Are these clumps dead phytoplankton?

[leonardomanzano]

I left this gallon of phytoplankton outside in the sun (~80 F), when I first took it out there were small particles at the bottom which would form if the phyto is left with no movement,
later today When I got home I went to shake it again and these large clumps had formed while I was gone, what exactly are they?
bacteria? dead phyto?

is this normal? or should I filter it out and start again?
can I reuse the saltwater? or is it contaminated?

I have viciously shaken the jug but they keep coming back

 

[leonardomanzano]

quick update, I added airline tubing and connected it to an air pump and let it do its thing instead of shaking the jug.
The particles are now smaller than what you see in the picture but they are still present.

I took a look at one of the cultures that were exclusively cultivated indoors and those particles are not visible at least not to my eyes.

I have tried looking online for contaminated cultures and unfortunately, I am mainly seeing text posts and none that have pictures.

The culture doesn't smell rotten or dying, it smells like healthy/alive algae exposed to air
or like one of those open air aquarium places on the coast where you can interact with the starfishes


as of right now I believe those clumps might be dead phyto as I left them in direct sunlight for a few hours at 70-80F
I will let the culture stay in its current bottle overnight and take a look at it in the morning.




at this rate, I'd rather not risk losing the whole culture so I will split it tomorrow and hopefully get some healthy phyto water in the new jug and see if clumpy culture dies or not.

 

[Kasrift]

quick update, I added airline tubing and connected it to an air pump and let it do its thing instead of shaking the jug.
The particles are now smaller than what you see in the picture but they are still present.

I took a look at one of the cultures that were exclusively cultivated indoors and those particles are not visible at least not to my eyes.

I have tried looking online for contaminated cultures and unfortunately, I am mainly seeing text posts and none that have pictures.

The culture doesn't smell rotten or dying, it smells healthy/alive algae exposed to air
or like one of those open air aquarium places on the coast where you can interact with the starfishes


as of right now I believe those clumps might be dead phyto as I left them in direct sunlight for a few hours at 70-80F
I will let the culture stay in its current bottle overnight and take a look at it in the morning.




at this rate, I'd rather not risk losing the whole culture so I will split it tomorrow and hopefully get some healthy phyot water in the new jug and see if clumpy culture dies or not.

I can’t answer exactly what those are, but from my experience culturing, phyto clumps without agitation. It could be alive and just clumping, as you mentioned adding a bubbler reduced the clumps.

 

[leonardomanzano]

I can’t answer exactly what those are, but from my experience culturing, phyto clumps without agitation. It could be alive and just clumping, as you mentioned adding a bubbler reduced the clumps.

Hopefully thats the case, I find it a bit weird how all those clumps formed in a matter of a few hours.
this jug has been outside for 3 days now and in those past few days your standard small dust like particles gathered at the bottom so when I came back to this I assumed the worst.

I'll see how it looks and smells tomorrow and decide from there

 

[biophilia]

Some species of phytoplankton settle out quicker than others without vigorous agitation. Ideally you want them in a somewhat conical shaped container so that anything that settles is concentrated into one spot that has heavy aeration to break it back up. This is probably a mixture of dead cells and live cells, but mostly live. Nanochloropsis parent stock used to re-seed cultures will settle out routinely, but does fine if shaken vigorously twice per day or so to keep it in suspension.

If you left it outside (or inside) unsealed it is contaminated and will eventually crash (or co-culture with something else). You can probably keep it going for a while though by splitting the culture and keeping it properly aerated.

 

[DaJMasta]

What phyto?

I've had some that can create a sort of film that can collect on the sides and surface (porphyridium, not this one), I've had some that can settle on the bottom especially in low agitation (tetraselmis), and I've had a dark, intensely green algae that grows as a contaminant on the side of my culture bottles that can break off and float.

At least in the case of the last one, it does smell quite foul after a few days of sitting after harvest - it settles and rots - but when in a growing culture (with light and aeration), there's no particular smell.

I'd remove some with a clean utensil or just collect some in a different vessel when you harvest it. If it's colored, it's likely photosynthetic and a growing contaminant, but if it's relatively clear or only barely colored, I'd say it's likely a bacterial contaminant film of some sort. Depending on the phyto species, there's some possibility it's the phyto itself clumping, but I think it's unlikely.

