Remove biofilms, make food safer

The following news brief is about a book dealing with food hygiene, an important issue. It reminds me about last year's news stories in USA following the contamination of E.Coli.Microorganisms while residing on foodstuffs create a thin film on them. If we could remove the film, we can make foods safer.

K.S.Parthasarathy






Public release date: 27-Aug-2007


Contact: Phyllis Picklesimer
p-pickle@uiuc.edu
217-244-2827
University of Illinois at Urbana-Champaign
Banishing biofilms: loosening their grip could make food supply safer

If you could see a piece of celery that’s been magnified 10,000 times, you’d know what the scientists fighting foodborne pathogens are up against, said University of Illinois microbiologist Hans Blaschek.

“It’s like looking at a moonscape, full of craters and crevices. And many of the pathogens that cause foodborne illness, such as Shigella, E. coli, and Listeria, make sticky, sugary biofilms that get down in these crevices, stick like glue, and hang on like crazy.

“Scientists and people in the food industry are intensely interested in how these biofilms form and behave. Understanding how they work could lead to targeted approaches for their prevention and removal,” he said.

The sales figures for his new book Biofilms in the Food Environment certainly support that sense of urgency. Blaschek says the book contains the accumulated wisdom of academics who study biofilms and industry food scientists who battle them on the front lines daily.

According to Blaschek, the problem faced by produce suppliers can be a triple whammy. “If you’re unlucky enough to be dealing with a pathogen--and the pathogen has the additional attribute of being able to form biofilms—and you’re dealing with a food product that’s minimally processed, well, you’re triply unlucky,” the scientist said.

“You may be able to scrub the organism off the surface, but the cells in these biofilms are very good at aligning themselves in the subsurface areas of produce.

“Over time, the sticky cells of the biofilm form on top of each other, creating a microenvironment that behaves more like a multicelled organism. And all these little bacterial cells communicate with each other. They’re fascinating really; unfortunately, they can also be deadly,” he said.

Blaschek says the biofilms book has generated a lot of interest from the food industry. “It’s really a comprehensive reference source for industry scientists, university researchers, and regulatory agencies. In particular, food engineers who design strategies and cleaning procedures for produce need to understand how biofilms form and behave so they can develop better protocols for removing them,” he said.

“There’s an interesting discussion of the correlation between a strain’s virulence and its biofilm-forming abilities, information about cutting-edge technologies to investigate microbial compositions in biofilm ecosystems and cell-to-cell interaction, and updated findings on the molecular attributes and mechanisms involved in biofilm development,” he said.

“It’s a very applied kind of approach, connecting the research that’s being done in labs across the country with the needs of food technologists,” he added.
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Co-edited by Blaschek, The Ohio State University’s Hua H. Wang, and food industry scientist Meredith Agle, Biofilms in the Food Environment is available from Blackwell Publishing.

A U of I study on removal of Shigella biofilms by M. E. Agle, S. E. Martin, and H. P. Blaschek was published in volume 68, no. 5, of the Journal of Food Protection. Chapters by former U of I doctoral student Agle in Biofilms in the Food Environment are “Biofilms in the Food Industry” and “Shigella: Survival on Produce and Biofilm Formation.” Agle’s U of I research was funded by a fellowship from the USDA National Needs program.

US nuclear neighbours no more NIMBY

Public started looking at nuclear power plants more benignly now according to a survey commissioned by the Nuclear Energy Institute, a nuclear power advocacy group in USA.
Dr K.S.Parthasarathy

WNN
World Nuclear News

NUCLEAR POLICIES
US nuclear neighbours not nimby

21 August 2007

Eighty-two per cent of people living close to US nuclear power plants are in favour of nuclear energy and 71% would be willing to see a new reactor near them, a new public opinion survey has found.

The telephone survey polled 1100 adults across the USA, all living within 10 miles (16 km) of a nuclear power plant but not employed by electric companies. Eighty-six per cent of respondents gave their local nuclear plant a 'high' safety rating and 87% declared their confidence that the operating company could run the plant safely.

The survey was carried out by Bisconti Research, whose president Ann Bisconti noted: "Nimby (not in my back yard) does not apply at existing plant sites because close neighbours have a positive view of nuclear energy, are familiar with the plant, and believe that the plant benefits the community."

