合,采用GriffingⅡ和Hayman法对玉米4个光合生理性状进行配合力分析和遗传参数估算。【结果】所用材料中自交系鲁原92和A150是较好的高光效亲本,平均值较高的杂交组合的亲本中至少有一个是高光效的。光合速率的遗传符合“加性-显性”模型,而气孔宽不符合“加性-显性”模型,广义遗传力分别为95.73%、81.47%,狭义遗传力分别为28.33%、32.39%。光合速率和气孔宽这2个光合性状的遗传均以非加性效应为主,显性方向均指向增效,适合中高代选择和优势育种。叶绿素含量的遗传符合“加性-显性”模型,加性效应比非加性效应更重要,显性方向指向增效,广义遗传力为78.78%,狭义遗传力为57.03%,适合早代选择。【结论】不同光合性状的遗传规律不同,高光效育种工作中,应筛选一般配合力较大的自交系作亲本,同时进行广泛测交。 相似文献