A Detailed Guide to the Latest Control Methods for Yeast Contamination in Ganoderma lucidum
Yeast in Ganoderma lucidum cultivation is a type of ascomycete that lacks filamentous mycelial structure and is widely distributed in nature. During the production and cultivation of edible mushroom spawn such as Ganoderma lucidum and Tremella fuciformis (silver ear), it can contaminate culture media and substrates, mainly contaminating the substrate, causing the substrate to deteriorate and inhibiting mycelial growth. Let us take a look at the control methods for yeast in Ganoderma lucidum cultivation!
Symptoms of Yeast Damage in Ganoderma lucidum
When yeast infects, it usually starts from the middle of the Tremella fuciformis substrate, causing the substrate to ferment and deteriorate, with a sour alcoholic odor being released, affecting the growth and development of mycelium, and further affecting its yield and quality.
Characteristics of Yeast Outbreaks in Ganoderma lucidum
Yeast lives on organic matter, and its spores spread through airflow. During spawn production or raw material cultivation, due to incomplete disinfection and sterilization, excessive and tightly packed material in bottles and bags, and close spacing between bottles and bags, this fungus is prone to occur. High temperature and high humidity favor yeast germination and reproduction. Excessive bed material thickness and excessively high water content in the substrate can both lead to substrate fermentation and deterioration.
Control Methods for Yeast in Ganoderma lucidum
1. During spawn production, use an appropriate amount of spawn bags and avoid packing the substrate too tightly. During sterilization, maintain an appropriate distance between bottles and bags to facilitate even and orderly arrangement. For stock cultures and cultivation spawn, the intermittent atmospheric pressure sterilization method should not be used. One-time atmospheric pressure sterilization should be maintained at 100°C for at least 8 hours.
2. Perform aseptic operations during inoculation, and workers must strictly follow inoculation procedures.
3. During cultivation, mix 0.2% of 25% carbendazim or 0.1% thiophanate-methyl based on the dry material weight into the substrate. Maintain appropriate water content and temperature of the substrate. Spray with clean water to reduce the occurrence of pathogens.
3. During cultivation and production, if the substrate temperature is found to be too high and emits a sour odor, promptly irrigate the substrate with lime water (pH 13-14) to control yeast reproduction.