Biological activity of bacteria isolated from wetland sediments collected from a conservation unit in the southern region of Brazil

Priscila R Jankoski,Adriano Brandelli,Ana Paula F Correa,Amanda S Da Motta

doi:10.1590/0001-3765202120191269

Priscila R Jankoski, Adriano Brandelli + Show 2 more

Open Access

https://doi.org/10.1590/0001-3765202120191269

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Abstract

Wetlands are ecosystems rich in biodiversity and their ecological importance is recognized worldwide. Sediment samples were subjected to physical-chemical analysis and organic carbon content varied from 3.0% to 4.8%, the clay between 32 and 40%, silt with 41% and 43%, sand coarse varied between 6 and 11% and fine sand between 7 and 16%. The nitrogen values varied from 0.25% to 0.48%, the pH from 5.4 to 7.5 and the humidity varied from 44 to 56%. The selected isolates were evaluated for enzymatic properties and 64% showed positive results for amylase, 16% for gelatinase, 37% for lipase, 91% for protease and 2.7% for inulinase. Six bacterial isolates were selected for the overlapping assay and Bacillus sp. sed 2.2 showed inhibitory activity against Corynebacterium fimi NCTC 7547, and the antimicrobial substance was partially purified. The characterization of the substance was carried and the substance was stable at 100° C for up to 10 minutes and sensitive to the enzymes papain and trypsin. This substance was active against some species of Listeria, including Listeria monocytogenes ATCC 7644. The microorganims obtained from sediment samples were important sources of bioactive compounds, including enzymes and peptides, being a source of bioactive compounds to be studied.

Highlights

Wetlands are important ecosystems with high dynamism found in virtually all regions of the world (Jungblut et al 2012)
In order to characterize the composition of the bacterial community in the soil of a humid area, the technique of equations of the 16S rRNA gene was used by Ansola et al (2014) and the main microbial groups found were: Proteobacteria, Verrucomicrobia and Chloroflexi
Some studies have shown that organic matter, total nitrogen, inorganic nitrogen, chemical oxygen demand (COD), and pH are determinants of bacterial community composition found in soil (Ansola et al 2014, Ligi et al 2014, Arroyo et al 2015, Ding et al 2015)

Summary

Introduction

Wetlands are important ecosystems with high dynamism found in virtually all regions of the world (Jungblut et al 2012). The microorganisms present there play important ecological roles and are fundamental for the adequate functioning of these environments (Hu et al 2014). Panosyan et al (2018) analyzed the composition of the bacterial community of a soil and most of the bacterial genera found were Halobacillus (41.2%), Piscibacillus (23.5%), Bacillus (23.5%) and Virgibacillus (11.8%). The importance of studying these environments goes far beyond just identifying the microbial community, since many of these microorganisms are producers of compounds involved in different active biological processes. Li et al (2017) investigated the diversity of extracellular protease-producing bacteria in China and, of the 121 isolates studied, identified bacteria belonging to the Pseudoalteromonas (40.5%), Bacillus (36.3%), and Photobacterium (5.8%) genera. Li et al (2017) investigated the diversity of extracellular protease-producing bacteria in China and, of the 121 isolates studied, identified bacteria belonging to the Pseudoalteromonas (40.5%), Bacillus (36.3%), and Photobacterium (5.8%) genera. Ghani et al (2013) isolated different strains of Bacillus licheniformis for

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