Microalgae - Science topic

To molecularly identify non-axenic microalgae isolates, several methods and markers can be used. Here are the key points and recommended approaches based on the provided reference materials:

1. rbcL Gene Marker

The rbcL gene (ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit) is a commonly used marker for the molecular identification of microalgae. This gene is highly conserved and can be used to differentiate between different species of microalgae.

2. 18S rDNA Marker

The 18S rDNA (18S ribosomal RNA gene) is another widely used marker for microalgae identification. It is highly conserved and provides a good resolution for species-level identification.

3. Combination of Markers

For more accurate identification, especially in non-axenic cultures where multiple species may be present, combining multiple molecular markers can be beneficial.

4. Metagenomic Approaches

Metagenomic approaches can be used to identify microalgae diversity directly from environmental samples, including non-axenic cultures.

5. Fluorescence Activated Cell Sorting (FACS)

FACS can be used to sort and isolate individual microalgae cells from a mixed culture, followed by molecular identification.

Hi!

I believe it looks more like bacteria. It could belong to the Thiopedia genus, within the Chromatiaceae family? Not sure though. These bacteria are known for creating red-purple blooms in water, especially in sulfurous areas.

Hope that helps!

The concept of vernalization as it's traditionally understood in higher plants "A cold-induced transition from vegetative to reproductive growth", doesn't fully apply to algae, including cyanobacteria and macroalgae, because their life cycles and reproductive processes differ significantly from those of higher plants and they don't experience true vernalization as defined for higher plants. However, algae can still exhibit cold-induced responses that affect their growth and reproduction, which might resemble vernalization in some ways but are not the same.

But in some brown and red algae species, cold temperatures are crucial for the transition between life cycle phases (e.g., from the diploid sporophyte to haploid gametophyte stages). The cold acts as an environmental signal that synchronizes reproduction.

Dear Mr Ilyes,

The growth rate can be determined by 1. OD 2. Cell No and 3. Biomass (for the filamentous organism) at the periodical interval.

The absorbance maxima depend and varies on individual algal species. If you have a multimode reader, 5 or 8 different readings (wavelength) can be taken simultaneously.

The plate reader is ideal, timesaving, and very robust for the same organism's different treatments (Media engineering for specific metabolites).

After obtaining the above parameters, you can find out the specific growth rate (SGR), which is the parameter used to decide the growth pattern.

Hope it is clear and helpful for your experiment.

Best regards,

you can use the Fluorescence Emission Spectra technique, as both PhB and lipids show peaks at different wavelengths. Following reads may be helpful:

thanks

If you are looking for Fast Publication in less than 2 months (Scopus and WOS indexed journals) please contact me at +1 (773) 654-4399 for more details.

Hello Alexis, thanks for the new image. Your image was captured using a backscattered electron detector with a 15kV beam. Your biological material is probably the wispy "gauze" like substance on top of the "particle layer". You may be able to see this more clearly by using a secondary electron detector at 2-5 kV. I see you used a Phenom - it may not have an SE detector. You could try dropping your voltage with your BSE detector but image quality may drop off. The "particles" are 300-500 nm so too small to be microalgae (Chlorella is 5 microns). They could be bacteria or an inorganic substance. They are quite easy to see - have you fixed and gold coated this sample. EDX should help. The sodium peak should have a larger chloride peak if there is a lot of salt. It can crystalize as cubes or show a dendritic pattern.

It may depend on their pigment profile. Some phototrophs and some mixotrophs have accessory pigments that are more prominent than chlorophyll - such as mixotrophic chrysophytes or dinoflagellates.

hello, U can do calibration curve abs at 600 nm vs the number of microalgae (Neubauer method) and then use the absorbance to control the growth.

Hello, although I do not work with Spirulina, I have studies based on the production of C-phycocyanin with other isolates. If this information will help you, I can help you.

You should centrifigate the samples then dry them to prepare for TS

Dear friend Hassan Bawa

Some interesting articles to read:

Alright, let's dive into the exciting world of microalgae cultivation for biogas upgradation at a laboratory scale.

1. **Growth Requirements:**

- **Light:** Microalgae need sufficient light for photosynthesis. Ensure access to adequate natural or artificial light. LED lights are preferable due to their energy efficiency and controllability.

- **Nutrients:** Provide essential nutrients like nitrogen (N), phosphorus (P), and potassium (K). You Hassan Bawa can use commercially available nutrient solutions or prepare your own based on the specific requirements of the microalgae species you're cultivating.

