To optimize culture conditions for xylanase production by solid state fermentation (SSF) using Bacillus pumilus, with paddy husk as support, solid medium contained 200 g of paddy husk with 800 mL of liquid fermentat...To optimize culture conditions for xylanase production by solid state fermentation (SSF) using Bacillus pumilus, with paddy husk as support, solid medium contained 200 g of paddy husk with 800 mL of liquid fermentation medium [xylan, 20.0 g/L; peptone, 2.0 g/L; yeast extract, 2.5 g/L; K2HPO4, 2.5 g/L; KH2PO4, 1.0 g/L; NaCl, 0.1 g/L; (NH4)2SO4, 2.0 g/L, CaCl2-2H2O, 0.005 g/L; MgCl2.6H2O, 0.005 g/L; and FeCI3, 0.005 g/L] at pH 9.0 was applied. The highest xylanase activity (142.0 ±0.47 U/g DM] was obtained on the 6th day at 30℃ The optimized paddy husk to liquid fermentation medium ratio was 2:9, and the optimized culture temperature was 40℃. When commercial Birchwood xylan was replaced with different concentrations of corncob, xylanase production was maximized (224.2 U/g DM) in the medium with 150 g/L corncob. Xylanase production was increased by sucrose, fructose and arabinose, whereas reduced by glucose, galactose, lactose and amylose. When organic nitrogen sources were replaced with locally available nitrogen sources such as groundnut powder or sesame seedcake powder or coconut seedcake powder or soy meal powder, the highest xylanase production (290.7 U/g DM) was obtained in the medium with soy meal powder and 16.0 g/L of soy meal powder was the optimum (326.5±0.34 U/g DM). Based on the optimization studies, B. pumilus produced 2.3 times higher xylanase activity. The medium cost was reduced from 2 458.3 to 178.3 SLR/kg and the total activity which could be obtained from 1 kg of the medium was increased from 48 624 to 220 253 Units.展开更多
Proteases due to their wide range of applications in biotechnological processes have been the??focus of intense research for many decades. However, from industrial?application view point most of the available protease...Proteases due to their wide range of applications in biotechnological processes have been the??focus of intense research for many decades. However, from industrial?application view point most of the available proteases lack desired properties;?therefore, search for better and efficient thermostable alkaline proteases are?always on.?Bacillus pumilus?D-6, isolated from dairy plant soil sample, in the?current study produced protease which showed activity and stability at high?alkaline?pH (8 - 12) and high?temperatures (70。C- 100。C). Enzyme activity remained unfazed even in presence?of inhibitors like Pb2+and Hg2+which are considered?universal inhibitors of enzyme activity. Besides, the organism successfully?utilized crude agriculture based substrates as carbon and nitrogen source and?produced substantial enzyme titre.展开更多
Background: Viruses can cause different diseases in plants. To prevent viral infections, plants are treated with chemical compounds and antiviral agents. Chemical antiviral agents usually have narrow specificity, whic...Background: Viruses can cause different diseases in plants. To prevent viral infections, plants are treated with chemical compounds and antiviral agents. Chemical antiviral agents usually have narrow specificity, which limits their wide application. Alternative antiviral strategy is associated with the use of microbial enzymes, which are less toxic and are readily decomposed without accumulation of harmful substances. The aim of this work is to study the effect of Bacillus pumilus ribonuclease on various phytopathogenic viruses with specific focus on the ability of enzyme to eliminate them from plant explants in vitro. Materials and methods: Extracellular ribonuclease of B. pumilus is tested as an antiviral agent. To study the antiviral effect of RNase, depending on concentration and the time of application several plant-virus model systems are used. Virus detection is conducted by serological testing and RT-PCR. Results: Bacillus pumilus ribonuclease possesses antiviral activity against plant Rna-viruses RCMV (red clover mottle virus), PVX (Potato Virus X) and AMV (Alfalfa Mosaic Virus). The maximum inhibitory effect against actively replicating viruses is observed when plants are treated with the enzyme in the concentration of 100 ug/ml prior to infection. In case of local necrosis ribonuclease in the concentration of 1 ug/ml completely inhibits the development of RCMV virus on bean plants. The enzyme is able to penetrate plants and inhibit the development of viral infection, inhibiting effect for untreated surfaces decreased on average for 20%. It is also found that B. pumilus ribonuclease protects apical explants of sprouts of potato tubers from PVM and PVS viruses. Conclusion: B. pumilus ribonuclease possesses antiviral activity against plant Rna-viruses and produces viruses-free plants in the apical meristem culture.展开更多
