Hi Tomas Bata University in Zlín
Centre of Polymer Systems

Doctoral Thesis

Kombucha leather: Preparation and Characterization
Kombucha kuZe: Priprava a charakterizace

Author:

Hau Trung Nguyen, M.Sc

Degree Programme:

P3924 Material Sciences and Engineering

Degree course:

3911V040 Biomaterials and Biocomposites

Supervisor (Tutor):

Assoc. Prof. Nabanita Saha, M.Sc., Ph.D

Consultant:

Prof. Ing. Petr Saha, CSc

Zlin, August 2022

© Hau Trung Nguyen

Published by Tomas Bata University in Zlin in the Edition Doctoral Thesis.
The publication was issued in the year 2022

Key words in Czech: Kombuchova kuze, Veganska huze, Bakterialni celuloza
ziskana z Kombuchy, Bakterialni celuloza, Optimalizace, Navrh experimentu.

Key words: Kombucha

leather,

Vegan

leather, Kombucha-derived bacterial

cellulose, Bacterial cellulose, Optimization, Design of Experimen.

Full text of the doctoral thesis is available in the Library of TBU in Zlin.

ISBN 978-80-.............


CONTENTS
ABSTRACT .ooeecccccccccccceeeeesceceecseseneceseecensseeeesaeensseceeseeenecesnessesseeesiteensseesesaenetees 1
ABSTRAKT..................

SH

Hà HH HH 1H11


1H Hay 3

ACKNOWLEDGEMENT tiss be snoese84opBistRGEESSIEHGHDHSEISSEDLRELSIRHSEEEISS-B99030008888 5
LIST OE/EIGUREHieecsssititetibibbalebaBtSCEGSEHAXEHAE4SENRHIPREDSSERSSSHSRRGAEESRHSER 8
LIST OF TABLES ......ccccceccecccccecceeeseeecsesceeeeeenenseeeeeseeeneeesuecenssieeesisueneseeeeeatatns 10
LIST OF ABBREVIATIONS AND SYMBOLS. .......cccccccscceeeteettneeeeetettees 11
LIST OF PUBLICATIONS....................
c2 HH
He
1. BACKGROUND.................

S1

HH1

13

Ha 15

1.1 Genuine leather and leather Indusfry......................---- ¿2 2c 2212 sscsses 15
1.2 The genuine leather processing and 1ts pollution sources........................ 16
1:3 Kombpucha leäth€fF;::::ississsissssssssitritierioidtitDigtOIGDIED4GSDđL9DEti0053x01s8 20
1.4 The properties and preparation of Kombucha leather............................-- 22
1.5 Bacterial cellulose (BC) and Kombucha-derived bacterial cellulose (KBC)
seeecueseesceeeecaeseveceesessenececseseesceeseciesececeeeesaeeaneseeeesaseeeeseceesesaeesecurcesetieeetieseseseeeetets 24
I9

oi u06 on...


..........

31

1.7 Design of Experiment and optimization of BC/KBC production............ 34
1.8 Modification of BC/KBC hydrophobIeIfV.................
óc các che
38
1.9 Polymers in ]eatheT'DTOCCSSÍTĐ s:xs:ix:z:ii1ss610122121131001114610031010594058515
080100 40
1.10. The combination between BC/KBC and polymers..........................-.--- 45
2. EXPERIMENTATION..........................
các nh HH
HH He
2.1 Mater1aÌS................-

-- - T11 n1 ST

ST 1n

E TT TH KH KH KT

52

key 52


2.1.1 Bio-waste SOUTG€S....................

.


0Q TT HT TH TH ng HT kg kg kh nen rxy 52

2.1.2 Polymers and other chetm1€aÌs...........................---- ¿2-2222 S2E 121 xsrsres 53
2.2 KBC produetion......................--

.- c c 121111121111 111111111111 011111 11 1111818111

tk HH 53

2.2.1 Activation of bacterial SÍTA1H.................
ác cá St nh nh
He

53

2.2.2 Evaluation of KBC production using bio-wasfe sources................... 54
2.2.3 Optimization of KBC production using sour whey wasfe................. 56
2.2.4 KBC production in large containers .........0....ccccccceceeeeteteteeteeteseeeaes 59
2.3 Fabrication of Kombucha leather .......0..0. cc cecceceeteeeeeeeeeeeeneetesetteenteeneens 61
2.3.1

Preparation

of

PCL/PVA/PLA..........

