International Journal of Environmental Science and Technology
Rhizospheric bacteria with potential to degrade landll leachate
· L. Centa Malucelli
· M. Regina Pincerati
· L. Teresinha Maranho
Received: 31 July 2017 / Revised: 23 February 2018 / Accepted: 11 May 2018
© Islamic Azad University (IAU) 2018
Landﬁll leachate shows negative impacts to environment. Designed as a conventional treatment it may not, however, be
able to reduce pollutant load to acceptable levels according to legislation and environmental laws. Therefore, complemen-
tary post-treatment is often necessary for that matter, where they cooperate with conventional one. For the present work,
a rhizospheric bacterium was isolated from Alternanthera philoxeroides (Mart.) Griseb., aquatic macrophyte commonly
used in wetland leachate treatment. The bacterium was isolated from rhizosphere and identiﬁed through deoxyribonucleic
acid sequencing and assessed for its leachate degradation potential. Obtained biomass through bench bioreactor was freeze-
dried for preserving its catalytic activity. The results suggest that the isolated bacterium is tolerant in leachate added media,
where it presented biomass growth of 1.1 g L
after fermentation. When under enriched mineral media conditions, biomass
growth was higher (3.9 g L
), as expected. Once proved to be tolerant and able to grow on a media with high pollutant load
(leachate), the isolated bacterium can be exploited for enhancing present landﬁll leachate post-treatment.
Keywords Biodegradation · Biomass freeze-drying · Rhizodegradation · Rhizosphere · Environmental biotechnology
Landﬁll is considered a simple, yet, low-cost option for
municipal solid waste (MSW) ﬁnal disposition (Diaman-
tis et al. 2013; Fernandes et al. 2015). Often evaluated as
the most appropriate option for waste treatment, resulting
leachate is the main issue in this process. Leachate is pro-
duced from rainwater inﬁltration within MSW decomposi-
tion products, presenting high levels of both organic and
inorganic matter, which makes its treatment diﬃcult (Lange
et al. 2006; Ganigué et al. 2007). Intense contamination may
occur if leachate is not controlled under strict conditions
(Wagh et al. 2007).
Phytoremediation is used to degrade, bioaccumulate
and/or stabilize soil, air and water pollutants by plants and
microorganisms association in its rhizospheric region (Rah-
man and Hasegawa 2011; Surriya et al. 2014; Ojoawo et al.
2015; Ma et al. 2016). Phytoremediation of wetlands reduces
organic and inorganic pollutants mainly by decreasing tur-
bidity and odor (Ojoawo et al. 2015).
In a previous work at Curitiba’s Landﬁll (Curitiba, PR,
Brazil), inactive since 2010, Alternanthera philoxeroides
(Mart.) Griseb. was selected as one of the main species in
region for its leachate post-treatment potential (Preussler
et al. 2015). In this process, phytostimulation takes place,
as the plant positively inﬂuences on rhizospheric micro-
organisms’ development for pollutant stabilization and
Taking this into consideration, microorganisms were iso-
lated and assessed for their potential in organic and inorganic
pollutant removal (Arjoon et al. 2013; Hassanshahian et al.
2014; Ponsin et al. 2015). Alternatively, resulting biomass
may be immobilized for enhancing its degradation capability
and aiding in biomass recovery for in situ bioremediation.
Preliminary studies indicated a rhizospheric bacterium of A.
philoxeroides was present only under leachate conditions.
Taking the hypothesis that exclusive presence of this bacte-
rium should indicate potential for leachate biodegradation,
this work aimed to characterize, stimulate biomass growth
and assess for its potential in pollutant load reduction using
landﬁll leachate as substrate. This research was conducted
in Curitiba’s Landﬁll and Positivo University laboratories
(Curitiba, PR, Brazil) during 2015–2016.
Editorial responsibility: Tanmoy Karak.
* L. Teresinha Maranho
Universidade Positivo (UP), R. Prof. Pedro Viriato Parigot
de Souza, 5300, Curitiba, PR 81.280-330, Brazil