The application of natural pigments from bacteria as the colorant in ballpoint and highlighter pen ink has been studied. The scope of this study includes the extraction of violacein and prodigiosin from Chromobacterium violaceum and Serratia marcescens cultures, antimicrobial test for violacein and prodigiosin through disk diffusion and spread plate method, and the application of violacein and prodigiosin in ballpoint and highlighter pen ink formulation. From this study, the extracted violacein and prodigiosin showed antimicrobial activity against Grampositive (S. aureus and B. cereus) and Gram-negative (P. aeruginosa and E. coli) bacteria. Formulation for ballpoint pen ink consists of gum arabic, carrageenan, ethanol, water and pigment. For highlighter pen ink, the ink was formulated using pigment, glycerol and citric acid. Application of violacein produced blue coloured highlighter pen ink while prodigiosin gave pink coloured highlighter pen ink. Violacein and prodigiosin pigment were successfully applied as an alternative to hazardous synthetic pigment in ballpoint and highlighter pen ink formulations
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