Suitability of Immobilized Systems for Microbiological Degradation of Endocrine Disrupting Compounds

Review

Suitability of Immobilized Systems for Microbiological Degradation of Endocrine Disrupting Compounds

Danuta Wojcieszyn´ska , Ariel Marchlewicz and Urszula Guzik *

Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Science, University of Silesia in Katowice, Jagiellon´ska 28, 40-032 Katowice, Poland; [email protected] (D.W.); [email protected] (A.M.) * Correspondence: [email protected]; Tel.: +48-3220-095-67

Academic Editors: Urszula Guzik and Danuta Wojcieszyn´ska Received: 10 September 2020; Accepted: 25 September 2020; Published: 29 September 2020

ꢀꢁꢂꢀꢃꢄꢅꢆꢇ

ꢀꢁꢂꢃꢄꢅꢆ

Abstract: The rising pollution of the environment with endocrine disrupting compounds has increased

interest in searching for new, eﬀective bioremediation methods. Particular attention is paid to the search for microorganisms with high degradation potential and the possibility of their use in the degradation of endocrine disrupting compounds. Increasingly, immobilized microorganisms or enzymes are used in biodegradation systems. This review presents the main sources of endocrine disrupting compounds and identiﬁes the risks associated with their presence in the environment. The main pathways of degradation of these compounds by microorganisms are also presented. The last part is devoted to an overview of the immobilization methods used for the purposes of

enabling the use of biocatalysts in environmental bioremediation. Keywords: EDCs; hormones; degradation; immobilization; microorganisms

1. Introduction

The development of modern tools for the separation and identiﬁcation of chemical substances

has drawn attention to the so-called micropollution of the environment. Many of these contaminants

belong to the emergent pollutants class. According to the Stockholm Convention they are characterized by high persistence, are transported over long distances in the environment through water, accumulate

in the tissue of living organisms and can adversely aﬀect them [

include pharmaceuticals, the presence of which are not only found in hospital or municipal sewage but

also in Arctic water or drinking water [ ]. In many laboratories, new methods for the degradation

1]. Substances meeting these criteria

1,2

of these compounds are being developed, with the use of microorganisms that have an increased

potential for the degradation of these compounds. Biological treatment is a promising technology due

to its low cost and reduced energy requirements [

these microorganisms in the complex microbial consortia of wastewater treatment plants [

more and more attention has been paid to immobilized systems, in which these strains are protected by binding them to a carrier [ ]. The use of microorganism immobilization in the drug’s biodegradation

3

,4

]. However, the main problem is the survival of

5

]. Hence,

4

,6,7

not only protects them from harmful environmental conditions, but also leads to an increase in the intensity of the biotransformation processes as a result of the local thickening of the biomass and a higher tolerance of the bacterial cells to these pharmaceuticals [

4

,7]. The intensive development of

immobilization methods has led to the discovery of many carriers and immobilization techniques [

7

,8

].

The new techniques differ in the level of difficulty of the procedure used, cost-effectiveness, efficiency

of the processes carried out in the immobilized systems and the usefulness in the immobilization of the

microorganisms. For this reason, the purpose of this work is to review the achievements to date in the

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ﬁeld of using immobilized systems in the endocrine disrupting compounds biodegradation processes.

This will systematize the existing knowledge about the subject and indicate the advantages and

disadvantages of the methods used, as well as the needs and perspectives for the further development

of immobilization methods.

2. Endocrine Disrupting Compounds (EDCs) in the Environment and Associated Risks

Endocrine disrupting compounds (EDCs) are natural or synthetic substances that, when introduced into the environment, aﬀect the endocrine and homeostatic system of non-target organisms by disabling

their communication and response to environmental stimuli. These include estrogens- natural and synthetic female and male hormones that play an important role in both the reproductive and the

non-reproductive systems [

considered to be the strongest among the endocrine factors in the environment [10]. Synthetic estrogens

have been divided into steroidal, such as 17 -ethynylestradiol and 3-methyl ether of ethynylestradiol,

used as ingredients of birth control pills, and nonsteroidal estrogens such as diethylstilbestrol used to

prevent miscarriages [ 11]. Human use of the latter was banned in 1972 due to its negative eﬀects,

3,6,9]. Estrone, estriol and 17β-estradiol are natural estrogens. The latter is

α

3

,7,

however, it is still used in China as a growth promotor for terrestrial livestock or ﬁsh [11]. The presence

of estrogens has been reported in many aquatic environments (Table 1).

