ABSTRACT
Citric acid is a ubiquitous intermediate product of metabolism and is found in practically all plants and animals. The aim of the study was to utilize orange peel as biomass for the production of citric acid using A. niger. Samples of orange (Citrus sinensis) peels were obtained from a national citrus processing plant and was processed. The study revealed the presence of Aspergillus niger isolated from soil was able to produce citric acid from dried orange peels. The effect of inoculum concentration on citric acid production from the present study revealed that at 96hrs of incubation the inoculum concentration increased to 0.93g/L of 0.30g/L optical density while yield of citric acid from varying amounts of the fruit peel obtained were 0.42g/L, 0.66g/L, 0.73g/L, 0.81g/L and 1.04g/L respectively. In conclusion the production of citric acid using peels by Aspergillus niger has been reported to be easy, economical and eco-friendly. This method produced fairly high yield of citric acid and also it is an effective waste management method for the production of citric acid in the food and pharmaceutical industries.
TABLE
OF CONTENTS
Title
page i
Certification ii
Dedication iii
Acknowledgement
iv
Table
of contents v
List of
Tables viii
Abstract
ix
CHAPTER ONE
1.0 Introduction
1
1.1
Aim and Objectives 3
1.2
Objectives 3
CHAPTER TWO
2.0
LITERATURE REVIEW 4
2.1
Citric Acid Production by Aspergillus
niger (A. niger) 4
2.1.1 Formation of Citric Acid 4
2.2 Microbial Production of Citric Acid 6
2.4 Citric Acid Production Techniques 8
2.4.1 Submerged Fermentation 10
2.4.2 Surface Fermentation 11
2.4.3 Solid State Fermentation (SSF) 11
2.5 Factors Affecting Citric Acid Production 12
2.5.1 Medium and Its Components 12
2.6 Process parameters 16
CHAPTER THREE
3.0 MATERIALS AND METHODS 19
3.1
Sample Collection 19
3.2
Media to be Used 19
3.3
Microorganisms Used 19
3.4 Citric Acid Production Principle 19
3.4.1 Citric Acid Production Medium 20
3.5 Culturing Aspergilus niger 20
3.5.1 Estimation Citric Acid by
Titrimetric Method 20
CHAPTER
FOUR
4.0 Results
21
CHAPTER FIVE
5.0
Discussion, Conclusion and Recommendation 25
5.1
Discussion 25
5.2
Conclusion 27
5.3
Recommendation
27
References 28
Appendix
LIST
OF TABLES
Table Title Page
1 Macroscopic and Microscopic Features of Fungal Isolate 22
2 Effect of Inoculum
Concentration on Citric acid Production (g/L) 23
3 Yield
of Citric acid from varying amounts of the fruit peel 24
CHAPTER ONE
1.0 INTRODUCTION
Citric acid is a ubiquitous intermediate
product of metabolism and is found in practically all plants and animals (Papagianni,
2019). The widespread presence of citric acid in animal and plant kingdom is
proof of its nontoxic nature and it has high water solubility (Padvi and Pawar,
2011; Ghosh, 2013), biodegradability, palatability and is a product adjudged to
be Generally Recognized As Safe (GRAS) (Nwoba et al, 2012; Bezalwar et
al, 2013). It is a biotechnological and biochemical product which is most
used and produced through fermentation in tones with an annual production of
1.6 million tonnes (Nadeem et al, 2010; Nwoba et al, 2012). About
70% of total citric acid produced is consumed by food industry, 12% by
pharmaceutical industries and the remaining 18% consumed by other industries
(Da Silva et al, 2012).
