Enhancement of microbial motility due to speed-dependent nutrient absorption

TL;DR

This paper models how marine microorganisms might increase their speed to boost nutrient absorption, revealing that even small increases in nutrient uptake can significantly enhance microbial motility, with implications for understanding microbial behavior.

Contribution

The study introduces a model linking microbial speed to nutrient absorption, showing that modest absorption increases can substantially boost microbial motility, which is a novel insight.

Findings

Modest increases in nutrient absorption can significantly raise microbial speed.

The model predicts stable steady states with enhanced motility due to nutrient absorption.

Realistic parameters suggest large speed increases are possible in bacteria.

Abstract

Marine microorganisms often reach high swimming speeds, either to take advantage of evanescent nutrient patches or to beat Brownian forces. Since this implies that a sizable part of their energetic budget must be allocated to motion, it is reasonable to assume that some fast-swimming microorganisms may increase their nutrient intake by increasing their speed v. We formulate a model to investigate this hypothesis and its consequences, finding the steady state solutions and analyzing their stability. Surprisingly, we find that even modest increases in nutrient absorption may lead to a significant increase of the microbial speed. In fact, evaluations obtained using realistic parameter values for bacteria indicate that the speed increase due to the enhanced nutrient absorption may be quite large.