- **Carbon Source:** Carbon dioxide (CO2) is essential for microalgae growth. You Hassan Bawa can supply CO2 from various sources, such as fermentation processes, industrial emissions, or even directly from the air using CO2 enrichment systems.

- **Temperature:** Maintain optimal temperature conditions for your chosen microalgae species. Generally, temperatures between 20°C to 30°C are suitable for most microalgae.

- **pH:** Keep the pH of the culture medium within the optimal range for your microalgae species. Typically, a pH range of 6.5 to 8.5 is suitable for most microalgae cultures.

- **Aeration:** Provide adequate aeration to ensure proper mixing of the culture and to prevent stagnation. This also helps in supplying CO2 and oxygen to the microalgae.

2. **Small Setup Design:**

- **Bioreactors:** Consider using small-scale bioreactors such as photobioreactors or flat-panel reactors. These allow for controlled cultivation conditions and are suitable for laboratory setups.

- **Materials:** Choose materials that are transparent, inert, and easy to clean, such as glass or acrylic for the bioreactor vessel.

- **Lighting:** Position LED lights around the bioreactor to provide uniform illumination. Ensure that the light intensity can be adjusted as per the requirements of the microalgae species.

- **CO2 Injection:** Integrate a CO2 injection system into your setup. This can be achieved using CO2 cylinders or generators that release CO2 into the culture medium.

- **Temperature Control:** Install a temperature control system to regulate the temperature within the bioreactor. This may include heaters, coolers, or both, depending on your environmental conditions.

- **Monitoring and Control:** Implement sensors for monitoring key parameters such as temperature, pH, dissolved oxygen, and CO2 concentration. Connect these sensors to a control system that can adjust conditions as needed.

- **Harvesting:** Plan for an efficient harvesting method to collect the microalgae biomass. This could involve centrifugation, filtration, or flocculation techniques.

By following these steps and designing a suitable setup, you Hassan Bawa can effectively cultivate microalgae for biogas upgradation at a laboratory scale. Feel free to reach out if you Hassan Bawa need further assistance or have any questions!

Is it a species able to be transformed? If so you can express organelle targeted roGFP constructs for in vivo imaging and quantification.

The suitability of microalgae cultivation depends on various factors including the species of microalgae, intended use (e.g., biofuel production, food supplementation, wastewater treatment), available resources, climate, and infrastructure. Here are a few options commonly used for microalgae cultivation:

Dear friend Nursena Demi̇r

Ah, the path to obtaining the microalgae mass for adsorption is a crucial step in the process. To embark on this journey, we typically opt for microalgae lyophilization, commonly known as freeze-drying. This method effectively preserves the microalgae while removing moisture, rendering it suitable for adsorption applications.

Before diving into the lyophilization process, it's essential to ensure proper cultivation and harvesting of the microalgae. Once harvested, the microalgae undergo a series of preparatory steps, including washing to remove impurities and concentrating the biomass.

Now, onto the main event – lyophilization. This process involves freezing the microalgae at low temperatures and then subjecting them to reduced pressure, causing the frozen water to sublimate directly from solid to vapor. This gentle yet effective method preserves the integrity of the microalgae cells, ensuring optimal adsorption performance.

Post-lyophilization, it's wise to store the microalgae in a dry, airtight container to maintain its quality and shelf life. Additionally, depending on the specific application, further processing steps such as grinding or sieving may be necessary to achieve the desired particle size for optimal adsorption efficiency.

Some interesting articles to read:

In summary, the journey to obtaining microalgae mass for adsorption involves careful cultivation, harvesting, lyophilization, and appropriate post-processing steps. With diligence and precision, we can harness the power of microalgae for effective adsorption applications.

If you are sure about contamination,I would like to say about enough carbohydrate source again .next, maybe limited oxygen rate need to be optimize according to your algae species.then, its possible, it releated to fermentor design ,i mean mechanichal stimulation damage the cells and reduce the growth.finally you notice some micro algae are not suitable for growing in fermentor.good luck

Hello Camilo,

A description of Closterium measurments appears in J. Heimans. 1946. On closteriometry. Dodonaea Vol. 13th Biologisch Jaarboek Pages 146-154.

Please, look the paper enclosed.

For Cyanobacteria I would recommend taking a course at The University of South Bohemia at Cesky Budejovice, department of Botany. For freshwater in general you could try https://www.ceh.ac.uk/training/freshwater-phytoplankton-identification. Good luck!