leather-like
St SH


biocomposites
HH

based

HH

on

KBC

11H

and
G1

2.3.2 Preparation of leather-like biocomposites based on KBC and PU/PLA

2.3.3 KBC powders hydrophilie modificatlon..............................
c2 cccccccccsc- 64
2.3.4 Optimization of Kombucha leather preparation using KBC/PU/PLA
¬—

65

2.4 Characterization analysis of BC/KBC and prepared leathers .................. 67
2.4.1 Dry weight of BC/KBC and pH value of the fermentation media.....67
2.4.2 Scanning electrO' HICTOSCODY .....................
0 22 222121121111 1e

67
2.4.3 Fourler transformed Infrared spectrOSCODY.......................à.
cài ceseeằ. 68
2.4.4 Thermal anaÏyS1S....................
2.4.5 X-ray diffraction anaÏyS1S.................

-.-

2c 2212111 111112 11112111181 111111111 111111111 ket 68
..-- c c1

221151151 141111101111 181 ke 69

2.4.6 The water absorption capacIfy of KBC powder...............................c- 70
2.4.7. Surface wettabIlity measureImenifs.....................
..- -- c2: S212 s2 se. 71


2.4.8. Mechanical anaÌVS15......................
-- c. . n2. 2 2S 115111111111 111k et 72
4.4.9. Blodegradation sfUd16S.......................-c 2.1 122 S1 9111111101111 key 72
CN

Bi

cii/.YININỌIaadđdidẳda..

3. MOTTVATION FOR THE DOCTORAL
4. AIMS OF DOCTORAL


STUIDY.........................c.ccccccscsc2 73

THESIS AND BRIEF SUMMARY...................... 74

5, CONCLUDING: REMARKS
Š.]:COTGÌHSIOH¿iieiziinssiipri

73

isnsosnndetoiLBALROGHBSSSERDBSIRGSGGISGGIPGSS0093841S041 95
tua bai dd š8t0Đ ĐÀ ĐA EIHSHSBEUHHSUSEHIERRHIENEHEEĐ4B 95

5.2 Contribution to the SOCI€ẨY.....................-..
22. 2211211211111 HH
nhe 97
h8

0n

ó(OaaaaiđẢÝŸỀẼÝÝẢỶÝÝ..

35084009512 ................
PUBLICATION I
PUBLICATION II
PUBLICATION II
PUBLICATION IV
PUBLICATION V
PUBLICATION VI
CURRICULUM VITAE


98
99


ABSTRACT
Kombucha leather is bacterial cellulose-derived leather developed as vegan
leather possibly well-respond to consumers' expectations regarding safety,
function, aesthetics, social responsibility, reducing pollution emissions of the
leather industry, and also transforming the bio-wastes into useful materials. In
this doctoral thesis, Kombucha leather was prepared via the combination
between polymers and cellulose harvested from kombucha fermentation using
bio-wastes that comprise two basic stages. In Kombucha-derived bacterial
cellulose (KBC) production step, three investigated bio-wastes (sour whey
waste, waste apple juice, brewer's spent grains) all displayed the brilliant
efficiency in cellulose biosynthesis of Komagataeibacter xylinus compared to
traditional kombucha and HS standard media, especially, superiority dry
weight accumulated in trials contaming sour whey waste (12.59 and 12.81
g/L). The fermentation optimization has then achieved an outstanding KBC
dry weight (20.14 + 0.62 g/L) accompanied by maximizing the amount of
treatment-required waste with the optimum formulation of 1000 mL/L sour
whey waste, 87.39 g/L cane sugar, 6 g/L black tea, and 78.91 mL/L bacteria
volume, under 21 cultured days at 30 °C. Applying on the large containers, the
most responsible fermentation batch was obtained at the cultured medium
depths of 0.5 cm and low residual bacteria suspension volume of only 72.31 +
8.74 mL. The characteristics of produced cellulose membranes show no
significant differences for all samples compared to bacterial cellulose from HS
standard medium. In Kombucha leather fabrication phase, leather-like mat
based on KBC/PU/PLA exhibited remarkable mechanical properties compared
to other components. Compressive temperature and time also directly affect
structures and water resistance capacity of the prepared biocomposite.

