Metabolic Potential of Some Functional Groups of Bacteria in Aquatic Urban Systems

Bianca Ojovan,Rodica Catana,Madalin Enache,Mirela Moldoveanu,Anca Ioana Lucaci,Roxana Cojoc,Simona Neagu,Larisa Florescu,Luminita Marutescu,Robert Ruginescu

doi:10.3390/fermentation7040242

Abstract

This study analyzed the metabolic potential of some functional groups of bacteria in aquatic urban systems and evaluated the abundance of communities of total heterotrophic bacteria in the water in relation to the monitored physico-chemical factors. The results obtained showed seasonal differences, especially in spring. The high values of the abundance of heterotrophs in winter are related to human activity at the sampling stations. Screening for four types of extracellular hydrolytic enzyme with potential for degradation of organic matter (amylases, lipases, proteases and cellulases) led to the conclusion that lipolytic bacteria were dominant in the studied ecosystems, while proteolytic bacteria were observed in low numbers, but were present in urbanized areas. The presence of cellulolytic bacteria is correlated with the development of macrophytic vegetation. The aim of the present study was oriented towards the evaluation of the anthropogenic input in several lakes surrounding Bucharest in the Nord-Eastern region. These urban ecosystems are generated as a requirement of city development. The microbiological and general enzymatic approaches generated some novel results concerning the pollution degree of aquatic urban ecosystems and could be considered as a platform for further investigation.

Highlights

Communities of microorganisms are essentially involved in the process of organic matter decomposition
The importance of microorganisms in the organic matter pathways along the food web has been reconsidered beginning with the recognition of the existence of the microbial loop by Azam [1]
The present study aimed to evaluate the production capacity of microbial extracellular hydrolytic enzymes potentially involved in the organic matter degradation processes in the lakes along Colentina River

Summary

Introduction

Communities of microorganisms are essentially involved in the process of organic matter decomposition. Since the 20th century, several important publications have stated the role of microorganisms in the primary production and consumption of dissolved organic substances [2,3,4]. These findings supported the hypothesis that microorganisms provide a link in the food web between phytoplankton, dissolved nutrients, and zooplankton. Several studies had as their main purpose the investigation of the processes by which microorganisms decompose organic matter and restore to other trophic levels the nutrients necessary for the functioning of the ecosystem

Objectives

Methods

Results

Discussion

Conclusion