Converting waste into highly profitable and useful products

Background

A large variety of pathogenic bacteria and fungi cause numerous problems in humans and animals. They also result in huge economic losses such as increased animal mortality (agriculture), waste in production (food) and increasing health costs (hospital bacteria). An example is the spread of COVID-19 in hospitals here in Singapore.

As certain bacteria began to become resistant to oppose commonly used antibiotics, curing the illness caused by the bacteria was less attractive an option compared to killing the bacteria on and around all the people.

A biofilm is a complex aggregation of micro-organisms in a protective and adhesive matrix. Biofilm-dwelling cells display greater tolerance to antimicrobial agents than those that are free (Sanchez- Visuete, et.al., 2015). Such biofilms are usually made up of more pathogens and are in particular more resistant against antibiotics, detergents and biocides. This renders traditional sanitising methods less effective due to the ineffectiveness of removing the biofilm.

Probiotic cleaners

Therefore, probiotic cleaners are able to disinfect through microbial management. By striking a healthy balance between good and bad bacteria, the risk of harmful bacteria will be much smaller. Through the probiotic cleaners, a stable microflora can be achieved, fighting pathogens, with good baceria.

Probiotic cleaners will pro-actively avoid the formation of biofilm by removing proteins, sugars and glycerides which are inputs for the build-up of the biofilm through detergents. Additionally, probiotic cleaners will break down the present active biofilm. After the removal of the biofilm, the surface is kept clean.

After biofilm removal, the probiotic cleaners, which contain enzymes and probiotic bacteria, stabilize the microflora, such that the areas are populated with harmless bacteria, decreasing the risk of development of harmful bacteria. After 3-4 weeks, there was a reduction by 50 to 89% of healthcare-associated infections-related pathogens, and the reduction was stable over time (Vandini et. al., 2014). Thus, microbial cleaning is a more effective and sustainable alternative to chemical cleaning and non-specific disinfection in healthcare facilities.

Currently, one of the probiotic cleaners supplied is the PIP Lite Sanitary by Chrisal S E Asia, which retails at $15.00 SGD for 1.2kg. Per ml, it contains at least 50 million probiotics per ml.

Food waste from the kitchens at Tai Seng provide large amounts of lactose, soluble proteins, lipids and mineral salts, which are substrates for L. plantarum to produce biomass and lactic acid. From biomass, probiotic extraction methods have also been developed and optimized for industrial scale (Enshasy, Elmarzugi, Malek - Academia.edu) using bioreactors. In this semi-industrial process, 8.2 g per litre of cell mass is produced. The possibility of utilising kitchen waste to produce probiotics economically is very high, as after 24h, total count of viable cells reached 2.24x10^10 CFU/g, which was higher than that obtained in any single probiotic strain culture (Yin et. al., 2013). Other than kitchen waste, the use of dried distillers' grains and solubles (DDGs) can be an alternative carbon source (Fochesato et. al., 2018).

Biomass and lactic acid are the most important ingredients for probiotic cleaners. Furthermore, since bacteria multiplies, the production of 1 unit of probiotic cleaner would consume very little biomass.

Cost Advantage

Due to The Good Hub's partnership with Suki Group, the food waste can be obtained at low to virtually no cost, thus with the in-house composting facility, transport costs is minimal. One of the main obstructions of the production of yeast (of which some of its strains are probiotics) is the cost of raw materials. Therefore, efficient and profitable factoryscale processes need to obtain the highest biomass yield with the minimal cost. Economic evaluation of the yeast production process has suggested that the major contributor to the overall cost is the cost of carbon source (Handbook of Industrial Chemistry and Biotechnology, 2007).