Pigment production by cold-adapted bacteria and fungi: colorful tale of cryosphere with wide range applications

Abstract

Pigments are an essential part of everyday life on Earth with rapidly growing industrial and biomedical applications. Synthetic pigments account for a major portion of these pigments that in turn have deleterious effects on public health and environment. Such drawbacks of synthetic pigments have shifted the trend to use natural pigments that are considered as the best alternative to synthetic pigments due to their significant properties. Natural pigments from microorganisms are of great interest due to their broader applications in the pharmaceutical, food, and textile industry with increasing demand among the consumers opting for natural pigments. To fulfill the market demand of natural pigments new sources should be explored. Cold-adapted bacteria and fungi in the cryosphere produce a variety of pigments as a protective strategy against ecological stresses such as low temperature, oxidative stresses, and ultraviolet radiation making them a potential source for natural pigment production. This review highlights the protective strategies and pigment production by cold-adapted bacteria and fungi, their industrial and biomedical applications, condition optimization for maximum pigment extraction as well as the challenges facing in the exploitation of cryospheric microorganisms for pigment extraction that hopefully will provide valuable information, direction, and progress in forthcoming studies.

Diverse Bacterial Communities From Qaidam Basin of the Qinghai–Tibet Plateau: Insights Into Variations in Bacterial Diversity Across Different Regions

“…This study presents a complete assessment of soil ecosystem bacterial diversity in surface and subsurface niches at the lower temperature limit for life and provides insights into ecosystem complexity under extreme stresses. The highly specialized bacterial communities in these niches face severe environmental challenges/factors; as a result, these bacterial communities adapt several protective strategies to cope with this hostile environment (Sajjad et al, 2020a). Several reports over the last decade have revealed that some bacterial taxa are distributed in restricted ranges of environmental factors (Van Horn et al, 2013;Griffiths et al, 2016;Wang et al, 2017).…”

Natural Pigments of Microbial Origin

“…Pigments are extensively produced among microorganisms, including microalgae, fungi and bacteria. Although there is still no precise classification of all pigments that can be naturally synthesized by microorganisms, in vitro and in vivo studies indicate that some of these molecules can be helpful in the prevention or treatment of degenerative diseases (Shen et al, 2018;Sajjad et al, 2020). Some examples of microbial pigments showing bioactivities are presented in Supplementary Table 1.…”

“…Valuable bioactive properties like anticancer, antioxidant, antimicrobial, anti-inflammatory and immune-suppressor have been associated with fungal pigments (Mapari et al, 2009;Lopes et al, 2013). Thus, they present applications in the food and healthcare industries, as dyeing agents in the textile industry, and as cosmetic additives due to the capacity of absorb harmful UV rays (Chen et al, 2019;Lagashetti et al, 2019;Sajjad et al, 2020).…”

“…Most common bacterial pigments are carotenoids, aryl polyenes that in some cases are esterified with a dialkylresorcinol system, melanins, phenazines, quinones, tambjamines, prodigiosines, violacein ( Supplementary Figure 3). These pigments are reported for their antioxidant and UV protection properties, and many bacterial pigments demonstrated potential biomedical applications such as antimicrobial, antimalarial, and anticancer properties (Sajjad et al, 2020).…”

Physiological and Molecular Responses to Main Environmental Stressors of Microalgae and Bacteria in Polar Marine Environments

“…To cope with polar stress conditions, bacteria have adopted a plethora of protective strategies resulting in morphological and metabolic alterations. Among stressors, low temperature certainly represents the main factor affecting microbial life in cold environments, as it lowers biochemical reaction rates, increases viscosity of solvents and solubility of gasses (e.g., oxygen molecules and reactive oxygen species, ROS), negatively influences solute transport and diffusion, and causes ice formation and osmotic stress, with deleterious effects on biological processes [ 112 , 133 ]. Such transformations do not simply derive from a short-term acclimatization phenomenon, but rather they are driven by permanent and genetically regulated modifications, as discussed in Section 3.2 .…”