When faced with the question: "If a new power plant were needed to supply electricity, would it be acceptable to you... to add a new nuclear reactor at the site of the nearest nuclear power plant?" 71% of all respondents said it would be acceptable. Twenty-six per cent felt it would not be acceptable and three per cent voted 'don't know'. These figures changed to 77% in favour and only 20% against in communities where steps are already underway to build new reactors.

The strong support for new reactors among residents already living near nuclear plants was welcomed by Scott Peterson, Vice President for Communications at the Nuclear Energy Institute (NEI), the US nuclear industry policy organization. "This bodes well for the prospect of new plant construction, particularly for those companies considering adding new reactors at existing nuclear plant sites," he said.

The survey, which included adults living near each of the 64 nuclear power plant sites in the USA, was commissioned by the NEI, and comes at a time when US power companies are embarking on a new regulatory process for licensing new plants. Seventeen companies have announced plans to file licence applications for up to 31 reactors to be built over the next 10-15 years. Four applications for Early Site Permits (ESP) have already been submitted to the US Nuclear Regulatory Commission (NRC), all to assess the suitability of existing reactor sites for possible new construction projects. The NRC received the first part of the construction and operating licence (COL) application for a new reactor at the Calvert Cliffs site in Maryland in July and anticipates up to another seven applications covering 12 units by the end of 2007.

Further information

Nuclear Energy Institute
US Nuclear Regulatory Commission

WNA's US Nuclear Power Industry information paper

WNN: NRC: First part of COL application in

Thin layer solar cell will bring cheaper "green" power

SOLAR POWER

Scientists believe that thin-layer PV cells would be used to make solar panels that could be fitted to roofs to help power homes with any surplus electricity being fed back to The National Grid. If successful it will lead to cheaper electric power and less reliance on fossil power technology

K.S.Parthasarathy
Public release date: 23-Aug-2007
Contact: Alex Thomas
media.relations@durham.ac.uk
01-913-346-075
Durham University
'Thin-layer' solar cells may bring cheaper 'green' power

Scientists are researching new ways of harnessing the sun’s rays which could eventually make it cheaper for people to use solar energy to power their homes.

The experts at Durham University are developing light-absorbing materials for use in the production of thin-layer solar photovoltaic (PV) cells which are used to convert light energy into electricity.

The four-year project involves experiments on a range of different materials that would be less expensive and more sustainable to use in the manufacturing of solar panels.

Thicker silicon-based cells and compounds containing indium, a rare and expensive metal, are more commonly used to make solar panels today.

The research, funded by the Engineering and Physical Sciences Research Council (EPSRC) SUPERGEN Initiative, focuses on developing thin-layer PV cells using materials such as copper indium diselenide and cadmium telluride.

Right now the project is entering a new phase for the development of cheaper and more sustainable variants of these materials.

The Durham team is also working on manipulating the growth of the materials so they form a continuous structure which is essential for conducting the energy trapped by solar panels before it is turned into usable electricity. This will help improve the efficiency of the thin-layer PV cells.

It’s hoped that the development of more affordable thin-film PV cells could lead to a reduction in the cost of solar panels for the domestic market and an increase in the use of solar power.

Solar power currently provides less than one hundredth of one percent of the UK’s home energy needs.

The thin-layer PV cells would be used to make solar panels that could be fitted to roofs to help power homes with any surplus electricity being fed back to The National Grid.

This could lead to cheaper fuel bills and less reliance on burning fossil fuels as a way of helping to generate electricity.

Professor Ken Durose, Director of the Durham Centre for Renewable Energy, who is leading the research, said: “One of the main issues in solar energy is the cost of materials and we recognise that the cost of solar cells is slowing down their uptake.

“If solar panels were cheap enough so you could buy a system off the shelf that provided even a fraction of your power needs you would do it, but that product isn’t there at the moment.

“The key indicator of cost effectiveness is how many pounds do you have to spend to get a watt of power out"

“If you can make solar panels more cheaply then you will have a winning product.”

