1 DECEMBER 1999
Sent: November 24, 1999
From: <schippg@ozemail.com.au>
To: <AQUA-L@killick.ifmt.nf.ca>
QUESTION:
I am seeking information from people who have experience/ knowledge of continuous microalgal culture systems. The type of system I have in mind (have heard of these operating in some parts) is a clear polycarbonate culture vessel linked to an incoming seawater supply that passes through a pasteurizer. Nutrients are also added through a sterile system.
If anyone has experience (good or bad) with such a system or similar or can suggest something better, I would be interested in hearing from you. We have a daily requirement of between 20 and 100 litres of each of up to five species of algae for our experimental work. We currently use 300 l bag cultures on a batch culture system.
Glenn Schipp
Darwin Aquaculture Centre
GPO Box 990
Darwin NT 0801
Australia
Tel: +61 8 89244260
Fax: +61 8 89244277
mobile: 0417 851 380
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COMMENTS 1:
In principle that is the way we operate the BIOCOILs for periods of up to 200 days continuously. The keys are
(1) good mixing
(2) ability to keep out contaminants long-term (the MAJOR problem)
(3) ways to reduce sticking and/or localised build-up of algae.
Michael Borowitzka
School of Biological Sciences & Biotechnology
Murdoch University
Perth, W.A. Australia 6150
Tel: +61 8 9360 2333
Fax: +61 8 9360 6303
E-mail: borowitz@possum.murdoch.edu.au
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COMMENTS 2:
Contact Gary Wickfors at the National Marine Fisheries Service Lab at
Milford, Connecticut Phone 203-783-4225 or 203-783-4200.
Someone at Harbor Branch Oceanographic Institute in Florida (Russian woman... name escapes me now) has used continuous coils of transparent tubing to culture marine algae monocultures. Gary Wickfors knows of her work. I have a few choice ideas on a similar system using special gas exchange tubing developed by NASA.
K.Rusch, R. Malone, and T. Pfeiffer at Louisiana State University
Engineering Department use several approaches to continuous algal culture, including the HISTAR system ( Hydraulically Integrated Serial Turbidostat Algal Reactor) and a computerized integrated algal turbidostat in a recirculating upwelling system for the culture of clams.
Ted
E-mail: ground@thrifty.net
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COMMENTS 3:
There is also an industrial-scale continuous algal production system design based around pre-sealed polythene bags and pasteurization of incoming water, which works very well for most hatchery-cultivated species. The design isn't mine .... it belongs to John Bayes of Seasalter Shellfish (Whitstable, UK) .... but I have used it to good effect on several sites, now for many years. The output which you describe, Glenn, is quite small; but I'm sure the equipment could be scaled down to your requirement.
If interested in purchasing the design/technology, I suggest you ...... or anyone else who's interested ...... get directly in touch with Mr Bayes at seasalter@compuserve.com
As far as using continuous algal production technology is concerned, by far the greatest advantage is labour saving. Instead of re-inoculating each unit of production volume every 5-10 days, properly functioning systems only need reinoculation every 100 days or so, yielding major saving on pre-inoculum preparation and washing up. (I haven't ever tried to keep a bag going for 200 days, but I feel it in my bones that I might be pushing my luck if I did.) Depending on the design of the system, you either have to empty and strip down the whole thing before re-inoculating, or you can do it progressively (say, 5%-10% every week) whilst keeping the remaining 90%-95% working at full capacity. As you rightly state, Michael, the key to success is keeping the contaminants out, long term, but this is eminently feasible as has been demonstrated by the successful operation of various systems and designs across the world.
I'm not going to beat the drum about any system in particular, since I don't think this is either the time or the place; but as a general observation, I really don't understand why so many commercial hatcheries persist in using batch culture methods for algal production.
Tony Broadhurst
E-mail: karenb@santandersupernet.com