Biochemical and Metabolomic Responses of Antarctic Bacterium Planococcus sp. O5 Induced by Copper Ion

Comprehensive insights on environmental adaptation strategies in Antarctic bacteria and biotechnological applications of cold adapted molecules

Climate change and the induced environmental disturbances is one of the major threats that have a strong impact on bacterial communities in the Antarctic environment. To cope with the persistent extreme environment and inhospitable conditions, psychrophilic bacteria are thriving and displaying striking adaptive characteristics towards severe external factors including freezing temperature, sea ice, high radiation and salinity which indicates their potential in regulating climate change's environmental impacts. The review illustrates the different adaptation strategies of Antarctic microbes to changing climate factors at the structural, physiological and molecular level. Moreover, we discuss the recent developments in "omics" approaches to reveal polar "blackbox" of psychrophiles in order to gain a comprehensive picture of bacterial communities. The psychrophilic bacteria synthesize distinctive cold-adapted enzymes and molecules that have many more industrial applications than mesophilic ones in biotechnological industries. Hence, the review also emphasizes on the biotechnological potential of psychrophilic enzymes in different sectors and suggests the machine learning approach to study cold-adapted bacteria and engineering the industrially important enzymes for sustainable bioeconomy.

Measuring the effect of climate change in Antarctic microbial communities: toward novel experimental approaches

The Antarctic continent is undergoing a rapid warming, affecting microbial communities throughout its ecosystems. This continent is a natural laboratory for studying the effect of climate change, however, assessing the microbial communities' responses to environmental changes is challenging from a methodological point of view. We suggest novel experimental designs, including multivariable assessments that apply multiomics methods in combination with continuous environmental data recording and new warming simulation systems. Moreover, we propose that climate change studies in Antarctica should consider three main objectives, including descriptive studies, short-term temporary adaptation studies, and long-term adaptive evolution studies. This will help us to understand and manage the effects of climate change on the Earth.

Biological effects of Thymol loaded chitosan nanoparticles (TCNPs) on bacterial plant pathogen Xanthomonas campestris pv. campestris

Engineered nanomaterials can provide eco-friendly alternatives for crop disease management. Chitosan based nanoparticles has shown beneficial applications in sustainable agricultural practices and effective healthcare. Previously we demonstrated that Thymol loaded chitosan nanoparticles (TCNPs) showed bactericidal activity against Xanthomonas campestris pv campestris (Xcc), a bacterium that causes black rot disease in brassica crops. Despite the progress in assessing the antibacterial action of TCNPs, the knowledge about the molecular response of Xcc when exposed to TCNPs is yet to be explored. In the present study, we combined physiological, spectroscopic and untargeted metabolomics studies to investigate the response mechanisms in Xcc induced by TCNPs. Cell proliferation and membrane potential assays of Xcc cells exposed to sub-lethal concentration of TCNPs showed that TCNPs affects the cell proliferation rate and damages the cell membrane altering the membrane potential. FTIR spectroscopy in conjunction with untargeted metabolite profiling using mass spectrometry of TCNPs treated Xcc cells revealed alterations in amino acids, lipids, nucleotides, fatty acids and antioxidant metabolites. Mass spectroscopy analysis revealed a 10-25% increase in nucleic acid, fatty acids and antioxidant metabolites and a 20% increase in lipid metabolites while a decrease of 10-20% in amino acids and carbohydrates was seen in in TCNP treated Xcc cells. Overall, our results demonstrate that the major metabolic perturbations induced by TCNPs in Xcc are associated with membrane damage and oxidative stress, thus providing information on the mechanism of TCNPs mediated cytotoxicity. This will aid towards the development of nano- based agrochemicals as an alternative to chemical pesticides in future.