Abstract
Steroids are abundant molecules in nature, and various microorganisms evolved to utilize steroids. Thermophilic actinobacteria play an important role in such processes. However, very few thermophiles have so far been reported capable of degrading or modifying natural sterols. Recently, genes putatively involved in the sterol catabolic pathway have been revealed in the moderately thermophilic actinobacterium Saccharopolyspora hirsuta VKM Ac-666T, but peculiarities of strain activity toward sterols are still poorly understood. S. hirsuta catalyzed cholesterol bioconversion at a rate significantly inferior to that observed for mesophilic actinobacteria (mycobacteria and rhodococci). Several genes related to different stages of steroid catabolism increased their expression in response to cholesterol as was shown by transcriptomic studies and verified by RT–qPCR. Sequential activation of genes related to the initial step of cholesterol side chain oxidation (cyp125) and later steps of steroid core degradation (kstD3, kshA, ipdF, and fadE30) was demonstrated for the first time. The activation correlates with a low cholesterol conversion rate and intermediate accumulation by the strain. The transcriptomic analyses revealed that the genes involved in sterol catabolism are linked functionally, but not transcriptionally. The results contribute to the knowledge on steroid catabolism in thermophilic actinobacteria and could be used at the engineering of microbial catalysts.
Funder
Russian Science Foundation
Subject
Inorganic Chemistry,Organic Chemistry,Physical and Theoretical Chemistry,Computer Science Applications,Spectroscopy,Molecular Biology,General Medicine,Catalysis
Reference63 articles.
1. Olivera, E.R., and Luengo, J.M. (2019). Steroids as environmental compounds recalcitrant to degradation: Genetic mechanisms of bacterial biodegradation pathways. Genes, 10.
2. Delineation of steroid-degrading microorganisms through comparative genomic analysis;Bergstrand;mBio,2016
3. Thermophilic and alkaliphilic Actinobacteria: Biology and potential applications;Shivlata;Front. Microbiol.,2015
4. Ecology of Streptomycetes;Goodfellow;Front. Appl. Microbiol.,1987
5. Bioremediation of soils contaminated with polycyclic aromatic hydrocarbons, petroleum, pesticides, chlorophenols and heavy metals by composting: Applications, microbes and future research needs;Chen;Biotechnol. Adv.,2015
Cited by
3 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献