23 | Putri et al.; Screening of Extracellular Enzymes on Serratia marcescens
Jurnal Riset Biologi dan Aplikasinya, Volume 3, Issue 1, March 2021
Screening of Extracellular Enzymes on Serratia marcescens strain MBC1
Meishy Handerlin Putri*, Kusuma Handayani, Wawan A. Setiawan, Berliana Damayanti, Cindy Lukyta
Ratih, Achmad Arifiyanto
Biology Departement, Faculty of Mathematics and Natural Sciences, Lampung University
Jln. Prof Soemantri Brojonegoro 1, Rajabasa District, Bandar Lampung, Lampung 35144, Indonesia
*Corresponding Author:
e-mail: handerlinmeishy@gmail.com
Article History ABSTRACT
Received : 14 Februari 2021 Hydrolase enzymes are a class of enzymes used to break down the organic
substrates into simpler molecules. Hydrolase enzymes play a role in biocontrol,
industry, and public health. One of the hydrolase enzyme producers is bacteria.
Serratia marcescens strain MBC1 is a collection in the Microbiology Laboratory of
the Department of Biology, Faculty of Mathematics and Natural Sciences,
University of Lampung which enzymatic activities haven’t been known yet. This
research aimed to determine the enzymatic activity of S. marcesescens strain MBC1
that can be used as a candidate for biocontrol agents, biosurfactant producers,
industry, or in the health sector. The screening was carried out using a qualitative
method plate assay using selective solid media for each test, with three replications
for each test. The data obtained were analyzed statistically using non-parametric
Kruskall Wallis test. The lipolytic activity of the S. marcescens strain MBC1
showed high efficacy with an enzymatic index of 5.52 and amylase, cellulases,
protease, mannanase, and chitinase with enzymatic indexes, respectively, 4.17, 1.50,
0.69, 0.35, and 0.27. This enzyme activity of this isolate can be used as a candidate
for biological control agents, biosurfactant producers, industry, or the health
sector.
Revised : 4 Maret 2021
Approved : 22 Maret 2021
Published : 31 Maret 2021
Keywords
Hydrolase enzymes; Serratia marcescens
strain MBC1; enzymatic activity
How to cite: Putri, M.H., Handayani, K., Setiawan, W.A., Damayanti, B., Ratih, C.L., & Arifiyanto, A. (2021). Screening of
Extracellular Enzymes on Serratia marcescens strain MBC1. Jurnal Riset Biologi dan Aplikasinya, 3(1): 23-29.
DOI: https://doi.org/10.26740/jrba.v3n1.p23-29.
INTRODUCTION
Serratia marcescens is a gram-negative bacteria
and a member of the Enterobacteriaceae family.
This bacteria can be found in water, soil, insects,
vertebral digestive, and plant surfaces (Kahrarian et
al., 2019). S. marcescens strain NMRL 65 has
enzymatic activity lipase and protease based on
research conducted by Mohanram et al. (2020).
Furthermore, the research on the activity of the
cellulase and chitinase enzymes of S. marcescens was
also reported by Cahyani et al. (2017) and
Tubkanlu et al. (2019).
According to their ability to catalyze a
reaction, enzymes can be divided into several
groups. One group of enzymes that can catalyze
hydrolysis reactions is known as hydrolase enzymes
(Wardoyo & Aprilia, 2018). Hydrolase enzymes
have an essential role in various reactions in living
cells as a catalyst. Hydrolase enzymes can be used
to break chemical bonds with water and break down
organic substrates into simpler molecules (Wijaya
et al., 2017). Cellulases, amylases, proteases,
mannanases, and glycosidases were over hydrolase
groups. These enzymes will hydrolyze
polysaccharides into monosaccharides (Puspadewi
et al., 2018).
In biotechnology, lipase is involved in fat-
digesting supplements (Mohanasrinivasan et al.,
2018). Moreover, the amylase enzymes can catalyze
cereal foods such as wheat and bread (Padmavathi
et al., 2018). The extracellular enzymes produced by
microorganisms contributed to agriculture sectors,
and industrial interests (Mohanasrinivasan et al.,
2018; Susilowati et al., 2018).
Natural enzymes were outweighed because of
safety and also eco-friendly. One of the enzyme
producers is bacteria. Several bacteria that are
Jurnal Riset Biologi dan Aplikasinya
https://journal.unesa.ac.id/index.php/risetbiologi
https://doi.org/10.26740/jrba.v3n1.p23-29
Jurnal Riset Biologi dan Aplikasinya, 3(1): 23-29, March 2021 | 24
capable of producing various types of enzymes are
Bacillus licheniformis, Aspergillus sp. (Wijaya et al.,
2017) Serratia marcescens (Cahyani et al., 2017)
Acinetobacter sp., and Pseudomonas sp. (Puspadewi et
al., 2018).
