In Living Color: Pigment-Based Microbial Ecology At the Mineral–Air Interface

Abstract

Pigment-based color is one of the most important phenotypic traits of biofilms at the mineral–air interface (subaerial biofilms, SABs), because it reflects the physiology of the microbial community. Because color is the hallmark of all SABs, we argue that pigment-based color could convey the mechanisms that drive microbial adaptation and coexistence across different terrestrial environments and link phenotypic traits to community fitness and ecological dynamics. Within this framework, we present the most relevant microbial pigments at the mineral–air interface and discuss some of the evolutionary landscapes that necessitate pigments as adaptive strategies for resource allocation and survivability. We report several pigment features that reflect SAB communities’ structure and function, as well as pigment ecology in the context of microbial life-history strategies and coexistence theory. Finally, we conclude the study of pigment-based ecology by presenting its potential application and some of the key challenges in the research.

The Sustainability of Rock Art: Preservation and Research

“…In our recent experience in rock art research in a variety of remote locations, we tried to establish a procedure to reduce sampling and, at the same time, increase the possibility of mining information using different methodological approaches [5,27,33,148]. In remote locations, it is hard to transport (or export) portable instrumentation; thus, we decided to proceed with several steps: (1) biogeomorphological survey of the rock substrate to assess the potentially many and diversified types of surface rock decay and SABs formation at the rock surface and/or below it; (2) micro-sampling (using small sterile chisels) of each type of deterioration evidence on the rock surface, far from rock art representations; (3) very microinvasive sampling of painting (pigments) or rock decay evidence related to representations.…”

More than a colour; how pigment influences colourblind microbes

“…We assume, reflected by the article title, that the microbes may sense the chemistry of the pigment, but not the colour of the pigment. Some marine microbes, however, such as certain halophiles, can recognize different colours of light [49]. Perhaps these microbes can select hosts based on the different colours of light absorbed and reflected by the pigmented surfaces of marine animals and thereby use that energy for survival or growth.…”

Enhancing hyperspectral imaging through macro and multi-modal capabilities

“…The accurate understanding of the exact role of the biofilm on stone heritage is crucial for the management of stone heritage, which calls for new non-invasive, portable diagnostics methods. In subaerial biofilms (SABs), microorganism photosynthetic pigments grow as colourful complex sessile communities on mineral surfaces exposed to the atmosphere, such as the stone surfaces of historic buildings [29]. The SAB pigments are influenced by the nature of the substrate [30,31] as well as by the location and environmental conditions [32].…”

“…The SAB pigments are influenced by the nature of the substrate [30,31] as well as by the location and environmental conditions [32]. Since the physiological state of photosynthetic microorganisms is closely related to the activity of the photosynthetic system, any variation in their spectroscopic properties indicates changes in the microbial community physiology [29,33]. SAB sample on limestone was prepared according to the protocol reported by Villa et al [34] and detailed in supplementary information [35,36].…”