Phân lập và tuyển chọn vi khuẩn lactic có khả năng kháng vi sinh vật gây bội nhiễm mụn trứng cá do sử dụng sản phẩm chứa corticoid tt tiếng anh

MINISTRY EDUCATION AND TRAINING
CAN THO UNIVERSITY

SUMMARY
MAJOR: MICROBIOLOGY
CODE: 9420107

DUONG THI BICH

ISOLATION AND SELECTION OF LACTIC
ACID BACTERIA INHIBITING THE
PROLIFERATION OF ACNE-CAUSING
BACTERIA USING TOPICAL
CORTICOSTEROID

2018


THESIS FULFILLED
AT CANTHO UNIVERSITY

First Supervisor: Assoc, Prof. Nguyen Van Ba
Secondary Supervisor: Assoc, Prof. Huynh Van Ba

Thesis was defended at basis valuattion comittee
Location: Thesis Defend Room, 2nd Floor–
CanTho University Rectorate

at 14 h 00 12/7/2018

Oponent person No 1: Dr. Mai Nguyet Thu Hong

Oponent person No 2: Assoc. Prof. Duong Xuan Chu

For referencing:
Learning Resource Center, Can Tho University
Viet Nam National Library


Literature
1. Duong Thi Bich, Nguyen Van Ba, Huynh Van Ba, 2014.
Presence of Propionibacterium acnes, Staphylococcus
aureus, Staphylococcus epidermidis in patients with acne
using topical corticosteroids. Journal of 108-Clinical
Medicine and Pharmacy, 1 9 (5): 65-70.
2. Duong Thi Bich, Nguyen Van Ba, Huynh Van Ba, 2015.
Isolation and selection off lactic acid bacteria inhibited
capacity of Propionibacterium acnes, Staphylococcus
aureus, Staphylococcus epidermidis in acne patients using
topical. VietNam Medical Journal, 427 (1): 41-45.
3. Duong Thi Bich, Nguyen Van Ba, Huynh Van Ba, 2016.
Inhibited ability of lactic acid bacteria isolated from skin on
acne-causing bacteria. VietNam Medical Journal, 448 (1):
23-27.
4. Nguyen Kim Đong, Duong Thi Bich, Nguyen Chi Toan,
2017. The Estimation method of S-acid lactic the
fermentation products Aloe vera gel by High-Performance
Liquid Chromatography. Jounal of Natrura Science, 126
(1B/2017).


Chapter 1. INTRODUCTION

The necessary of dissertation
.The acne is diseases of sebum folliculitis popular
in skin, especially in sebum-increasing skin like facial,
back and chest areas. Many researches indicated that
acnes relate to four main factors including: the increase
sebum production, abnormal follicular keratinization,
abundant of Propionibacterium acnes (P. acnes), and
production of inflammation. Besides, unsuitable
cosmetic – consuming problems, especially topical
corticoid, impacted seriously on skin such as: more
serious acnes, serious skin problems, decrease of
collagen, and increase of superinfection bacteria.
Nowadays, the treatments of acnes are being applied by
many methods including antibiotics, hormones, and
retinoids. However, those methods have still had some
problems such as resistance of superinfection
microorganisms or side effects on consumers. For this
reason, finding out the new methods for inhibiting
superinfection microorganisms on acnes have been
necessary in order to manage and treat the acnes.
Purpose of dissertation
Selection of lactic acid bacteria inhibiting the
proliferation of acne-causing bacteria using topical
corticoid. The introduces a bio-competitive approach to
acne skin care
Research contents
(1) Evaluating the presences of (P. acnes,
Staphyloccocus aureus (S. aureus), Staphylococcus
epidermidis (S. epidermidis), Demodex) in patients with
acne using topical corticoid. (2) Surveying the