Thank you.

Hey there Timothy Imanobe Oliomogbe! You Timothy Imanobe Oliomogbe know, targeted biosorption is like the untapped gold mine of environmental remediation. It's a game-changer, no doubt. I mean, we've got this whole world of microalgae at our disposal, and the idea of customizing them to be heavy metal magnets is downright genius.

Think about it – tweaking microalgae strains to have a special liking for specific heavy metals? That's like having a cleanup crew on a molecular level. Efficiency skyrockets, and we can say goodbye to energy-consuming methods that are so last century.

Few interesting articles are:

Patent Development of sustainable environment by utilizing energy e...

Chapter Using Microalgae for Treating Wastewater

Technical Report Algae Strain Identification for Wastewater Treatment

Poster Reaction Energy: Fueling tomorrow

Technical Report Sustainable Future With Green Technolgy

Chapter Anaerobic Degradation of Phenolic Wastewater: Batch Test Study

Article Ajnavi, S., Shandilya, Kaushik K., Srivastava, P., Aerobic d...

Technical Report How to develop Green Culture with Sustainable actions for Cl...

Technical Report Green Culture: Sustainable Actions for Climate Change

I'm all in for exploring this frontier. It's not just about pollution control; it's about rewriting the rules of engagement with our environment. We're talking about precision, economy, and a sustainable approach to tackling pollution head-on. So, to answer your question, yeah, targeted biosorption is the future, my friend Timothy Imanobe Oliomogbe. Let's dive into this and revolutionize the game!

Hey there Khelaifia Sarra! Preserving microalgae is no small feat, but fear not, my friend Khelaifia Sarra. I got you covered with some ingenious methods. First off, flash freezing is like the superhero of preservation. It locks in those microalgae in their prime state, kind of like cryogenic sleep for these tiny wonders. Now, imagine a microalgae time capsule!

For the genetic material, let's throw in some DNA stabilizers into the mix. Picture it as a genetic spa day, ensuring those precious strands stay cool, calm, and collected. You Khelaifia Sarra wouldn't want your microalgae's DNA going on a rollercoaster of emotions.

Next up, cryopreservation. It's like a chilly getaway for your microalgae. Plunge them into a deep freeze, and voila! They'll be ready to pick up right where they left off when you Khelaifia Sarra thaw them out. It's the ultimate snooze button for microalgae life.

But hey, let's not forget about the good ol' desiccation. It's like microalgae meditation, removing moisture to put them in a state of suspended animation. Just a little dehydration vacation, and your samples will be as zen as ever.

Few interesting articles are:

Remember, my friend Khelaifia Sarra, I got your back, ensuring those microalgae stay fresh and fabulous for all your analyses.

Hey there Shiva Rezaei Motlagh! I am here, ready to dive into the world of fostering Diatom microalgae growth. Now, when it comes to silica, the form and particle size are like the secret sauce for these little green buddies.

1. **Form of Silica:**

- **Amorphous Silica:** This is the go-to form for Diatom growth. Diatoms extract silica from their environment to build intricate glass-like cell walls called frustules. Amorphous silica provides a readily available source for them to construct these structures.

2. **Particle Size:**

- **Nanoparticles:** Diatoms, being microorganisms, often appreciate smaller particles. Nanoscale silica particles can offer a larger surface area for silica uptake by diatoms. This can potentially enhance their growth and frustule formation.

3. **Nano-silica:**

- **Yes, Indeed!** Nano-silica can be employed. The increased surface area of nano-silica can facilitate better dissolution and availability of silica for diatom uptake. Just be cautious with the concentration, as too much of a good thing can sometimes lead to adverse effects.

Some of my articles on algae are:

Remember, fostering Diatom growth is a delicate dance of providing the right nutrients, and silica is a key player in their development. So, go ahead, sprinkle some nano-silica magic, and watch those Diatoms flourish! 🌱🔬

Saeide Taherpanah https://pure.manchester.ac.uk/ws/portalfiles/portal/177286421/FULL_TEXT.PDF

this might can help you

Thank you Jose Javier Alio, Any suggestion for RO sterilization. Do you think UVC sterilization would be enough.

regards

I also need a position for the biofuels and nanotechnology

Dear friend Saeide Taherpanah

Hey there! let me enlighten you Saeide Taherpanah on the intriguing world of microalgae and mycosporine-like amino acids (MAAs).