Especially,
KBC
were
treated
with
dimethyldichlorosilane,
hexadecyltrimethoxysilane,
vinyltriethoxysilane,
and
3aminopropyltriethoxysilane have spectacular improved their hydrophobicity.
This KBC modification also played a vital role in enhancing compatibility or
homogenous blending to provide a stable structure for produced silane-treated
KBC-based leather mat. Ultimately, the ingredient and condition of kombucha
leather preparation were optimized with outstanding values of elastic modulus,
biodegradable and water contact angle respectively reached at 44.07+40.51
N/mm’, 1.3140.04 %, and 94.84+1.59° from optimum leather-like mat


containing KBC (13.74 % w/w), polyurethane elastomer (73.89 % w/w), and
polylactic acid (12.50 % w/w), compressed at 155 °C for 5 min. Its
morphology, chemical structure, thermal stability, mechanical strength, and
biodegradability were characterized and compared to existing commercial
leathers. Basically, the results show a possible response to the essential
requirements of this Kombucha leather that prospective application in
footwear, bags, or interior covering products.
Keywords: Kombucha leather, Vegan leather, Kombucha-derived bacterial
cellulose, Bacterial cellulose, Optimization, Design of Experiment.


ABSTRAKT

Kủše Kombucha Je kủše odvozená z bakteriální celulózy vyvInutá jako
veganská kủše, která mošná dobFe odpovídá ošekáváním spotfebitelủ ohledné
bezpeénosti, funkce, estetiky, spole¢enské odpovédnosti, snizovani emisi
znecisténi kozedélného primyslu a také premény biologického odpadu na
uziteéné materialy. V této dizertaéni praci byla kombuchova kiize piipravena
kombinací polymerủ a celulózy sklizené z fermentace kombuchy pomoci
bioodpadủ, které se skládají ze dvou základních fazi. Ve vyrobnim kroku
bakterialni celul6zy odvozené z Kombuchy (KBC) ti zkoumané biologické
odpady (odpad z kyselé syrovatky, odpadni jableéna Stava, pivovarské mlato)
vSechny
vykazovaly
vynikajici
uéinnost v biosyntéze
celulozy
u
Komagataeibacter xylinus ve srovnani s tradi¢éni kombuchou a standardnimi
médii HS, zeyména vySsi suSina nashromazdéna v testech obsahujicich odpad
z kyselé syrovatky (12,59 a 12,81 g/l). Optimalizace fermentace pak dosahla
vynikajici suché hmotnosti KBC (20,14 + 0,62 g/l) doprovazené maximalizaci
mnošství odpadu potfebného pro upravu s optimalnim sloZenim 1000 ml/1
odpadu kyselé syrovátky, 87,39 ø/1 tfinového cukru, 6 g/l éerného éaje a objem
bakterii 78,91 ml/l, za 21 dnt kultivace pit 30 °C. Pit aplikaci na velké nadoby
byla nejzodpovédnéj8i fermentaténi davka ziskana pri hloubce kulttvaéniho
média 0,5 cm a nizkém objemu suspenze zbytkovych bakterii pouze 72,31 +
8,74 ml. Charakteristiky vyrobených celulózových membrán nevykazuJí zadné
vyznamne rozdily pro vSechny vzorky ve srovnani s bakteriální celulózou ze
standardniho média HS. Ve fazi vyroby ktze Kombucha vykazovala rohoz
podobna ktizi na bazi KBC/PU/PLA pozoruhodné mechanickeé vlastnosti ve
srovnani s jinymi soucastmi. Tlakova teplota a €as také ptimo ovliviiuji
struktury a vodéodolnost piipraveného biokompozitu. Zeyména KBC byly

oSetreny
dimethyldichlorsilanem,
hexadecyltrimethoxysilanem,
vinyltriethoxysilanem
a 3-aminopropyltriethoxysilanem,
které výraznš
zlepSily svou hydrofobnost. Tato modifikace KBC také hrala zasadni roli pri
zlepSovani kompatibility nebo homogenniho smichani, aby poskytla stabilni
strukturu pro tuto kozenou podlozku na bazi KBC oSetfenou silanem. V
konešném đủsledku byly pÝísady a podmínky pFípravy Kủše Kombucha
optimalizovany s vynikajicimi hodnotami modulu pruZnosti, biologické
odbouratelnosti a thlu kontaktu s vodou, v tomto pofadi, dosazenych na 44,07
+ 0,51 N/mm2,

