The alginate fermentation strain Pantoea sp. F16-PCAi-T3P21 and ethanol production

Bio-ethanol production from algae is a promising way to help solve the energy problem. Alginate is a major component of algae, but it cannot be utilized by existing ethanol fermentation microorganisms. In order to improve the utilization rate of brown algae, high alginate fermentation strains should be obtained. In this research, strains for algae fermentation were got from several experiments. The ethanol yield of strain A was the highest, which was 0.095 g/g (ethanol to alginate). The identification of strain A was carried out and it was 99% identical to Pantoea sp. F16-PCAi-T3P21. Fermentation experiments with different substrates were carried out, such as laminaran, mannitol, L. japonica and acid hydrolysate of L. japonica, and the ethanol yield rate of L. japonica acid hydrolysate was the highest, which reached 0.17 g/g ethanol to L. japonica. It showed that strain A can converse alginate to ethanol in a relatively high yield rate, and might be a promising strain with L. japonica as the substrate, we believe more research should be carried out on this strain.     

Fermentation of table cream by Lactobacillus plantarum strains: effect on fungal growth,aflatoxin M1 and ochratoxin A

Aflatoxin M1 (AFM₁) and ochratoxin A (OTA) are two main mycotoxins in milk and dairy products. In the present work, the ability of four Lactobacillus strains (L. plantarum PTCC 1058, L. plantarum LP3, L. plantarum AF1 and L. plantarum LU5) to remove AFM1 and OTA in fermented cream was studied during 24 h fermentation. The antifungal activity of the mentioned lactobacilli against the defined fungi (Aspergillus flavus PTCC 5004, Aspergillus parasiticus PTCC 5018, Aspergillus nidulans PTCC 5014, Aspergillus ochraceus PTCC 5060) was also evaluated. The results showed that the cell counts of all strains were increased by 64–70% during fermentation. All Lactobacillus strains decreased the amount of AFM₁ significantly (P ≤ 0.05) in the range of 26–52%, which the highest AFM₁-reducing effect was related to L. plantarum LU5 (from 0.5 to 0.24 μg kg⁻¹). The mean OTA removal by Lactobacillus strains in fermented cream also ranged from 32 to 58%. Amongst Lactobacillus strains, the cell-free culture supernatants of L. plantarum LU5 showed the highest (inhibition zone of 26.7 ± 1.2 mm) and L. plantarum LP3 and L. plantarum PTCC 1058 the lowest antifungal activities. The fermented creams contained Lactobacillus strains exhibited the highest and lowest antifungal activities against A. ochraceus and A. parasiticus, respectively. L. plantarum LU5, with the inhibition zone of 27.6 ± 0.9 mm, was the most effective fungal inhibitor, while L. plantarum PTCC 1058 had the lowest antifungal activity.     

小米曲奇预拌粉配方的优化

以预糊化小米粉为主要原材料,研制小米曲奇预拌粉。通过单因素试验,研究小米粉添加量、吉士粉添加量、奶粉添加量、泡打粉添加量、糖粉添加量对小米曲奇感官评分和硬度的影响。采用Box–Behnken法设计试验方案,运用响应面分析法建立二阶多项式非线性回归方程和数值模型,以感官评分和硬度为评判指标,优化小米曲奇预拌粉配方。优化后配方为:小米粉60.00g、低筋面粉40.00 g、吉士粉6.50 g、泡打粉1.00 g、糖粉45.00 g、奶粉8.00 g。在此条件下小米曲奇的理论感官评分为95.04分、硬度为510.11 g。在此配方下制作的小米曲奇呈棕黄色,与市售黄油曲奇相比,具有独特的小米香气和风味。预拌粉降低了小米曲奇制作的专业性、技术性,提高生产效率,利于生产品质稳定、健康味美的小米曲奇产品。     

