Highly efficient synthesis of boldenone from androst-4-ene-3,17-dione by Arthrobacter simplex and Pichia pastoris ordered biotransformation

Engineering a two-enzyme system in Mycolicibacterium neoaurum for efficient biotransformation of phytosterols to dihydrotestosterone

Dihydrotestosterone (DHT) is a valuable steroid drug with widespread clinical applications, but traditional chemical synthesis is environmentally harmful and requires complex reaction conditions. This study introduces a one-step microbial transformation method for the production of DHT from inexpensive phytosterols (PS) using engineered Mycolicibacterium neoaurum (MNR). The heterologous expression of 5α-reductase (5α-R) and 17β-hydroxysteroid dehydrogenase (17β-HSD) in MNR enabled the efficient conversion of PS to DHT. To further enhance 5α-R activity, semi-rational mutagenesis was employed, which significantly increasing DHT production. Molecular dynamics simulations provided insights into the underlying mechanisms driving this enhancement. Additionally, the incorporation of a PntAB-based NADPH regeneration system further improved DHT yield. Process optimization resulted in a maximum DHT concentration of 1.123 g·L-1, representing the first gram-scale microbial production of DHT. Compared to traditional chemical synthesis, this biotransformation method offers milder reaction conditions, reduced environmental impact, and eliminates the need for toxic catalysts. This work demonstrates a sustainable and efficient microbial method for DHT production, with significant industrial potential for the greener manufacturing of steroid hormone drugs.

Efficient One-Step Biocatalytic Multienzyme Cascade Strategy for Direct Conversion of Phytosterol to C-17-Hydroxylated Steroids

Steroidal 17-carbonyl reduction is crucial to the production of natural bioactive steroid medicines, and boldenone (BD) is one of the important C-17-hydroxylated steroids. Although efforts have been made to produce BD through biotransformation, the challenges of the complex transformation process, high substrate costs, and low catalytic efficiencies have yet to be mastered. Phytosterol (PS) is the most widely accepted substrate for the production of steroid medicines due to its similar foundational structure and ubiquitous sources. 17β-Hydroxysteroid dehydrogenase (17βHSD) and its native electron donor play significant roles in the 17β-carbonyl reduction reaction of steroids. In this study, we bridged 17βHSD with a cofactor regeneration strategy in Mycobacterium neoaurum to establish a one-step biocatalytic carbonyl reduction strategy for the efficient biosynthesis of BD from PS for the first time. After investigating different intracellular electron transfer strategies, we rationally designed the engineered strain with the coexpression of 17βhsd and the glucose-6-phosphate dehydrogenase (G6PDH) gene in M. neoaurum. With the establishment of an intracellular cofactor regeneration strategy, the ratio of [NADPH]/[NADP⁺] was maintained at a relatively high level, the yield of BD increased from 17% (in MNR M3M-ayr1_S.c) to 78% (in MNR M3M-ayr1&g6p with glucose supplementation), and the productivity was increased by 6.5-fold. Furthermore, under optimal glucose supplementation conditions, the yield of BD reached 82%, which is the highest yield reported for transformation from PS in one step. This study demonstrated an excellent strategy for the production of many other valuable carbonyl reduction steroidal products from natural inexpensive raw materials. IMPORTANCE Steroid C-17-carbonyl reduction is one of the important transformations for the production of valuable steroidal medicines or intermediates for the further synthesis of steroidal medicines, but it remains a challenge through either chemical or biological synthesis. Phytosterol can be obtained from low-cost residues of waste natural materials, and it is preferred as the economical and applicable substrate for steroid medicine production by Mycobacterium. This study explored a green and efficient one-step biocatalytic carbonyl reduction strategy for the direct conversion of phytosterol to C-17-hydroxylated steroids by bridging 17β-hydroxysteroid dehydrogenase with a cofactor regeneration strategy in Mycobacterium neoaurum. This work has practical value for the production of many valuable hydroxylated steroids from natural inexpensive raw materials.

