BACTERIA AND FUNGI INVOLVED IN YOGURT PRODUCTION
Yogurt sold at the different manufacturers, in Ilorin Kwara State was taken to the laboratory and examined, different bacteria and fungi were found in all the yogurt tested using conventional methods. The implications of these micro organisms were discussed.
TABLE OF CONTENTS
Title page i
Table of contents v
List of tables vi
List of figures vii
1.0 Introduction and literature review
2.0 Materials and method
2.1 Sterilization of apparatus
2.2 Collection of samples
2.3 Preparation of culture media
2.3.1 Nutrient agar (NA)
2.3.2 Potato dextrose agar (PDA)
2.4 Preparation serial dilution
2.4.1 Serial dilution for nutrient agar
2.4.2 Serial dilution for potato dextrose agar
2.5 Bacteria examination and isolation
2.6 Fungi examination and isolation
2.7 gram staining
2.8 Catalyses test
3.1Colonial morphology and biochemical characteristics of bacteria isolate
3.2 Colonial morphology of fungal isolates
3.3 Description and identification of fungi isolates
LIST OF TABLE
Table 1: Colonial morphology of bacterial Isolates
Table 2: Colonial morphology of fungal Isolates
Table 3: Total colony count of bacteria lml (CFU)
Table 3B: Total colony count of fungi lml (CFU)
Table 4A: Distributions of bacterial isolates among sample
Table 4B: Distributions of fungi isolates among sample
Table 5A: Characterizations of bacterial Isolates
Table 5B: Characterizations of fungi Isolates
LIST OF FIGURE
Figure 1: Rhizopus
Figure 2: Aspergillus niger
Figure 3: Saccharonyces
INTRODUCTION AND LITRERATURE REVIEW
Yogurt is a popular and healthy snacks and it has a lot of advantages over fresh milk despite the fact that yogurt is also a bye product of milk. The advantages it has over milk includes
(a) It can’t get perish like milk which get soured when it is not in refrigerator.
(b) It is thicker than milk which makes it easier to store and broadens it cooking.
(c) It gives a lot tangy flavour that people find appealing
(d) It also contain low lactose unlike milk that has high lactose which makes it to be easily digestible for some people that has low lactose tolerance.
The bacterial that helps in converting milk into this yogurt are
(a) Bacterial which are of two strains
(1) LACTOBACILLUS BULGARICUS
(2) STREPTOCCOCCUS THERMOPHILLIUS. Along with bacteria fungi also take part in the formation of yogurt production. These micro organisms were mistakenly added to milk along with a plant like bacteria LACTOBACILLIUS BULGARICUS which is related to the strain of plant dwelling bacteria.
In the process of adding more LACTOBACILLIUS BULGARICUS into the milk produce more yogurt. it was now noted that STREPTOCOCCUS THERMOPHILLIUS has same symbiotic relationship with LACTOBACILLIUS BULGARIUM.
Yogurt is form through the conversion of lactose to lactic acid by LACTOBACILLIUS BULGARIUM so yogurt are made acidic through this process and also makes the milk’s protein thicken and thereby making it viscous. The acidity also prevents colonization from other microbes which aids in preservation.
By breaking down lactose to make the lactic acid the microbes lower the levels of lactose in the yogurt while the presence of STREPTOCOCCUS THERMOPHILLIUS helps to fight along with LACTOBACILLIUS BULGARIUM against any microbes from outside during the early stage of the process <MILLER GD 2000 >.
Originally a simple fermented diary product, yogurt now has many variations and personalities. It can be thin and runny or thick and firm. It can be made from cow milk, goat milk, sheep milk, nut milk, soy milk, rice milk and from numerous other creamy substances.
In some countries the milk of buffalo, horse, yorks or camels is used for most of this discussion, we refer to yogurt in its originally form for fermented dairy milk. This was how yogurt was first developed, and most of the yogurt in the world is made this way. Essential yogurt is the product of beneficial bacteria fermenting milk and turning it into a thickened, acidic food that will stay fresh longer than milk itself, and that contains millions of bacteria that are welcomed by the human gut.
The word yogurt comes from Turkish word meaning to curdle or to thicken. Its probable that the earliest yogurt was made by accident in Mesopotamia around 5,000 BC, when milk producing animal were first domesticated. The milk was, likely stored and transported in bags made from the stomach of these animals, and the digestive juice and bacteria in the stomach livings made the milk coagulated and become acidic. Not only was it a new and interesting food, but the acidity helped to keep it edible for longer than if it had just sat out in a bowl or jar, the acidity of the yogurt helps clean away dirty and rust and also helps clear away dead skin and nourish healthy skin cells. Yogurt was a popular food in the Middle East for thousands of years and has been a staple of the eastern European diet. Its now eaten throughout the world, as a main course, a snack, an ingredient in many recipes and a condiment. It has a gained considerable popularity in America in the last forty or fifty years. Yogurt can be mildly tart or quite sour, and can be thick enough to stand up on a plate, or thin enough to pour or anywhere in between. It contain protein and calcium as well as variety of vitamins. Additionally, the process of yogurt fermentation is very similar to the process of digestion, so it can be easily consumed.
Not only does yogurt contain the same amount of protein and fat as the milk from which it is made, it also contain calcium, riboflavin, vitamin B6, and vitaminB12 while numerous claims have been made regarding the health benefits and digestibility of yogurt.
Hahai (2009)reported that a new type of yogurt prevent gastrointestinal distress; A new yogurt, containing urea’s antibodies, as been shown to prevent helicobacter pylori from binding to stomach walls and causing infection such as gastritis and stomach ulcers. This yogurt is made using vaccine-making technology urea injected into chickens allowed their immune system to produce an antibody to increase called igy-urease. The antibody is then harvested from chickens eggs and made into yogurt containing lactobacillus acidophilus, Bifid bacterium and egg yolk igy-urease. This yogurt is particularly significant in developing countries where standard of care treatment like antacid and antibiotics are either unavailable or unaffordable it is currently available in Japan, Korea, and Tawan, Fleet G.,(1990).
The aim and objectives of this project work, apart from the academic on our part by the independent, is to make the public know different types of microorganism that takes part in yogurt production, to put the mind of the public at rest that not all microorganisms are harmful to human, to give the types, roles, effect and importance of these micro-organisms that involve in the production of yogurt and to produce good personelles..