Microbial environmental monitoring of the refectory in the monastery of St. Anna in Foligno, Italy

For the preservation of monuments and sites of cultural heritage, microbiological methods based on defined standards are needed to evaluate the problems associated with biodeterioration. In this study Microbial Environmental Monitoring (MAM from the Italian acronym Monitoraggio Ambientale Microbico) was applied to air and surface monitoring of art works before and during restoration. Microbial monitoring of the refectory in the monastery of St. Anna (Foligno, Italy) was performed on frescos from 1400. The results obtained with MAM were consistent, reproducible, and beneficial in the evaluation of the efficacy of restoration. Microbial monitoring of solid surfaces using membrane filters was not destructive and allowed the study of microbial fall-out on the surface of art works. The application of MAM proved to be a valuable means not only for monitoring but also for a better understanding of microbial pollution and its dynamics on the surface of art works. The constant application of MAM could be a valuable tool in the preservation of cultural heritage through strict collaboration with microbiologists, restorers, and authorities.     

Biodeterioration of ornamental marble statues in the Boboli Gardens (Florence, Italy)

The colonisation of ornamental marble statues in theBoboli Gardens of Florence (Italy) by photosyntheticmicro-organisms was investigated. The greenmicroalga Coccomyxa was the first colonizer ofnewly restored marble surfaces, appearing one yearafter the periodic cleaning and restoration of thestatues. Two years after restoration this alga gaverise to very thin green biofilms, with densitiesreaching about 3 × 10² cells cm^-2. Later,the biofilms were enriched by cyanobacterial forms,which became dominant. In about six years, aphotosynthetic microbial community, amounting to about3 × 10⁴ cells cm^-2, and structurally similarto that occurring on the unrestored statues wasdeveloped. This epilithic community showed amarked biodiversity; the main representative formsincluded Chroococcidiopsis, Leptolyngbya,Pleurocapsa, Coccomyxa and Apatococcus.Coccomyxa initiated the colonisation of themarble surfaces, favoured in this process by itsfacultative oligotrophic capacity and high cellsurface hydrophobicity, combined with tolerance ofhigh light intensity. The other investigated isolatedstrains did not show this set of features. Thesecretion of polysaccharidic substances and cellsurface hydrophobicity enhancing the capacity toadhere, favoured permanent colonisation of thecyanobacterial population. Indeed, the majority of thecyanobacterial strains (90%), were shown to besurrounded by exopolysaccharidic envelops, whichcontributed to the formation of stable microbialbiofilms, and possessed variable cell surfacehydrophobicity.     

Microbial Communities on the Monuments of Moscow and St. Petersburg: Biodiversity and Trophic Relations

Stone monuments situated in the Alexander Nevsky Abbey, the Summer Garden, and the Smolenskoe Cemetery, St. Petersburg, and marble and limestone sculptures and tombstones situated in the Novodevichy Convent and the Donskoy Monastery, Moscow, were investigated for their microbial contamination. The architectural objects studied date back to the 12th century. The monuments in the Alexander Nevsky Abbey were found to be severely contaminated with micromycetes belonging to 24 genera (primarily of the class Deuteromycetes). The analysis of the samples taken from the monuments of the Donskoy Monastery by the serial dilution technique showed that they were contaminated with bacteria at a density of (1–1.7) × 10⁵ cells/g. This value, however, turned out to be 1 to 2 orders greater when the bacterial population was evaluated by the luciferin–luciferase method. We succeeded in identifying 12 bacterial genera; however, this number may be increased in the course of further studies. Some preventive measures to control the biodeterioration of stone heritage are discussed.     

Biodegradation of Diesel Fuel in Soil Under Various Nitrogen Addition Regimes

Bioremediation is a growing technology for treating fuel-contaminated soils. Many biological, physical, and chemical parameters control the rate and efficiency of this process, including type and concentration of contaminants, temperature, oxygen content, and nutrient status. This study investigated the effect that nitrogen sources and concentrations had on the degradation rate of diesel fuel in nutrient limited soil at two carbon-to-nitrogen ratios. The different sources of nitrogen studied were ammonium nitrate, ammonium sulfate, potassium nitrate, urea, and urea oligomers (control release fertilizer). Laboratory experiments were conducted on field-contaminated soil using sealed bioreactors at a controlled temperature of 25°C. For both carbon-to-nitrogen ratios tested, hydrocarbon degradation rates were the highest for the ammonium sulfate (20:1 at 0.032?d^?1; 40:1 at 0.019d^?1) and urea treatments (20:1 at 0.025?d^?1; 40:1 at0.011?d^?1). A degradation rate correlation as a function of nitrate and ammonia concentrations was developed. The correlation suggests the occurrence of nitrate inhibition at elevated nitrate concentrations.     