Table 1. Occurrence of EDCs in the environment.
EDCs

Estrone

Concentration

10.4 ng/L

Occurrence

Sampling Period

Spring to autumn Spring to autumn Spring to autumn December to May December to May December to May
May

References

[4]
Leca River (Portugal) Leca River (Portugal) Leca River (Portugal) Wuluo River
(Taiwan) Wuluo River
(Taiwan) Wuluo River
(Taiwan)
17β-Estradiol
Estriol

5.9 ng/L

[4]

4.4 ng/L

[4]

Estrone

1.27 ng/L

[12]

[12] [12] [13] [13] [14] [14] [15] [16] [16] [17] [17] [18]
17β-Estradiol
Estriol
313.60 ng/L 210.00 ng/L 40–117 ng/L
9.78–151 ng/L
0.076–0.233 ng/L
0.68 ng/L
Surface water of Taihu Lake, China Sediments of Taihu
Lake, China Lake Balaton, Hungary River Zala, Hungary
Yangtze estuary,
China
Themi River, Tanzania
Kalansanan River,
Malaysia
Fenholloway River,
USA
Fenholloway River,
USA
17β-Estradiol 17β-Estradiol 17β-Estradiol
May No data

17α

-Ethynyl-estradiol

Estrogen
No data
3.22–20.61 ng/L
20.4–439 ng/L
16,689 ng/L
40 ng/L
Four seasons

March

Progesterone

No data

Androstenedione Progesterone

May and December May and December

High rainy periods
2060 ng/L
Atibaia River,
Brazil

17α-Ethynyl-estradiol 981–4390 ng/L

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Table 1. Cont.

EDCs

Concentration

17–501 ng/L

Occurrence

Sampling Period

Dry winter period High rainy periods Dry winter period

References

[18]
Atibaia River,
Brazil
Atibaia River,
Brazil
Atibaia River,
Brazil

17α-Ethynyl-estradiol

17β-Estradiol

464–6806 ng/L

106–2273 ng/L
[18]

17β-Estradiol

[18]

High rainy periods and dry winter period
Atibaia River,
Brazil

Estrone

16 ng/L

[18]

Atibaia River,
Brazil
Atibaia River,
Brazil
Atibaia River,
Brazil
Atibaia River,
Brazil
Progesterone Progesterone Levonorgestrel Levonorgestrel
20 ng/L
20–195 ng/L
19 ng/L
High rainy periods Dry winter period High rainy periods Dry winter period
[18] [18] [18]

[18]

19–663 ng/L

Atibaia River,
Brazil

4-Octylphenol

21 ng/L

[18]

Atibaia River,
Brazil

4-Nonylphenol

18 ng/L

[18]

Testosterone Testosterone Estrogen Estrogen Estriol
1.9–2.7 ng/L 1.0–3.8 ng/L 0.6–2.2 ng/L 1.2–3.4 ng/L 0.9–1.8 ng/L 0.9–2.9 ng/L

Lower Jordan River Lower Jordan River Lower Jordan River Lower Jordan River Lower Jordan River Lower Jordan River

May October May October May October
[19] [19] [19] [19] [19]

[19]

Estriol

One of the main sources of estrogens in a highly urbanized environment is urine and faeces getting

into wastewater. It has been shown that annually 33 and 49 tonnes of estrogen excreted from farms

in the European Union and the United States, respectively, are released into the environment [12,20].

In human and animal organisms, estrogens are usually hydroxylated or conjugated with glucuronide

or sulfate hence these forms most often get into wastewater. It is estimated that about 90% of urine

estrogens are in the form of conjugates. Most estrogen conjugates are more polar than parent molecules,

so they can be more mobile in the environment. Despite the fact that conjugates have low estrogenic

potential, they can be chemically or enzymatically hydrolysed to active forms in the environment. For example, the Escherichia coli strain KCTC 2571 has β-glucuronidase, which cleaves glucuronide

moieties, releasing free estrogen [20,21].

