The companies say they have already started piloting their technologies for potable water targeting the poor in different countries including Bangladesh with the help of local NGOs and Japan International Cooperation Agency (JICA).
In the bicycle method, Cycoclean, a fully functional bicycle with an additional vertically placed chain and gear is needed.
A water purification system that uses the energy generated by pedalling is attached to the rear seat of the bicycle in a small suitcase-like box.
"Only by a minute it can purify up to 5 litres of water, which is more than the average human drink in a day," said Nippon Basic Co President Yuichi Katsuura, who invented the technique.
He said his invention is not only 'great for long-distance bike rides', but could save lives of millions in remote villages and disaster zones of the world where clean drinking water sources are limited.
Japan's public broadcaster NHK termed it a 'remarkable simple device' that purifies water in Japan's tap water safety standard.
Katsuura, who started the company with 33 million Yen paid-up capital, said the cycle carries three filters with the system.
First filter removes suspended small particles of water while second one with activated carbon removes odour of water and also absorb substances and chemicals.
Then it goes to the 'key' filter with a stainless steel pipe before running out through tap.
"It (the third one) filters bacteria by its special hollow membrane that do not allow larger than 0.1 micron particles. The sizes of bacteria like Escherichia coli are usually 0.3 micron."
The whole system runs after switching from the cycling mode to water purifying mode when the vertical chain rotates by pedalling.
"A user can produce drinking water by pedalling a bicycle. Water sources can be rivers, ponds and swimming pools," Katsuura said during a visit on Wednesday.
He said they aimed at the business for the poor who do not have access to clean drinking water.
The price of the whole system including the specially-made bicycle is $7,000 in Japan, where people in city suburbs use it.
"We've set up a factory in Dhaka where we can make the whole system at half the cost in Japanese," Katsuura said.
"But even then it will not be affordable for the poor. It's pricey because of the third filter and special chain and gear."
"If someone buy the system and sell water, the problem can be solved," he said.
He said they would tie up with BRAC to spread the device in rural Bangladesh.
Katsuura said the system cannot purify seawater or water with salinity, a problem that part of southern Bangladeshi people face.
To purify saline water they have invented another gasoline-run machine named Desaliclean.
"Bicycle can exert 0.1 mega Pascal pressure while for making salt water drinkable it needs 5 mega Pascal pressure," the inventor said.
"But both the techniques are convenient for the non-electrified areas as none of the systems require electricity."
Another company founded by scientist Dr Kanetoshi Oda that invented Flocculant, an agent clarifying water by extracting ingredient from Natto, also started piloting in southern Bangladesh's Barguna district.
He said it can clean as much as 10 tonnes of water in an hour.
During a visit on Monday, he demonstrated how suspended particles of dirty water settled down within a minute of adding the power.
"This water can be drinkable after sand filtration," he said.
The scientist said it took eight hours for him to develop Flocculant, which is used mainly to purify pond water. "It cleans ponds as large as a soccer field in only a day."
He said their main target is to work with slum people. "They will get pure water and at the same time can own the business."
"It's very cheap. Everyone can buy it. Those who cannot read also can use it as there is no strict level to add it in water. It's safe to use at any level."
Kanetoshi said 1,000 litres of water can be purified only by $2 powder.
But, he said, for killing germs in water for countries like Bangladesh, they are using an ultraviolet systems system.
The United Nations estimates suggest about 1 billion people do not have access to pure drinking water in the world while Unicef says thousands of children die due to drinking of unsafe water.