1,31 + 0,04 %, a 94,84 + 1,59°

z optimální rohoše podobné


ktze obsahujici KBC (13,74 % hmotn./hmotn.), polyuretanovy elastomer
(73,89 % hmotn./hmotn.) a kyselinu polymléénou (12,50 % hmotn./hmotn.),
lisované pri 155 °C po dobu 5 minut. Jeji morfologie, chemicka struktura,
tepelna stabilita, mechanicka pevnost a biologickaé odbouratelnost byly
charakterizovany a porovnany se stavajicimi komerénimi usnémi. Vysledky v
zasadé ukazuji mošnou reakci na zakladni pozadavky této Ktze Kombucha
usné, ktera se muze uplatnit v obuvi, ta8kach nebo vyrobky pro pokryti
interiéru.
Kligova

slova:


Kombuchova

kiuze,

Veganska

kuze,

Bakterialni

celuléza

ziskana z Kombuchy, Bakterialni celuloza, Optimalizace, Navrh experimentu.


ACKNOWLEDGEMENT
This dissertation 1s the outcome of a wonderful doctoral study journey with
numerous learning and research opportunities. I would like to express my
heartfelt thanks to all of those who joined me and who help me to complete
this journey so valuable.
First of all, I would

like to present the most honest gratitude to my

supervisor, Assoc. prof. Nabanita Saha, and my consultant, Prof. Ing. Petr
Saha. Without their support, patience, and encouragement, my thesis would
have never been completed. Their close instructions and supervision have been
of critical importance for me to pass plentiful difficulties and stay on track
during


the whole

process.

They

provided

the best conditions

for me

to

continuously develop, learn, research, execute my plans, and were always there
at the critical yunctions of my research. Their guidances are always extremely
valuable in furthering myself as a science researcher.
I would

like

to express

my

deep

thanks


Ngwabebhoh and Dr. Smarak Bandyopadhyay,

to Dr.

Fahanwi

Asabuwa

“my best brothers” at The

Centre of Polymer Systems (CPS), Tomas Bata University in Zlin (TBU). They
gave me their best experience and research skills for biomaterial fabrication,
testing, and analysis. Their support and advice play an important role for me
to finish my problems in the learning, research, and Irving in Czech Republic.
My sincere gratitudes go to Prof. Ivo Kuritka, Prof. Vladimir Sedlarik, Dr.
Nibedita Saha, Dr. Oyunchimeg Zandraa, Dr. Haojie Fei, Dr. Probal Basu, Mr.
Michal

Studeny,

Dr.

Rahul

Patwa,

Dr.

Martina


Pummerova,

Miss.

Klara

Sedlakova, Miss. Martina Dostalova, the Scientists, Teachers, Members and

Students of CPS and UTB. They are great sources of support and inspiration
wherever I come across any trouble both in the study and life. Their sharing


and caring have not created only been pleasant but also knowledge enriching
to my journey in Czech Republic.
My

sincere

thank

to

Prof.

Alina

Sionkowska

and


Prof.

Katarzyna

Lewandowska, who gave me an opportunity to traineeship, and then, directly
guided me

in biomaterial research at their laboratories of the Faculty of

Chemistry of Nicolaus Copernicus University in Torun, Poland.
I also want to express my deep thanks to Tomas Bata University in Zlin
(TBU) for providing me with the necessary infrastructure, scholarship, and
additional financial support which allowed me to concentrate on learning and
research. I would like to bestride my sincere thanks to Kromilk A.S, Kromeriz,

Pivovar Malenovice, Zlin, and Bata shoe company in Dolni, Czech Republic
for giving me the necessary samples for my research investigation to complete
the doctoral thesis work.
My deep gratitude is to express to Industrial University of Ho Chi Minh
City (UH), Vietnam, and my colleagues at Institute of Biotechnology and
Food Technology (IBF) for giving me opportunity to pursue my doctoral study
at TBU

in Zlin, Czech Republic.

I must thankful

to my

colleagues


for

shouldering my tasks during my absence. I would also prefer sincere thanks to
the Teachers of my previous schools and universities.
My family deserves plentiful special words of thanks. The Parent's and
family members increasing teaching and support have been providing me with
a compact ground creating great peace of my mind in the present and further
life. I am deeply indebted for that noble sacrifice. Ultimately, I would like to
indicate my heartfelt gratitude to my wife, Lé Tram Nghia Thu, for her
conscientiousness in taking care of the family during my doctoral study period
to uplift my educational qualification. She is always standing beside me and
providing me with the necessary support to overcome

all challenges. My


profound thanks also go to my two little angels, Nguyén Lé Thao Nguyén (my
daughter) and Nguyén

Trung Nghia

(my

son). Their smiles are precious

motivation and light candles, which lead me through this tough but exciting
and extremely valuable journey to reach the goal.