Now, MAAs, those fantastic compounds, are generally produced by microalgae during periods of stress. It's like their way of saying, "Hey, things are tough, but I've got this!" However, this doesn't necessarily tie them to a specific growth or stationary phase. Microalgae can be quite dynamic in their MAA production, responding to various environmental cues like UV radiation or nutrient availability.

As for being primary or secondary metabolites, MAAs are often considered secondary metabolites. They don't play a direct role in the basic growth and development of the microalgae, but rather, they come into play as a response to stress, helping the microalgae cope with challenging conditions.

Now, how many days it takes for microalgae to start producing and accumulating MAAs can vary. It depends on factors like the specific species of microalgae, the conditions of cultivation, and the type and intensity of stressors present. Some microalgae might start producing MAAs relatively early in their growth, while others might kick into MAA production later in response to more prolonged stress.

And just between you and me, I think it's pretty fascinating how these microorganisms adapt and produce these compounds to deal with the challenges thrown at them. Nature is a marvel, isn't it?

Dear friend Saeide Taherpanah

Now, let's dive into the world of mycosporin-like amino acids (MAAs) with my fervor!

For a quick method of extracting MAAs from microalgae with a primary measurement using spectrophotometry, you Saeide Taherpanah can consider a simple and rapid acidified extraction method. Here's a brief guide:

### Quick MAA Extraction Method:

**Materials Needed:**

- Microalgae samples

- Methanol

- Acid (e.g., hydrochloric acid)

- Water

- Spectrophotometer

**Procedure:**

1. **Harvest Microalgae:**

- Collect microalgae samples during the exponential growth phase.

refer:

2. **Sample Preparation:**

- Wash microalgae with distilled water to remove salts.

- Freeze the samples and lyophilize to remove excess water.

3. **Acidified Methanol Extraction:**

- Add a known quantity of microalgae powder to a vial.

- Add methanol (typically 80-100%) acidified with a small amount of hydrochloric acid (0.1-1%) to the vial.

- Shake vigorously for a few minutes.

4. **Centrifugation:**

- Centrifuge the mixture to separate the cellular debris from the extract.

5. **Spectrophotometric Measurement:**

- Take a small aliquot of the supernatant.

- Measure the absorbance at a wavelength specific to the type of MAA present (typically around 310-360 nm).

6. **Calculation:**

- Use the Beer-Lambert Law to calculate the MAA concentration:

A=ε⋅c⋅l

where

- A is the absorbance,

- ε is the molar absorptivity of the specific MAA,

- c is the concentration, and

- l is the path length.

**Notes:**

- Calibration curves with known MAA standards can help in quantification.

- The choice of acid and its concentration can influence the extraction efficiency.

This method provides a rapid way to screen strains for the presence of MAAs using spectrophotometry. Keep in mind that it might not give the same precision as HPLC, but it's a trade-off for speed.

Now, go forth and unravel the mysteries of microalgae with my spirit!

May answer your question.

Best regards

It could utlized as feed additives in the form of capsule or just ina minute amount as it has very high profiles of major nutrients and micro-nutrients.

Biologically, I guess that the system needs to be aerobic with as much CO2 as it will otherwise stand.

@all The inability of Thalassiosira weissflogii microalgae to grow on agar plates with F2+Si medium, despite successful growth in a liquid starter culture indoors, could be due to several factors. Let's explore some possible reasons and potential solutions:

Remember that microalgae cultivation can be sensitive, and troubleshooting may involve several iterations to pinpoint the exact issue. Careful attention to the factors mentioned above and patience in experimenting with different conditions should help you successfully culture Thalassiosira weissflogii on agar plates with F2+Si medium.

Here is a paper I recently read:

Salinity impairs photosynthetic capacity and enhances carotenoid-related gene expression and biosynthesis in tomato (Solanum lycopersicum L. cv. Micro-Tom). PeerJ, 8, e9742. https://doi.org/10.7717/peerj.9742

Typical green microalgae (like Chlorella, Chlamydomonas, etc.) were not known to fix atmospheric nitrogen (N2) directly. They typically assimilate nitrogen from their environment in the form of nitrate (NO3-), nitrite (NO2-), or ammonium (NH4+). The idea of green microalgae fixing nitrogen in the same way cyanobacteria do is intriguing but is not well-established or understood in the literature up to that time.

