What is the type of agitation used in microalgae photobioreactors?
The agitation used in the photobioreactors is SALT, a spiral vertical movement created by an AirLift. This agitation is gentle and does not use pumps or screw propellers. SALT is induced by specific hydrodynamics linked to the patented shape of our photobioreactors.
This spiral agitation fosters gas exchanges (carbon input and O2 degassing), makes the culture medium homogeneous, and optimises access to light. It is also energy efficient.
I currently use tanks. How many PBRs do I need to replace my production?
The number of tanks that a SALT PBR can replace will depend on your current concentration and on the volume harvested.
Let’s take as an example a culture with the microalga Tisochrysis, which is widely used in aquaculture.
A 285 L JUMBO produces a concentrated culture at 80M cells per ml, diluted at 20% every day, giving a fresh medium of 57 L per day, which results in 4,560 “algae units” per day.
Let’s consider a 300 L tank, which produces a concentrated culture at 5M cells per ml, and grows over 5 days, which results in 300 “algae units” per day.
The ratio between a JUMBO and a tank is 15.2.
In addition, it is necessary to take into account the whole process of assembly and scaling up to inoculate the tanks, which demands a lot of human time (transplanting) and the use of many containers (conical flasks, round-bottom flasks, etc.).
In conclusion, a JUMBO (285 L) replaces 15.2 300 L tanks + 15.2 30 L tanks + 15.2 2 L round-bottom flasks + 15,2 0.25 L conical flasks. It means 285 L of culture and 1 container against 5,019.8 L and 60.8 containers.
We carry out audits to provide you with a more precise comparison between your current production and a production with a SALT photobioreactor.
What do I need to put a PBR into operation?
SALT PBRs must be provided with:
– Electricity for the light and the control system
– Air to agitate the culture
– Salt or fresh water depending on the strain
– A starting strain
– A suitable environment
I work in a very saline environment, are your PBRs resistant to this type of environment?
Yes, our PBRs are made of materials resistant to saline environments, such as anodised aluminium, PMMA, and 316 L stainless steel probes, etc.
What type of air is required?
In order for the spiral agitation to be functional, air is required. The air must be as “clean” as possible. Check that there is no water or oil in your air networks or compressor. A compressed air supply is preferred, minimum of one bar. We offer air kits (booster and compressor), if required.
What is the warranty on the PBRs?
The standard warranty is one year for the parts based on normal use of the photobioreactor.
It can be extended to two years.
Microalgae: compatibility, optimisation of cultures
Does your technology affect the physico-chemical parameters of the algae?
We, as equipment manufacturers, have not carried out tests in that respect. However, our clients working in hatcheries have made comparisons between microalgae produced in SALT photobioreactors and those produced in tanks (or traditional cultures). They have not observed any differences. Larvae had an appetite for both microalgae cultivated in PBRs and those cultivated in tanks. And no differences were noted in terms of transplants either.
On the contrary, if your goal is to vary the physico-chemical parameters of microalgae, you can change the culture parameters in that respect.
Can we cultivate fragile microalgae (which cannot withstand agitation)?
This technology has been developed specifically for the culture of fragile microalgae and, in particular, T-Iso, which is a shear-sensitive flagellated microalga. Thanks to gentle agitation, we can cultivate many different species of microalgae. If you have any concerns, we offer an in situ test service.
How do I know if the strain that I wish to cultivate is compatible with your SALT technology?
We have a database that validates a dozen strains.
For those that have not yet been tested, we offer to test your microalgae in our equipment prior to your project. Such tests are carried out in our laboratory in a SALT photobioreactor. We will provide you with a complete report of the concentrations and productivities achieved. Ask us for a quotation for this service!
Are the machines optimised for salt water and freshwater microalgae?
You can cultivate salt water, brackish water, and freshwater microalgae. For example, you can grow an Isochrysis culture in salt water, a Chlamydomonas culture in fresh water, and then Spirulina in brackish water.
Can I cultivate in mixo- or heterotrophy?
Our photobioreactors are designed for cultivation in autotrophy, therefore they are equipped with LEDs. Some of our users have already successfully used them for heterotrophy.
I have excess waste heat/CO2, can I make use of this with microalgae?
Microalgae can be a solution for making use of your waste, such as excess CO2, waste heat, or water rich in nitrates, phosphates, etc.
For microalgae to develop in autotrophy, they need CO2, nutrients (potassium, phosphorus, azote, etc.), water, light, and some of them need heat.