1


antibiotic resistances of acne-causing bacteria and
selection the indicator bacteria (IB) for further study.
(3) Isolation and selection of lactic acid bacteria
inhibiting IB. (4) Surveying the bioactivities of selected
lactic acid bacteria and screening for applying them in
skin care. (5) Using Aloe vera gel as carier substrate to
ferment and apply on skin care .
New contributions of dissertation
- Determination of popular acne-causing bacteria
using topical corticoid and evaluation of antibiotic
resistance of them.
- Looking for the lactic acid bacteria for the
capacity of inhibiting the growth of three kinds of acnecausing bacteria. These lactic acid bacteria can be
produce the antioxidant and moisturizing compounds.
- First step to establish the method to ferment
Aloe vera gel with L. plantarum 05SL3 for-skin care.
Chapter 2. LITERATURE REVIEW
2.1. Acnes overview
Acne is skin inflammation, popular in juvenility
ages with clinical manifestations including whiteheads,
blackheads, pustules (Medical Ministry , 2015). Acnes
usually relate to endogenous and exogenous factors
such as the increase sebum productiona, abnormal
follicular
keratinization,
abundant
of

Propionibacterium acnes (P. acnes), and productin of
inflammation (Tahir, 2010).
2.2. Superinfection bacteria on acnes
Many researchers relating superinfection bacteria on

acnes indicated that P. acnes, S. aureus, S. epidermidis,
and Demodex on acnes accounted for 32%, 45%, 49%,
2


and 75,5%, respectively (Dolenc-Voljc et al., 2005;
Dhillon and Varshney, 2013).
P. acnes is one of skin microbiome, about 105106 cfu/cm2 on sebaceous glands areas such as face,
head, and back, besides about 102 cfu/cm2 on others. P.
acnes can produce enzymes damaging host cells
including sialidase, neuraminidase, lipase, hyaluronan as
well as attract macrophages and dendritic cells
stimulating inflammatory responses (Bru¨ggemann,
2010).
S. aureus is skin and mucosa microbiome
developing well on hand, chest, abdomen, and nose.
Healthy humans containing S. aureus are about 10-35%
usually and 20-75% unusually, respectively. S. aureus
can cause diseases by producing staphylokinase and A
protein inhibiting C3b, C1q and IgG so on. S. aureus
can cause diseases with clinical manifestations such as
pustules, abscesses, skin scabs.
S. epidermidis is skin microbiome inhibiting
inflammatory responses via activities of lipoteichoic
acid (LTA). S. epidermidis is an opportunistic bacteria

on acnes with 6,8-49% (Dhillon and Varshney, 2013).
S. epidermidis can cause diseases via producing
exopolysaccharides, and then forming biological
membranes inhibiting attacks of host’s macrophages
and antibacterial factors, decreasing growth and
mutation of antibiotics – resistant genes, producing
poly-γ-glutamic acid, PNAG/PIA and PSMs protecting
bacteria cells from host’s innate immunity.
Demodex is the mite – sizing parasites among
arthropods in hair follicles located near the noses,
eyebrows, heads, and eyelids. Demodex causes diseases
via making hair follicle lesions, blockage of pores
3


causing inflammations, and create opportunities for
other invasive pathogens like P. acnes và S. aureus
(Tchernev, 2011). Some clinical manifestations include
hair follicles, itching, redness, rough skin, pustules.
2.3. Topical corticoid impacts on acne

Corticoid’s full name is corticosteroid, a
compound owning bioactivities similar as hormone
steroids secreted from the adrenal glands with antiinflammatory and anti-allergy activities. However, the
over-uses of corticosteroid also have many side effects
such as atrophy, thinning of skin, redness or stretch
marks, vasodilatation, collagen depletion, loss of
pigments, severe acnes, skin lesions and opportunities
for pathogens such as S. aureus, P. acnes and Demodex
(Klein et al., 2001).

2.4. Overview of lactic acid bacteria and their
applications in skin care

The term of lactic acid bacteria (LAB) refers to
the group of bacteria that are capable of fermenting
carbohydrates to form lactic acid. LABs have some
characteristics such as Gram - positive; non-spore;
anaerobics or micro - aerobics; rod or sphere forms;
negative catalase test, oxidase and gelatinase.
LABs often grow with nutrient-rich media such as
development on a variety of foods (milk, meat,
vegetables), and some are members of the oral,
intestinal and vaginal microbiota. In the process of
metabolism, LABs can inhibit other microorganisms by
nutrient competition or producing products such as
lactic acid; acetic acid; hydrogen peroxide; carbon
dioxide; bacteriocin; diacetyl; and so on.
LABs are beneficial bacteria and have been
widely applied in a huge of fields including livestock,
fisheries, and food processing. Recently, LABs have
4


been widely applied in medicine such as preventing
diarrhea, improving lactose tolerance, stimulating
immunity system, preventing allergies, reducing cases
of colon cancer, and improving diseases related to
cardiovascular.
In addition, LABs can be used to caring and
protecting skin through immune stimulating features,

inhibition of superinfective bacteria on the skin,
decrease of melanin formation, skin anti-aging,
elasticity and hydration (Chen et al., 2006; Tsai et al.,
2013).
2.5. Overview of Aloe vera and its applications in
cosmetics