Its applications citric acid include
acidulation, preservation, anti-oxidation, flavour enhancement, plasticizer and
synergistic agent (Nadeem et al, 2010; Femi-Ola and Atere, 2013;
Bezalwar et al, 2013; Ghosh, 2013). Citric acid can be produced by many
microorganisms and related yeast species (Pawar and Pawar, 2014). At the present
day most citric acid is produced using fungi A. niger (Ali et
al, 2016). The reasons for choosing A. niger over other potential
citric acid producing microorganisms are; its high citric acid productivity at
low pH without secretion of toxic metabolites (Nwoba et al, 2012;
Haider, 2014), ease of handling (Nadeem et al, 2010), and ability to
ferment a variety of cheap raw materials such as brewers spent grain (Femi-Ola
and Atere, 2013), orange peel (Torrado et al, 2011), cotton waste, cane
molasses, bagasse, wheat bran, coffee husk and pumpkin (Majumder et al,
2010; Kareem and Rahman., 2011; Pawar and Pawar., 2014).
Citric acid is an important commercial
product, its global production has reached to 1.7 million
tons per year and its annual increasing
growth rate is 5% (Faisalabad and Faisalabad, 2013). Considerable amounts of
citric acid are required in several industrial processes. Approximately
70% of citric acid produced is used in the
food and beverage industry as pH adjuster, flavor
enhancer, a preservative in processed food
and as an acidulant in drinks (Dhandayuthapani et al,
2013). Pharmaceutical industry consumes 12%
of citric acid to enhance flavors of medicines, as
an acidulant and anti-coagulator, Cosmetic
industry uses citric acid in the composition of different cosmetic products
(Dhillon et al, 2010). Citric acid
has also found other application
such as metal cleaning, electroplating,
fabric dyeing; detergent etc. (Faisalabad and Faisalabad,
2013). Citric acid production can be carried
out by different groups of microorganisms. Although yeast, bacteria and other Aspergillus
species can produce citric acid, Aspergillus niger (A. niger)
remained the organism of choice for
commercial production, due to ease of handling, its ability to ferment a
variety of cheap raw materials and produces more citric acid per time unit
(Kishore
et al, 2013).
A cost reduction in citric acid production
can be achieved by using cheap agricultural wastes
(Rahman, 2013). It is possible to produce
citric acid by bacteria, however, not able to produce
commercially acceptable yields due to the
fact that citric acid is a metabolite of energy metabolism and its accumulation
rises in appreciable amounts only under conditions of drastic
imbalances (Yalcin et al, 2010). The problem in the production of citric acid by yeast
is the simultaneous formation of isocitrate (Show et al, 2015). Recently, a wide range of citric acid production has
been reported in response to different levels of nutrient supplementation under
different articles. A. niger is capable of producing very high levels of
citric acid, about 90% of the theoretical yield from a carbohydrate source. A
high rate of acidogenesis in A. niger is observed only under conditions
of high glycolytic metabolism and can be induced by the addition of an excess
amount of sucrose or other carbohydrates (Ali, 2016). Citric acid accumulation
is known to be stimulated by high sugar concentration suggesting it may be
influenced by osmotic stress (Ali and Haq, 2014).
1.1 AIM AND OBJECTIVES
The aim of this study is to utilize orange
peel as biomass for the production of citric acid using A.
niger.
1.2 OBJECTIVES
1. To determine the effect of inoculum
concentration on citric acid production
2 To yield of citric acid from varying
amounts of orange peels.
3. To isolate and characterize the features
of the fungal isolate
Buyers has the right to create
dispute within seven (7) days of purchase for 100% refund request when
you experience issue with the file received.
Dispute can only be created when
you receive a corrupt file, a wrong file or irregularities in the table of
contents and content of the file you received.
ProjectShelve.com shall either
provide the appropriate file within 48hrs or
send refund excluding your bank transaction charges. Term and
Conditions are applied.
Buyers are expected to confirm
that the material you are paying for is available on our website
ProjectShelve.com and you have selected the right material, you have also gone
through the preliminary pages and it interests you before payment. DO NOT MAKE
BANK PAYMENT IF YOUR TOPIC IS NOT ON THE WEBSITE.
In case of payment for a
material not available on ProjectShelve.com, the management of
ProjectShelve.com has the right to keep your money until you send a topic that
is available on our website within 48 hours.
You cannot change topic after
receiving material of the topic you ordered and paid for.
Login To Comment