Microbial transformation of steroids, an old and novel drug opportunity strategy: a review

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Samira Meza-Ruiz , Juan Manuel Sánchez-Yáñez

Environmental Microbiology Laboratory Ed B3, Institute of Chemical Biological Research. University City, Universidad Michoacana San Nicolas de Hidalgo, Francisco J. Mujica N/N. Colonia Felicitas del Rio ZP 58030, Morelia, Michoacán, México

Corresponding Author Email: syanez@umich.mx

DOI : https://doi.org/10.51470/JPB.2025.4.1.22

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Introduction

Steroids comprise a wide range of naturally common compoundsdistributed in all the animal and plant kingdoms, with huge physiologically active derivatives that play crucial roles in biological systems[1-4].Steroids are key components of cell membranes, for stability and growth in cellularand development. Steroidsare precursors to bile acids and steroid hormones[5-8].Steroids have base structure consisting of 17 carbon atoms in a tetracyclic ring system well known as cyclopentanoperhydrophenanthrene, now as gonane and estrane[3-6].Steroid products are found indiversityof living species, ecdysteroids in insects, phytosterols and diosgenin in plants, cholesterol and corticosteroids: glucocorticoids, mineralocorticoids as well as sex hormones, bile acids, and vitamin D; neurosteroids, in vertebrates, and in yeasts and fungi are ergosterol and ergosteroids as part of its membrane cells [7,8,10].Steroids and its diversity areessential in medical practice, functioning as scaffolds for synthesizing new pharmacologically potent compounds [5,11,13,14].Steroids control a cascade of physiological activities at target sites and play key roles in cancer research [5,8,11,12].The physiological activity of steroids is closely associated to their molecular structure, as well as, the number, spatial orientation, and reactivity of functional groups in the steroid nucleus, as well as the oxidation state of the rings [1,4,13,15-17].For example, the presence of an oxygenated group at C-11β is essential for anti-inflammatory activity, besides a hydroxyl group at C-17β determines androgenic properties [3,5,8,19,20]. Aromatization of steroids at the A-ring affects estrogenic activity, and corticosteroids feature a 3-keto-5-ene group or a pregnane side chain at C-17 [2,11,14,21,22].In steroids functional modifications involve simple, chemically defined reactions catalyzed by microbial enzymes [1,4,13,15].Genetic MIT ability provides these enzymes to facilitate the transformation reactions, enhancing the efficiency and specificity of steroidsby MIT[6,7,9,23,24].The chemical modification of steroids, which requires high temperatures, pH, expensive reagents, and protective groups for reactive centers, has been a chemical method to obtain valuable new or improved drugs [3,8,16,17,25]. However, MIT offers an alternative approach that enables the production of biologically active steroid derivatives with high regio- and stereoselectivity under mild, environmentally friendly conditions [17-19,27-31].The aim of this short review is to analyze the potential of microbial biotransformation of steroidal compounds of value in the pharmaceutical industry and its connection with other related industries.

Microbial transformation of steroids

There are currently around 300 known steroidal drugs, used for several aims: immunosuppression, anti-inflammation, and contraception. Steroid applications have expanded to treating cancers, osteoporosis, human immunodeficiency virus (HIV)Infections or Acquired Immune Deficiency Syndromeor AIDS[3-5,7,8,32]. The therapeutic effects of certain steroid hormones are related to its interaction to intracellular receptors that regulate gene expression as transcription proprieties[13,20-22].Some steroids, as well as dehydroepiandrosterone, progesterone, pregnenolone, and itsproducts, like 17β-estradiol and allopregnanolone, are classified as neurosteroids due to steroidsactivity on the central nervous system[1,2,14].The MIT of exogenous steroid compounds is commonly by wide groups of bacteria and fungi, to enhancepharmacological activityand efficiency[27,30,33,34]. Several types of MIT reactions, as well as hydroxylation, dehydrogenation, side-chain degradation, ring A aromatization, reduction and esterification are used to achieve specific modifications [16-19, 22,23].MIT techniques diverse processes in culture media with microorganisms, free enzymes, biphasic systems, liposomes, microemulsions, methods altering cell wall permeability and the use of immobilized cells and enzymes [1,6,15,17,24].The spectrum of steroids that can be transformed by microbial cells is wide [4,7,9,18,25].Most advances in steroid happenedin 1950 at that time researchers had not clear idea about the pharmacological properties of cortisol and progesterone [8,14,16,30].