Aloe vera grows in temperate and tropical areas.
Aloe vera gel contains 99% of water and other organic
compounds including phenolics such as emodin aloe,
aloe, aloein; organic acids such as saponins and
terpenoids; polysaccharides such as arabinan,
glucuronic acid, galactan, as well as many minerals,
amino acids, vitamins. With these ingredients, aloe vera
gel is used to moisturize, slow down the skin aging
process, be cool and anti-bacteria, anti-fungi.
Moreover, it can treat mild skin infections such as
boils, cysts benign, inflammation. (Nandal and
Bhardway, 2012; Sanghi, 2015) Therefore, aloe vera is
widely used in the cosmetic industry.

5


Chapter 3. METHODOLOGY
3.1. Evaluating the presences of (P. acnes, S.
aureus, S. epidermidis, Demodex) in patients with
acne using topica corticoid.
The purpose is to identify common superinfection
factors in acnes using topical corticoids for subsequent

researches.
Survey period from March - 2013 to October –
2014: Interviews collected informations from acne
patients and sampling specimens for microbiological
examination.
Screening of corticoids in cosmetics by thin-layer
chromatography with standard dexamethasone acetate
and chemical methods.
3.2. Survey of antibiotic resistances of acnecausing bacteria and selection the indicator bacteria
Using Kirby-Bauer agar plating method with,
climdamycin, erythromycin, doxycycline, oxacillin, and
tetracycline, trimethoprim/sulfamethoxazole. Selected
strains with high prevalent and high resistance to
antibiotics were tested, extracted DNA, and identified
by sequencing for bacterial indicator.
3.3. Isolation and selection of LAB strains inhibiting
bacterial indicator

a) Isolating LAB
rice washing water, powdered making waste ,
tofu whey, shaving skin… samples were collected to
ferment during 1-2 days. Using MRS agar medium with
CaCO3 1% for isolating microorganisms. The bacteria
were selected (contain lactic acid dissolving CaCO3)
for morphological and biochemical tests ( Gram stain,
catalase, oxidase, gelatinase testings). LABs were
cultured in liquid MRS with glycerol 20% at -40°C for
coservation.
6

b) Investigating the inhibited ability of IB
1) Well diffusion agar method
Using well diffusion agar method was the
replacement of centrifuged bacteria borth by bacterial
suspension. The inhibition of indicators was determined
by measuring aseptic distances excluding the diameter
of well
2) Inoculating selected LAB into cultured broth
containing IB.
The moving on 1 mL of 2-2,5x105 CFU / mL of
LABs was added into 20 mL of TSB medium
containing 2-2,5x105 CFU/mL of indicating bacteria.
Results were defined by colony -counting method at 2,
6, 12, 24, and 30 hours with formula.

With:
N = Number of bacteria in 1 mL of medium
C = total number of colonies counted on plates
ni = Number of plate count in dilution i
di = dilution factor i
3.4. Survey some biological properties of selected LABs
applied in skin care

a. Testing for bacteriocin production
Using spot method wthi Bacillus coagulans JCM
T
2257 ; Micrococcus leteus NBRC 12708; S. aureus
ATCC 12600T; Pediococus pentosacus JCM 5885 were
IB.

b. Antioxidant activity
The 24 hours - cultured broth of LAB in MRS
medium was centrifuged to remove cells (Dn-Lp), then
diluted to 30%, 50%, 70% and 100%. Assay of
antioxidant activity with DPPH (2.2- Diphenyl-17


picrylhydrazyl) was tested, vitamin C as a control.
Reaction mixtures were measured by Genesys 10S UVVis spectrometer at 517 nm. Antioxidant activity (%)
(average of 3 measurements) was calculated by the
formula:
(ODc − ODt )
HTCO (%) =
 100
ODc
Trong đó:
ODc: Optical density of DPPH and ethanol.
ODt: Optical density of DPPH and LAB.
c. Moisturizing ability
LAB - cultured broth was filtered to remove cells,
and then diluted into 10%, 50% and 100%. 1 mL was
added on 2 mL tubes and incubated at 50 oC, humidity
60% during 96 hours. Each test concentration was
repeated 3 times, control was glyceril 5%, 10% and
water. The results were calculated by the following
formula:

