The Role of Dioxygen in Microbial Bio-Oxygenation: Challenging Biochemistry, Illustrated by a Short History of a Long Misunderstood Enzyme.

A Special Issue of devoted to 'Microbial Biocatalysis and Biodegradation' would be incomplete without some form of acknowledgement of the many important roles that dioxygen-dependent enzymes (principally mono- and dioxygenases) play in relevant aspects of bio-oxygenation. This is reflected by the multiple strategic roles that dioxygen -dependent microbial enzymes play both in generating valuable synthons for chemoenzymatic synthesis and in facilitating reactions that help to drive the global geochemical carbon cycle. A useful insight into this can be gained by reviewing the evolution of the current status of 2,5-diketocamphane 1,2-monooxygenase (EC 1.

Bicyclo[3.2.0]carbocyclic Molecules and Redox Biotransformations: The Evolution of Closed-Loop Artificial Linear Biocatalytic Cascades and Related Redox-Neutral Systems.

The role of cofactor recycling in determining the efficiency of artificial biocatalytic cascades has become paramount in recent years. Closed-loop cofactor recycling, which initially emerged in the 1990s, has made a valuable contribution to the development of this aspect of biotechnology. However, the evolution of redox-neutral closed-loop cofactor recycling has a longer history that has been integrally linked to the enzymology of oxy-functionalised bicyclo[3.

Inter-Species Redox Coupling by Flavin Reductases and FMN-Dependent Two-Component Monooxygenases Undertaking Nucleophilic Baeyer-Villiger Biooxygenations.

Using highly purified enzyme preparations throughout, initial kinetic studies demonstrated that the isoenzymic 2,5- and 3,6-diketocamphane mono-oxygenases from ATCC 17453 and the LuxAB luciferase from ATCC 7744 exhibit commonality in being FMN-dependent two-component monooxygenases that promote redox coupling by the transfer of flavin reductase-generated FMNH by rapid free diffusion. Subsequent studies confirmed the comprehensive inter-species compatibility of both native and non-native flavin reductases with each of the tested monooxygenases. For all three monooxygenases, non-native flavin reductases from ATCC 11105 and ATCC 29600 were confirmed to be more efficient donators of FMNH than the corresponding tested native flavin reductases.

Tuberculosis infection among youths in overcrowded university hostels in Kenya: a cross-sectional study.

Background: Tuberculosis (TB) remains a top global health problem and its transmission rate among contacts is higher when they are cohabiting with a person who is sputum smear-positive. Our study aimed to describe the prevalence of TB among student contacts in the university and determine factors associated with TB transmission.

Methods: We performed a cross-sectional study with an active contact case finding approach among students receiving treatment at Kilifi County Hospital from January 2016 to December 2017.

The Isoenzymic Diketocamphane Monooxygenases of ATCC 17453-An Episodic History and Still Mysterious after 60 Years.

Researching the involvement of molecular oxygen in the degradation of the naturally occurring bicyclic terpene camphor has generated a six-decade history of fascinating monooxygenase biochemistry. While an extensive bibliography exists reporting the many varied studies on camphor 5-monooxygenase, the initiating enzyme of the relevant catabolic pathway in ATCC 17453, the equivalent recorded history of the isoenzymic diketocamphane monooxygenases, the enzymes that facilitate the initial ring cleavage of the bicyclic terpene, is both less extensive and more enigmatic. First referred to as 'ketolactonase-an enzyme for cyclic lactonization'-the enzyme now classified as 2,5-diketocamphane 1,2-monooxygenase (EC 1.