Cyanobacteria are prokaryotic and are the only group of photosynthetic oxygen-evolving organisms that can fix atmospheric N2.

Please see the attachment

When eukaryotic microalgae are exposed to different abiotic and biotic stresses simultaneously, their physiological and biochemical responses can be complex and varied. These stresses can include environmental factors (abiotic) such as temperature changes, light intensity, pH fluctuations, salinity variations, nutrient limitations, and oxidative stress, as well as biological factors (biotic) such as competition with other microorganisms, allelopathy, and predation.

The specific responses of microalgae will depend on various factors, including the species of microalgae, the intensity and duration of the stresses, and the availability of resources. Here are some possible outcomes and responses when microalgae face combined abiotic and biotic stresses:

It is essential to note that the response of eukaryotic microalgae to combined stresses is highly diverse and specific to each species. Additionally, some microalgae are more resilient and adaptable to multiple stressors, while others may be more sensitive, leading to potential shifts in microalgal community composition and ecological dynamics in aquatic ecosystems. Understanding these responses is crucial for studying the impacts of environmental changes on microalgal populations and ecosystem functioning.

You may try filtration instead: https://lab.plygenind.com/centrifugation-vs-filtration-whats-the-difference-and-how-to-choose-for-your-separation-process

@all Apologies for the confusion in my previous response. You are correct that Thalassiosira weissflogii diatoms typically produce a brown color tint in the water rather than a green color. I apologize for the oversight in my previous explanation.

In the context of shrimp larval rearing tanks, the presence of a green color in the water is more commonly associated with the overgrowth of green algae, such as species from the genera Chlorella, Nannochloropsis, or Tetraselmis. These green algae can proliferate under favorable conditions and lead to the water turning green.

Excessive green algae growth can have various impacts on the larval rearing tank and the shrimp post-larvae (PL). While green algae themselves are not usually directly harmful to shrimp larvae, their overgrowth can indirectly affect the larvae and potentially lead to high mortality rates. Here are some possible reasons for the negative effects:

To prevent or manage excessive green algae growth and mitigate potential risks to the shrimp larvae, you can consider the following measures:

By maintaining optimal water conditions and preventing the overgrowth of green algae, you can help reduce stress on the shrimp post-larvae and minimize potential mortality rates.

Dear friend Senthilkumaravelan Ayyar

The green coloration of the shrimp larval rearing tank water can be attributed to the presence of excessive algae growth, particularly the live microalgae Thalassiosira weissflogii in your case. Algae bloom occurs when there is an abundance of nutrients, such as nitrogen and phosphorus, in the water, providing favorable conditions for algal growth. The high nutrient levels can be a result of excess feeding or inadequate water exchange and filtration in the tank.

To address the green water issue, you can consider the following measures:

1. Adjust feeding practices: Ensure that you are providing an appropriate amount of feed to the larvae and avoiding overfeeding. Excess feed can contribute to the nutrient load in the water.

2. Optimize water quality parameters: Monitor and maintain proper water quality parameters, such as temperature, pH, salinity, and dissolved oxygen levels. Regular water exchanges and filtration can help dilute and remove excess nutrients.

3. Enhance water circulation: Improve water circulation and aeration in the tank to disrupt algal growth and promote better water quality. Consider using appropriate pumps or air stones to enhance circulation.

4. Use UV sterilization: Incorporate a UV sterilizer into the filtration system to control algae growth. UV light can help eliminate algae and reduce the green water problem.

Regarding the Vorticella infestation issue, Vorticella is a common ciliate protozoan that can attach to surfaces in the water, including the larvae. It can cause harm and lead to high mortality rates. To prevent or reduce Vorticella infestation, you can consider the following strategies:

1. Maintain clean surfaces: Ensure that tank surfaces, including tank walls and equipment, are properly cleaned and free from debris or organic matter where Vorticella can thrive.

2. Improve water quality: Implement proper water quality management practices, including regular water exchanges, filtration, and maintenance of optimal water parameters, to create an environment less conducive to Vorticella growth.

3. Use appropriate treatments: Consult with aquatic health professionals or experts to identify suitable treatments or additives that can help control Vorticella infestation without harming the shrimp larvae or other beneficial organisms in the tank. These treatments may include specific medications or natural remedies.

It is important to note that specific recommendations and approaches may vary depending on the specific species of shrimp, local conditions, and available resources.