Researchers also discovered that genus fungi as well-knownspecies, could biotransform11α-hydroxylation, a critical reaction essential for synthesizing biologically active steroids [11,25,34,36,]; includingfungal transformation of Azorellane and Aqulinanetypes diterpenoids have unique tricyclic fused 5-, 6-, and 7-membered systems and a wide spectrum of biological properties: antimicrobial, antiprotozoal, spermicidal, gastroprotective [3,8,9,17,26].These discoveries marked the onset of a basic of development of steroids as a pharmaceutical, and the main point potential of microbial systems in the synthesis of valuable steroid compounds[10,11,13,32].Currently, the main objectives in steroid pharmaceutical research and development in target on identifying, and isolating microbial strains with unique activities or improving transformation capabilities [33-35, 37-39]. Genetic engineering and metabolic engineering of bacteria, fungi, and plants play a keyrole in these tasks[15,22,24,28,40]. Industrially, microbial hydroxylation activities, like are:  C-11α, C-11β, C-15α, and C-16α, are performed with high yields and enantioselectivity [2,9,13,14, 22,27]. Since steroids have hydrophobicity, which caused steroids to be tolerant to biodegradation, the mechanisms of steroid metabolism by both aerobic and anaerobic microorganisms have been investigated [18,23,26,28-30].For effective MIT, precursor steroids are required, that are then converted into valuable intermediates and final products [7,11,17,25,31].MIT are:  regiospecific and stereospecific, allowing the modification of compounds into suitable isomers through simple, chemically defined reactions catalyzed by microbial enzymes [1,3,15,32-33]. These enzymes act on compounds to design highly selective reactions, with easy techniques of isolation and purification of the new target compounds [3,6,17,19,22,27]. Besides, MITare is easy to use with necessary sterility conditions and allows for repeated working withthese enzymes [15,31,34].  SteroidMITare possible under several conditions of pressure and temperature, which is a viable alternative to chemical and ecological synthesis [2,23,24,40,41]. Although challenges such as productivity and chemical purity of steroids released, have non risk of contamination, microbial cells are systems can optimize and reduce costs by eliminating the need for isolating, purifying, and stabilizing pure enzymes [1,7,9,25]. Microbes naturally secrete all necessary cofactors and provide a stable environment for the enzymes, preventing protein structural changes and maintaining enzyme reactivity for many repeated processingto optimize steroid transformation[26,30,34,].Oxidation of steroid[6,12,35,].Common steroid precursors including cholesterol, steroidal alkaloids, steroidal sapogenins, and phytosterols, are readily available for MIT processes [16,18,19].

Types of steroids

Cholesterols and corticosteroid

Figure 1 illustrates the classification of steroids according to their biological functions or activities, including: bile acids, steroid hormones, cardioactive glycosides, aglycones, and steroid saponins[2,6,25].

Steroid hormones

Estrogens and androgens play a crucial role in maintaining homeostasis and regulating development [34,36,40]. The gut microbiota significantly influences systemic sex hormone levels by metabolizing these hormones into various derivatives [24,27,32,37]. Under normal physiological conditions, estrogens undergo rapid deactivation in the liver through processes such as glycosylation, sulfation, or methylation, followed by their elimination via urine and feces [30,31,37,38]. Gut microbes can alter this process by enzymatically reactivating estrogens, thereby modulating their bioavailability [8,32,35].

Microbial β-glucuronidase enzymes, primarily found in genera such as Clostridium and Bacteroides, facilitate the removal of glucuronides from deactivated estrogens, thereby restoring their activity [1,3,42]. Similarly, sulfatase-producing bacteria like Bacteroides fragilis and Peptococcus niger have been shown to convert estrone sulfate back into estrone, further influencing systemic estrogen levels [9,11,39]. Additionally, Bacteroides thetaiotaomicron and other gut microbes can act on sulfonated estrogen precursors, such as dehydroepiandrosterone (DHEA), altering hormone metabolism and potentially affecting inflammatory pathways [12-14,24]. Estrogen metabolism, gut microbes also impact androgen regulation [16,40-43]. For example, Mycobacterium neoaurum-derived 3β-HSDH (3β-hydroxysteroid dehydrogenase) has been implicated in the conversion of testosterone to androstenedione, a process linked to behavioral changes, including depression-like phenotypes in animal studies [16,40-43]. Collectively, these microbial interactions with sex steroid hormones highlight the critical role of the gut microbiome in endocrine regulation, with potential implications for metabolic, reproductive, and neuropsychiatric health.