 

[Kasrift]

Some species of phytoplankton settle out quicker than others without vigorous agitation. Ideally you want them in a somewhat conical shaped container so that anything that settles is concentrated into one spot that has heavy aeration to break it back up. This is probably a mixture of dead cells and live cells, but mostly live. Nanochloropsis parent stock used to re-seed cultures will settle out routinely, but does fine if shaken vigorously twice per day or so to keep it in suspension.

If you left it outside (or inside) unsealed it is contaminated and will eventually crash (or co-culture with something else). You can probably keep it going for a while though by splitting the culture and keeping it properly aerated.

Oh, this is really smart and I never thought of that. Hmm. I use the Poseidon Reef culture vessels and have been doing it for a year, great culturing but you are right some doesn’t agitate and settles at the bottom. Since that system uses a bag, now I’m thinking of using a small bottle (like a plastic bubble bottle from my kiddo) outside the plastic bag to make a cone like you stated and have the rigid straw for the bubbler in there, that way nothing settles in the corners.

 

[leonardomanzano]

What phyto?

I've had some that can create a sort of film that can collect on the sides and surface (porphyridium, not this one), I've had some that can settle on the bottom especially in low agitation (tetraselmis), and I've had a dark, intensely green algae that grows as a contaminant on the side of my culture bottles that can break off and float.

At least in the case of the last one, it does smell quite foul after a few days of sitting after harvest - it settles and rots - but when in a growing culture (with light and aeration), there's no particular smell.

I'd remove some with a clean utensil or just collect some in a different vessel when you harvest it. If it's colored, it's likely photosynthetic and a growing contaminant, but if it's relatively clear or only barely colored, I'd say it's likely a bacterial contaminant film of some sort. Depending on the phyto species, there's some possibility it's the phyto itself clumping, but I think it's unlikely.

I beleive it is a 4-blend solution so as of right now I am not sure which is the dominant one
Unfortunately, I threw away the container it came in weeks ago so I am not entirely sure what those 4 are.

when it came to the contamination in the tetraselmis culture was it a tan-colored mold/flakey thing?

I had that happen to one of my cultures a while back, the culture in the mason jar is also the same type of phytoplankton I used for the culture in the gallon jug
Here's a picture of the mold thing.

This culture was an experimental culture, I kept this culture alive in a mason jar using a magnetic stirrer and LED lights.
it did pretty well, that mold-like thing appeared about 3 weeks in.
for air exchange, I used the same filter paper that you would use to keep a mycelium culture safe from contaminants
I likely introduced this from the many times I opened up the container to take some phyto out.


If there are still clumps tomorrow I will definitely take some out and put them under a microscope and check it out.

 

[DaJMasta]

Color wise, I'd say it's probably some sort of bacterial mat, but a microscope could probably tell you.

It doesn't seem like multi-species culturing stays that way particularly well, and it's going to make it somewhat harder to diagnose, and as you indicate it's likely one will mostly win out within a few harvests.

Also worth mentioning: in my experience, gas exchange is very important when optimizing for growth rate and culture density, so I'd replace the magnetic stirrer with some rigid airline and a pump. Less parts to clean/power consumption/better scalability to more cultures probably, too.

 

[leonardomanzano]

Color wise, I'd say it's probably some sort of bacterial mat, but a microscope could probably tell you.

It doesn't seem like multi-species culturing stays that way particularly well, and it's going to make it somewhat harder to diagnose, and as you indicate it's likely one will mostly win out within a few harvests.

Also worth mentioning: in my experience, gas exchange is very important when optimizing for growth rate and culture density, so I'd replace the magnetic stirrer with some rigid airline and a pump. Less parts to clean/power consumption/better scalability to more cultures probably, too.

I will personally have to disagree with some of the points you made,

In the mason jar experiment there wasn't anything I had to clean as I only exported the culture and added new saltwater.
But after a while the lid started to oxidize due to me getting water on the lid.

I was able to induce high air exchange by setting the stirrer to a high rate where the whirlpool would introduce a lot of air through the bottom but I decided against this as I felt like the movement was way too much.

I would still be using this method but I left this outside and it killed my stirrer as it rained overnight :/

for the culture density It was pretty low as the LEDs I used were very cheap the picture of the jar was from when I was using LEDs. The density was higher once I started leaving it outside though.