浓香型白酒生产中耐酒精酵母菌的选育研究

以宋河酒厂窖泥、酒糟、酒厂废水为样品,从中分离出100株菌株,经初筛、复筛和酒精发酵试验,最终获得1株耐酒精度为18%vol酵母菌,编号为A16。通过单因素实验确定最佳发酵条件为:发酵温度30℃、p H值4.5、碳源为葡萄糖、氮源为复合氮源(酵母膏和蛋白胨的比例为2∶1)、无机盐为Mg SO4·7H2O、接种量为10%、转速100 r/min、装液量为150 m L/250 m L;通过正交试验确定培养基最佳配比为:葡萄糖25%,酵母膏2%,蛋白胨1%,Mg SO4·7H2O 1%,(NH4)2SO41%,KH2PO41%,菌株A16的酒精得率70%。     

Bacterial Growth and Volatile Compounds in Yoghurt-Type Products from Soymilk Containing Bifidobacterium ssp

The growth of bacteria normally used to produce yoghurt was compared in soymilk and cow milk. Whether or not Bifidobacterium ssp. was present, fermented soymilks [soyoghurt (S), soyoghurt + bifi-dobacteria (SB)] were less acidic than fermented cow milks [yoghurt (Y), yoghurt + bifidobacteria (YB)]. When bifidobacteria were present (in SB), streptococci were more numerous than lactobacilli. Bifidobacteria in YB stimulated maximal growth of both yoghurt bacteria. In comparison to nonfermented milks, acetaldehyde and diacetyl increased in all cultures. Ethanol increased only in S/SB and acetone was detected only in Y/YB. Quantities of volatile products in Y/'YB were slightly lower than those in Y/S. In all cultures, n-hexanal was almost totally absent.     

T-RFLP微生物监测技术及矿场应用研究

运用基于聚合酶链式反应的分子生态学监测技术,分离和纯化了油藏产出液中微生物的总DNA,以纯化的DNA样品为模版扩增出代表油藏微生物种群特征的。16SrDNA,然后进行基因末端限制性片断长度多态性的分析,建立了分子水平的油藏微生物监测方法,为微生物驱矿场试验中注入功能菌的跟踪分析提供了快速、简便、可靠的监测手段。文章介绍了T-RFLP微生物监测技术在罗家油田罗801块微生物驱油现场试验中的应用情况。     

驱油微生物及其代谢产物对固体润湿性和原油物性的影响

从宋芳屯油田筛选到了3株驱油微生物,将其复合培养后具有产表活剂、产酸、产气活性.运用检测接触角的方法,研究了细菌的代谢作用及产物对固体润湿性的影响.结果表明,微生物具有剥离油膜的作用,并能使固体表面的润湿性向水湿方向改变,其中微生物代谢产生的表活剂发挥了重要作用.从糖和液体石蜡含菌培养体系的不同实验结果来看,虽然大体趋势是相同的,但液蜡的作用结果要好于糖.这是由于石英片的亲油性使它的表面覆盖一层液蜡,细菌因以液蜡为碳源而在其表面富集,进行在位繁殖产生局部高浓度表活剂所致.微生物的代谢作用和产物能显著改善原油粘度,但其代谢产物对蜡含量无影响.     

吉林油田微生物提高原油采收率现场试验研究

本文介绍了吉林油田现场试验研究的历程.建立了采用DNA鉴定用于微生物提高原油采收率的微生物的新技术.筛选出了用于现场试验的有用的微生物.通过就地注入糖蜜微生物单井吞吐与驱替试验,考察了油藏中被激活细菌的行为,原油收率,含水率及原油的粘度.代谢生物多糖的CJF-002用于现场试验中的微生物中最好的菌种.因为它可以使用糖蜜作为营养源,产生少量的CO2及大量的水不溶性的生物聚合物.它在油藏的代谢行为表明CJF-002具有微生物提高原油采收率良好潜力.     

Sodium Lactate/Sodium Chloride Effects on Aerobic Plate Counts and Color of Aerobically Packaged Ground Pork

Ground pork (15% fat) was formulated to contain 0% to 3.0% sodium chloride and/or 0% to 3.0% sodium lactate (SL) resulting in 28 treatment combinations. Five replications consisted of two with low initial microbial loads (< 10³ CFU/g) and three with high initial loads (> 10⁵ CFU/ g). Ground pork (454g) was overwrapped in PVC and stored (4°C) aerobically for 21 d. A significant salt × SL interaction existed for redness of samples with low initial aerobic plate count (APC). Red color was best preserved by 2.0% or 3.0% SL. Initial pH values of low and high initial APC samples were similar. Initial product pH was best maintained by higher SL levels in low initial load samples and by higher sodium chloride levels in high initial load samples. Samples containing 3.0% SL had the lowest APC regardless of salt level.     