Inhibition of bacilli in industrial starches by nisin

The properties of Bacillus coagulans and of other bacilli that contaminate paper and paperboard manufacturing processes were investigated under simulated industrial conditions. Nisin (0.05 to 0.125 μ2g ml⁻¹) blocked growth of indigenous bacilli that contaminate sizing starches. B. coagulans starch isolates, B. licheniformis, B. amyloliquefaciens, and B. stearothermophilus grew at ≥250C in industrial starch and produced α2-glucosidase and cyclodextrins. The industrial isolates and reference strains of B. amyloliquefaciens, B. cereus, B. coagulans, B. flexus, B. licheniformis, B. pumilus, B. sporothermodurans, B. stearothermophilus and Alicyclobacillus acidoterrestris were inhibited by ≤20.125 μ2g of nisin on agar. B. coagulans and B. stearothermophilus were similarly inhibited by ≤20.025 μ2g of nisin ml⁻¹ and by 3 μ2g of the biocide DBNPA ml⁻¹ in industrial starch. B. licheniformis and B. amyloliquefaciens strains were less sensitive. About 40% of nisin added to starch was retained after cooking. Fifty percent of the nisin remained active after 11 h of storage at 60C. The results show that nisin has potential as a preservative for modified industrial starches. Journal of Industrial Microbiology & Biotechnology (2001) 26, 107–114. Received 22 May 2000/ Accepted in revised form 05 November 2000     

生物柴油的应用研究进展

综述了国内外生物柴油的应用和生产现状,介绍了生物柴油的主要特性以及直接混合、微乳液、高温热裂解、化学酯交换、生物酶催化和超临界甲醇法等生产生物柴油的方法,阐述了我国发展生物柴油的重要意义,并提出了我国发展生物柴油技术的建议。     

Uncertainty Analysis in Biofuel Systems

This article evaluates the implications of uncertainty in the life cycle (LC) energy efficiency and greenhouse gas (GHG) emissions of rapeseed oil (RO) as an energy carrier displacing fossil diesel (FD). Uncertainties addressed include parameter uncertainty as well as scenario uncertainty concerning how RO coproduct credits are accounted for (uncertainty due to modeling choices). We have carried out an extensive data collection to build an LC inventory accounting for parameter uncertainty. Different approaches for carbon stock changes associated with converting set‐aside land to rapeseed cultivation have been considered, which result in different values: from ?0.25 t C/ha.yr (carbon uptake by the soil in tonnes per hectare year) to 0.60 t C/ha.yr (carbon emission). Energy renewability efficiency and GHG emissions of RO are presented, which show the influence of parameter versus scenario uncertainty. Primary energy savings and avoided GHG emissions when RO displaces FD have also been calculated: Avoided GHG emissions show considerably higher uncertainty than energy savings, mainly due to land use (nitrous oxide emissions from soil) and land use conversion (carbon stock changes). Results demonstrate the relevance of applying uncertainty approaches; emphasize the need to reduce uncertainty in the environmental life cycle modeling, particularly GHG emissions calculation; and show the importance of integrating uncertainty into the interpretation of results.     

一株高产表面活性剂的南极土地杆菌的分离及其特性

【背景】生物表面活性剂具有毒性低、生物兼容性好和可降解等优点,是化学表面活性剂的优良替代物。目前产生物表面活性剂的微生物多为常温菌,从低温环境中挖掘高产新型生物表面活性剂的生产菌株具有重要的意义。【目的】从南极土壤中筛选产表面活性剂的低温微生物,对其表面活性剂进行纯化和结构解析并评估其性能。【方法】采用排油圈法对分离自南极菲尔德斯半岛土壤样品中的细菌菌株进行筛选,获得一株在菌苔表面产白色固体颗粒的菌株,对菌株进行形态观察和16SrRNA基因序列分析以确定该菌株系统发育地位。利用高效液相色谱法(high performance liquid chromatography, HPLC)分离产物,并用核磁共振波谱(nuclear magnetic resonance,NMR)技术对产物的化学结构进行鉴定。采用单因素试验和响应面设计方法对发酵培养基进行优化。此外,对产物的乳化性能及其对柴油的降解能力进行评估。【结果】得到了一株高产生物表面活性剂的耐冷土地杆菌属(Pedobacter)GW9-17,其最优发酵培养基(g/L)组成为：可溶性淀粉18.0、胰蛋白胨9.0、C3H3NaO3 4.4、K...     

Evidence that dirty electricity is causing the worldwide epidemics of obesity and diabetes

The epidemics of obesity and diabetes most apparent in recent years had their origins with Thomas Edison’s development of distributed electricity in New York City in 1882. His original direct current (DC) generators suffered serious commutator brush arcing which is a major source of high-frequency voltage transients (dirty electricity). From the onset of the electrical grid, electrified populations have been exposed to dirty electricity. Diesel generator sets are a major source of dirty electricity today and are used almost universally to electrify small islands and places unreachable by the conventional electric grid. This accounts for the fact that diabetes prevalence, fasting plasma glucose and obesity are highest on small islands and other places electrified by generator sets and lowest in places with low levels of electrification like sub-Saharan Africa and east and Southeast Asia.