Cold-stress response during the stationary-growth phase of Antarctic and temperate-climate Penicillium strains

Fungal survival under temperature stress: a proteomic perspective

BACKGROUND

Increases in knowledge of climate change generally, and its impact on agricultural industries specifically, have led to a greater research effort aimed at improving understanding of the role of fungi in various fields. Fungi play a key role in soil ecosystems as the primary agent of decomposition, recycling of organic nutrients. Fungi also include important pathogens of plants, insects, bacteria, domestic animals and humans, thus highlighting their importance in many contexts. Temperature directly affects fungal growth and protein dynamics, which ultimately will cascade through to affect crop performance. To study changes in the global protein complement of fungi, proteomic approaches have been used to examine links between temperature stress and fungal proteomic profiles.

SURVEY METHODOLOGY AND OBJECTIVES

A traditional rather than a systematic review approach was taken to focus on fungal responses to temperature stress elucidated using proteomic approaches. The effects of temperature stress on fungal metabolic pathways and, in particular, heat shock proteins (HSPs) are discussed. The objective of this review is to provide an overview of the effects of temperature stress on fungal proteomes.

CONCLUDING REMARKS

Elucidating fungal proteomic response under temperature stress is useful in the context of increasing understanding of fungal sensitivity and resilience to the challenges posed by contemporary climate change processes. Although useful, a more thorough work is needed such as combining data from multiple -omics platforms in order to develop deeper understanding of the factor influencing and controlling cell physiology. This information can be beneficial to identify potential biomarkers for monitoring environmental changes in soil, including the agricultural ecosystems vital to human society and economy.

Validating biochemical features at the genome level in the Antarctic bacterium Hymenobacter sp. strain UV11

We present experimental data that complement and validate some biochemical features at the genome level in the UVC-resistant Antarctic bacterium Hymenobacter sp. UV11 strain. The genome was sequenced, assembled and annotated. It has 6 096 246 bp, a GC content of 60.6% and 5155 predicted genes. The secretome analysis, by combining in silico predictions with shotgun proteomics data, showed that UV11 strain produces extracellular proteases and carbohydrases with potential biotechnological uses. We observed the formation of outer membrane vesicles, mesosomes and carbon-storage compounds by using transmission electron microscopy. The in silico analysis of the genome revealed the presence of genes involved in the metabolism of glycogen-like molecules and starch. By HPLC-UV-Vis analysis and 1H-NMR spectra, we verified that strain UV11 produces xanthophyll-like carotenoids such as 2'-hydroxyflexixanthin, and the in silico analysis showed that this bacterium has genes involved in the biosynthesis of cathaxanthin, zeaxanthin and astaxanthin. We also found genes involved in the repair of UV-damaged DNA such as a photolyase, the nucleotide excision repair system and the production of ATP-dependent proteases that are important cellular components involved in the endurance to physiological stresses. This information will help us to better understand the ecological role played by Hymenobacter strains in the extreme Antarctic environment.