Long derided for delivering empty calories in attractive packaging, plastic cola bottles are finally getting a more edifying makeover – as mini planters. This and a host of other projects that marry the best of biotechnology and eco-friendly initiatives, are currently being studied in-depth at Srimad Andavan Arts & Science College in Thiruvanaikovil.
Visitors to the college will be pleasantly surprised to see a considerable stretch of the campus grounds turned over to researching concepts such as ‘bottle-gardens’, which reuse soft drink bottles as hanging pots for both ornamental and edible plants, a mushroom unit that uses substrate material from plant fibres other than paddy hay and the study of zebra fish genome for possible ways to reduce human obesity, besides a biogas project that relies on canteen food waste for raw material.
“Biotechnology studies should have an industrial focus,” says Thirumalai Vasan, head and assistant professor, Postgraduate and Research Department, Srimad Andavan Arts & Science College. “We have tried to base all the projects on market requirements, and we are taking up the reuse of waste products mainly because the success of biotechnology is based on its cost-effectiveness.”
‘Hanging gardens’
The four-month-old bottle garden is a case in point. Thought to be the first of its kind in the city, the project was started to reduce the use of plastic among students. “There are several types of bottle shapes, and we have tried experimenting with vertical and horizontal planters. At present there are around 100 bottles in our patch, but eventually this number will increase as we want to spread the concept across the entire campus,” says Dr. Thirumalai.
The planters, which are perforated on one side, need no more than a fistful of gardening soil, and a minimal amount of watering. “Though we have used only ornamentals like table rose in our pots, it is quite possible to grow spinach and other kitchen vegetables in bottle gardens,” adds Dr. Thirumalai. The project has got the participation of 35 students and 7 staff members.
The possibilities of using bottle gardens as air-purifiers in closed room settings are also endless. “Tulsi (holy basil) is good for oxygen generation, so bottles with this plant can be placed in areas where harmful gases are common (such as laboratories),” says T. Siva Vijayakumar, assistant professor at the department. “Compared to conventional gardening, bottle gardens cost almost next to nothing, and are suited to urban areas where green zones are absent. Even a child can do it.”
Composting
The biotech team has been studying the effectiveness of organic farming from scratch, by starting its own compost production. Vegetable and other edible food waste collected from the college canteen is allowed to decompose in a tumbler bin whose sealed edges help to speed up the rotting process by retaining an even temperature.
“What takes 45 days to decompose in an open compost pit, takes only 30 days in a tumbler,” says Dr. Thirumalai.
A 50-litre tumbler is currently supplying manure for the patches of land where the department is growing greens like chilli, brinjal, tapioca, aloe vera, radish and tomato.
“We sell our produce to our staff members. Students have to do the harvesting, as part of their project, and also as a means of gaining work experience,” says Dr. Siva.
The manure is supplemented with that generated by the vermicompost project undertaken by the Department of Microbiology across the ground.
Biogas
Canteen waste also forms the base material for an in-house biogas project that is expected to be adapted for mass catering in the college kitchen next year. “Usually cow dung is used to generate methane in biogas projects. But as cow dung is in short supply these days, we decided to combine it with the bio-waste from our canteen,” says Dr. Thirumalai.
It takes 10 days for the faculty-made biogas tank to ferment the organic material that will release different gases. Methane, required for cooking, is isolated by allowing the tank’s gases to be released into a bottle of water before it is piped into a cooking station.
“Around 20 kg of waste can get you 2 hours worth of cooking gas,” says Dr. Thirumalai. “We are hoping to shift our canteen catering to biogas in the coming year. At least 100 kg of waste material will be needed to serve a big kitchen’s cooking needs,” he adds.
Mushroom unit
Moving away from the practice of using paddy straw for creating the planting beds, Dr. Thirumalai and his team have opted for a mixed substrate (the surface or material on or from which an organism lives, grows, or obtains its nourishment) in the college’s oyster mushroom unit.
“Mushroom is very high in yield – for a Rs. 20 package of substrate, you can easily get 1 kg of mushroom within 45 days of planting,” says Dr. Thirumalai. “But instead of focusing on just paddy straw, which is getting harder to procure these days, we have started to experiment mixing it with coconut, banana and sugarcane fibre in a 50:50 ratio.”
The mixed substrate costs considerably less than the paddy straw beds.
The project also serves as an income-generator. “Mushrooms can cost up to Rs. 300 per kilo during the wedding season, because of its demand in vegetarian mass catering. Learning how to cultivate this cash crop can be useful to underprivileged students,” says Dr. Thirumalai.
At present the unit has 50 3-kg farming bags which yield a harvest of around a kilo of mushrooms per bag every 20-27 days.
Aquaculture
It has been scientifically proven that 70 per cent of protein-coding human genes are related to genes found in the zebra fish ( Danio rerio ), and 84 per cent of genes known to be associated with human disease have a zebra fish counterpart.
The college biotech team has set up an indigenous aquaculture project to see how obesity could be reduced in human beings by studying the effect of certain parameters on zebra fish.
“We treat the zebra fish with different levels of chemicals, and then see if we can correlate to human experience,” says Dr. Siva. “We are also trying to increase the nutrient value of the ‘jalebi’ fish (Tilapia), which is normally discarded in farm ponds due to its small size, by using natural growth promoters like ‘panchakavya’ (an Ayurvedic product made by fermenting cow dung, urine, milk, curd and ghee),” he adds.
The next step in these and other projects would be to reach out to the public. “We have not teamed with any outside agency on these ideas, but would welcome inputs from experts,” says Dr. Thirumalai. “We can also share the results of our work with anyone who is interested, particularly farmers and self-help groups. We want the students to not just pass exams, but also find a way to become self-sufficient while they are learning.”
