Purification and Properties of a New L-Sorbose Dehydrogenase Accelerative Protein from Bacillus megaterium Bred by Ion-Beam Implantation

Bacillus megaterium BM302 bred by ion-beam implantation produces L-sorbose dehydrogenase accelerative protein （SAP） to accelerate the activity of L-sorbose dehydrogenase （SDH） of Gluconobacter oxydans in the 2-keto-L-gulonic acid （2KLG） fermentation from L-sorbose by the mixed culture of B. megaterium BM302 and G. oxydans. The SAP purified by three chromatographic steps gave 35-fold purification with a yield of 13% and a specific activity of 5.21 units/mg protein. The molecular weight of the purified SAP was about 58 kDa. The SDH accelerative activity of SAP at pH 7 and 50℃ was the highest. Additionally, it retained 60% activity at a pH range of 6.5 ～ 10 and was stable at 20℃ ～ 60℃. After 0.32-unit SAP was added to the single cultured G. oxydans strains, the SDH activity was apparently accelerated and the 2KLG yield of GO29, GO112, GO and GI13 was enhanced 2.1, 3.3, 3.5 and 2.9 folds respectively over that of the strains without the addition of SAP.

A Study of Pt^(4+)Adsorption and Its Reduction by Bacillus Megaterium D01

The properties of Pt 4+ adsorption and its reduction by Bacillus megaterium D01 were studied by means of ICP, anode stripping voltammetry, TEM, IR and XPS. The results of ICP analyses showed that the Pt 4+ adsorptive efficiency of the strain D01 was as high as 94.3% under the conditions of 100 mg Pt 4+ /L, 1 g biomass/L, pH 3.5 and at 30 ℃ for 24 h. Moreover, it was confirmed from anode stripping voltammetry that the strain D01 possessed a strong reducibility. The TEM analysis indicated that the strain D01 was able to adsorb and reduce Pt 4+ to Pt 0, small particles. The XPS result further supported the reduction of Pt 4+ to Pt 2+ , followed by the further recuction to Pt 0. The IR spectrum implied that D01 biomass adsorption of Pt 4+ may result in the complexation of the CO bond to the Pt species.

Study on the Effect of Mutated Bacillus megaterium in Two-Stage Fermentation of Vitamin C

Bacillus megaterium as a companion strain in two-stage fermentation of vitamin C could secrete some active substances to spur growth of Gluconobacter oxydans to produce 2-KLG. In the fermenting system where Gluconobacter oxydans was combined with GB82-a mutated strain of B. megaterium by ion implantation, the amount of 2-KLG harvested was larger than that produced by the original B. megaterium BP52 being substituted for GB82. In this paper, we studied the effect of the active substances secreted by GB82 to enhance the capability of Gluconobacter oxydans to produce 2-KLG. The supernate of GB82 sampled at different cultivation times all had much more activity to spur Gluconobacter oxydans to yield 2-KLG than that of the original B. megaterium, which might be due to the genetic changes in the active components caused by ion implantation. Furthermore, the active substances of GB82's supernate would lose a part of its activity in extreme environments, which is typical of some proteins.

Brain Abscess Caused by Bacillus megaterium in an Adult Patient

Bacillus megaterium, a Gram-positive, aerobic, spore-forming, rod-shaped bacterium, has been found in widely diverse habitats and has been widely used as a source of recombinant protein in the industry. With a cell length of up to 4 lain and a diameter of 1.5 μm, B. megaterium belongs to one of the largest known bacteria.

一种多功能化内生型巨大芽孢杆菌的菌肥对反季节鲜食玉米品质提升效果的研究

为了验证研制的一种多功能内生型巨大芽孢杆菌肥料的肥效,在红棕紫泥的旱坡地上,采用简单对比试验方法,将其施用在反季节鲜食玉米上。试验结果表明,在210 m2的土地上使用该菌肥2.94 kg后,相对于对照,同样面积上施用有机无机混合肥料76.048 kg(按当地农民常规施肥水平),显著提高了鲜食玉米的品质,水溶性氨基酸提高了40%、可溶性还原糖提高了198%、维生素C提高了30%,鲜玉米的粗纤维含量降低了0.15%,淀粉含量降低了10.68%。该菌肥对土壤培肥作用的研究具有一定的价值。

Isolation and characterization of a high-efficiency marine diesel oil-degrading bacterium

