Less abundant bacterial groups are more affected than the most abundant groups in composted tannery sludge-treated soil

Ana Roberta Lima Miranda,Paul J Van Den Brink,Ademir Sergio Ferreira De Araujo,Jadson Emanuel Lopes Antunes,Vania Maria Maciel Melo,Fabio Fernando De Araujo,Walderly Melgaco Bezerra

doi:10.1038/s41598-018-30292-1

Ana Roberta Lima Miranda, Paul J Van Den Brink + Show 5 more

Open Access

https://doi.org/10.1038/s41598-018-30292-1

Copy DOI

Abstract

The application of composted tannery sludge (CTS) has promoted shifts in soil chemical properties and, therefore, can affect the soil bacterial community. This study assessed the effect of the CTS on the soil bacterial community over time. The CTS was applied at five rates (0, 2.5, 5, 10 and 20 t/ha), and the bacterial community was evaluated for 180 days. The principal curve response (PRC) analysis showed that the most abundant phyla were not influenced by the CTS rates over time, while the analysis of the bacterial community showed that some of the less abundant phyla were influenced by the CTS rates. Similarly, the PRC analysis for the bacterial classes showed the significant effect of the CTS rates. The redundancy analyses for the bacterial phyla and classes showed the relationship between the significant chemical properties and the bacterial community of the soil after the CTS amendment over time. Therefore, there was a shift in the bacterial community over time with the application of the composted tannery sludge. Our study has shown that the less abundant bacterial groups were more influenced by the CTS than the most abundant bacterial groups and that these bacterial groups were driven by soil chemical properties, primarily chromium (Cr) and the soil pH.

Highlights

The application of composted tannery sludge (CTS) has promoted shifts in soil chemical properties and, can affect the soil bacterial community
Principal response curve (PRC) analysis of the chemical properties showed that the CTS rates explained 85% of the total variance and indicated that the values of most of the chemical variables increased in all CTS treatments
Cr and the soil pH were the primary chemical variables influenced by the CTS amendment, showing a weight higher than 1.0, followed by Ca, P, electric conductivity (EC) and total organic C (TOC) with a weight higher than 0.25

Summary

Introduction

The application of composted tannery sludge (CTS) has promoted shifts in soil chemical properties and, can affect the soil bacterial community. Tannery industries have released annually high amounts of tannery sludge (TS), a type of solid waste that contains large amounts of chromium (Cr), salts, carbonates, and hydroxides[1] It is well-known that TS transfers these chemical elements, this has not precluded its use as a soil conditioner in agriculture[2,3]. Previous studies have found a significant influence of the CTS on the chemical properties of soil[5], and these changes have affected the soil microbial biomass and enzyme activities[1]. Previous studies have assessed the effect of the TS on the bacterial community[6,7], the effect of the CTS on bacterial community remains unclear

Methods

Results

Conclusion