延长初发酵培养时间对大肠菌群结果影响分析

阐述了将《大肠菌群多管发酵法》(GB/T 4789.28-2003)初发酵时间24h延长至48h的原因,通过对139份不同种类样品进行大肠菌群总数检测,发现有12份样品增加了大肠菌群数,表明延长初发酵培养时间,可以增加迟缓发酵大肠菌群成员检出。指出迟缓发酵大肠菌群在44.5℃培养时,均无产酸产气现象,表明引起迟缓发酵的大肠菌群不属于粪大肠菌群成员。

延长初发酵培养时间对大肠菌群检测结果的影响

目的:为了解延长初发酵培养时间对各类样品大肠菌群检测结果的影响。方法:依据国标法检测大肠菌群数,将初发酵培养18～24 h未产酸产气的阴性管样品继续培养至36～48 h,对7类358份样品进行大肠菌群数的检测。结果:延长初发酵培养时间至36～48 h,另有68份迟缓发酵样品检出大肠菌群,大肠菌群检出率平均提高了19.0%,各类样品大肠菌群检出率分别提高了:酱卤肉9.8%、冷菜24.4%、果汁饮料40.7%、含奶冰冻饮品21.2%、食用冰块17.1%、桶装纯净水13.2%和表面涂抹样品6.4%。比较各类样品在18～24 h和36～48 h大肠菌群数的不合格率,果汁饮料有比较显著的差异(χ2=7.0,P<0.01)。结论:延长初发酵培养时间可不同程度提高样品的大肠菌群检出率,为某些样品大肠菌群测定的国标修订提供了实验依据。

延长初发酵培养时间对大肠菌群检测结果的影响

目的为了解延长初发酵培养时间对各类样品大肠菌群检测结果的影响。方法依据国标法检测大肠菌群,将初发酵培养18～24h未产酸产气的阴性管样品继续培养至36～48h,对7类358份样品进行大肠菌群的测定。结果延长初发酵培养时间至36～48h,另有68份迟缓发酵样品检出大肠菌群,大肠菌群检出率平均提高了19.0%,各类样品大肠菌群检出率分别提高了:酱卤肉9.8%、冷菜24.4%、果汁饮料40.7%、含奶冰冻饮品21.3%、食用冰块17.1%、桶装纯净水13.2%和表面涂抹样品6.5%。比较各类样品在18～24h和36～48h大肠菌群数的超标率,果汁饮料有比较显著差异(χ2=7.0,P<0.01)。结论延长初发酵培养时间可不同程度提高样品的大肠菌群检出率,为某些样品大肠菌群测定的国标修订提供了实验依据。

响应曲面法优化大肠菌群初发酵培养基

在标准LST培养基基础上,通过单因素实验、Box-Behnken响应曲面法优化大肠菌群初发酵培养基,探讨了乳糖、胰蛋白胨和酵母粉各因素对大肠菌群菌落总数的影响。确定适宜的培养基组成为乳糖0.5g/100mL,胰蛋白胨1.64g/100mL,酵母粉0.29g/100mL。在此条件下,大肠菌群菌落总数为1.025×107cfu/mL,经验证实际值为1.033×107cfu/mL,与理论值无明显差异。

职初教师培养微创新变革—区域见习教师规范化培训述评

自2012年上海市推行基础教育系统实施见习教师规范化培训制度以来,历时5年,Y区教师进修学院作为这一研训任务的承担者,勇尝试,努力创新,就创新职初教师培养模式,领航专业发展,深化见习教师规范化培训成效积累了丰富的经验,并明确了未来努力的方向。

CO_2增施对苹博一号快繁中试管苗的影响

研究了在苹博一号快繁过程中增施CO2的必要性和可行性。结果表明:CO2的增施可促进试管苗的生长,改善其光合生理结构并能大大提高繁殖速度。

大肠菌群测定初发酵培养基的改进

用我国国家标准乳糖胆盐培养基(GB4789.3-94,简称GB)、日本卫生协会煌绿乳糖胆盐肉汤培养基(简称BGLB)和美国食品与药品管理局(FoodandDrugAdministration,简称FDA)月桂基硫酸盐胰蛋白胨肉汤培养基(简称LST)对大肠杆菌菌液以及蔬菜中的大肠菌群进行检测对比试验。结果表明:LST培养基对大肠菌群的检出率比BGLB培养基和GB培养基分别高35.93%、67.71%。以LST培养基为基础并优选出A3培养基(LST+0.2%吐温),扩大实验表明:A3培养基对大肠菌群的检出率比GB培养基和LST培养基分别高出577.12%和143.72%。