Trong đó:
Rr (%): % moisturising
W0LAB: weight of DN-Lp at 0h

WtLAB weight of DN-Lp at 96h
W0C: weight of water at 0h
WtC: weight of water at 96h
d. The activity of lactic acid production
LAB strains cultured in liquid MRS were
centrifuged removing cells. Lactic acid production was
determined by high performance chromatography
(HPLC) (using US HPLC-1210 and RSpak SH-1011
column) at 75oC, HClO4 3mM as the mobile phase,
flow rate 0.6 mL/min and 2 mL of sample volume.
8


Lactic acid was determined by the BF-5 biosensor
(Japan).
e. Screening on antibiotic resistance for acne
treatment
Using Kirby-Bauer agar plating method with,
climdamycin, erythromycin, doxycycline, oxacillin, and
tetracycline, trimethoprim/sulfamethoxazole
3.5. Fermenting aloe vera gel for skin care
products
3.5.1. Surveying media and conditions biomass
LAB culture
The purpose of experiment was to find a costeffective alternative media of LAB cultured biomass
providing for Aloe vera fermentation.
a. Survey growing time: Bacteria were cultured in
liquid MRS, counted by colony counting method after
2, 6, 12, 24, 30 hours.
b. Survey on the use of carbon sources: LABs

were cultured on TSA with 20% of glucose, lactose,
saccharose, and starch. The growth of bacteria at 37 °C
during 24 hours were observed.
c. Screening on medium compositions and
conditions of biomass
1) Ability using sugar
The experiment was designed according Table
3-1
Bảng 3.1: Composition medium of LAB
Composition
Whey tofu (%)
Glucose (%)
Sacarose (%)
Lactose (%)
KH2PO4 (%)
(NH4)SO4 (%)

MT 1
100
20
0
0
2
2

MT 2
100
0
20
0

2
2

9

MT 3
100
0
0
20
2
2


The experiment consisted of 3 tests, 1 factor and 3
replicate. Control was MRS cultured broth. The
surveying criteria were bacterial biomass after culturing
24 hours.
2) Screening on the ratio of medium components
The experiment was designed according Table 32.
Bảng 3.2: Ratio of LAB culture medium
Composition
Whey tofu (%)
Carbohydrat (%)
KH2PO4 (%)
(NH4)SO4 (%)

level
1
100

15
1,5
1,5

level
2
100
20
2
2

level 3

Variabiity

100
25
2,5
2,5

0
5
0,5
0,5

The experiment consisted of three factors, three
levels and two replications. The surveying criteria were
bacterial biomass after culturing 24 hours.
3) Screening on cultured conditions
The experimental design consisted of two factors

including temperature and pH, three levels of
replication, three replications (Table 3.3). The
surveying criteria were bacterial biomass after culturing
24 hours.
Bảng 3.3: Conditions of growth of LAB
T (oC)
30
37
45

pH
6,5
3
3
3

5,5
3
3
3

7
3
3
3

3.5.2. Fermenting aloe vera gel for skin care
production
a. Sceening the ratio of composition
Fermentation ingredients included FOB aloe vera

gel, vinamilk condensed milk and LAB. The threefactor, three-level, two-replication tests were performed
10


at room temperature (25-30 °C) (Table 3.4). Target
monitoring: pH, LAB, bacterial and sensory (smell,
color, product status).
Bảng 3.4: Ratio of composition fermenting
Composition
Water (%)
Aloe vera Gel (%)

