When I was a child I loved to play pirates. How many of you have ever dreamed of leaving for an adventurous journey across the ocean, fighting against thousands of difficulties, such as storms, sharks, giant wawes and… floating islands of plastic. In case you decide to quit everything and turn yourself intoa seaman, be aware that it is easy to run aground on one of the many plastic islands floating on our oceans. An island of plastic deemed being as large as the Iberian Peninsula has been spotted in the Pacific Ocean.
Bioplastics seem to be a nice alternative to plastics derived from petrol, Beware, though, since not all the bioplastics are biodegradable; it depends on the material they are made of. Presently, biodegradable plastics can be made starting from vegetal components, such as corn starch, cellulose and… insects. It sounds incredible, but a group of researchers has perfected a technique to produce plastic from some insect larvae. Professor and researcher Lara Maistrello, an entomologist at the University of Modena-Reggio Emilia, tells us about this unique project named ValoriBio (BioValues).
Q-What is ValoriBio?
R- It’s a pioneering project of circular economy financed by the Emilia-Romagna region, intended to enable the production of completely biodegradable plastics starting from animal organic waste and passing through insects.
Q-Who did take part into this project?
R- The project is a co-operation between public research centres and some private companies. The Centri Interdipartimentali BIOGEST-SITEIA and InterMech, both of the University di Modena-Reggio Emilia, take care of the entomological-agronomical aspect and the mechanical-engineering aspect respectively. The centro SITEIA-Parma of the University of Parma takes care of the chemical issue, while Reggio Emilia Innovazione is in charge of the spreading.
D-How did this project arise?
R-The project stems from the need of Gruppo Amadori (a leading Italian company in the poltry market) to find out a valid alternative to dispose their poultry droppings. Normally, because of the high amount of ammonium, poultry litters with droppings must undergo a special treatment before being disposed, Companies in the sector have to invest large sums of money to dispose droppings. We have found out an economic, clean and ecological solution to this problem: we let insects do the job! In this way, not only can we reduce the costs, but also get high value-added products.
-Q – What kind of insects are used for this project?
R- We use the black soldier fly larvae. These larvae can grow even where a high concentration of ammonium is found, and they can basically feed on any kind of organic matter. Larvae bred on poultry litters and fed on droppings are super-efficient bioconverters; in a very short time they digest and process the organic matter, in order to grow up. When they reach a particular growth stage, called pre-pupa, we collect them.
D-What happens then?
R-We transform larvae into natural plastic material. In order to do that, the chemists of the University of Parma split them to get protein, lipd and chitin, i.e. the most important substances present in their body. The engineers of the University of Modena-Reggio Emilia need protein to produce bioplastics. With it, they have projected moulching films, used in agricolture and gardening to prevent the growth of weeds. They are made of protein, hence they totally degrade. No synthetic or non-degradable substances have been found in them. Hence, in no way they pollute the environment, on the contrary, the moulching films by degrading turn into manure for the soil, adding nitrogen, one of the basic elements for the growth of plants.
Q-How do you use the remaining subastances?
R- Lipid (i.e. fats) could be used as a component for feed or to produce biodiesel. The European Directive CE 999/2001 bans the use of animal protein in animal feed. This directive was adopted after cases of bovine spongiform encephalopathy (BSE) – the so-called mad cow disease- occurred. In my opinion, as far as the poultry farming is concerned, this directive should be updated, and insect meal as a source of food should be permitted. At present, insect meal are only used in fish farming.
Q-What are the main challenges you face when breeding black soldier flies? What about the industrial prospects?
R-We faced three basic problems: how to get a massive mating of adult specimens, how to collect eggs from which larvae come to life, and how to balance nutrient on the substratum where larvae are bred. We had to study the influence of light on the fertility and vitality of adult specimens. Light plays a key role in insect metabolism, and may even change their reproductive rate. We delevoped a LED Lights system that casts particular blue and green lights, able to maximize the egg production.
The main problem was collecting eggs in a practical and quick way. In co-operation with our partner-company Kour Energy srl we developed a pilot plant for the factory farming of black soldier flies. The plant consists of several parts: one bioconverter where larvae grow up, and a space where adults mate and lay eggs. In order to collect the eggs, we had to force females to lay eggs only on one site. By means of a 3D printer we have built plastic cylinders with some discs stacked on each other in order to create some cracks. In the centre of the cylinders we placed a rotten-smelling mixture of natural substances that attracts the females to lay eggs. Each cylinder is removable, and when we open the room we don’t disturb the flies. Then the eggs are collected from the discs and placed into the bioconverter, where larvae start to grow.
Q-Does this process generate waste?
R-Any waste has its proper role. We are even able to re-use the residual substratum after the larvae have grown up. The agronomists of the University of Modena-Reggio Emilia have carried out researches to assess the potentials of this by-product as manure for planting. From the initial results obtained on tomatoes, basil and salads we have discovered that adding this by-product to soil makes the production of vegetables increase like we used chemical manure, but this one is 100% natural.
Q_So it’s just a perfect circular system!
R-Well, not fully circular, actually the field tests carried out on bioplastics proved that they degrade too quickly! We have to work a little harder if we want them to play their part as mouching films.
Thanks a lot to you to Professor Lara Maistrello who talked about this project.