S. marcescens is one of the bacteria with
enzymatic capabilities to produce several types of
enzymes. S. marcescens strain MBC1 is one of the
bacteria culture collection in the Microbiology
Laboratory of FMIPA, the University of Lampung
which was isolated from the agar media
contaminated by Droshophila sp. and the enzymatic
activities haven’t been known yet. Therefore, this
research to determine the enzymatic activity of S.
marcesescens strain MBC1 that can be used as a
candidate for biocontrol agents, biosurfactant
producers, industry, or in the health sector.
MATERIALS AND METHODS
S. marcescens strain MBC1 Bacterial Isolate
Culture
Tryptic Soy Agar (TSA) medium was used to
culture the bacteria 1.5 g of TSA was dissolved in
100 mL distilled water. The medium was sterilized
at autoclave for 15 minutes. S. marcescens bacterial
isolate strain MBC1 was cultured on TSA using a
streak plate technique and then incubated at room
temperature for 24-48 hours.
Gram Staining
One loop of Serratia marcescens strain MBC1
was added to an object-glass. The smear was
stained with crystal violet for one minute. Then, it
was washed under running water and Gram's iodine
was added for one minute after that was exposed to
acetone for decolorization. Then, as a counterstain,
dilute safranin was applied and washed after 30
seconds. The Gram reaction and morphology were
observed microscopically with the help of oil
immersion objective after the bacteria was dried.
KOH String Test
A loopful of a bacterial colony from the culture
plate was emulsified over a glass slide in 3% KOH.
The suspension was stirred continuously for one
minute and then the loop was gently pulled up from
it. If the loop lift was sticky within the first 30
seconds of mixing in KOH solution, the result was
considered positive.
Enzymatic Activity
Enzymatic activity tests were conducted using
qualitative methods with solid fermented agar
media. Three replications were taken place for each
test.
Lipolytic activity tests were conducted based
on the method used by Ervina et al. (2020) with
modifications. This test uses Nutrient Agar (NA), 1%
of olive oil, 0.04% of methyl red, and 0.6% tween-80.
A total of one loop of S. marcescens strain MBC1 was
grown on the medium using the point method.
Then the media was incubated at room temperature
for 24-48 hours Lipolytic activity was characterized
by the formation of a clear zone around the bacterial
colony.
The proteolytic activity test was conducted
based on a modified form of Pratika et al. (2021).
The media composition consisted of Nutrient
Agar (NA) and 1% skim milk. One loop of the S.
marcescens strain MBC1 isolate was taken and at a
point on the medium. Then the media was incubated
at room temperature for 24-48 hours. Positive
proteolytic activity had indicated by a clear zone
around the bacterial colony on the media’s surface.
The amylolytic activity test was conducted
based on Artha et al. (2019) with modifications
using NA media supplemented with 1 % starch. S.
marcescens strain MBC1 was grown on solid media
by point method and incubated at room temperature
for 24-48 hours. Lugol iodine 1% was poured into
the culture to observe the clear zone for
identification of amylase activity. A clear zone
around the bacterial colony was a positive sign of
amylase.
The chitinolytic activity tests were conducted
based on Rosa et al. (2020) by using NA that was
supplemented with 1% of colloidal chitin media.
Then the media was incubated at room temperature
for 24-48 hours. Colloidal chitin was made by
dissolving 5 g of chitin powder in 80 ml of
concentrated HCl solution for 30 minutes by a
magnetic stirrer and left 24 hours at 4◦C. The
mixture was filtered using glass wool. The filtrate
obtained was added with 40 ml of cold distilled
water and homogenized using a magnetic stirrer.
Then, the filtrate adjusted to the pH. Then it was
centrifuged at 7,500 rpm for 15 minutes. The
filtrate obtained was separated from the supernatant
and added with cold distilled water and centrifuged
at 7500 rpm for 15 minutes. The filtrate obtained is
colloidal chitin which is ready for use. The clear
zone was visualized with 0.1% congo red staining
and rinsed using 1 M NaCl.
The cellulose degradation was captured using
the method used by Artha et al. (2019). The media
composition consisted of 1% Nutrient Agar (NA) and
25 | Putri et al.; Screening of Extracellular Enzymes on Serratia marcescens
CMC media. One loop of S. marcescens strain MBC1
was inoculated on the media and incubated at room
temperature for 24-48 hours. Congo red solution
was poured into the culture to observe the clear
zone was cellulolytic activity.