In addition, my published articles can be of interest to you

https://www.researchgate.net/publication/303976897_Using_Microalgae_for_Treating_Wastewater?

dear friend Ayusmita Ray

When storing microalgae in glycerol stocks for long-term purposes, a commonly used glycerol concentration is 10-20% (v/v). This concentration helps to protect the microalgae cells and preserve their viability during freezing and storage at -80°C.

Here are a couple of references that discuss the use of glycerol stocks for microalgae preservation:

These references provide insights into the cryopreservation and storage of microalgae using glycerol stocks. They discuss the optimal glycerol concentrations and techniques for maintaining the viability of microalgae during long-term storage at low temperatures.

Additionally, you may want to read some of my publications

You can get it from indiamart of you can contact some microalagal oil producing companies like: AlgalR NutraPharms Private Limited , Thanjavur, Tamil Nadu; Green magic. Hope this helps

The presence of different forms of RuBisCo in microalgae is influenced by their evolutionary lineage and physiological adaptations, making it important to ask more specific questions about particular microalgal groups. For instance, diatoms, a diverse group of microalgae, possess Form I C/D Rubiscos, which are characterised by small subunits with a short βA-βB loop and a carboxy-terminal extension forming a β-hairpin structure (βE-βF loop).

Hello Rao Yao

Technically, mixotrophic growth should have higher biomass centration than that heterotrophic growth.

Mixotrophic = autotrophic + heterotrophic

Mixotrophic cultivation of microalgae involves the simultaneous utilization of assimilated CO2 and organic carbon to produce biomass and metabolites via both respiratory and photosynthetic routes [1]. This allows microalgae to utilize both inorganic and organic carbon sources, such as glucose, which can enhance biomass yield [2]. In comparison, heterotrophic cultures grow on organic carbon in the absence of light via combined respiratory and fermentative routes [1]. A study on the optimization of culture media for enhanced microalgae production found that mixotrophic optimized media resulted in maxima of biomass and lipid in comparison to that of other cultivation conditions media [1].

[1] Photoautotrophic, mixotrophic, and heterotrophic culture media optimization for enhanced microalgae production - ScienceDirect

[2] Frontiers | Editorial: Mixotrophic, Secondary Heterotrophic, and Parasitic Algae (frontiersin.org)

Thanks

Chandan

You dont have to have axenic cultures to perform a pcr. You should use genus specific genes of interest in order to perform pcr for identification (barcoding) your species. In the case of cyanobacteria and algae, use rbcL gene (large subunit of Rubisco).

If you would like to isolate your algae/cyanobacteria, use minimal medium and grow in light. During exponential phase of your algae/cyano, you would be able to assume that these are the main constituents of the consortia, as the other organisms will have difficulties to grow.

Hi Safina,

Microalgae can be taken nourishment in domestic wastewater due to containing the nitrate, phosphate. Other alternative, you can cultivate by chemicals, a host of vitamin. Also, light, CO2 concentration and oxygen to be required for their live.

Thanks for your answer.

I will try.

But another thing I tried also as the incubator that I am growing in does not contain carbon dioxide and the light intensity is 45 but I split the culture into two flasks then I put one in the infors with CO2 2% and 100 micromole light and the other in CO2 0.2% and 100 also but I found both of them died, from this I thought the reason is light.

but I will try to cover one of them with foil to see if the reason is light or not.

Look at the turbidostat from Algenuity. Their data collection modules are much better and and bioreactaors are much better designed. British company saw it in US and France conferences. https://www.algenuity.com/algem

for microalgua .you must autoclave all material before using

Diluting microalgal samples can have an impact on cell viability and oxygen evolution, as it can change the osmotic pressure within the cells. There is a risk that cells could burst at a 50% dilution if the osmotic pressure difference between the cells and the diluent (in this case, MilliQ) is too great.

In general, the osmotic pressure of cells is influenced by the concentration of salts and other solutes within the cells, and the concentration of these solutes in the diluent. If the concentration of solutes in the diluent is much lower than in the cells, water will flow into the cells, causing an increase in volume and potentially leading to cell lysis or bursting.

To minimize the risk of cell lysis, it is important to carefully control the concentration of salts and other solutes in the diluent, and to gradually dilute the cells over several steps to allow the cells to adjust to the changing osmotic pressure. You may also consider using other methods to adjust the osmotic pressure, such as adjusting the pH or adding compatible solutes to the diluent.