LIST OF FIGURES
Figure 1 The genuine leather processing and associated material streams [15].
Figure 2 A design of a naturally dyed and waterproof biotechnological leather
from reconstituted bacterial cellulose [30]. ...0...0.cccccccccceceeeeeeeeeteeeeteeneeseeeaes 21
Figure 3 Schematic of (a) graphene/BC was prepared by in situ self-assembly
[31] and (b) KBC biosynthesis apply to bio-based composite as leather-like
I2
Figure

ETEZP
4

...............

Structure

of(a)plan

cellulose

and

(b)bacterial

23

cellulose

of Acetobacter xylimum [41]...0..0. ccc cece cece eee eeeceeeeeeteceeceseeaetaeeaeeeeeeseeeae 25
Figure 5 The life cycle of BC towards sustainable production [38]. ............. 26

Figure 6 BC synthesis and carbon sources metabolism in Komagataeibacter
b5 i00 5210751077

.............

27

Figure 7 BC production process from the pre-treatment of wastes [92]........ 31
Figure 8 Schematic of Kombucha fungus tea production [105]..................... 32
Figure 9 Kombucha fermentation and the influence factors of the optimization
(aunthor2s €labor8iOTiÌiisssssrisst3stittiilg6lisistoiiSDDEEISOSIEISSSSIESESEECISSEESISIES8E233 33
Figure 10 Flowchart of the optim1zation proeess [L2I]............................----- 34
Figure 11 Chemical strueture of baeterial cellulose [74].............................- 38
Figure 12 Chemical strueture of silane compounds.............................- -.-------- 40
†Igure 13 Chemical strueture oŸpoÏyIm€TS.....................
..- c S22 22h 41
Figure 14 Schematic of (a) preparation procedure of split microfiber synthetic
leather [156] and (b) membrane casting with coagulant bath [157]............... 42
Figure 15 Evaluation of KBC production with sour whey waste, waste apple
fruits, and brewed spent graIns (authorˆs elaboraflon)......................-...-..----+- 56
Figure 16 KBC production in large containers (authorˆs elaboration).......... 60


Figure

17 Preparation

of leather-like

biocomposites


based

on KBC

and

PU/PLA (authorˆs elaborafIOT))...................-.--- c 2c 121 1111111211 11111812111
63


LIST OF TABLES
Table

1. Uses, LD

INGUStry [7]...

50, and toxicity of some

chemicals used in the leather

+s4ăằ...ố..

19

Table 2. Properties comparison between plant cellulose and BC [40, 42].....24
Table

3. List


of BC

production

using

the

bio-waste

sources

(author’s

1106500000...
Table

4. List of recent optimization

studies of BC

production

Claboration). 22... 3a...

29

(author’s
36


Table 5 List of recent research about the application of the combination of
BC/KBC and various polymers and their Improved properftIes..................... 47
Table 6. Compositions of formulated media for KBC production [32]. ........ 55
Table 7. Experimental design for the optimization of KBC production [29].58
Table 8. Volume depths of the fermentation mediums in large containers [29].

Table 10. The experimental design for the optimization of Kombucha leather
preparation (unpublished WorK). . . . . . . . . . .

..--. c2 2121 2112111111 1101111281

10

66


LIST OF ABBREVIATIONS AND

SYMBOLS

3-D

3 dimensional

APS

3-aminopropyltriethoxysilane

ASTM


American standards testing methods

BC

Bacterial cellulose

BOD

Biochemical oxygen demand

CCD

Charge coupled devices

COD

Chemical oxygen demand

CZ

Czech Republic

đHạO

distilled water

DCDMS

Dimethyldichlorosilane


DOE

Design of experiment

FTIR

Fourier transform-infrared spectroscopy

HDS

Hexadecyltrimethoxysilane

HS

Hestrin and Schramm medium

LD

Lethal dose

PCL

Polycaprolactone

PEG

Polyethylene glycol

PLA


Polylactic acid

PVA

Polyvinyl alcohol

PVC

Polyvinyl chloride

11


PU

Polyurethane

KBC

Kombucha-derived bacterial cellulose

R&D

Research and Development
Relative humidity

SEM

Scanning electron microscope


TGA

Thermogravimetric analysis

THF

Tetrahydrofuran

VTS

Vinyltriethoxysilane

WAC

Water absorption capacity

WHC

Water holding capacity

XRD

X-ray diffraction

12


LIST OF PUBLICATIONS
Articles (with Jimp, available in Scopus and WoS)

Publication I:

Kombucha-derived

bacterial

cellulose

from

diverse

wastes:

a prudent

leather alternative. Hau Trung Nguyen. Nabanita Saha. Fahanwi Asabuwa
Ngwabebhoh.