Steroid saponins

For the steroid industry, natural steroid sapogenin, diosgenin is one more important raw material and it can be used for the microbial production of some new steroids of useful therapeutic action [21,44–45].The developing alternative methods for synthesizing therapeutically effective steroids, such as prednisone and prednisolone, has gained significant attention [42,46,47]. The glucocorticoids cortisone and hydrocortisone exhibit potent anti-inflammatory activity; however, their clinical use is often limited due to numerous side effects. Consequently, the development of improved derivatives, such as prednisone and prednisolone, allows for lower therapeutic doses, thereby reducing adverse effects [18,19,21].

Recent studies have highlighted the potential of microbial biotransformation in steroid synthesis. Among 13 screened Rhodococcus strains, Rhodococcus coprophilus DSM 43347 demonstrated the highest catalytic activity, efficiently performing Δ1-dehydrogenation of cortisone and hydrocortisone. This process resulted in the formation of prednisone with a 94% yield and prednisolone with a 97% yield, offering a promising biotechnological approach to steroid drug development [47-49].

Phytosterols

Phytosterols are plant-derived sterols, primarily sourced from Glycine max (soybean) or produced from tall oil or pitch [9,20,34,55].These plant steroids are extracted from specific parts of domestic plants for this purpose, as well as from press mud, generated during the extraction of edible oils [5,37,45,50].MIT of phytosterols has high economic value for the pharmaceutical industry, especially those derived from the activity of Mycobacteriumspp [12,27,51-53]. Besides sterol-containing waste from food, agricultural, and cellulose manufacturing processes can be utilized to produce valuable steroid compounds without requiring extensive purification of the phytosterols [28,33,35,47,54].

Ecdysterols

Ecdysteroids are defined according to their chemical structure and/or biological action (metamorphosis hormones), in insects and crustaceans, that is a cause of controversy[22,30,33,34,57].Ecdysteroids are organic compounds structurally similar to ecdysone, they are polyhydroxysteroids and are widely distributed in nature[4,5,55,56,58]. More than 250 ecdysteroids of different origins have been extracted and purified, especially from plants [7,8,10]. Ecdysteroids possess one or more vicinal diols, notably at the C-2 and C-3 positions of the A ring in the steroid nucleus, as well as at C-20 and C-22 in the side chain. Recent findings indicate that the molecular chaperone 4-phenylbutyrate (PBA) enables the selective extraction of ecdysteroids containing a C-20,22 diol group, while those with only a C-2,3 diol structure remain unextracted. This selective affinity offers a promising approach for the targeted isolation of specific ecdysteroid derivatives[14,17,30, 32,42]. In plants, it is attributed to chemical defense activity against predatory insects [34,37,43,55-58].

Ergoestrols

Ergosterol (ergosta-5,7,22-trien-3β-ol) is a sterol that serves as a biological precursor to vitamin D₂, by the action of ultraviolet light into ergocalciferol, or vitamin D2, through a photochemical reaction involving the cleavage of the B ring [7,9,10,12]. Ergosterol is the sterol that composes the cell membranes of fungi and certain protists such as trypanosomatids [5,6,14,17,32]. For these organisms, the synthesis of ergosterol is essential, it is a source of sterols[22,35,36,40,50]. Ergosterol is synthesized and exists in the cell membranes of fungi and plants as beta-sitosterol [53,55,56,59-61].

Types of steroids and its microbial transformation

Currently, there is a growing trend to isolate, analyze, and heterologously express enzymes that catalyze the microbial transformation of steroids [44,45,47,51,62,63].This approach not only expands the wide specter of target steroidsbut also holds the potential for scaling up production in the future [33,52,53].Several reactions are involved in the biotransformation of steroids, with key sites of these reactions on this specific molecule illustrated in Figure 2 [44,5254,61,64].

Figure 2.Show main sites of MITreactions,it has been described and discovered as a result of extensive and detailed research with a wide diversity of microorganisms that indicate that these changes could have occurred in the evolutionary past of these biological processes [9,40,49,50,65,66–70]. With the use of genetically improved microorganisms or those obtained by genetic engineering to produce molecules that are naturally difficult to obtain, as results indicate that it is even feasible to synthesize these molecules into bioreactors for safe pharmaceutical use,7α-Dihydroxylation[11,19,31,71,72].This pathway facilitates the removal of the 7α-hydroxy or 7β-hydroxy group from primary bile acids, leading to the formation of secondary bile acids, such as deoxycholic acid (DCA) and lithocholic acid (LCA)[8,16,18,20,22,73].While the production of secondary bile acids via 7α-dehydroxylation is specific, deconjugation, oxidation, and epimerization are commonly carried out by several genera and species of intestinal bacteria, such as Bacteroides, Clostridium, Bifidobacterium and others bacterial genus [64,66,70,73-75].

