BBC News is investigating the changing face of business in Africa, a continent once regarded as a high risk location for investors but now increasingly a place to do business.

Sam Olukoya reports from Lagos where a local entrepreneur is benefiting from a niche in the market - providing portable toilets.

Isaac Durojaiye was sure that his business would succeed

"Years back those who evacuated human waste in Nigeria were ashamed to do the job - they covered their faces so nobody could recognise them.

"But all that is changing now," says Isaac Durojaiye - also known as Otunba Gaddafi - who runs a mobile toilet business called Dignified Mobile Toilets (DMT).

"I named it dignified to show the world that there is dignity in the business," says the former bodyguard whose code name while working in government security circles was Gaddafi.

"There is nothing to be ashamed about human waste, it is a reality - we all have to answer the call of nature."

Confident of success

He started the business in 1992 after observing that there were only about 500 functional public toilets in Nigeria, a country with a population of more than 130m.

The toilets are becoming a familiar sight in Nigeria's major cities

"Even then most of the public toilets were poorly maintained," he says.

Mr Durojaiye says his mobile toilets which are made of high quality plastic materials are available for sale, rent and for leasing. DMT maintains the toilets and its specialized trucks evacuate the human waste twice a week from each toilet.

He recalls that when he set up the business he was confident of success given that with a population of Nigeria's size, there is a huge demand for public toilets.

Social service

The toilets are becoming a familiar sight at densely populated public places like bus stops and motor parks in major Nigerian cities.

"We are performing a major social service as we are eliminating the need for people to defecate in public places," he says.

Each toilet according to him typically serves about 100 people each day for a fee of 20 Nigerian naira per usage.

A typical day's proceeds works out at about $15 which is a fairly good income by Nigerian standards.

And for a fee, businesses can advertise their products on the toilet doors. To date, about 25% of DMT's revenue comes from advertising.

The company is also working on plans to recycle the waste collected to generate bio-gas, electricity and fertilizer for farmers.

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