中国近代酿酒微生物研究史料

中国酿酒历史源远流长，对酿酒微生物的研究始于近代。日本人齐藤在1904年就对我国的绍兴酒酿造的丝状菌进行了研究，我国对中国酒曲微生物的研究始于20世纪30年代初。老一辈的科技人员的研究成果及文献，对中国酒曲微生物的种类及分布、菌粪学、酒曲的效用等均作了较详细的记载。这些重要参考史料对研究中国酿酒微生物很有帮助。     

Biodegradation of monoaromatic hydrocarbons in aquifer columns amended with hydrogen peroxide and nitrate

The ability of indigenous microorganisms to degrade benzene, toluene, ethylbenzene and xylenes (BTEX) in laboratory scale flow-through aquifer columns was tested separately with hydrogen peroxide (110 mg/l) and nitrate (330 mg/l as NO₃⁻) amendments to air-saturated influent nutrient solution. The continuous removal of individual components from all columns relative to the sterile controls provided evidence for biodegradation. In the presence of hydrogen peroxide, the indigeneous microorganisms degraded benzene and toluene (> 95%), meta- plus para-xylene (80%) and ortho-xylene (70%). Nitrate addition resulted in 90% removal of toluene and 25% removal of ortho-xylene. However, benzene, ethylbenzene, meta- and para-xylene concentrations were not significantly reduced after 42 days of operation. Following this experiment, low dissolved oxygen (< 1 mg/l) conditions were initiated with the nitrate-amended column influent in order to mimic contaminated groundwater conditions distal from a nutrient injection well. Toluene continued to be effectively degraded (> 90%), and more than 25% of the benzene, 40% of the ethylbenzene, 50% of the meta- plus para-xylenes and 60% of the ortho-xylene were removed after several months of operation.     

Steam Surface Pasteurization of Beef Frankfurters

Meat and poultry products are sources of foodborne bacterial contamination. We used flash steam heating followed by evaporative cooling to quickly reduce bacterial contamination on the surface of beef frankfurters without degrading appearance. The rate of heat transfer was studied by measuring surface temperature in a pressure chamber during steam heating. Quality changes were determined by measuring color and weight as functions of steam temperature and treatment time. Efficacy of the process was verified by microbiological experiments using L. innocua. Treatment times of 30–40 set at 115–136°C gave a 4 log reduction in bacterial counts on the surface without severely affecting color or weight. After long-term storage at 6°C and at 19°C, levels of bacteria on inoculated frankfurters remained reduced and there was no difference between treated and untreated products in color or weight.     

An Eco-Friendly Approach to the Control of Pathogenic Microbes and Anopheles stephensi Malarial Vector Using Magnesium Oxide Nanoparticles (Mg-NPs) Fabricated by Penicillium chrysogenum

The discovery of eco-friendly, rapid, and cost-effective compounds to control diseases caused by microbes and insects are the main challenges. Herein, the magnesium oxide nanoparticles (MgO-NPs) are successfully fabricated by harnessing the metabolites secreted by Penicillium chrysogenum. The fabricated MgO-NPs were characterized using UV-Vis, XRD, TEM, DLS, EDX, FT-IR, and XPS analyses. Data showed the successful formation of crystallographic, spherical, well-dispersed MgO-NPs with sizes of 7–40 nm at a maximum wavelength of 250 nm. The EDX analysis confirms the presence of Mg and O ions as the main components with weight percentages of 13.62% and 7.76%, respectively. The activity of MgO-NPs as an antimicrobial agent was investigated against pathogens Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans, and exhibited zone of inhibitions of 12.0 ± 0.0, 12.7 ± 0.9, 23.3 ± 0.8, 17.7 ± 1.6, and 14.7 ± 0.6 mm respectively, at 200 µg mL⁻¹. The activity is decreased by decreasing the MgO-NPs concentration. The biogenic MgO-NPs exhibit high efficacy against different larvae instar and pupa of Anopheles stephensi, with LC50 values of 12.5–15.5 ppm for I–IV larvae instar and 16.5 ppm for the pupa. Additionally, 5 mg/cm² of MgO-NPs showed the highest protection percentages against adults of Anopheles stephensi, with values of 100% for 150 min and 67.6% ± 1.4% for 210 min.