As a result of the operation of sewage treatment plants, 19–94% of estrogens are biodegraded

and biotransformed. Typically, concentrations in the range of 1–3 ng/L are observed in the eﬄuents

from treatment plants [3]. Although these compounds occur in the environment in concentrations of ng/L, it is known that they can have a strong negative impact in amounts below 1 ng/L because

they have a high aﬃnity for nuclear estrogen receptors. This biological activity can lead to low levels

of estrogen in the environment causing endocrine disorders in the wildlife population. Negative

effects on development, sex differentiation, reproduction of different animal species and production

of vitellogenin have been documented [ negative impact on the sexual behaviour of frogs in suburban areas in the United States have been

observed [12]. In addition, it has been shown that 17 -estradiol, at concentrations of 0.1–1 ng/L, causes

3,4,7,11,12]. Intersexual disorders in ﬁsh in Europe, and a

β

reproductive disorders in aquatic animals. Disrupting in the development, spawning and fertility of Japanese medaka (Oryzias latipes) was showed at low estrogen concentrations [20]. An increase in osteoblast activity was also detected in ﬁsh such as goldﬁsh and wrasse, which resulted in the

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mobilization and mineralization of ﬁsh scales [22]. The presence of this compound in the environment

may cause disturbances in the secretion of endogenous gonadal sex hormone in humans and reduce

sperm production, as well as increase the incidence of cancer [6]. In addition, it has been observed

that often the response to estrogens is dependent on the age of the organisms. For instance, adults of

common roach showed a slight response to the presence of estrogens, while exposure to hormonal

compounds during the embryonic period caused 100% feminization in ﬁsh. In toxicological studies at

various developmental stages, Atlantic salmon showed a higher level of vitellogenin mRNA in the presence of EDCs in all stages, except in embryos. In addition, embryos were only sensitive to the

highest levels of 17α-ethynylestradiol while the remaining stages responded to the intermediate and

highest doses not only of 17α-ethynylestradiol, but also 17β-estradiol, and nonylphenol. Moreover,

fry have been shown to be the most sensitive of the salmon life stage on EDCs [23]. Czarny et al. [24]

showed a dose-dependent eﬀect of estrogens on the growth of cyanobacteria Microcystis aeruginosa. Concentrations below 1 mg/L did not aﬀect the growth of cyanobacteria, whereas concentrations of hormones above 10 mg/L inhibited their growth. This is due to the phenomenon of hormesis.

Low hormone concentrations activate the repair functions of cyanobacteria and induce the activity of

proteins involved in them. Higher concentrations damage the maintenance and repair functions of cells. It was also observed that the eﬀect of chronic toxicity depended on the hormone used and it decreased according to the series: 17-α-ethynylestradiol > progesterone > 17ß-estradiol > 5-pregnen-3β-ol-20-one > testosterone > estrone> levonorgestrel > estriol. Moreover, the hormone mixture caused a signiﬁcant

increase in toxicity compared to the same concentrations of individual hormones. The range of EC₅₀

values obtained for the mixture of hormones and individual hormones were 56.66–166.83 mg/L and

88.92–355.15 mg/L, respectively (according to the EU classiﬁcation, pollutants with EC₅₀values of

10–100 mg/L are harmful to aquatic organisms). The negative impact of hormones on cyanobacteria is

connected with the rapid penetration of hormones into cells and the impact on photosynthetic activity

by interfering with the ﬂow of electrons through the photosystem II [24]. A signiﬁcant increase in the

toxicity of the mixture compared to individual substances may translate into more serious ecological

eﬀects. This observation is all the more important because of the environment where we usually deal

with mixtures of hormones. Moreover, estrogens can accumulate in the food chain and the eﬀects may appear in the next generation, threatening the health of the human population [4,11,24]. Also,

the World Health Organization classiﬁed estrogens as group 1 carcinogens and some of their catechol

metabolites such as 4-hydroxyestrone are also carcinogens [12,25].

Another group of endocrine substances that can be found in the environment are androgens.

Like estrogens they can interfere with the normal functioning of the endocrine system of non-target

organisms in trace concentration and they have many sources from which they get into the water, and due to ﬁltration they also get into underground water. One of the most commonly identiﬁed androgens in the environment is testosterone, its presence in the environment may cause a high

percentage of males in the aquatic environment, appearance of male secondary sex characteristics in

female ﬁsh, inhibition of vitellogenin induction, reduction of reproductive capacity and masculinization

in mammals [26]. For example, defeminisation has been observed in fathead minnows that have been

exposed to wastewater from cattle farms [27]. Moreover, it has been showed that male Atlantic salmon

exhibit an odorant response to testosterone at extremely low concentration (0.003 ng/L) [28].