促烟草种子萌发的细菌菌株筛选及促生特性研究

以芽孢杆菌属、贪铜菌属、假单胞菌属及土壤杆菌属的7株细菌菌株对烟草K326种子进行浸种处理，通过测定发芽率、发芽势、发芽指数及活力指数筛选到能够促进种子萌发的2株菌株；以钼蓝比色法测定培养液可溶磷含量，Salkowski法测定产IAA能力，CAS法测定分泌铁载体能力，对筛选出的2株菌的促生特性进行分析。结果表明，从贵州烟区土壤分离的2株高效氨化芽孢杆菌菌株可显著提高烟草种子的发芽指标，幼苗苗长显著高于未浸种处理。促生特性分析显示Bacillus toyonensis AMM-2和Bacillus mobilis AMM-5菌株的溶磷量分别为26.26和26.80 mg/L，产IAA的能力分别为21.57和7.40 μg/mL，铁载体分泌活性分别为35.08%和8.64%。研究显示，2株高效氨化细菌菌株具有优良的促生特性及显著的促种子萌发效应，可应用于烟草漂浮育苗，为促生有机肥的研制提供依据。     

抑烟除味剂对SMA-13沥青混合料路用性能影响评价

选用SMA-13级配,通过添加抑烟除味剂来改善热拌沥青施工环境,研究其对沥青及其混合料性能影响,并评价了抑烟除味剂对于沥青烟的降解效果。结果表明,抑烟除味剂的添加降低了施工、拌和温度并且减少了烟气的排放,同时其沥青及混合料的路用性能均满足热拌沥青混合料相关规范要求。     

半柔性复合路面在重交通长大纵坡路段的应用

重点阐述半柔性复合路面技术在国道丹霍线(G304)本溪段重载长大纵坡试验路段的应用,对原路路况及改造方案、配合比设计、人员与设备要求、工程实施工艺等方面进行分析。     

Coherency strain induced hardening in bulk polycrystalline ceramics: A case study with MgO-based “ceramic alloys”

The role of coherency strain at the matrix/precipitate interface toward hardening of bulk polycrystalline “ceramic alloys” has been established here. Formation of “near ideal” bulk polycrystalline ceramic microstructure characterized by the presence of uniformly distributed coherent “ultra-fine” MgCr₂O₄ particles (size: ~25 nm) within matrix (MgO) grains was achieved via solid-state precipitation during aging treatment of bulk supersaturated MgO–Cr₂O₃ solid solutions (formed during pressureless sintering in air, followed by fast cooling). The as-aged MgO–MgCr₂O₄ “ceramic alloys” exhibited hardness increment by ~73% over that of phase pure bulk MgO upon aging for just 10 hours at 1000°C in air. Evidences toward the presence of significant coherency strains across the MgO/MgCr₂O₄ coherent interfaces were obtained with transmission electron microscopy. Analysis based on hardening mechanisms and comparisons with MgO–MgFe₂O₄ system, having lesser hardening due to lower misfit strain at MgO/MgFe₂O₄ coherent interfaces (despite greater content of second-phase particles), confirm the dominant role of coherency strains toward hardness enhancement in “ceramic alloys.”     

Reacting flow coupling with thermal impacts in a single solid oxide fuel cell

Thermal impacts are the major concern for the designs of electrolyte of Solid Oxide fuel cells (SOFCs) due to the high temperature operating conditions. In this study, the coupling dynamics of electrochemical reacting flows with heat transfer and generations of thermal strains and stresses (thermal impact) of solid electrolyte and porous electrodes are investigated in a single SOFC by numerical simulations. Modeling results from a test case show that the coupling is necessary as the electrochemical and thermal properties of the cell strongly depends on temperature, meanwhile, the thermal strains and stresses on temperature gradients. The differences in current density and thermal strain gradients predicted by coupling and decoupling simulations are as larger as 20% because of the strong dependents of ionic conductivity of the electrolyte material on temperature, the maximum thermal strain, thermal stresses, and temperature are all about 5%. It is identified that the high operation voltage benefits to the thermal strain, which decreases 20% when the cell operating from 0.5 V–0.7 V.