The mannanolytic activity was approached by
the method of Sumardi (2005). The media was into
two layers. The lower layer medium consisted
of yeast extract 0.35%, tryptone 0.35%, MgSO4
0.03%, KH2PO4 0.245%, ammonium sulfate 0.25%
and NaCl, 0.2%. While the composition of the top
layer media consisted of 0.03% MgSO4, 0.245%
KH2PO4, 0.25% ammonium sulfate, 0.2% NaCl and
0.35% locust bean gum (LBG). S. marcescens strain
MBC1 was spotted on the medium. Then, incubated
at room temperature for 24-48 hours. The plate was
stained with 0.5% congo red for 15 minutes and
then rinsed with 1 M NaCl to observe mannanolytic
activity in the presence of a clear zone. The
determination of enzymatic index calculated using
the formula according to the method used by Rosa
et al (2020). The enzymatic index determination of
the results can be calculated using the following
formula by Rosa et al (2020).
The enzymes activity were analyzed using the
non-parametric test of Kruskall Wallis with a
significance level of 95%.
Figure 1. Measurement of clear zone
AB, CD, EF : Diameter of clear zone
ab, cd, ef : Colony diameter
Average clear zone diameter (Dz) : AB + BC + CD / 3
Average colony diameter (Dk) : ab + bc + cd / 3
Average total clear zone diameter (RDz) : Dz1 + Dz2 + Dz3 / 3
Average total colony diameter (RDk) : Dk1 + Dk2 + Dk3 / 3
RESULTS AND DISCUSSION
The isolate has been identified as Serratia
marcescens strain MBC1. It was a Gram-negative
bacterium which had confirmed by KOH 3% test
(Figure 2). From the gram staining, it can be seen
that the bacteria are rounded (cocci) in shape with
red color. The enzymatic ability had been calculated
based on the colony compared to the clear zone
diameter, to obtain the enzymatic index. S.
marcescens strain MBC1 isolate has different
enzymes activities (Figure 3).
Based on the research that has been done,
cellulose concentration 1% was the optimum for the
production of cellulase enzymes. The media used for
testing the activity of the cellulase enzyme contains
a carboxymethyl cellulose (CMC) substrate
(Halimah et al., 2019). S. marcescens strain MBC1
isolate is known to have enzymatic activity because
it can produce a clear zone amount 0.53 mm and is
classified as cellulolytic bacteria. Based on research
by Cahyani et al. (2017) S. marcescens has cellulase
enzyme activity. The utilization of cellulose has
been conducted in various fields, including for the
production of paper, fiber, and chemical derivatives
plastics, and photographic film.
S. marcescens strain MBC1 isolate was able to
degrade lipase-selective media by showing the
hydrolysis zone around the colony by having a clear
zone of 2.03 mm. Based on the research by Isti’anah
et al. (2019) if the ratio extracellular enzyme and
activity index value is above 2, it is included in the
high extracellular ratio. In this method, the Tween-
80 substrate is used to detect lipase activity because
it contains oleic acid esters, that can be hydrolyzed
by the bacteria into mono oleic acid. This mono
oleic acid will bind with calcium to form color
cloudiness around the colony (Ervina et al., 2020).
Jurnal Riset Biologi dan Aplikasinya, 3(1): 23-29, March 2021 | 26
Figure 2. a) Macroscopic S. marcescens strain MBC1 b) KOH Test 3%
Figure 3. Clear zone on enzyme activity a) Lipase, b) Mannanase, c) Cellulase, d) Amylase,
e) Chitinase, f) Protease
In the amylase enzyme activity, an isolate of S.
marcescens strain MBC1 was cultured on a medium
containing 1% starch substrate. The amylolytic
ability was characterized by the formation of a clear
zone in bacterial isolates after 0.1 M iodine was
dropped (Arfah et al., 2020). S. marcescens can
produce amylase enzyme with form clear zone. The
clear zone was formed because starch has been
hydrolyzed to glucose, hence iodine did not absorb
in the spiral flow of starch (amylose), whereas the
blue color occurs due to the presence of iodine
molecules entering the spiral stream of starch
(amylose).
Chitin is a polymer that can be found in fungus
and crustacea. The activity of the chitinase enzyme
will be positive if it can produce a clear zone, this is
caused by the isolate of S. marcescens strain MBC1
can break down the chitin in the medium (Linda et
27 | Putri et al.; Screening of Extracellular Enzymes on Serratia marcescens
al., 2018). This is in line with research by Okay et
al (2013) that used S. marcescens strain MO-1 grown
on NA plates containing chitin and its chitinase
activity was shown via the formation of a clear zone
due to chitin degradation. This character will
advantage to inhibit fungus and degraded chitin
enriched materials.