Sweetened condensed milk (%)
LAB (%
pH

1
2
3
25
50
75
50
30
20
1
2
3
1
2

3
6±0,5 6±0,5 6±0,5

b. Screening storage time and temperature
Storage conditions including temperature and time
were screened. The temperatures were investigated at
three levels of 15 °C, 25 °C and 30 °C, three repeated
times. Monitoring indicators: pH, LAB, bacterial
infection, and sensory
Chapter 4. RESULTS AND DISCUSSION
4.1. Evaluating the presences of P. acnes, S.aureus, S.
epidermidis, Demodex in patients with acne using
topical corticoid
During surveying period from March 2013 to
October 2014 at Can Tho Dermatology Hospital with
the total of volunteer patients was 148. The results
showed that disease was popular among 19-25 yearolds. The patiens used topical corticoid were more
popular than others (Corticoid – causing acnes were
53.4%, other products were 39.9%).
The acnes infecting P. acnes, S. epidermidis, S.
aureus, and Demodex were 56.8%, 89.9%, 60.8%, and
8.9%, respectively. The most common bacterial species
were S. epidermidis, P. acnes and S. aureus accounting
for 45.6% (P <0.001) (Figure 4.1). As a result, abuse of
corticoids were given rise to many microorganisms,
making acne worse.
11


Hình 4.1: Ratio of acne-causing bacteria

(SE: S. epidermidis; SA: S. aureus; PA: P. acnes; DE: Demodex)

4.2. Surveying on antibiotic resistance of
superinfection bacteria in corticoid – causing acnes
and selecting IB
The sixty three strains of P. acnes, 70 strains of S.
epidermidis and 44 strains of S. aureus were isolated
from a total of 79 samples using topical corticoid and
antibiotic test. Consequently, P. acnes, S. aureus and S.
pidermidis had a high rate of resistance from 55.6% to
95.4%. Resistance of superinfective bacteria in acnes
had been reported by many domestic and international
studies.
As a result, the 10Sa, 09Se and 46Pa strains were
sequenced showing 10Sa as S. aureus, 09Se as S.
epidermidis and 46Pa as P. acnes. These strains were
selected for the following investigations
4.3. Isolation and selection of LAB inhibiting
IB
4.3.1. Isolation of LAB
A total of 82 LAB isolations from 41 samples
washing water rice, fresh milk, powder water, and
12


microorganisms from skins were identified in Table
4.1.
Bảng 4.1: Characteristics of 82 LAB trains
train
Characteristic

white
whitish
brownish
< 0,5
0,5–1
>1
postive
cocci
bacilli
negative
negative
positive

color
Colony

Size (mm)

Gram
Cell
Catalase
Oxydase
CaCO3

55
22
5
15
53
14

82
25
57
82
82
82

Ratio (%)
67,0
26,9
6,1
18,29
64,63
17,08
100
30,48
69,51
100
100
100

By well diffusion agar method, 25 of 82 LAB strains
showed the inhibited ability to at least one indicator
(Table 4.2).
Bảng 4.2: Ration of LAB the inhibited ability IB
IB

n
25
12

8

P. acnes 46Pa
S.aureus 10Sa
S. epidermidis 09Se

LAB
Ratio (%)
44,64
21,48
14,28

The 05SL3 strain isolated from human skin
without acne showed inhibited three indicators with 8
mm of S. aureus 10Sa and S. epidermidis 09Se as well
as 18 mm of P. acnes 46Pa (Figure 4.2)

a

b

c

Hình 4.2: The ability IB of LAB 05SL3
(a: S. aureus 10Sa; b: S. epidermidis 09Se; c. P. acnes 46Pa)

13


LAB 05SL3 were inoculated into broth of IB,

monitoring microbial density at 2, 6, 12, 24 and 30
hours. Result showed that LAB 05SL3 was able to
reduce 48,6% of S. aureus 10Sa, 47,3% of S.
epidermidis 09Se, and 60,2% of P. acnes 46Pa
compared to control at 30h (P <0.001). Inhibition of
isolated LAB may be because of the ability of
bacteriocin or other inhibiting compound production
such as lactic acid, acetic acid, hydrogen peroxide,
carbon dioxide, etc. (Figure 4.4; 4.5; 4.6). LAB 05SL3
was selected to investigate some of characteristics that
can be applied to skin care.

Hình 4.4: Viable cells of S. aureus 10Sa and LAB 05SL3 in the mixed cultures
as a function of the incubation time

Hình 4.5: Viable cells of S. epidermidis 09Se and LAB 05SL3
in the mixed cultures as a function of the incubation time

14


Hình 3.1: Viable cells of P. acnes 46Pa and LAB 05SL3
in the mixed cultures as a function of the incubation time

The 05SL3 strain was identified as L. plantarum
with rod cells, 2.26x0.61 μm, gram positive (Figure
4.3).