The secondary bile acids, DCA and LCA, undergo oxidation and epimerization mediated by 3α/β-HSDH, resulting in the formation of various bile acid derivatives, including isoDCA, isoLCA, 3-oxoLCA, and isoalloLCA, which have recently been identified for their immunomodulatory functions in the gut[54,73,75-77,81]. Besides this other source of these organic compounds as derivates of cholesterol and hormones such as sulfonated cholesterol and estrogen, can be readily isolated from waste blood collected at slaughterhouses [24,69,71,78–81].In vertebrates, microbial lipids not only modulate host metabolism but also act as immune signaling molecules in the gut mucosa. Microorganisms regulate the development and functionality of wide intestinal immune cells and contribute to mucosal homeostasis and disease susceptibility [17, 20,37, 77,79,80]. Recent research has shown that working withRhodococcuspre-grown on n-alkanes can increase the yield of 9α-hydroxy androstenedione, achieving double the efficiency compared to cells grown on glucose [30,33,35,8,87].

Oxidation

A fundamental aspect for the MIT of steroids is to select microorganisms, that not only have the capacity in the molecular structure of these compounds but, also have or develop natural or induced tolerance of their enzymes that, facilitate MIT [1,5,8,9,29,33], under different chemical conditions, biochemical actions that are necessary for microorganisms involved in MIT of steroids [12,44, 46,82]. As well as oxidation of alcohols to ketone: 3β-OH to 3-keto by Aspergillussppor Rhizopus sppgenus fungi [7,35,44,47,52,61].

Hydroxylation

The substitution of a hydroxyl group directly for a hydrogen atom at a specific position in a steroid molecule, whether in the α or β configuration, can be achieved while retaining the molecule’s overall structure. Hydroxylation processes at positions 11α, 11β, 15α, and 16α are well-developed and are primarily used in the production of adrenal cortex hormones and their analogs [10,14,53,54,58]. In that sense, fungi are among the most active microorganisms for catalyzing hydroxylation reactions [25,32,43,46,48,83].Certain bacteria genera, as well as Pseudomonas aeruginosa[3,7,11,84]the spore-forming Bacillus or genus of actinomycetes and its specieslike:Streptomyces and Nocardia, exhibiting notable hydroxylation activity [32,34,41. Specifically, 11α- and 11β-hydroxylations are generally performed by some fungi genus as well known: as Rhizopus spp or Aspergillus spp [6,9,13,32,85]. While 16α-hydroxylation is carried out by other fungi genus as:Curvulariaspp., and Cunninghamellaspp [36,44,51]also is included the actinomycete genus Streptomycessp [2,3,16, 40,47].

Dehydrogenation

An example of bacterial dehydrogenation is the Δ1-dehydrogenation of 6α-methyl-cortisol, to 6α-methyl-prednisolone by resting cells of Arthrobacter globiformisand another bacterial genus [7,59,61,86].Based on a gene encoding 17β-hydroxysteroid dehydrogenase (17β-HSD), that was identified in the genome of Rhodococcussp P14. Recombinant of E. coli BL21 cells, expressing this enzyme successfully transformed estradiol, into estrone with up to 94% efficiency. TheRhodococcussp P14, could utilize other steroids, such as estriol and testosterone, as sole carbon sources[50,52,53,87].The genome screening also led to the identification of a gene for a short-chain dehydrogenase, that catalyzes the conversion of estradiol to estrone, estriol to 16-hydroxyestrone and testosterone to androst-4-en-3,17-dione [62,63,88-89]. Microbial dehydrogenation using Escherichia coligenetically modified has yielded promising results.[90]also reported in other bacteria[54,57,59,64,65,91], can also be applied to produce derivatives of cortisone and hydrocortisone having improved anti-inflammatory properties and reduced side effects [5,8,10]. This is achieved by introducing double bonds at specific positions in the steroid’s ring A structure [74,85,86,88,92].In that sense genera of both fungi and bacteria are able to dehydrogenate the secondary alcohol groups of steroids, generating corresponding carbonyl derivatives is well-known that microbial whole cells are particularly effective at performing Δ1-dehydrogenation [22,43,92,100,102].