The ability of the S. marcescens strain MBC1 to
produce protease was characterized by the
formation of a clear zone around the colony on the
media with a clear zone of 0.6 mm, as a sign that the
bacteria are producing protease to hydrolyze
peptone and skim milk by producing protease. The
protein contained in the media is a protease inducer.
The clear zone was an indicator of the presence of
these bacterial isolates being able to utilize protein
in the media as a source of nutrition (Pratika et al.,
2021). This was in line with studies performed by
(Mohanram et al., 2020). Using S. marcescens strain
NMRL 65 hydrolyzed casein in skimmed milk agar
producing a clear zone around colonies after 48
hours, which indicated the protease enzyme
production.
The ability of the S. marcescens strain MBC1 to
produce protease is characterized by the formation
of a clear zone around the colony on the media with
a clear zone of 0.6 mm, as a sign that the bacteria
was producing protease to hydrolyze peptone and
skim milk by producing protease. The protein
contained in the media is a protease inducer. The
clear zone is an indicator of the presence of these
bacterial isolates being able to utilize protein in the
media as a source of nutrition (Pratika et al., 2021).
This is in line with studies performed by
(Mohanram et al., 2020) Using S. marcescens strain
NMRL 65 hydrolyzed casein in skimmed milk agar
producing a clear zone around colonies after 48
hours which indicated the protease enzyme
production.
S. marcescens strain MBC1 showed the growth
on a substrate containing locust bean gum (LBG) the
size of the clear zone is 0.44 mm. This is in line with
studies performed by Olaniyi & Arotupin (2013)
that S. marcescens has mannanase activity and has
shown the highest ratio of the clear zone to the
colony. It by determiner of a clear zone that forms
around the bacterial colony after being incubated.
LBG which is present in the media is broken down
by bacteria as a source of carbon in the metabolic
process. This is because bacteria can break down
galactomannan with the help of the β-mannanase
enzyme complex reaction which produces mannose
and mano-oligosaccharides (Sumardi, 2005). The
enzyme activities of the S. marcescens strain MBC1
showed in Table 2. The enzymes activity were
analyzed using the non-parametric method of
Kruskall Wallis with a significance level of 95%.
The results showed that S. marcescens strain MBC1
had the highest index value on lipase and amylase
activity of 5.52 and 4.17.
Table 2. Results of Kruskal-Wallis Enzyme Test Statistic
Enzymes
Average of Colony
(mm)
Average of Clear Zone (mm)
Enzymatic Index
Lipase 0.33 ± 0.11 2.03 ± 0.32 5.52
Amylase 0.34 ± 0.08 1.79 ± 0.68 4.17
Cellulase 0.33 ± 0.05 0.53 ± 0.05 1.50
Chitinase 1.27 ± 0.15 1.6 ± 0.1 0.27
Mannanase 0.73 ± 0.05 0.44 ± 0.05 0.35
Protease 0.37 ± 0.05 0.6 ± 0.1 0.69
sig Kruskal
Wallis
0.162 0.011 0.025
Enzyme activity was influenced by pH,
temperature, and substrate. Enzymes have an
active site that compatible with the substrate.
Hence, they can form the appropriate substrate
enzymes with maximum results. On the other
hand, unoptimized conditions related to pH and
temperature conditions influenced conformational
change on the enzyme, or even losing its activity
(Irdawati et al., 2020).
S. marcescens strain MBC1 can produce the
hydrolase enzyme, it can be used based on the
needs. Lipase activity had potentially developed
Jurnal Riset Biologi dan Aplikasinya, 3(1): 23-29, March 2021 | 28
for biosurfactant production. Indeed, it often
became a preliminary test to determine
biosurfactant activity (Arifiyanto et al., 2017).
The amylase activity also can catalyze cereal foods
such as wheat and bread (Padmavathi et al., 2018).
Besides, utilization of cellulase, amylase, and
protease enzymes can be utilized in agriculture,
industry, marine, and other sectors (Arifiyanto et
al., 2017).
CONCLUSION
Based on the results, it can be concluded that
S. marcescens strain MBC1 exhibits lipase, amylase,
cellulase, protease, mannanase, and chitinase
activities with the enzymatic index 5.52, 4.17,
1.50, 0.69, 0.35, and 0.27. This enzyme activity of
this isolate can be used as a candidate for
biological control agents, and is used in
biosurfactant producers, industry, or the health
sector
ACKNOWLEDGEMENT
The authors thank to Ms. Oni Mastuti as a
laboratory assistant, who had helped in the
process.
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