Microalgea

Safety Training Requirements[edit | edit source]

• Dr. Pearce Safety Lab Tour
• Worker Health & Safety Awareness
• WHMIS 2015 - Workplace Hazardous Materials Information System
• Laboratory Safety & Hazardous Waste Management
• List all others

Safety Issues With Method[edit | edit source]

1. Biological and chemical contamination

Personal protective equipment[edit | edit source]

PPE is to keep you safe so that you can keep doing what you want to do.

1. Safety glasses – always required
2. lab coats are always required

SDS and other[edit | edit source]

Knowing what chemicals are in the lab and how they interact with each other is critical when accidents happen.

1. Appropriate SDS sheets should be viewed online.
2. Note the hazards listed on the door to the lab. If you introduce any new equipment or materials, you must clear them with the responsible person listed on the lab door. If the responsible person is out of date, contact the departmental administrators to get it updated.

Equipment Name[edit | edit source]

1. Room #, building location where procedure is done
2. vendor or link to OS documentation
3. vendor location and contact info
4. Equipment specifications

Calibration & Tolerances[edit | edit source]

Operation & Procedure[edit | edit source]

1.1 Chlorella culture and growth conditions preparation[edit | edit source]

For 10L photobioreactor capacity[edit | edit source]

1. Photobioreactor build: Establish a pre-cleaned 10L column as a photobioreactor, equipped with a pH and temperature control system and stirring functionality. Sterilize the setup by exposing it to UV light for a duration of 2 hours.
2. Nureients addition: Introduce approximately 20% of the total microalgae capacity, weight 10g lant food from the analytical balance, or add 1 teaspoon (10g ) miracle-gro water-soluble all-purpose plant food (no study showed),add the PO₄^-3 to the culture mumdia up to 25ml/L, and the range from 20- 35 ml/L, and for NO₃^- added up to 50 mg/L.^[1]

For 1L photobioreactor capacity[edit | edit source]

1. Prepare sterlization media, fuilld with following components: Sodium nitrate (NaNO3) at a concentration of 1.5 g/L Potassium dihydrogen phosphate (K2HPO4·3H2O) at 0.04 g/L Magnesium sulfate heptahydrate (MgSO4·7H2O) at 0.075 g/L Calcium chloride dihydrate (CaCl2·2H2O) at 0.036 g/L Sodium carbonate (Na2CO3) at 0.02 g/L Citric acid at 0.006 g/L., and ferric ammonium citrate at 0.006 g/L, add the 20% microalgea of the whole capacity.^[2]
2. Carbondioxide and oxgen setting: the reactors are aerated with sterilized air (mixing with carbon dioxide and oxygen)at a rate of 0.5 vvm (volumes of air per total).

1.2 Phisical and Parameter Setting[edit | edit source]

(1) Photoperiod[edit | edit source]

For our lighting setup, employ continuous cool-white fluorescent lighting at 3000 lux, following an 18-hour light cycle complemented by 6 hours of darkness.^[1] To ensure precision, maintain a steady light density, aiming for 250 μmol/m2s, with measurements in lux or lumens per square meter. Additionally, utilize an insulating and opaque cover for the bioreactor to emulate natural light and dark cycles, safeguarding the experiment from external environmental fluctuations and ensuring consistent, controlled lighting conditions.

(2) PH value[edit | edit source]

In the operational phase, Initially, buffer solutions will be prepared by utilizing 1N hydrochloric acid (HCl) and 1N sodium hydroxide (NaOH) solutions create and maintain three distinct pH values: 7.5, 8, and 8.5.^[1]

Prior to commencing the experiment, the pH adjustment will begin by using 1N HCl to lower the pH and 1N NaOH to increase the pH. This procedure ensures that the pH remains within a targeted range, specifically spanning from 7 to 9, and maintain a stable pH level, ultimately set at 8, to provide the ideal conditions for our microalgae culture.

(3) Temperature[edit | edit source]

Calculating both the ambient and bioreactor temperatures. The system's temperature will be set at around 25°C. In the event that the ambient temperature falls below 30°C or exceeds 22°C,^[1] appropriate methods will be employed to adjust the temperature to maintain the desired conditions.

1.3 Operating Bioreactor[edit | edit source]

Utilize a 25-watt pump to keep microalgae suspended by mixing gas (oxygen and carbon dioxide) at a rate of 0.9 m⁻³·h⁻¹, and simultaneously employ a magnetic stirrer to thoroughly mix nutrients and microalgae from below, with the photobioreactor operational for 14 days, including parameter setup beforehand.^[3][4]

1.3 Data Handling[edit | edit source]

Cell counting analyses were performed on the first day of the experiment and then after 5, 10, and 15 days, Recording PH, Temperture and light density from Day 2 to day 15. Upon completing the experiment, the cultured microalgae were subjected to centrifugation at 10,000 revolutions per minute (rpm) for a duration of 10 minutes to facilitate the separation of the microalgae from the medium. Subsequently, the concentrated microalgae were dried in an oven at 65°C for a duration of two days.^[5]

1. Cell Growth Rate: An "Established Model"^[6] can be developed using software like MATLAB to create a systematic framework for analyzing and interpreting data.

2. Dry Weight Calculation:This involves measuring the weight of microalgae after the concentration process. OD Reading (Optical Density):The optical density is determined by employing UV light and a UV-visible spectrophotometer. Typically, the OD value is measured at 658 nm, serving as an indicator of cell density. Additionally, absorbance readings within the 550-680 nm range can be employed to estimate yield, employing the Beer-Lambert Law as a mathematical basis.

3. Cell Population:The total number of cells within the culture is determined through a method involving a Thomas hemacytometer.^[5] This process entails filling the hemacytometer with culture samples, allowing for an accurate assessment of cell count.

Shutdown[edit | edit source]

References[edit | edit source]

[1] M. I. Khan, J. H. Shin, and J. D. Kim, “The promising future of microalgae: current status, challenges, and optimization of a sustainable and renewable industry for biofuels, feed, and other products,” Microbial Cell Factories, vol. 17, no. 1, p. 36, Mar. 2018, doi: 10.1186/s12934-018-0879-x.

[2] P. Ratomski and M. Hawrot-Paw, “Production of Chlorella vulgaris Biomass in Tubular Photobioreactors during Different Culture Conditions,” Applied Sciences, vol. 11, no. 7, p. 3106, Mar. 2021, doi: 10.3390/app11073106.

[3] O. Bernard and L.-D. Lu, “Optimal optical conditions for Microalgal production in photobioreactors,” Journal of Process Control, vol. 112, pp. 69–77, 2022, doi: 10.1016/j.jprocont.2022.03.001.

[4]M. Martinez-Ruiz et al., “Microalgae growth rate multivariable mathematical model for biomass production,” Heliyon, vol. 9, no. 1, p. e12540, 2023, doi: 10.1016/j.heliyon.2022.e12540.

[5]Y. Feng, C. Li, and D. Zhang, “Lipid production of Chlorella vulgaris cultured in artificial wastewater medium,” Bioresource Technology, vol. 102, no. 1, pp. 101–105, 2011, doi: 10.1016/j.biortech.2010.06.016.

[6] S. Suthar and R. Verma, “Production of Chlorella vulgaris under varying nutrient and abiotic conditions: A potential microalga for bioenergy feedstock,” Process Safety and Environmental Protection, vol. 113, pp. 141–148, 2018, doi: 10.1016/j.psep.2017.09.018.