There are also substances in the environment that disturb the action of endogenous compounds

due to the similarity of their structure to hormones (chemicals mimic hormones), such as bisphenol

A, 4-nonylphenol, parabens and phthalate, as well as antibacterial triclosan [29,30]. Moreover, some mycotoxins, such as zearalenone produced by several Fusarium spp., have strong estrogenic activity [31]. These compounds are resistant to microbiological degradation and their duration in sediments can be up to 40 years and, similar to hormonal substances, sometimes they can be food

contaminants and thus, they can cause reproductive and developmental disorders of aquatic animals

and humans [29,31]. Kriszt et al. [31] showed that zearalenone signiﬁcantly increased the uterus weight

in a dose dependent manner and upregulated complement component 2, calbindin-3 expression,

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and decreased apelin and aquaporin 5 mRNA levels. This is due to the high aﬃnity of zearalenone

for estrogen receptors. Moreover, this compound and its metabolite α-zearalenol stimulate the

proliferation of MCF-7 human adenocarcinoma cells [31]. Nonylphenol may cause various disorders of

the male reproductive system, such as a reduction of testicle size and decrease of sperm production in

Oncorhynchus mykiss. This mimic hormone was also observed to induce the proliferation of the human

breast cancer cell line [32]. Due to the prevalence of endocrine compounds and other pharmaceuticals

in the environment and their possible negative eﬀect on non-target organisms, more and more attention

is being paid to the methods of their removal from the environment.

3. Microbiological Degradation of EDCs

In developed countries, where the problem of endocrine substances is the greatest, sewage treatment plants play a key role in their removal. Organisms involved in the removal of estrogens

from the environment include bacteria, as well as fungi and microalgae (Figure 1) [11].

Figure 1. The main mechanisms for removing EDCs [3,9,26,30].

Bacteria that degrade these hormones belong to genera such as Bacillus, Virgibacillus,

Novosphingobium, Rhodococcus, Acinetobacter, Pseudomonas, Sphingomonas, Enterobacter, Klebsiella, Aeromonas, Comamonas, Thauera, Deinococcus, Stenotrophomonas and cyanobacteria [ 28 31 33 39]. Raphidocelis subcapitata, Chlorella vulgaris, Chlorococcus and Scenedesmus quadricauda

belong to algae capable of removing hormones [11 26 40 41]. Fungi from genus Trichoderma,

3,4,6,7,10,12,25,

,

–

,

Trametes, Phanerochaete, Pleurotus, Aspergillus, Lentinula, Drechslera, Curvularia, Penicillium, Acremonium,

Fusarium, Gibberella, Beauvaria, Doaratomyces, Scopulariopsis, Chaetomidium, Thielavia, Neurospora, Absidia,

Cunninghamella, Actinomucor, Rhizopus, Phycomyces, Mortierella, Circinella and Ganoderma (Table 2) were

also described as being capable of hormone biodegradation/biotransformation [22,30,42–46].

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Table 2. Microorganisms engaged in EDCs biodegradation/biotransformation.

Organism

EDCs

Dose

Eﬃciency [%]

References

Virgibacillus halotolerans
Bacillus ﬂexus
Bacillus licheniformis

Novosphingobium sp. ARI-1

17β-estradiol 17β-estradiol 17β-estradiol estrone
5 mg/L 5 mg/L 5 mg/L
1.75 µg/L 1.52 µg/L 0.71 µg/L 30 mg/L 2 mg/L
100 100 100
80.43
100
94.76
94
[3] [3] [3] [4] [4] [4] [6] [7] [7] estriol
17β-estradiol 17β-estradiol
17α-ethynylestradiol 17α-ethynylestradiol

Rhodococcus sp. JX-2 Rhodococcus zopﬁi Pseudomonas putida F1
Acinetobacter sp.

86.5

73.8

0.5 mg/L

17β-estradiol

40 mg/L

90

[10]

DSSKY-A-001

Acinetobacter sp. LHJ1 Acinetobacter sp. BP8 Acinetobacter sp. BP10

Novosphingobium sp. SLCC

Sphingomonas sp. KC8