Hình 4.3: Cell of L. plantarum 05SL3
(a. photo Sem at 5.500 lần; b. Gram +)

4.4. Survey of L. plantarum 05SL3 characteristic applied
in skin care

a. The ability of bacteriocin production by spot method
The result showed that L. plantarum 05SL3 could
not produce bacteriocin (Figure 4.7). Thus, the
inhibitory activity of L. plantarum 05SL3 on indicating
bacteria may be caused lactic acid or other active
substances produced during bacterial development.

15


Hình 4.7: Baceriocin test of L. plantarum 05SL3
(A. Pediococus pentosacus JCM 5885; B. Bacillus coagulans JCM 2257T)

b. The production of lactic acid
Kết quả cho thấy L. plantarum 05SL3 sinh acid
lactic cao nhất ở 37 oC là 14,23 g/L với hiệu suất
chuyển hóa glucose là 84%. (Hình 4.8).
The results showed that L. plantarum 05SL3
produced the highest lactic acid at 37 oC of 14.23 g /L
with yield 84%.
80000

05ｓｌ
3-37 - CH2

5 Lactate

Intensity [µV]

60000

40000

3 Glucose

20000

1 Unknown
2 Unknown

6 Acetate
4 Unknown

7 Unknown
8 Unknown

0
0.0

2.0

4.0

6.0

8.0

10.0
Retention Time [min]

12.0

14.0

16.0

18.0

Hình 4.8: HPLC spectrum on the Rspak SH-1011 column of DN-Lp

c. Ability of antioxidant
HTCO's test result at 100% concentration is
86.06%. The IC50 value is 31.85% lower than vitamin
C 1.75 times (IC50 of vitamin C is 18.19 μg/mL).
HTCO of DN-Lp was 1.2 times higher than that of L.
rhamnosus in MRS (HTCO = 71.7%) in the study of
Tsai et al. (2013) (Figure 4.9; 4.10)

16


Hình 4.9: DPPH

radical scavenging activities of DN-Lp

s
Hình 4.10: Viable of IC50 of viatmin C and DN-Lp

d. Ability moisturizing
The moisturizing ability of at 100% of DN-Lp
was 7.61 ± 0.0% equivalent to 5% glycerin (Rr =
7.75%). The 100% of DN-Lp concentration was 1.68
times lower than compared with glycerin 10%, ad 1.37
times lower than that of L. rhamnosus in MRS
(Rr=10.5%) in study of Tsai et al. (2013) (Figure
4.11).

17


Hình 4.11: Moisture retentions

of standard samples and
DN-Lp samples

d. Resistance activity of antibiotics
The Kirby-Bauer agar diffusion method.
Consequently, the L. plantarum 05SL3 strain was
resistant to all of antibiotics used in acne treatment.
This result indicated that bacteria are not destroyed by
antibiotics when using acning skin care (Figure 4.12).

Hình 4.12: Kết quả kháng sinh đồ của L. plantarum 05SL3

Through some biological characteristics, L.
plantarum
05SL3

exhibited
inhibitions
into
superinfective bacteria, antioxidant, moisturisation,
lactic acid production and resistance to various
antibiotics. These are good properties that are needed in
skin care products of L. plantarum 05SL3. Thus,
researches of L. plantarum 05SL3 strain are necessary,
in order to apply the beneficial bacteria into skin care
product.
4.5. Fermenting Aloe vera gel for skin care
a. Design cultured media and conditions of L.
plantarum 05SL3 biomass
Based on the growth time, carbohydrate consuming availability indicated that the growth rate of
L. plantarum 05SL3 reduced after 24 hours in MRS
medium (Figure 4.13). L. plantarum 05SL3 could use
saccarose and coul not use starch. Improvement of
biomass-culturing media included 100% of whey tofu,
20% of saccharose, 2% of potassium and 2% of
18


nitrogen at pH 6.5 and 37 °C. The result, bacterial
biomass in improving media and MRS control were
2.7±0.2 g/L, and 3.9±0.1 g/L (p <0.001), respectively.
This is an improved environment, making use of
available and cheap resources. The improving media
used available and cheap resources that were costly 3.3
times lower than that of MRS (Figure 4.13).

