Biology subjects

Manoj, K. M.

Publications and source records attributed to Manoj, K. M..

4 recordsLinked to original sources

bioRxiv2026

Redox heterogeneity as an engine of biodiversity: A quantitative murburn formalism for micro-oxic ecosystems

Biodiversity frequently peaks in fluctuating micro-oxic environments such as marine oxygen minimum zone interfaces, rhizospheric aggregates, sediments, microbial mats, and gut mucus layers. Yet, classical ecological theories do not adequately explain why intermediate oxygen tensions repeatedly favor coexistence and diversification. Herein, we propose a murburn ecological formalism wherein oxygen acts not merely as a metabolic substrate but as a generator of dynamic redox heterogeneity through partial reduction and diffusible reactive species (DRS) and redox-intermediates formation. Integrating empirical observations from marine, gut, soil, and aquatic-interface ecosystems with a reaction-diffusion framework, we show that intermediate oxygen tensions naturally maximize radical-field heterogeneity and produce dynamically shifting fitness landscapes. Numerical simulations demonstrate spontaneous coexistence, biodiversity maxima within micro-oxic zones, localized diversification, and coexistence stabilization without externally imposed niche partitioning. Additional simulations suggest that aquatic macrofauna indirectly enhance biodiversity by restructuring oxygen gradients and generating ecosystem-scale diffusional redox architectures (ESDRA). The framework proposes that fluctuating redox interfaces function as potential ecological zones of elevated adaptive turnover across biological scales.

ecology↗

bioRxiv2026

From biofilms to birth: Quantitative murburn rationale for hydrated polymer-centred biological transduction, coherence, and evolution of complex life

Hydrated extracellular polymeric phases (such as mucus, biofilms, and extracellular matrices) have traditionally been viewed as passive barriers. We complement and extend this view by analysing these systems through the murburn framework and liquid-liquid phase separation (LLPS) biophysics. Using quantitative modeling, we first demonstrate how frothy mucus in amphibian egg-masses enhances oxygen delivery while buffering diffusible reactive species (DRS), leading to improved developmental synchrony. We then model the human cervical mucus system, showing its cycle-dependent transitions between coherent barriers (pregnancy), active transduction media (ovulation), and controlled inflammatory remodeling (labor). Finally, we present thiolated polyglycerol sulfate (dPGS-SH) as a synthetic validation (another groups recently published work): this rationally designed mucolytic agent recapitulates native mucuss DRS-modulating properties and shows superior efficacy for addressing cystic fibrosis pathology. With such pan-systemic perspectives, we argue that phase-separated hydrated polymeric matrices represent one of evolutions most conserved solutions for regulating stochastic murburn chemistry, enabling organisms to exploit oxygen while preserving biological coherence. From biofilms to birth, this framework unifies the physicochemical basis of lifes most fundamental processes.

biochemistry↗

bioRxiv2026

A parsimonious murburn model for microbial motility connects metabolic water ejection to observable mechanical outcomes

The classical model of bacterial flagellar motility posits a rotary engine driven by proton motive force (pmf), with torque generated by stator-rotor interactions and transmitted through a flexible hook to a helical filament. Despite decades of acceptance, this model faces fundamental challenges in thermodynamics, structural mechanics, evolutionary parsimony, and direct observational evidence. We develop and quantitatively test the murburn model, a new paradigm for bacterial motility in which water, produced as an inevitable byproduct of metabolic redox activity, is ejected via the basal secretory module and channelled along the spiral grooves of the flagellar filament. The ejected flow creates a local shear field that induces a transverse bending wave; the precession of this wave is observed as apparent rotation and generates thrust through anisotropic viscous drag, without any rotary motor, ion gradient, or axial rotation. The principal contribution of this work is a self-contained, first-principles treatment of this mechanism: for a unipolar flagellated cell we derive the governing low-Reynolds-number elastohydrodynamic relations from slender-body theory and show that physiologically realistic rates of metabolic water production reproduce the observed swimming speeds and apparent-rotation frequencies at a small fraction of the cellular energy budget, while direct jet propulsion is quantitatively excluded. Building on this derivation, we provide a force-balance comparison of the competing propulsion mechanisms, obtain a set of falsifiable predictions that distinguish the murburn model from the rotary motor, and report a structural analysis of cryo-EM flagellar-hook architectures that reveals solvent-accessible radial canals consistent with lateral water transport. The same single principle accounts for swimming, tumbling, gliding, spirochete undulation, and archaeal motility, without requiring rotating shafts, ion-gradient coupling, or complex switching mechanisms.

biophysics↗

bioRxiv2019

Murburn concept explains the acutely lethal effect of cyanide

Cyanide (CN) toxicity is traditionally understood to result from its binding of hemeFe centers, thereby disrupting mitochondrial cytochrome oxidase function and oxygen utilization by other globin proteins. Recently, a diffusible reactive oxygen species (DROS) mediated reaction mechanism called murburn concept was proposed to explain mitochondrial ATP-synthesis and heat generation. Per this purview, it was theorized that CN ion-radical equilibrium dissipates the catalytically vital DROS into futile cycles, producing water. In the current study, a comparative quantitative assessment of the above two explanations is made for: (i) lethal dosage or concentrations of CN, (ii) thermodynamics and kinetics of the binding/reaction, and (iii) correlation of CN with the binding data and reaction chemistry of H2S/CO. The quantitative findings suggest that the hemeFe binding-based toxicity explanation is untenable. CN also inhibited the experimental in vitro DROS-mediated coupling of inorganic phosphate with ADP. Further, pH-dependent inhibition profiles of heme enzyme catalyzed oxidation of a phenolic (wherein an -OH group reacts with DROS to form water, quite akin to the murburn model of ATP synthesis) indicated that- (i) multiple competitive reactions in milieu controlled outcomes and (ii) low concentrations of CN cannot disrupt activity via a coordination (binding) of cyanide at the distal hemeFe. Therefore, the M-level IC50 and the acutely lethal effect of CN on cellular respiration could be explained by the deleterious interaction of CN ion-radical equilibrium with DROS in matrix, disrupting mitochondrial ATP synthesis. This work supports the murburn explanation for cellular respiration.

biochemistry↗