The misuse of Bacillus anthracis as a bioweapon continues to be a serious concern. Medical personnel and researchers are served well if appropriate non-pathogenic anthrax simulants can be used as countermeasures in pr...The misuse of Bacillus anthracis as a bioweapon continues to be a serious concern. Medical personnel and researchers are served well if appropriate non-pathogenic anthrax simulants can be used as countermeasures in preparative planning. While there are several accepted simulants of B. anthracis, the addition of another model organism would be beneficial. This investigation was undertaken to evaluate the suitability of B. pumilus as a simulant for B. anthracis. All organisms were grown on AK Agar #2 to foster sporulation. Optimum conditions for spore formation were determined for B. pumilus as well as for currently used anthrax surrogates B. atrophaeus and B. thuringiensis. Spore dimensions were determined by scanning electron microscopy. Comparative antibody binding studies using commercially available anti-Bacillus antisera were completed with the simulants as well as with a negative control organism, Clostridium sporogenes. We report that B. pumilus sporulated readily (2.9 × 1010 viable spores per plate), had appropriate spore size (1.24 μm × 0.59 μm) and reactivity with anti-Bacillus antibodies. The characteristics of B. pumilus determined in this study suggest this organism represents a novel, suitable model for B. anthracis.展开更多
This study examined that the efficiency of Bacillus pumilus(BP)on growth performance and meat quality of broiler chickens.A total of day old 240 male broiler chicks were purchased from local hatchery Hyderabad.The chi...This study examined that the efficiency of Bacillus pumilus(BP)on growth performance and meat quality of broiler chickens.A total of day old 240 male broiler chicks were purchased from local hatchery Hyderabad.The chicks were allocated into four groups with six replicates of 10 birds in each replicate.Four diets were prepared for experiment,which included control as basal diet,BP-0.1(CONT+0.1%BP),BP-0.2(CONT+0.2%BP)and AGP(CONT+zinc bacitracin 20 ppm)as antibiotic growth promotor.The results showed that live body weight(LBW),average daily gain was recorded higher(P<0.01)in birds fed diet with BP-0.1 than control and BP-0.2 groups,as well as ADFI also increased in BP-0.1 than control group.BP-0.1 supplementation significantly reduced feed conversion ratio(FCR)than other groups(P<0.01).Both moisture and crude protein(CP)content influenced by supplementation of BP-0.1 than other groups.However,birds fed diet with BP-0.1 had least fat content in breast meat compared with the other groups(P<0.01).In addition,BP-0.1probiotic-fed birds had the lowest(P<0.01)pH,cooking loss(CL)and drip loss(DL)as compared to control,BP-0.2 and AGP groups.The water holding capacity(WHC)were found higher in BP-0.1 as compared to other groups(P<0.01).In conclusion,Bacillus pumilus probiotic supplementation is a promising approach for substitution of antibiotics in broiler diet for enhancement of growth performance and physiochemical properties of meat.展开更多
对从连云港东西连岛海泥样品中分离得到的菌株Bacillus pumilus HX2-2的分类地位、生长条件和抑菌活性进行了研究。经过形态特征、生理生化性质及16S r DNA序列分析鉴定,该菌属于短小芽胞杆菌。不同温度、盐度、pH培养条件下测定菌液吸...对从连云港东西连岛海泥样品中分离得到的菌株Bacillus pumilus HX2-2的分类地位、生长条件和抑菌活性进行了研究。经过形态特征、生理生化性质及16S r DNA序列分析鉴定,该菌属于短小芽胞杆菌。不同温度、盐度、pH培养条件下测定菌液吸光度OD600值,表明该菌是一株轻度嗜盐菌,最适温度、盐度、pH分别为30℃、3%、7.0~8.0。在不同病原真菌的平板抑菌活性试验中,该菌对草莓尖胞镰刀菌、马铃薯炭疽病菌和水稻立枯丝核菌表现出显著的抑菌作用。菌株B.pumilus HX2-2是一株短小芽胞杆菌,具有广谱抑菌活性,具有进一步研究的价值。展开更多
[ Objective] The paper was to screen the antagonistic strain against Phytophthora sojae with biocontrol potential, and provide basis for searching control measures and designing new control strategies against P. sojae...[ Objective] The paper was to screen the antagonistic strain against Phytophthora sojae with biocontrol potential, and provide basis for searching control measures and designing new control strategies against P. sojae. [ Method] The rhizosphere soil of soybean was collected from three different places in Heilongjiang Province, and various soil microorganisms were isolated. Dual culture method was used to screen the microorganism with antagonistic effect against P. sojae. On this basis, the growth inhibition rate of the microorganism with stronger antagonistic effect against P. sojae was determined, and its control effect against P. sojae was also measured. [ Result] A strain of bacterium with relatively good antagonistic effect was isolated from soil, and named as strain B048. Dual test showed that the growth inhibition rate of antagonistic bacterium 11048 against P. sojac reached 97.5%. Antagonistic endurance tests showed that the width of inhibition zone was still 20.0 mm after dual culture with P. sojac for21 d. In potting experiment, the control effect of B048 against P. sojae was 100%. The antagonistic bacterium was primarily identified to be Bacillus pumilus through morphology and 16S rDNA sequence analysis. [Condusion] The antagonistic bacterium B048 had good prospect to be developed as the biocontrol bacterium against P. sojae.展开更多