Hình 4.13: Growth of L. plantarum 05SL3

Hình 3.2: Biomass of L. plantarum 05SL3 after 24 h

19


a. Fermentation for skin care
Aloe vera is a potential nutrient and medicinal
properties. It is both suitable for cosmetic industry and
can be fermented by lactic acid bacteria. Thus, Aloe
vera was selected as the raw material fermented by L.
plantarum 05SL3. The compositions and conditions of
fermentation were included 30% of Aloe vera gel, 2%
of sweetened condensed milk, 1% of L. plantarum
05SL3 and stored at 25oC. After 40 days, the products
were still remained a bacterial density of 4.7x108 CFU /
mL (p <0.001).

Hình 4.15: Lp. Gel store at 25 oC after 60 days

The aloe vera gel fermented by L. plantarum
05SL3 (Lp. Gel) irritated mildly the skin and reached
pH of 3.5 (Table 4.3).
Bảng 4.3: Result test Lp. Gel
Object

pH
Lead
Cadimi

Hg
S. aureus
Candida
albicans
Pseudomonas
aeruginosa
Skin irritation

Result
3,5
0,01 ppm
0,002 ppm
0
0
0

Method
SOP/AA/5.4/02/01.00
SOP/AA/5.4/02/01.00
SOP/AA/5.4/02/01.00
TCVN 6972-2001
TCVN 6972-2001

0

TCVN 6972-2001

trivial

TCVN 6972-2001

20


L.plantarum

6

3,77x10 cfu/g

Chapter 5. CONCLUSION AND SUGGESTION
5.1. Conclusion
Though of acne- causing bacteria on the acne
patiens from March 2013 to October 2014 at the Can
Tho Dermatology Hospital, 148 patients volunteered
for the study. The results showed that acnes were
prevalent in the 19-25 age group, accounting for 45.9%.
The acnes using corticoid were 53.4%. Besides. the
infective rate of P. acnes, S. epidermidis, S. aureus,
and Demodex on using topical corticoid were 56.8%,
89.9%, 60.8%, and 8.9%, respectively. Three common
bacterial infections were P. acnes, S. epidermidis, and
S. aureus (45.6%).
All bacterial strains isolated from acnes were
resistant to antibiotics used in acne treatment including
erythromycin,
clindamycin,
doxycycline
and
tetracycline, oxacillin, trimethoprim / sulfamethoxazole

with a tolerance rate from 55.6% to 95%.
A total of 82 LAB strains were isolated from 41
samples of , , ? The selected L. plantarum 05SL3
derived from human skin without acnes could inhibit P.
acnes, S. epidermidis, S. aureus and other strains with
clear-area distances from 18mm, 8mm, 8mm,
respectively. After 30h of incubation, the population of
S. aureus 10Sa, S. epidermidis 09Se, P. acnes 46Pa
was reduced to 48.6%, 47.3% and 60.2% compared
with control, respectively. The
L. plantarum
05SL3 owned characteristics inluding Gram-positive,
rod-shaped, 2.26×0.61 μm, single or short chain,
oxidase and catalase-negative, able to grow at 50oC;
using glucose, lactose, or saccharose for growth, lactic
acid production of 14.23 g / L at 37 oC with yield 84%,
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no bacteriocin , IC50 value of 31.18% in antioxidant,
5% glycerin - equivalent moisturizing activity,
resistance to antibiotics such as tetracycline, oxacillin,
erythromycin, climdamycin, doxycycline, trimethoprim
/ sulfamethoxazole.
L. plantarum 05SL3 biomass could be fermented
in media with whey tofu broth (100%), saccharose
(20%), KH2PO4 (2%) and (NH4) 2SO4 (2%) at pH =
6.5, 37 °C. The biomass was used for 24 hour fermenting aloe vera gel with 30% of Aloe vera gel, 2%
of sweetened condensed milk, 1% of L. plantarum
05SL3 and stored at 25 °C. After 40 days, the products

still remained a bacterial density of 4.7 x 108 CFU /
mL.

5.2. Suggesstion
- Investigating the safety of L. plantarum 05SL3
in advance and conducting skin care tests.
- Researching on optimal conditions and
developing the production process of skin care products
from L. plantarum 05SL3 more effectiveness.

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