Side chain biodegradation

Side-chain cleavage of steroidsis performed generally by fungi genus:Curvularia spp. or Cunninghamellaspp, however [3,7,9,16]: such reactions are described also differentanother genus of bacteria for example:actinobacteria, that is able to performthe basic step of the side-chain oxidation of sterols and other C-27 steroids is hydroxylation at C 26 or C-27 [27-30,34]. The aliphatic side-chain is degraded by an array of β-oxidation reactions [36,41,48,102].The terminal hydroxylation of C-27sterol is catalyzed by an enzyme known as cytochrome P450125 [97]That enzyme, also known as steroid 26-monooxygenase [51-53,59,64], is produced by various actinomycetes, including Rhodococcus jostii. It has been successfully purified and characterized [71,72,84,93].

Oxidation to ketone through hydroxylation

The chemical functionalization of different carbon atoms in the sterane skeleton is closely related to the MIT activity of the molecule [88,89,93,99,102]. Microbial transformations play a crucial role in obtaining these compounds through chemical processes, including the oxidation of hydroxyl groups at C-3 and C-17, isomerization of the double bond from Δ5-6 to Δ4-5, hydrogenation of double bonds at Δ1-2 and Δ4-5, and reduction of the carbonyl group at C-17 and C-20 with a β orientation[82-6,94,];with relative success, reason why new strategies with natural microorganisms and genetically modified microorganisms of plant origin, are still being investigated at MIT [95,96,100-103].Specifically, to achieve MIT in specific steroid sites that ensure chemical stability and sufficient product performance, through processes based on enzymes and microorganisms. that involve those naturally selected by genetic engineering to achieve efficiency in an effective hydroxylation of the steroid [14,16,97,98, 104-107]. 

RingA aromatization

Ring aromatization of suitable substrates by microorganisms forms aromatic compounds. For example, steroids like estrogens and estrones can be produced by ring Aromatization of steroid precursors or intermediates [21-25]. MIT of steroids has been successful even in aromatic molecules on functional groups, that determine specific pharmaceutical properties, which increases the spectrum of use in medicine [48,50,99–100].This is the case of MIT from diosgeninsuccessfully in other steroid compounds[13,51-53,101].

Reduction

This type of MITas well as the reduction of ketones and aldehydes to alcohols [62-65,69-71]. This process could be done by some genera and species of: algae, bacteria andfungi, which commonly undergo the reduction of exogenous compounds, like some important androgens can be produced by making use of these processes [7,84-86,93, 100,102],especially under the consideration of the natural microbial potential, to make direct modifications on steroids directly or indirectly with the immobilized enzymes, thus, the genetic design of microorganisms that make precise changes in the molecules to expand, or improve their pharmaceutical spectrum in medicine [12,13,16,17,30,103].

Hydrolysis of esters

The systemic side effects of steroids applied as drugs is to design molecules, of relatively easy metabolic deactivation after performing the action, in the pharmaceutical target site [104-105].For this purpose, during the MIT of steroids, it is feasible to apply: esterase enzymes for control and regulation of the activity of the steroid, with pharmacological value, since the esters are located in specific sites [106].It is possible to use microorganisms that act, on ester bonds sensitive to enzymatic activity, it has been a subject of research, thus microbial actions have been evaluated, with enzymes of such selectivity that its facilitate the hydrolysis activity of esters, with esterasesdue bacterial genera and species as well as other microbial species in the generation of polyester, today with better results with the use of genetic engineering[21,64,107].

Esterification

It is possible to obtain, through MIT, molecules similar to those reported in steroids, to make esterification with esterase enzymes by protein engineering in enteric bacteria, that synthesize them by optimizing  genetic potential for manipulation and complementing it with the use of organic solvents[108-110].In this sense, microbial synthesis of esters is relevant, from organic acids and alcohols, that accumulate in high concentration by bacteria such as Escherichia coli, capable of direct esterification by means of esterase enzymes efficient by expressing genes of the ethanol and lactic acid metabolic pathway for MIT steroids[1,64,121].