The effect of Ketogenic diet on vitamin D3 and testosterone hormone in patients with diabetes mellitus type 2

A keto diet is well-known for being a low carb diet in which the body produces ketones in the liver to be used as energy. When something high in carbs is eaten, the body will produce glucose and insulin. Glucose is the easiest molecule for the body to convert and use as energy, so it will be chosen over any other energy source. The aim of this study is to examine the effect of a ketogenic diet on type 2 diabetic patients and the effect it has on testosterone, vitamin D3, HDL, LDL levels, in comparison to non-ketogenic diet subjects. In the study, Type 2 diabetic patients undergoing a keto diet were selected and serum D3 levels and testosterone levels were examined and compared with control subjects. The result show a significant increase in testosterone hormone in patients with diabetes mellitus type 2 following a Ketogenic diet (mean± Std. Error 427.4±2.52) as compared with the control group (mean ± Std. Error 422.2±0.24) and as compared with patients with diabetes mellitus type 2 who are not following a Ketogenic diet (mean± Std. Error 151.4±1.41). The results show no significant level in LDL level in patients with diabetes mellitus type 2 following a Ketogenic diet (mean ± Std. Error 78.53±0.17), as compared to a control group (mean ± Std. Error 75.0.3±0.14) and no significant level in HDL level in patients with diabetes mellitus type 2 following a Ketogenic diet (mean± Std. Error 46.3±1.55), as compared with a control group (mean ± Std. Error 46.2±2.43), and with patients with diabetes mellitus type 2 who are not following a Ketogenic diet (mean ± Std. Error 45.1±1.55). The results show a significant increase in vitamin D3 level in patient with diabetes mellitus type 2 who are following a Ketogenic diet (mean ± Std. Error 53.5±0.32), as compared with a control group (mean± Std. Error 57±0.24), and with patients with diabetes mellitus type 2 who are not following a Ketogenic diet (mean ± Std. Error 25.1±1.55). Herein, normal vitamin D3 levels in patients corresponds to normal testosterone hormone levels. In conclusion, this study shows that in patients with diabetes mellitus type 2, following a ketogenic diet has a positive effect on the patients’ health.

Yeast as a promising heterologous host for steroid bioproduction

With the rapid development of synthetic biology and metabolic engineering technologies, yeast has been generally considered as promising hosts for the bioproduction of secondary metabolites. Sterols are essential components of cell membrane, and are the precursors for the biosynthesis of steroid hormones, signaling molecules, and defense molecules in the higher eukaryotes, which are of pharmaceutical and agricultural significance. In this mini-review, we summarize the recent engineering efforts of using yeast to synthesize various steroids, and discuss the structural diversity that the current steroid-producing yeast can achieve, the challenge and the potential of using yeast as the bioproduction platform of various steroids from higher eukaryotes.

Biotransformation of androst-4-ene-3,17-dione by three fungal species Fusarium solani BH1031, Aspergillus awamori MH18 and Mucor circinelloides W12

The microbial transformation of androst-4-ene-3,17-dione (4-AD; I) by three fungal species, involved Fusarium solani BH1031, Aspergillus awamori MH18 and Mucor circinelloides W12, has been studied. The latter two fungi were studied for the first time on biotransformation of 4-AD. The main product obtained by Fusarium solani BH1031 was 17α-oxa-D-homo-androst-1,4-diene-3,17-dione (testolactone; IV), which can be used as an anticancer agent. The main derivative yielded by Aspergillus awamori MH18 was 11α-hydroxyandrost-4-ene-3,17-dione (11α-OH-4-AD; VI), which was an important intermediate to produce Eplerenone. Meanwhile, the microbial transformation of 4-AD by Mucor circinelloides W12 produced three derivatives. Possible metabolic pathway of 4-AD via Fusarium solani BH1031 was proposed. Furthermore, the optimization for the production of 11α-OH-4-AD was carried out and the conversion rate reached to 84.0%. In this process, the dextrin and corn flour showed significant effects by response surface analysis.