Differences in Primary Callus Induction among Different Anthurium andraeanum Varieties

[Objective] This research aimed to optimize continuously the highly efficient regeneration system of Anthurium andraeanum. [Method] The leaves and petioles of four A. andraeanum varieties were used as explants to investigate the differences in primary callus induction among different A. andraeanum varieties. [Result]The callus formation capacity of SAM and SST was stronger than that of SDM and SHG. Among the four varieties, the leaf regeneration capacity of SAM, SDM and SHG was stronger than the corresponding petiole regeneration capacity. However,the petiole regeneration capacity of SST was stronger. The optimum medium for petiole callus induction of SST was 1/2 MS ＋ TDZ 4.0 mg/L ＋ 2, 4-D 0.2 mg/L with induction rate of 87.5%; the optimum medium for leaf callus induction of SAM was 1/2 MS ＋ TDZ 2.0 mg/L ＋ 2, 4-D 0.2 mg/L with induction rate more than90%; the optimum medium for leaf callus induction of SDM and SHG was all 1/2MS ＋ ZT 2.0 mg/L ＋ 2, 4-D 0.2 mg/L with induction rates of 59.34% and 79.63%,respectively. [Conclusion] In addition to variety differences, the differences in differentiation ability among different types of calluses should be also taken into account in the establishment and optimization of tissue culture and rapid propagation technology system of A. andraeanum.

Study on Tissue Culture and Rapid Propagation of Lycium ruthenicum Murr.

[Objective] This study aimed to establish a tissue culture and rapid propagation system for Lycium ruthenicum Murr.[Method] Using tender stems of L.ruthenicum as explants,MS as basic culture medium,the effects of different factors on primary culture,subculture and rooting of L.ruthenicum plantlets were investigated.[Result] The most appropriate medium for primary culture of L.ruthenicum was MS ＋ ZT 0.2 mg/L ＋ IBA 0.01 mg/L,in which axillary buds grew well and were rarely vitrified with the germination rate of 88.73%.In addition,ZT exerted significantly better effects on subculture and proliferation of L.ruthenicum plantlets than 6-BA.The most appropriate medium for subculture and proliferation of L.ruthenicum plantlets was MS ＋ ZT 0.15 mg/L ＋ IBA 0.01 mg/L,in which L.ruthenicum plantlets grew rapidly and robustly without vitrification,and the proliferation multiple reached 5.83 times.The most appropriate medium for rooting of L.ruthenicum plantlets was MS ＋ IBA 1.0 mg/L,in which the rooting rate reached 100%.The most appropriate substrate for transplanting and hardening of L.ruthenicum plantlets was humus soil：perlite = 1：1,in which L.ruthenicum plantlets grew well with the survival rate of 92.37%.[Conclusion] This study provided theoretical basis for largescale production and popularization of L.ruthenicum.

Allelopathic interactions between Prorocentrum micans and Skeletonema costatum or Karenia mikimotoi in laboratory cultures

Algal allelopathy is an ecological/physiological phenomenon that has focused attention on the interactions among algae and the production of algal toxins. We investigated the allelopathic interactions between the dinoflagellate genus Prorocentrum micans and diatom genus Skeletonema costatum and between P. micans and dinoflagellate genus Karenia mikimotoi using bi-algal cultures. Because the effects were species-specific and size-dependent, we evaluated the effect of different initial densities. At low densities of P. mieans and high densities of S. costatum inoculated into the same medium, the growth of R rnieans was weakly restrained, whereas the growth of S. costatum was significantly suppressed. S. costatum and K. mikimotoi were strongly inhibited by P. micans, in both the bi-algal cultures and enriched filtrates. Direct cell-to-cell contact was not necessary to gain a competitive advantage, thus, our results suggest that P. micans inhibited the growth of S. costatum and K. mikimotoi by the release of allelochemical（s）. Last, a mathematical model was used to simulate growth and interactions between P. micans and S. eostatum and between P. micans and K. mikimotoi in bi-algal cultures.

