Microbial enzymes in the Mediterranean Sea: relationship with climate changes

Area of Science:

• Marine microbiology
• Biogeochemistry
• Environmental science

Background:

• Microorganisms drive nutrient cycles (Carbon, Nitrogen, Phosphorus) in aquatic ecosystems via extracellular enzyme activities.
• Extracellular enzymes like leucine aminopeptidase, alkaline phosphatase, and beta-glucosidase are adaptive and influenced by environmental factors.
• The Mediterranean Sea, a semi-closed basin, serves as a model for studying climate change impacts on marine ecosystems.

Purpose of the Study:

• To review and evaluate the effects of environmental changes on microbial extracellular enzymatic activity in the Mediterranean Sea.
• To understand how climate variability influences microbial processes and nutrient regeneration.

Main Methods:

• Review of long-term studies on enzymatic activities (leucine aminopeptidase, alkaline phosphatase, beta-glucosidase) in Mediterranean areas.
• Analysis of spatial and temporal variations in hydrolytic activities.
• Correlation of enzyme activities with environmental factors such as depth, season, and temperature.

Main Results:

• Enzymatic activities showed significant spatial and temporal variations.
• Highest hydrolytic activities were observed in the epipelagic layer (0-100m) and coastal zones during warmer periods.
• A direct relationship between temperature changes and enzymatic activity was identified in the Central Mediterranean Sea.
• Spatial variations in enzyme activities indicated shifts in prokaryotic community metabolic profiles and nutrient regeneration.

Conclusions:

• Environmental changes, particularly temperature, significantly modulate microbial extracellular enzymatic activity in the Mediterranean Sea.
• These findings highlight the biogeochemical implications for nutrient cycling and microbial metabolism.
• Long-term monitoring of microbial activity in response to rising temperatures can predict future ecosystem dynamics under climate change.