Anaerobic bacteria need their vitamin B12 to digest estrogen

Recent developments in the enzymatic modifications of steroid scaffolds

Steroids are an important family of bioactive compounds. Steroid drugs are renowned for their multifaceted pharmacological activities and are the second-largest category in the global pharmaceutical market. Recent developments in biocatalysis and biosynthesis have led to the increased use of enzymes to enhance the selectivity, efficiency, and sustainability for diverse modifications of steroids. This review discusses the advancements achieved over the past five years in the enzymatic modifications of steroid scaffolds, focusing on enzymatic hydroxylation, reduction, dehydrogenation, cascade reactions, and other modifications for future research on the synthesis of novel steroid compounds and related drugs, and new therapeutic possibilities.

Vitamin B12 coordinates ileal epithelial cell and microbiota functions to resist Salmonella infection in mice

Deprivation of vitamin B12 (VB12) is linked to various diseases, but the underlying mechanisms in disease progression are poorly understood. Using multiomic approaches, we elucidated the responses of ileal epithelial cells (iECs) and gut microbiome to VB12 dietary restriction. Here, VB12 deficiency impaired the transcriptional and metabolic programming of iECs and reduced epithelial mitochondrial respiration and carnitine shuttling during intestinal Salmonella Typhimurium (STm) infection. Fecal microbial and untargeted metabolomic profiling identified marked changes related to VB12 deficiency, including reductions of metabolites potentially activating mitochondrial β-oxidation in iECs and short-chain fatty acids (SCFAs). Depletion of SCFA-producing microbes by streptomycin treatment decreased the VB12-dependent STm protection. Moreover, compromised mitochondrial function of iECs correlated with declined cell capability to utilize oxygen, leading to uncontrolled oxygen-dependent STm expansion in VB12-deficient mice. Our findings uncovered previously unrecognized mechanisms through which VB12 coordinates ileal epithelial mitochondrial homeostasis and gut microbiota to regulate epithelial oxygenation, resulting in the control of aerobic STm infection.

Microbial and Genetic Resources for Cobalamin (Vitamin B12) Biosynthesis: From Ecosystems to Industrial Biotechnology

Many microbial producers of coenzyme B12 family cofactors together with their metabolically interdependent pathways are comprehensively studied and successfully used both in natural ecosystems dominated by auxotrophs, including bacteria and mammals, and in the safe industrial production of vitamin B12. Metabolic reconstruction for genomic and metagenomic data and functional genomics continue to mine the microbial and genetic resources for biosynthesis of the vital vitamin B12. Availability of metabolic engineering techniques and usage of affordable and renewable sources allowed improving bioprocess of vitamins, providing a positive impact on both economics and environment. The commercial production of vitamin B12 is mainly achieved through the use of the two major industrial strains, Propionobacterium shermanii and Pseudomonas denitrificans, that involves about 30 enzymatic steps in the biosynthesis of cobalamin and completely replaces chemical synthesis. However, there are still unresolved issues in cobalamin biosynthesis that need to be elucidated for future bioprocess improvements. In the present work, we review the current state of development and challenges for cobalamin (vitamin B12) biosynthesis, describing the major and novel prospective strains, and the studies of environmental factors and genetic tools effecting on the fermentation process are reported.

Suitability of Immobilized Systems for Microbiological Degradation of Endocrine Disrupting Compounds

The rising pollution of the environment with endocrine disrupting compounds has increased interest in searching for new, effective bioremediation methods. Particular attention is paid to the search for microorganisms with high degradation potential and the possibility of their use in the degradation of endocrine disrupting compounds. Increasingly, immobilized microorganisms or enzymes are used in biodegradation systems. This review presents the main sources of endocrine disrupting compounds and identifies the risks associated with their presence in the environment. The main pathways of degradation of these compounds by microorganisms are also presented. The last part is devoted to an overview of the immobilization methods used for the purposes of enabling the use of biocatalysts in environmental bioremediation.