ISOLATION AND IDENTIFICATION OF MICROORAGNISMS IN CASSAVA MILL EFFLUENT IN THE SOIL

ISOLATION AND IDENTIFICATION OF MICROORAGNISMS IN CASSAVA MILL EFFLUENT IN THE SOIL

Chapter one

INTRODUCTION

Background of the Study

The genus Manihot includes more than 200 species, the most significant of which is Manihotesculent or crantz, also known as cassava, manioc, tapioca, and yucca. Cassava (Manihotesculenta Crantz) is a root tuber crop grown extensively in tropical places around the world (Obohand Akindahunsi, 2003). It is primarily a food crop, with tubers harvested between 7 and 13 months depending on the cultivars sown.

The tubers are high in carbohydrate (85.9%) and low in protein (1.3%), as well as cyanogericglucoside (Nwabueze and Odunsi, 2007). Because of its high carbohydrate content, cassava is a popular food item among low-income people in most tropical nations, particularly Africa and Asia (Desse and Taye 2006).

Cassava is thought to have originated in South America and spread to other parts of Northern America. It was first introduced in the 16th century near Congo river basins. Cassava is a key staple food in sub-Saharan Africa, and it is widely consumed in processed forms.

In West Africa and Nigeria, the crop is mostly consumed as garri, a dry granulated meal derived from fermented cassava (IITA, 1990).

Nigeria is currently the world’s largest producer of cassava, with more cassava being grown and processed for home and international consumption. However, in order to boost cassava’s contribution to poor people’s livelihoods, post-harvest handling, processing, and marketing must be considered.

Both cassava roots and leaves can be eaten, but the roofs are normally more economically important, while in some parts of Africa, the leaves may be more essential than the roofs. Cassava is a major food crop in Africa.

Its significance stems from the fact that its starch-thickened tuberous roots are a vital source of cheap calories, particularly in underdeveloped nations where calories, caloric deficit, and malnutrition are widespread. Humans consume more than two-thirds of the total cassava crop in various forms, with increasing use as a source of ethanol for fuel, energy in animal feed, and starch for industry.

The crops are amenable to both agronomic and genetic development, have a high yield potential under favourable conditions, and outperform other crops under sub-optimal conditions. It is grown widely in numerous nations of Sub-Saharan Africa including Madagascar.

The importance of cassava in food security and nutritional issues has led IITA (International Institute of Tropical Agriculture) and the United Nations Children’s Education Fund (UNICEF) to establish joint household food security and nutrition programs with the goal of extending the benefits of IITA research to African countries through UNICEF’s country social mobilisation development programs (Nweke, 1992).

Africa, one of the world’s top producers, generates around 50 million tonnes of cassava each year (FAO, 1992). The total world cassava consumption is predicted to rise from 172.7 million tonnes to 275 million tonnes between 1993 and 2020, according to worldwide food policy.

Baseline data from the International Food Policy Research Institute (IFPRI). Higher demand and production growth projections place 2020 production at 291 million tonnes (Scott et al., 2000). Traditional garri production involves the discharge of huge amounts of water, hydrocyanic acid, and organic debris in the form of peels and sieves from the pulp as waste products.

Around cassava mills, liquid waste is discharged indiscriminately and allowed to accumulate, resulting in an objectionable stench and ugly scenes (FAO, 2004; Okafor, 2008; Shiadgonareetal, 2009).

The high cyanide level of the effluent poses a considerable threat to both persons and the environment, necessitating laws regarding waste discharge (Akani et al; 2006; Adewoyeet al; 2005).

Kolwanet al. (2006) described soil as the top layer of the earth’s lithosphere, generated from weathered rock and modified by living creatures. Weathering and the colonisation of geological debris by bacteria combine to generate soil (Wiley et al., 2008).

Soil contains multiple layers, with topsoil being the most productive. The biological components of topsoil are primarily soil organisms, particularly microorganisms, which play important roles in the cycling of nitrogen, sulphur, and phosphorus, as well as the decomposition of organic residues, all of which have an impact on global nutrient and carbon cycling.

Pollutants have the biggest influence on topsoils. When effluents are integrated into the soil, they affect the soil itself. When discharged, it is responded with by nutrients and soil microbes, releasing gases into the soil while trapping other breakdown products (Pelczaret al; 1993).