The Effect of Pseudomonas putida on the Microbial Community in Casing Soil for the Cultivation of Morchella sextelata

Author: mycolabadmin
10/27/2025
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Summary

Morel mushrooms are prized edible fungi, but growing them repeatedly in the same soil causes problems because toxic ethylene gas builds up and the soil microbiome becomes unbalanced. Scientists found that a beneficial soil bacterium called Pseudomonas putida can break down the ethylene precursor and improve the soil microbial community, making morels grow better and faster. This natural approach using microbial inoculation offers a practical solution to help farmers overcome these continuous cropping challenges.

Background

Morchella sextelata is a valuable edible and medicinal mushroom, but continuous cropping leads to reduced yields and crop failure due to alterations in soil microbial communities and accumulation of ethylene precursors. Pseudomonas putida, a plant-growth-promoting bacterium, is known to degrade 1-aminocyclopropane-1-carboxylic acid (ACC), an ethylene precursor, and has been identified as a core microorganism in morel cultivation soils.

Objective

This study evaluated the growth-promoting potential of P. putida KT2440 by measuring ACC depletion in casing soil and assessing its effects on the soil microbial community structure and function during Morchella sextelata cultivation. The objectives were to determine whether P. putida inoculation alters the casing soil microbial community and promotes morel growth through ACC degradation.

Results

ACC accumulated in soil following morel cultivation, and P. putida KT2440 utilized ACC as a sole nitrogen source. Inoculation enhanced bacterial diversity, improved soil microbial community stability, and accelerated morel mycelial growth with peak abundance at 30 days compared to 60 days in controls. A positive correlation was identified between P. putida abundance and ACC deaminase activity, while Streptomyces abundance declined in inoculated soil.

Conclusion

P. putida inoculation promotes Morchella sextelata growth through ACC decomposition and restructuring of the soil microbial community, offering a potential strategy for mitigating ethylene-related suppression in continuous cropping systems. The study demonstrates that microbial management strategies must be tailored to specific crop physiology and cultivation frameworks, with recommendations for complementary soil health practices.

Published in:Journal of Fungi (Basel),
Study Type:Experimental Study,
Source: 10.3390/jof11110775, PMID: 41295156