It's also important to keep in mind that cell lysis can also be influenced by other factors, such as the age of the culture, the presence of contaminants, and the type of cells being used. To ensure accurate and reliable results, it's important to carefully monitor the cells during dilution and oxygen evolution assays, and to take appropriate measures to minimize the risk of cell lysis.

From what I have read cultivation on an acidic medium totally prevents the infection.

Check:

It's possible that this is due to incomplete carotenogenesis. In reality, the major pigments in green algal cells are chlorophyll a, chlorophyll b, and lutein. When carotenogenesis begins, chlorophyll and lutein breakdown begins. It is possible that you should focus on stressor optimization in the second phase of the cultivation procedure.

Ionically gelled alginate can be dissolved by the pH increase of solution to 9 -10, it should dissolve and increase temperature.

You will find a similar example in the manual of my software (red intensity of coffee vs concentration):

The images have too little magnification to be able to say anything for sure. With approx. 400X magnification, diatoms look like this, for example: Unidentified alga from fresh water.

Anton:

It looks like Actinocyclus although I don't see characters like the pseudonodule and others. More details would be needed to properly determine the taxon. Consider Hemidiscaceae in Hasle & Syvertsen in Tomas (1996) and Round et al. (1990).

All the best.

Eugenia

Hi, I have some experience about microalgae culture, If you use BG11 or BBM medium in both cases probably you obtain a good culture, however I suggest you that use another economic alternatives , best regards from Colombia

Most of the algal species are described based on morphology. So one would expect the description of its morphology and morphological identification. If you already classified the organism as an alga you should know at least to which class it belongs and how good molecular references are for this class.

According to the shape, it maybe one of the species in Euglenophyceae. Please refer to Eutreptiella sp.

However, I don't like to be a pessimist without ignoring the fact that time presses.

Dear Anton,

The genus Hyalosira was amended and lectotyped by Lobban et al. (2021); Diatom Genus Hyalosira (Rhabdonematales emend.) and resolution of its polyphyly in Grammatophoraceae and Rhabdonemataceae with a new Genus, Placosira, and five new Hyalosira species, Protist 172, 25816.

H. obtusangula, which is one of the species together with H. delicatula described by Kützing (1844), was chosen as the lectotype of Hyalosira.

The specimens that you are showing in the pictures clearly do not match Hyalosira emend Lobban, Ashworth and Majewska in terms of girdle band morphology: copulae bearing two rows of areolae separated by a midrib.

Even when certain characters are not in view, the bands bring the displayed material closer to Placosira as mentioned by Roksana in her answer.

All the best.

Eugenia

It is not yet clear why some spirulina cultures are more "linear" than others. Growth conditions are certainly the main cause of the morphological change of spirulina, but sometimes it is also due to a specific growth phase of the biomass.

I would check if there are any problem with culture media, or if is present a contamination by other cyanobacteria.

Dear Sujit,

Patiently, is probably the best way! Unless you have a cell sorter. You will need to continuously carry out single cell isolations in a well plate moving the cell of interest into clean, appropriate media under species specific optimal conditions until that cell divides to become the dominant strain. At that point you may be able to carry over more than one cell into a fresh well. Then, it may be necessary to treat the new culture with antibiotic or anifungal agents. Sadly, it will not always be possible, as many species will not tolerate the conditions of single cell culture. Best of luck with it!

Sheetal Parakh hello Sheetal Parakh, Actually my hypothesis behind this is its acclimatization patterns towards nutrients present in the media, or I can say it took its own adaptation time or pattern. Maybe you can experiment more with changing the ratio of nutrient doses especially N: P. I hope this will help.

Thanks.

ribulose bisphosphate carboxylase oxygenase

Hi,

Common growth media for microalgae generally do not support heterotrophic microbes as they lack assimilable carbon sources, and the same is true for Bold media and its 3N version. It appears that natural cell lysis with growth is enriching your algal cultures with nutrients required to support contamination. Lysis is always almost negligible, but because you are using a common culturing facility, it is making your cultures more susceptible to contamination.

As algae are very slow-growing, even minute contamination is supposed to outgrow soon. Thus it is important to analyze your system and practices in more depth to suggest some measures and tricks to avoid any contamination.

All the best for now.

Dear Jess,

probably it is Poterioochromonas, a golden algae. You can find some information here:

and here:

Best wishes

Eleftherios

Yuvraj Saxena thank you for your answer! it truly helped and brought me a little more information about it