Culture monitoring: biomass strain, microalgae harvest
What is the quantity of strain that is needed to start a culture?
The volume will depend on the concentration of inoculum that you have, the strain, and the photobioreactor that you use.
In general terms, our photobioreactors make it possible to start cultures with small quantities of inoculum, in particular due to the precise management of light intensity.
Should I choose a batch or a continuous culture?
You can do both, and even all four modes: batch, fed-batch, semi-continuous, continuous. All our photobioreactors allow it. It is up to you to choose and use the programmes to help you to carry out your culture according to the chosen mode.
How does harvesting work?
A hose links the growth chamber to the carboy or harvesting tank. The gas and the harvest exit via this hose, called the overflow hose. Since the usable volume is almost the same as the volume of the reactor, there is an overflow effect when there is a supply of fresh medium. Therefore, if you put in new medium, for example 1 L, you will harvest 1 L of culture by overflow.
You can use two modes: semi-continuous (emptying then filling) or continuous (continuous liquid flow). You use peristaltic pumps to add the new medium, either manually or automatically. You enter the volume of new medium that you want to add. The harvest will pass through the overflow hose to fall into the carboy or harvesting tank.
Harvesting refers to microalgae mixed with their culture medium. The separation takes place after the harvesting stage and using other (centrifuge type) tools. We do not intervene in treatment solutions (post-harvesting).
For batch cultures, harvest your culture by emptying your reactor entirely at the end of your batch.
Which measures should I take to secure my production?
In order to avoid all contaminants coming from the inputs, it is recommended to filter or autoclave the water and nutrients. If you choose to filter them, it must end at 0.2 μm.
To filter air, we provide 0.2 μm filters.
We can advise you on filtration. Just ask for our help.
Can I take samples/specimens during cultivation?
Yes, either with the support of peristaltic pumps or valves designed for sample collection.
Proposed services: installation, training, after-sales service
How to install the equipment?
Installation is very simple. It can be done by you or by our microalgae project manager at the same time as training (in the case of on-site training).
Our assembly teams take care of the installation of JUMBO.
Is there training prior to use?
Training is provided by our microalgae project manager before you use the equipment for the first time. It can either be done on-site or remotely (video). It is divided into two parts: theoretical and practical training. The training content and duration can be adapted to your needs.
What after-sales services do you provide?
All of our equipment has a one-year warranty for parts and labour after installation. It is possible to extend the warranty.
Furthermore, our microalgae project manager remains at your disposal by telephone and email for 2 months after training. If necessary, follow-up can be extended after 6 months with a second day of training to revisit certain concepts.
An annual check-up can be made, in the form of an audit to check the status of the photobioreactor. We will advise you if there are parts that need to be renewed/changed.
To conclude, you will be informed of all software, PBR, and booklets/protocols updates. By integrating a Synoxis algae PBR, you also become part of the Synoxis algae community!
We defined different packages (standard, comfort, tranquillity, serenity) to accompany you during the integration of your photobioreactor. Ask us!
Can you deliver the equipment anywhere in France? And abroad?
Yes, we can deliver the equipment anywhere in France. We also deliver abroad, even if you live on an island!
Maintenance and cleaning: sterilisation protocol, machine maintenance
Which are the cleaning and sterilisation protocols?
All PBRs can be dismantled for cleaning purposes. However, we have implemented the Cleaning in Place (CIP acid/base), for cleaning the equipment without disassembling it.
For sterilisation, we recommend bleach or a product based on acetic acid and hydrogen peroxide. Autoclaving is also possible for certain parts and for the autoclavable NANO.
All these protocols are detailed during training, along with the appropriate dosages.
In our simulations, we count five cleans a year, i.e., about once every 10 weeks. But we have clients who keep their culture for 6 months or more before starting a cleaning cycle. Here again, the number of cleaning cycles will depend on the strain and the culture method (one clean at the end of each culture).
How long does it take before restarting a culture?
For a NANO or a LUCY, cleaning, sterilising, and re-inoculating takes four hours.
For a JUMBO, the cycle of cleaning, sterilisation, and starting the culture takes between one and two days. The time will vary depending on your water flow.
How does maintenance work?
Our equipment requires little maintenance. We recommend changing the air filters, and the injection and harvesting hoses after 10 autoclaves, and the pH probe and certain
fittings after a year of usage. These recommendations are mentioned in the user manuals.