Microbial transformation of Steroid Compounds 

For sterol MIT, some bacterial genera and specieshave been identified, as effective biocatalysts as well as: Arthrobacter oxydans 317,A.rubellus,Brevibacteriumsp,Mycobacterium smegmatis [27,48,67,100,111-113];Pseudomonassppand Rhodococcus spp. However, to prevent the degradation of the steroid nucleus during these transformations, inhibitors are often required [16-18,22-25]. For example,estrogen, a major component in orally administered contraceptives, also plays a crucial role in hormone replacement therapy for menopause [3,5,8,40]. Estrone can be produced through the biotransformation of 19-nor-testosterone by cell-free extracts of Pseudomonas testosterone, with a small amount of estradiol-17β also produced in this reaction [40-43,92,94]. Recently, the 4,5-seco pathway of 17β-estradiol biodegradation by Rhodococcusequi DSSKP-R-001 was discovered, identifying the enzymes and genes involved in the initial stages of catabolism, this process begins with the dehydrogenation of 17β-estradiol by a short-chain dehydrogenase encoded by the hsd17b14 gene, to form estrone [5,10]. Also, Estrone could be transformed by flavin-binding monooxygenase (At1g12200), into 4-hydroxyestrone [28,29,31,33]. Subsequent cleavage of the steroid ring A, is catalyzed by 3-hydroxy-9,10-secoandrosta-1,3,5(10)-triene-9,17-dione monooxygenase,encoded by the hsaC and catechol-1,2-dioxygenase encoded by the catA [35,43,49,112]. Özçınaret al., 2018 identified 14 biotransformed products based on neoruscogenin, a major spirostanol steroid from Ruscus aculeatus(butcher’s broom), as a substrate [36]. As well as withRhodococcusequi[87].R. aculeatus this plant, used in pharmaceutical preparations to treat conditions such as: chronic venous insufficiency, varicose veins, hemorrhoids, and orthostatic hypotension, was processed by the endophytic fungus Alternaria eureka,thatprimarily facilitated oxygenation, oxidation, and epoxidation reactions.Recent metabolomics and bioinformatics studies, have revealed that certain uncultured members of Cluster IV of bacterial anaerobic genus, belong toClostridium within the human gut microbiota carry genes for cholesterol dehydrogenases, specifically intestinal sterol metabolism A (ismA), that can convert cholesterol to coprostanol[11,16,17,114-115]. The regulation and transcription mechanisms of various isoforms of the KshAB gene are of particular interest to researchers [62-64]. According to data obtained by Baldanta et al. (2021), the KshA2 and KshA3 isoforms serve as the primary enzymes responsible for the degradation of androst-4-ene-3,17-dione and cholesterol, respectively, while KshA1plays a supportive role in these processes [85,86,9,116]. Beyond C-19 steroids, valuable 23,24-dinorcholane derivatives—important precursors for corticosteroid synthesis—have been microbially derived from sterols [4,66,86,93,97,103,117-118,123]. These transformations have also been reported in other bacterial genera [91,100-103,107-108,122], as well as through the catabolism of diosgenin by Mycolicibacterium sp. mHust-ΔkstD1,2,3 [68-69,101,124-130].

Conclusion

Steroids are naturally occurring compounds found throughout all living kingdoms. The chemical modifications of various carbon atoms, in the steroid framework are closely linked to the biological activity of these molecules. This is why MIT is avery important for producing these compounds, since the improvements facilitate specific chemical alterations that enhance its biological functions.Steroids can be synthesized through both chemical and microbial processes. Industrially, while well-known chemical methods are commonly used, microbial processes haveinteresting and valuable alternatives by enabling biotransformation or bioconversion. MIThas better and certain advantages over the chemical transformation, becauseits ability to produce steroids with precise modifications and high selectivity, making it essential for developing steroid-based pharmaceuticals, with better and widely targeted therapeutic effects.Microbial diversity such as microalgae, bacteria, and fungi are commonly employed for steroidbiotransformation. These processes are fundamental for releasing steroids used in a wide rangeof therapeutic applications, more than drug manufacturing, partial synthesis of new steroids, and evaluation for diverse applications such as hormones, diuretics, anabolic agents, anti-inflammatory agents, anti-androgens, contraceptives, and anti-tumor treatments.Interest in steroid MIT has increased in recent years due to the development of new, pharmacologically active compounds. This growth is supported by advancements in MITstrategies, as well as techniques of genetically modified microbial, newly isolated strains, immobilized enzymes, and optimized micriobiologicalculture conditions. These improvements enhance the efficiency and specificity of the MIT processes, making them quite essential for producing high-value new steroid products.

Acknowledgments

To Project 2.7 (2025) supported by the Scientific Research Coordination-UMSNH: “Aislamientoyseleccióndemicrorganismosendófitospromotoresdecrecimientovegetal para la agricultura y biorecuperacion de suelos. ToPhytonutrimentos de México and BIONUTRA, S.A de CV, Maravatío, Michoacán, México.

Conflicts of Interest: The authors declare no conflicts of interest

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