基金Sida/SAREC and International Science Programme in the Chemical Sciences (IPICS),Sweden, for the financial support
文摘To optimize culture conditions for xylanase production by solid state fermentation (SSF) using Bacillus pumilus, with paddy husk as support, solid medium contained 200 g of paddy husk with 800 mL of liquid fermentation medium [xylan, 20.0 g/L; peptone, 2.0 g/L; yeast extract, 2.5 g/L; K2HPO4, 2.5 g/L; KH2PO4, 1.0 g/L; NaCl, 0.1 g/L; (NH4)2SO4, 2.0 g/L, CaCl2-2H2O, 0.005 g/L; MgCl2.6H2O, 0.005 g/L; and FeCI3, 0.005 g/L] at pH 9.0 was applied. The highest xylanase activity (142.0 ±0.47 U/g DM] was obtained on the 6th day at 30℃ The optimized paddy husk to liquid fermentation medium ratio was 2:9, and the optimized culture temperature was 40℃. When commercial Birchwood xylan was replaced with different concentrations of corncob, xylanase production was maximized (224.2 U/g DM) in the medium with 150 g/L corncob. Xylanase production was increased by sucrose, fructose and arabinose, whereas reduced by glucose, galactose, lactose and amylose. When organic nitrogen sources were replaced with locally available nitrogen sources such as groundnut powder or sesame seedcake powder or coconut seedcake powder or soy meal powder, the highest xylanase production (290.7 U/g DM) was obtained in the medium with soy meal powder and 16.0 g/L of soy meal powder was the optimum (326.5±0.34 U/g DM). Based on the optimization studies, B. pumilus produced 2.3 times higher xylanase activity. The medium cost was reduced from 2 458.3 to 178.3 SLR/kg and the total activity which could be obtained from 1 kg of the medium was increased from 48 624 to 220 253 Units.
文摘Proteases due to their wide range of applications in biotechnological processes have been the??focus of intense research for many decades. However, from industrial?application view point most of the available proteases lack desired properties;?therefore, search for better and efficient thermostable alkaline proteases are?always on.?Bacillus pumilus?D-6, isolated from dairy plant soil sample, in the?current study produced protease which showed activity and stability at high?alkaline?pH (8 - 12) and high?temperatures (70。C- 100。C). Enzyme activity remained unfazed even in presence?of inhibitors like Pb2+and Hg2+which are considered?universal inhibitors of enzyme activity. Besides, the organism successfully?utilized crude agriculture based substrates as carbon and nitrogen source and?produced substantial enzyme titre.
文摘Background: Viruses can cause different diseases in plants. To prevent viral infections, plants are treated with chemical compounds and antiviral agents. Chemical antiviral agents usually have narrow specificity, which limits their wide application. Alternative antiviral strategy is associated with the use of microbial enzymes, which are less toxic and are readily decomposed without accumulation of harmful substances. The aim of this work is to study the effect of Bacillus pumilus ribonuclease on various phytopathogenic viruses with specific focus on the ability of enzyme to eliminate them from plant explants in vitro. Materials and methods: Extracellular ribonuclease of B. pumilus is tested as an antiviral agent. To study the antiviral effect of RNase, depending on concentration and the time of application several plant-virus model systems are used. Virus detection is conducted by serological testing and RT-PCR. Results: Bacillus pumilus ribonuclease possesses antiviral activity against plant Rna-viruses RCMV (red clover mottle virus), PVX (Potato Virus X) and AMV (Alfalfa Mosaic Virus). The maximum inhibitory effect against actively replicating viruses is observed when plants are treated with the enzyme in the concentration of 100 ug/ml prior to infection. In case of local necrosis ribonuclease in the concentration of 1 ug/ml completely inhibits the development of RCMV virus on bean plants. The enzyme is able to penetrate plants and inhibit the development of viral infection, inhibiting effect for untreated surfaces decreased on average for 20%. It is also found that B. pumilus ribonuclease protects apical explants of sprouts of potato tubers from PVM and PVS viruses. Conclusion: B. pumilus ribonuclease possesses antiviral activity against plant Rna-viruses and produces viruses-free plants in the apical meristem culture.