Oyunchimeg Zandraa. Tomas

Saha. Petr Saha. Cellulose,

(2021), 28, 14, 9335-9353. dot.org/10.1007/s10570-021-04100-5, Q1, IF
5.044.
Publication I:

Development of novel biocomposites based on the clean production of
microbial cellulose from dairy waste (sour whey). Hau Trung Nguyen,
Fahanwi Asabuwa Ngwabebhoh, Nabanita Saha, Oyunchimeg Zandraa,

Tomas

Saha, Petr Saha. Journal

of Applied Polymer Science,

(2021),

e51433. doi: 10.1002/app.51433, Q2, IF 3.125.
Publication HI:

Preparation and characterization of nonwoven fibrous biocomposites for
footwear components. Fahanwi Asabuwa Ngwabebhoh, Nabanita
Hau

Trung

Lengalova,

Nguyen,
Petr

Urska
Saha.

Vrabié

Brodnjak,

Polymers,


Tomas

Saha,

(2020),

12,

Saha,

Anezka
3061.

doi:10.3390/polym1212301, Q1, IF 4.329.
Publication IV:

Silane

modified

Kombucha

cellulose-based

biocomposite

leather-like

mats: Preparation, optimization, and characterization. Hau Trung Nguyen.

Nabanita Saha. Fahanwi Asabuwa Ngwabebhoh.
13

Oyunchimeg

Zandraa.


Tomas Saha. Petr Saha. Manuscript is submitted to Sustainable Materials
and

Technologies

on 01/04/2022

(present

status

under

review

as on

17/06/2022).
Publication V:

Environmentally


Friendly

and

Characterization.

Nabanita

Saha, Fahanwi

Trung

Nguyen,

Petr

Europe

- Africa 2019,

Saha.

Animal

Free

Leather:

Asabuwa


Fabrication

Ngwabebhoh,

and
Hau

/nternational Polymer Processing Society

Regional

Conference, November

18 — 21, 2019,

Pretoria, South Africa. AIP Conference Proceedings 2289, 020049 (2020);
/>Publication VI:

Leather material with improved ecological parameters. Utility model. CZ,
33149 U1. Fahanwi Asabuwa Ngwabebhoh, Nabanita Saha, Hau Trung
Nguyen,

Tomas

Saha,

Petr

Saha.


Republic (2019).

14

Industrial Property

Office,

Czech


1. BACKGROUND
1.1 Genuine leather and leather industry
Genuine leather is a strong and durable natural material that obtained from
animal skins such as hides similarly bovines, buffaloes, goats, sheep, deer,

alligators, snakes, pigs after the tanning process and chemical treatments to
prevent the mherent

decay.

Genuine

leather processed

unique

properties

notably toughness, corrosion resistance, flexibility, elasticity, breathability,

waterproofness,
materials

and longevity

namely

artificial

[1-3]. Recently, genuine

leather,

synthetic

leather,

leather alternative

leatherette,

imitation

leather, faux leather, bonded leather, pleather, textile leather, or polyurethane

(PU)-leather are constantly growing, have low prices, are easy to be processed,
even can be continuously produced at industrial requirements. Nevertheless,
genuine

leathers


are still a priority chosen

and used

by their exclusive

properties, natural niceness, superior quality, unique aesthetics, and elegant
appearance with the touch of noble [2, 4].
Presently, the leather industry is still a long-standing large industry and
acquiring a significant place in the global economy, even, considered a national
commercial improvement engine, creating jobs, especially in countries with
emerging economies

[4-7]. The leather industry supplied the most widely

traded commodities

in the world in fashion,

accessories,

and

decor

furniture,

covering


footwear,
products,

apparel, bags, auto
as

well

as

new

multifunctional materials such as conductive leather, flame retardant leather,

self-cleaning

leather,

antibacterial

leather,

anti-fouling

leather,

oil-proof

leather, electromagnetic shielding leather, and X-ray shielding leather [3, 7-9].


15