In the recent 50 years,marine oil spills had resulted in severe environmental pollution problems worldwide.In this study,12 petroleum-degrading strains named MJ1 to MJ12,which can use diesel oil as the sole carbon source for growth,were isolated from the seawater in Jiaozhou Bay,China.Strain MJ4 has the highest diesel-degrading rate which is up to 26.54%in 5 days with the diesel oil concentration of 10 g/L.According to the BLAST research,16SrRNA sequence of MJ4 showed 99%similarity to Bacillus megaterium strain.Single-factor experiments and response surface methodology were carried out to optimize the environmental factors and their reciprocal action for affecting the diesel oil degradation process of Bacillus sp.MJ4.Results of single-factor experiments revealed that the highest degradation rate was obtained with temperature of 28°C,pH of 8.8,diesel oil concentration of 25 g/L,P/N ratio of 0.56,nitrogen and phosphorus dosage quantity of 0.35 g/L and 0.18 g/L,respectively.A nonlinear regression equation of diesel oil degradation rate and pH,temperature,P/N ratio was obtained.The model predicted the maximum degradation rate of 72.21%with temperature of 28°C,pH of 8.88,P/N ratio of 0.31,respectively.

Investigating the Interaction Between Gluconobacter Oxydans and Bacillus M egaterium for 2-keto-L-gulonic Acid Biosynthesis in the Two-Step Vitamin C Fermentation

In the two-step vitamin C fermentation process, its precursor 2-keto-L-gulonic acid was synthesized from L-sorbose by mixed culture of Gluconobacter oxydans and Bacillus megaterium. The interaction between Gluconobacter oxydans and Bacillus megaterium remains unclear and it is a challenge to mathematically model the mixed growth of these two strains. The Monod-type equations were previously proposed to describe the coupled growth of Gluconobacter oxydans and Bacillus megaterium. However, in this study, we modeled the interaction of these two strains in a macroscopic view by introducing the population theory. Taking account of the fact that the density or concentration of Gluconobacter oxydans or Bacillus megaterium was hardly to measure accurately in the mixed culture broth, the data of concentrations of the substrate and product were used to indirectly investigate the relation between these two strains. Three batch experiments were used to validate our model. And according to the values of identified parameters, the type of interaction between Gluconobacter oxydans and Bacillus megaterium was concluded to be predation, where Gluconobacter oxydans was predator, and Bacillus megaterium was prey.

Studies on biodiversity and bioprospecting of active mud volcano associated bacteria and actinobacteria from Baratang,Andaman Islands,India

A total of 79 bacteria and 101 actinobacteria strains were isolated from the sediment samples of the different points of Baratang mud volcano viz.,point of the eruption(M),middle of the volcano(MD),and the dried part of the mud volcano(E).Based on the biochemical and molecular characterization,the isolates were categorized under the phyla Proteobacteria,Firmicutes and Proteobacteria included representatives of Classes Alphaproteobacteria,Gammaproteobacteria and Deltaproteobacteria of 29 genera with 38 distinct ribotypes.Thirty-eight bacterial strains from four different regions of mud volcano revealed excellent activity for indole-3-acetic acid(IAA)production.Excellent antagonistic property,plant growth promoting properties such as IAA production,phosphate,potassium and zinc solubilization were identified in Bacillus megaterium NIOT_MV 31 strain of 38 studied isolates.In this study,we investigated the optimization of IAA production by B.megaterium NIOT_MV 31 and its formulation as a plant growth promoter to improve economic and agricultural development.Maximum IAA yield was achieved using optimal conditions(42.63 mg/mL)in the presence of optimized tryptophan after 4 days of incubation.Twofold increase in the plant growth parameters were observed to that of control plants.Optimization of culture conditions resulted in a fourfold increase in IAA production by B.megaterium NIOT_MV 31 cells.The results clearly demonstrated that,B.megaterium NIOT_MV 31 holds great potential as a source for IAA production and may be useful for commercial applications.

Biological treatment of chicken feather waste for improved biogas production

A two-stage system was developed which combines the biological degradation of keratin-rich waste with the production of biogas. Chicken feather waste was treated biologically with a recombinant Bacillus megaterium strain showing keratinase activity prior to biogas production. Chopped, autoclaved chicken feathers （4%, W/V） were completely degraded, resulting in a yellowish fermentation broth with a level of 0.51 mg/mL soluble proteins after 8 days of cultivation of the recombinant strain. During the subsequent anaerobic batch digestion experiments, methane production of 0.35 Nm3/kg dry feathers （i.e., 0.4 Nm3/kg volatile solids of feathers）, corresponding to 80% of the theoretical value on proteins, was achieved from the feather hydrolyzates, independently of the pre- hydrolysis time period of 1, 2 or 8 days. Cultivation with a native keratinase producing strain, Bacillus licheniformis resulted in only 0.25 mg/mL soluble proteins in the feather hydrolyzate, which then was digested achieving a maximum accumulated methane production of 0.31 Nm3/kg dry feathers. Feather hydrolyzates treated with the wild type B. megaterium produced 0.21 Nm3 CH4/kg dry feathers as maximum yield.