文摘The misuse of Bacillus anthracis as a bioweapon continues to be a serious concern. Medical personnel and researchers are served well if appropriate non-pathogenic anthrax simulants can be used as countermeasures in preparative planning. While there are several accepted simulants of B. anthracis, the addition of another model organism would be beneficial. This investigation was undertaken to evaluate the suitability of B. pumilus as a simulant for B. anthracis. All organisms were grown on AK Agar #2 to foster sporulation. Optimum conditions for spore formation were determined for B. pumilus as well as for currently used anthrax surrogates B. atrophaeus and B. thuringiensis. Spore dimensions were determined by scanning electron microscopy. Comparative antibody binding studies using commercially available anti-Bacillus antisera were completed with the simulants as well as with a negative control organism, Clostridium sporogenes. We report that B. pumilus sporulated readily (2.9 × 1010 viable spores per plate), had appropriate spore size (1.24 μm × 0.59 μm) and reactivity with anti-Bacillus antibodies. The characteristics of B. pumilus determined in this study suggest this organism represents a novel, suitable model for B. anthracis.
文摘This study examined that the efficiency of Bacillus pumilus(BP)on growth performance and meat quality of broiler chickens.A total of day old 240 male broiler chicks were purchased from local hatchery Hyderabad.The chicks were allocated into four groups with six replicates of 10 birds in each replicate.Four diets were prepared for experiment,which included control as basal diet,BP-0.1(CONT+0.1%BP),BP-0.2(CONT+0.2%BP)and AGP(CONT+zinc bacitracin 20 ppm)as antibiotic growth promotor.The results showed that live body weight(LBW),average daily gain was recorded higher(P<0.01)in birds fed diet with BP-0.1 than control and BP-0.2 groups,as well as ADFI also increased in BP-0.1 than control group.BP-0.1 supplementation significantly reduced feed conversion ratio(FCR)than other groups(P<0.01).Both moisture and crude protein(CP)content influenced by supplementation of BP-0.1 than other groups.However,birds fed diet with BP-0.1 had least fat content in breast meat compared with the other groups(P<0.01).In addition,BP-0.1probiotic-fed birds had the lowest(P<0.01)pH,cooking loss(CL)and drip loss(DL)as compared to control,BP-0.2 and AGP groups.The water holding capacity(WHC)were found higher in BP-0.1 as compared to other groups(P<0.01).In conclusion,Bacillus pumilus probiotic supplementation is a promising approach for substitution of antibiotics in broiler diet for enhancement of growth performance and physiochemical properties of meat.
基金Supported by National Natural Science Foundation of China(30800040)Excellent Youth Science and Technology Fund of Anhui Province(10040606Y04)教育部留学回国人员科研启动基金资助项目~~
文摘[ Objective] The paper was to screen the antagonistic strain against Phytophthora sojae with biocontrol potential, and provide basis for searching control measures and designing new control strategies against P. sojae. [ Method] The rhizosphere soil of soybean was collected from three different places in Heilongjiang Province, and various soil microorganisms were isolated. Dual culture method was used to screen the microorganism with antagonistic effect against P. sojae. On this basis, the growth inhibition rate of the microorganism with stronger antagonistic effect against P. sojae was determined, and its control effect against P. sojae was also measured. [ Result] A strain of bacterium with relatively good antagonistic effect was isolated from soil, and named as strain B048. Dual test showed that the growth inhibition rate of antagonistic bacterium 11048 against P. sojac reached 97.5%. Antagonistic endurance tests showed that the width of inhibition zone was still 20.0 mm after dual culture with P. sojac for21 d. In potting experiment, the control effect of B048 against P. sojae was 100%. The antagonistic bacterium was primarily identified to be Bacillus pumilus through morphology and 16S rDNA sequence analysis. [Condusion] The antagonistic bacterium B048 had good prospect to be developed as the biocontrol bacterium against P. sojae.