ISOLATION AND CHARACTERIZATION OF MICRO-ORGANISMS

INTRODUCTION

1.1 BACKGROUND OF THE STUDY
Cereals have been known to man from the earliest times porridge prepared from cereals are eaten in different parts o the world, especially in developing countries where they may present the basic diet. This porridge could be baked to enhance the taste, quality and improve digestibility (Oke 1967, Adeniyi and Potter 1978, Uno and field 1981).
Corn (zea mays) is one of cereals which is an important raw material in human diet. In Nigeria, maize is grown mainly in the southern part of Nigeria while sorghum (Sorghum bicolor) and millet (perinisetum typhoideum) are grown in the northern part of the country. A fermented cereal product is known as paplogi). Corn is processed into traditional food such as paplogi) Umo and fields 1981).
Pap is a fermented non-alcoholic starchy food and is a major staple food widely consumed in west Africa. It is a sour fine past beverage which when cooked produces a thin semi solid porridge. Pap (Ogi) porridge has a smooth texture and a sour taste resembling that of yoghurt,. In Nigeria, some states such as Anambra, Imo, Enugu and Abia refer to it as Akamu but Ogi is a Yoruba name but most state of Nigeria, it refers to maize pap. On the other hand, sorghum pap is known as Ogi baba while millet pap is known as Ogi gero in Yoruba (Banigi 1977, Onyekwere and Akinrele 1977).
Pap logi) can be consumed with variety of other product including with bread, steamed been cake (moi-moi), fried bean cake (Akara), fried yam and plantain etc. it is used as a main meal for adult and sick patients and it is suitable for breakfast, lunch and dinner. Pap is widely used as the first native food given to babies at wearing to supplement breast milk and is a major breakfast cereal for pre-school children and adults. It is consumed as a main meal for convalescing patients because it can easily be digested. As a wearing food, it is utilized mainly by low income earners category, it is estimated that about 25 million or more adults eat it about 4-5 days weakly (Banigo 1972). Milk and sugar may be added to improved the taske and nutritional quality. Pap is cooked and turned into a stiff gel called Agidi which is similar to kenkey, a fermented shanian product (Muller 1988, withby 1968). Some Yoruba indigens beliwved that pap is capable of stimulating the production of breast milk in Nursing mother (Bassir 1962). However, there has been no qualitative evidence of support of this belief.
In spite of it’s important in the Nigeria diet, pap manufacture is essential a home based industry. There are at present no large scale factory operation for the production of pap. The manufacture is carried out on a small scale by some house wives as a commercial venture in many parts of the country. The cleaned grain free of dirt and impurities steeped in eastern ware, plastic or enamel pot for 1-3 days at room temperature, this is followed by wet milling and sieving. Twenty-four (24) hours of sleeping leads to a greater depletion of the fermentable carbohydrate. After sieving, the coarse material obtained is wash with water to separate more of the starch. The filtered slurry is allowed to sediment and undergo further fermentation for 1-2 days at room temperature. The coarse matter which is separated is used ad animal feed while the sediment (Pap) is boiled to obtain.

1.2 STATEMENT OF PROBLEM
Microorganisms are involved in the processing of pap especially during fermentation and equally during storage. Few organisms are found in the pap, if it is properly stored. Their presence in pap during storage leads to irregular of flavour and loss of nutrients (van veen and steinkrans 1990). This is the result of their metabolic activity in the stored pap.
The tradiitonal method of pap production using various grains encourage significant nutrient losses, Losses m,ay occur during steeping, milling and sieving. Large parts of the protein in the grain is located in the testa and germ that are shifted off during processing.
Losses of fibre, protein, ash as well as some vitamins have been reported by Banigo and Muller (1972). Losses in nutrients could be minimized by using an improved wet milling method devised by Banigo and Muller (1972). At the end of this work, the microorganisms found in stored pap was isolated and characterized.

1.3 AIM AND OBJECTIVES OF THE STDU
The aim of this study is to isolate and characterize micro-organisms from stored pap.
SPECIFIC OBJECTIVES ARE
i. To isolate and characterize bacterial contaminants from stored pap
ii. To isolate and characterize fungal contaminants from stored pap

1.4 HYPOTHESIS
HI: Bacteria and fungi are involved in the fermentation and storage of maize pap.

1.5 JUSTIFICATION OF THE STUDY
Not very much work has been done in this in recent times, with reference to the microbiology of the process. Some of the earliest workdone in this include those of Akiurele (1970-1977) and Barigo (1969, 1970, 1972, 1977).

1.6 SIGNIFICANCE OF STUDY
Pap stored improperly for a relatively length of time is likely to develop microorganisms. Therefore, the study is carried-out to identify this organisms and properly advice on the proper way of storing pap.

1.7 LIMITATION OF THE STUDY
This work is limited to viable microorganism present in the corn (zea mays) only which will be purchased from Ogbete in the Enugu Area.