mushroom sterilization 13,15.pptx

mushroom sterilization

1. Method of sterilization of substrates for Oyster cultivation. M

2. Prepared by: Mayur Baria 4011120015 Harsh Nayi 4011120017 Submitted to: Dr. Sneha Mistry

3. Introduction Oyster mushrooms, the common name for the species  Pleurotus ostreatus . They're also known as pearl oyster mushrooms or tree oyster mushrooms. Oyster mushrooms are eaten in a variety of cuisines and are especially popular in Chinese, Japanese, and Korean cooking. The mushrooms typically have broad, thin, oyster- or fan-shaped caps and are white, gray, or tan, with gills lining the underside. The caps are sometimes frilly-edged and can be found in clusters of small mushrooms or individually as larger mushrooms. Oyster mushrooms are more expensive than white button mushrooms.

4. Oyster mushroom 01

5. What Is Sterilization? Sterilization of mushroom substrates is a method of preparing substrates using a combination of steam, time, temperature and pressure to kill living organisms and spores.  To sterilize a substrate, you need temperatures higher than 250°F (121°C) for at least 2 hours. Most mushroom growers will need 15 PSI of pressure to increase the temperature of the steam to 250°F (121°C).

6. Does Mushroom Substrate Need to Be Sterilized? If you want more nutrient from substrates, you must go for sterilization. The more nutrients a substrate contains, the greater the chances of contamination. Moist, nutrient-rich substrates are not only appealing to mushroom mycelium. Other organisms, like mold and bacteria, also enjoy them and often grow faster than mushroom mycelium. Sterilizing a substrate kills all living and dormant organisms and fungal spores and gives your mushroom mycelium the best possible head start.

7. What’s the Difference Between Sterilizing and Pasteurizing Mushroom Substrate? The main difference between the two is that sterilization aims to kill all potential contaminants, while pasteurization eliminates most, but not all, competing organisms. There are several  pasteurization methods  that reduce the competing organisms in less nutritious substrates, like  straw  and sugarcane bagasse, enough to give fast-growing mushroom species an advantage.

8. 02 Pasteurizing Mushroom

9. Sterilize Mushroom Substrate With a Pressure Cooker Metal cooking rack   Water A pressure cooker Jars or bags of prepared substrate   01 03 02 04 To sterilize a substrate with a pressure cooker, you’ll need the following items:

10. Step 1: Check Your Pressure Cooker Step 2: Put Your Substrate in the Pressure Cooker Step 3:Add Adequate Water 

11. Step 4: Close the Lid and Turn up the Heat Step 5: Monitor Pressure and Sterilize the Substrate Step 6: Turn Off the Heat and Leave to Cool

12. How Do You Sterilize a Mushroom Substrate Without a Pressure Cooker? Barrel steam sterilizers are ideal for this and popular with small mushroom farmers who don’t have the funds for an autoclave. This article from Archer’s mushrooms shows you  how to build a barrel sterilizer   step by step. But you can also buy ready-to-use barrel steam sterilizers online, like these  mushroom substrate steamers   from Bubba’s barrels . 

13. When using a steam sterilizer, the substrate is super pasteurized rather than sterilized. Super pasteurization is also known as atmospheric sterilization and involves keeping the substrate as close to 212°F (100°C) as possible for long periods. When using a barrel steam sterilizer, you’ll need to keep the substrate between 194 and 212°F (90 and 100°C) for up to 18 hours. It takes much longer, but the results are almost identical to classic sterilization and suitable for most mushroom species. Conti…

14. You cannot sterilize mushroom substrate in the oven, but you can pasteurize it. This method is sometimes used for small quantities of substrate or casing material. One of the challenges when using an oven to pasteurize mushroom substrate at 250°F (121°C) for 30 minutes is that you can’t use bags. Sterilize Mushroom Substrate in an Oven

15. Conti… This means that as soon as the substrate cools down, it’s often exposed to airborne contaminants. The oven’s dry heat also dries out the substrate and may burn it, reducing the nutrients available for the mycelium. If the substrate dries out too much while in the oven, you’ll have to rehydrate it using distilled water to help prevent contamination.

16. As with the oven, you can pasteurize small quantities of mushroom substrate in the microwave. But it’s not a reliable way to sterilize substrate as it doesn’t kill all fungal spores. Microwaves work by causing the water molecules in substances to vibrate, creating heat that cooks or heats the food. Sterilize Mushroom Substrate in a Microwave

17. Conti… This means a microwave can’t reach temperatures much higher than boiling point 212°F (100°C). Fungal spores don’t contain much water, making them difficult to heat.   And steaming alone will not create temperatures high enough to kill them. But, you can use a microwave steamer to pasteurize small quantities of substrate and reduce the number of competitors. 

18. Sterilize by autoclave Autoclaves operate at high temperature and pressure in order to kill microorganisms and spores. They are used to decontaminate certain biological waste and sterilize media, instruments and lab ware and mushroom bag.

19. Sterilization by chemical Benzimidazole fungicides, viz, benomyl, carbendazim, and thiophanate-methyl , are the most utilized fungicide for substrate sterilization of mushroom.   The sterilization process is  8 hours at a temperature of 70–95 oC .

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