To aid its research the university has taken delivery of a £1.7 million suite of high powered electron microscopes, funded by the Science Research Investment Fund, which have nano-scale resolution allowing scientists to see the effects that currently limit the performance of solar cells.

One of the microscopes is the first of its kind in the UK and Professor Durose said: “This instrument will put the North East right out in front.

“We are working on new ideas in renewable energy and this opens up tremendous opportunities in research.”

Durham, Newcastle and Northumbria universities, The New and Renewable Energy Centre (NaREC), in Blyth, and the Centre for Process Innovation (CPI), in Wilton, have formed a consortium to bid to host the Energy Technologies Institute (ETI) in the North East.

The Consortium bidding to host the Energy technologies Institute (ETI) in NorthEast England, has been named as one of three short-listed finalists to host the headquarters of this national centre, which will be responsible for the allocation of approximately £1bn of private and public research funds into renewable and low carbon energy.

The North East Consortium will now face competition from Scotland and the Midlands, at a final selection presentation in London on September 6th. Made up of representatives from industry sponsors and Government, the selection panel will then make their recommendation to the ETI board, with the host location to be formally announced in early October.

Mark Pearson Energy and Process Innovation Manager at One NorthEast, a member of the ETI bid team commented: “This announcement by Durham University highlights the strength in depth we have in energy research and development in the North East, and the opportunities and change this can generate in our regional economy and built environment.

“Our bid to host the ETI recognises our capability across the region to make this initiative a success for the UK.”
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Net energy, a useless, misleading and dangerous metric, says expert

An original and thought-provoking concept from Professor Bruce Dale
K.S.Parthasarathy

Public release date: 8-Aug-2007
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Contact: Jennifer Beal
wbnewseurope@wiley.co.uk
44-012-437-70633
John Wiley & Sons, Inc.
Net energy -- a useless, misleading and dangerous metric, says expert

As oil becomes scarce, the world needs new transportation fuels. As new fuel options develop we need means of assessing which are most effective at replacing petroleum. So far many scientists have used a measure called ‘net energy’. However, Professor Bruce Dale from Michigan State University claims, “Net energy analysis is simple and has great intuitive appeal, but it is also dead wrong and dangerously misleading – net energy must be eliminated from our discourse.” Dale’s perspective is published in the first edition of Biofuels, Bioproducts and Biorefining.

Instead, Dale recommends comparing fuels by assessing how much petroleum fuel each can replace, or by calculating how much CO2 each produces per km driven.

A fuel’s ‘net energy’ is calculated by attempting to assess how much energy a new fuel supplies, and then subtracting the energy supplied by fossil fuels needed to create the new fuel. The calculation is often carried out in a way that leaves grain ethanol with a net energy of -29%, giving the impression that it uses more fossil fuels to produce it that the new fuel supplies. Dale claims that this figure is then used by opponents of biofuels to pour scorn on the new products.

The problem with net energy, says Dale, is that it makes an assumption that all sources of energy (oil, coal, gas etc) have equal value. “This assumption is completely wrong – all energy sources are not equal – one unit of energy from petrol is much more useful than the same amount of energy in coal…and that makes petrol much more valuable,” says Dale.

For evidence, he points to the markets, where a unit of energy from gas, petrol and electricity are worth 3.5, 5 and 12 times as much as a unit of energy from coal, respectively.

“Clear thinking shows that we value the services that energy can perform, not the energy per se, so it would be better to compare fuels by the services that each provides…not on a straight energy basis…which is likely to be irrelevant and misleading,” says Dale.

For example, biofuels could be rated on how much petroleum use they can displace or their greenhouse gas production compared with petroleum. His calculations indicate that every MJ of ethanol can displace 28 MJ of petroleum, in other words ethanol greatly extends our existing supplies of petroleum. Using corn ethanol provides an 18% reduction in greenhouse gasses compared with petrol, while fibre-produced ethanol gives a 88% reduction compared to petrol.

“As we embark on this brave new world of alternative fuels we need to develop metrics that provide proper and useful comparisons, rather than simply using analyses that are simple and intuitively appealing, but give either no meaningful information, or worse still, information that misleads us and misdirects our efforts to develop petroleum replacements,” says Dale.

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