Indian Journal of Experimental Biology Vol. 55, July 2017, pp. 441-447 Production of bacterial pigments in low cost medium and formulation of biodegradable ink Chidambaram Kulandaisamy Venil, Mohamad Ainuddin Bin Wahidin, Claira Arul Aruldass & Wan Azlina Ahmad* Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Skudai, Johor Bahru, Malaysia Received 03 January 2017; revised 31 March 2017 Bacterial pigment production is an emerging field of research for its wide potential industrial applications. Prodigiosin (Serratia marcescens UTM1) and violacein (Chromobacterium violaceum UTM5) are such pigments which possess several biological properties and and have gained increasing importance in industrial markets such as drugs, cosmetics, textile dyeing, etc. The present study demonstrates the use of low cost medium for growth of locally isolated red, violet pigment producing bacteria and their application as biodegradable ink on plastic materials. The natural inks were successfully formulated using polyvinyl butyral, ethyl acetate, methyl ethyl ketone, and applied on plastic materials. They were able to withstand heat up to 60°C and showed no damage to plastic material during physical contact. The hue and chroma values showed the formulated natural inks falls within the red and violet colour. The results have shown that the bacterial pigments act as natural colourants and have great potential as biodegradable inks. Keywords: Chromobacterium violaceum, Dyes, Ink formulation, Natural colourants, Prodigiosin, Serratia marcescens, Textile dyeing, Violacein The prolonged use of synthetic dyes has many concerns viz., allergy and toxicity to humans, hazardous waste generation, disposal related environmental issues and economic challenge 1 . Awareness on safety and environmental protection have fostered fresh enthusiasm for natural colourants which accordingly reflected its annual growth rate @7 % with a turnover of US $ 0.66 billion 2 . The Global Industry Analyst reported that the demand for organic and natural colourants is expected to reach almost 10 million tons by 2017 3 . Industrial production of natural colourants by microbial fermentation has several advantages such as easy propagation, faster fermentation, simple extraction and no seasonal variations 4 . However, to increase the production of bacterial pigments from low cost substrate for economical viability is a challenging task. The red pigment, prodigiosin from Serratia marcescens has a wide range of biological activities, such as antibacterial, antifungal and immunosuppressive agents 5,6 . Similarly, the violet pigment, violacein from Chromobacterium violaceum has exhibited cytotoxic, antileishmanial, antiulcerogenic and antitumoral activities 7-9 . Apart from pharmacological applications, the red and violet pigments are used in dyeing natural fibres 10 . The market of natural colourants has grown intensely in the recent years for their increased use in more and more products, and thereby providing opportunity to explore bacteria as a sustainable source of natural colourants 1 . In this study, we explored the possibility of producing the red and violet pigments from Serratia marcescens UTM1 and Chromobacterium violaceum UTM5, respectively using low cost medium and incorporate the pigments in the biodegradable ink formulation. Evaluation on the performance of formulated biodegradable ink was also carried out. Materials and Methods The red pigment producing bacterium, Serratia marcescens UTM1 isolated from an oxidation pond located at Universiti Teknologi Malaysia, Johor, Malaysia 10 and violet pigment producing bacterium i.e., Chromobacterium violaceum UTM5, isolated from the soil sample collected from the vicinity of a wastewater treatment plant in one oil refinery premise in Negeri Sembilan, Malaysia was used in this study 11 . The culture was grown and maintained by regular sub-culturing in nutrient broth NB (8 g/L, Merck, Germany). ——————— *Correspondence: E-mail: azlina@kimia.fs.utm.my