Production of Amylase Enzyme through Solid State Fermentation by Aspergillus niger

Traditionally, coconut dregs will be used as animal feed after the extraction of coconut oil and coconut milk from the copra. This study was carried out to discover the commercial value of coconut dregs as a solid substrate in the production of amylase through solid state fermentation （SSF） since this agro-waste is fairly rich in nutrients, providing the necessary nutrients supplementation for better microbial activity to produce enzymes. In this study, amylase is to be produced from coconut dregs by Aspergillus niger through solid state fermentation （SSF）. Three parameters were covered, which are incubation time, initial moisture content of substrate and inoculum sizes. SSF was carried out by using incubator at 37 ~C to test for enzyme activity at these following parameters： incubation time： 24, 48, 72, 96 and 120 hours; substrate moisture content： 64, 66, 68, 70 and 72% （w/w）; inoculum sizes： 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 mL spore suspension （5.5 × 10^6 spores/mL）. Enzyme activities were measured through the estimation of liberated reducing sugars after the assay of amylase enzyme by using DNS （3, 5 dinitrosalicylic acid） method. Highest enzyme activities were obtained at these following parameters： incubation time： 72 hours （31.76 U/gds）; initial moisture content ofsubstrate： 66% （26.66 U / gds） and inoculum sizes： 2.0 mL （30.56 U/gds）.

Denitrification in Natural Nutritious Medium

The intensive use of nitrogen fertilizers in Algeria caused a pollution of the waters by nitrates. This concentration reached in the region of Collo （Wilaya of Skikda, Algeria） 570 mg/L, which is beyond the WHO standard （50 mg/L）. This has negative consequences on human health （Methemoglobinemia） and on the environment （eutrophication）. In our works, we studied the elimination of this pollution with the use of a mixed culture of microorganisms. We replaced the standard synthetic carbon source and the nutritious medium by date powder. This contains minerals and sugars that can enhance bacterial growth. Our study showed that the effectiveness of denitrification is proportional to bacterial growth. It rises exponentially after a latency period of 8 hours. During the reaction of degradation we noticed a rise in pH in our engine, it moved from 7.00 to 8.38. In studying the influence of initial pH on the denitrification of the microorganisms, we observed that the ion hydrogen concentration modified the growth rate of bacteria and degradation of nitrates. An acid pH, the reduction of nitrates is incomplete; this is accounted for the accumulation of nitrous and nitric oxide that interferes in the reaction of denitrification. The velocity of the nitrate reduction is less important in an acid pH （0.0096 g.L^-l.h^-1） than in a basic pH （0.013 g.L^-1.h^-1）. The denitrification is optimal at temperature 35 ℃ for a ratio C/N = 2.5. In these conditions 95% of the nitrate initial quantity is eliminated after approximately 100 hour treatment.

Study on the Monascus Pigment of Monascus Strains JF-02 Fermentation

[ Objective] The aim was to study the fermentation technology of monascus pigment of monascus strains JF-02. [ Method] Single factor experiment was carried out to study the influence of temperature, initial pH, culture time, different agricultural byproduct, and nitrogen source on monascus pigment in fermentation solution. Meanwhile, orthogonal experiment was conducted to get the optimal culture medium and cultivation condition. [ Resultl The optimal gene in the pigment of monascus pigment was 200 g/L of rice, 30 g/L of sweet potato powder, 10 g/L of glucose, 15 g/L of monosodium glutamate, 0.1% of zinc sulfate, and 0.1% of magnesium sulfate. The optimal culture condition was 30 ℃ and initial pH was 6.0. Fermentation time was 72 h, but when 24-L fermentation pot was used, culture time can last to 84 h. [ Condusion] The study provided theoretical basis for the development and application of monascus strains.

Selection of Relevant Variables to the Enzyme Production on Red Grape Pomace by Solid-State Fermentation

With the aim of to valorise red grape pomace and to reduce its environmental impact, the production of enzymatic preparations appear as an interesting choice. Statistical experimental Plackett-Burman designs were applied for the selection of relevant medium components and culture conditions for cellulase, xylanase, polygalacturonase and tannase production by Aspergillus awamori, in solid-state fermentation on red grape pomace. Ten variables were tested： initial moisture content （IMC）, particle size （PS）, temperature, initial pH, time of cultivation, mixing （Mx）, and additions of： fructose, tannic acid, sodium phosphate, and ammonium sulphate （ASA）. Results indicate that the production of each enzyme was affected in a distinct way by the different variables. Also, for each of the enzyme activities considered, IMC must be carefully controlled, and optimized above 65%; PS and Mx, must not be taken into account and ASA must be discarded. The other variables studied, must be selected according to the enzyme activity that will be favored.

依托大数据技术的合训学员管理档案建设研究

随着大数据相关技术的高速发展,利用大数据信息进行科学有效管理日益成为各行业管理领域的热门课题。本文以大数据技术为基础,通过完善军队院校学员量化管理体系,搜集、分析、挖掘合训学员管理过程中的模块化数据,从而实现学员培养管理的"立体化"。