The current inclination towards exploiting bacterial pigments for various coloring functions, like food, cloth, painting, cosmetics, pharmaceuticals, plastics etc. is a well-recognized aspect. Nevertheless, the current bacterial pigment productions are not effective to meet their industrial needs. Current research going on world over on bacterial pigments signify that genetic engineering for strain improvement, optimization of bioprocess modelling and utilizing cheap agro-industrial residues as substrates are key developmental strategies to maximize pigment production from bacteria. Incidentally the superior performance characteristics of the bacteria for producing differing colouring compounds and the environmental acceptability of bacterial pigments are very encouraging factors to promote higher pigment production taking advantage of the current developmental strategies. This paper evaluates the current advances in bacterial pigment production, its recovery and wide-ranging scope of its industrial applications and commercial viability.

Synthetic pigments have been utilized in numerous industries including textile, cosmetic, food and pharmaceuticals. However, the drawbacks of these pigments, namely toxicity problems have kindled interest in natural pigments. In view of this, the use of natural pigments such as those from a bacterial origin offers an interesting alternative for industrial application. However, large scale applications of natural pigments are often hindered by the high production cost. This study evaluates the feasibility of using liquid pineapple waste for the production of violacein by a locally isolated Chromobacterium violaceum UTM5 both in a shake flask and a 50 L bioreactor. The use of optimized growth parameters including culture conditions, concentration of liquid pineapple waste and supplementation of L-tryptophan resulted in a violacein yield of 16 256 ± 440 mg L⁻¹. Post treatment of the effluent effectively reduced the COD, turbidity and TSS contents to less than 1 mg L⁻¹, 1.57 ± 0.2 NTU and 2.7 ± 0.6 mg L⁻¹ respectively. The violet pigment exhibited good stability during the entire storage period of 30 days at pH 7, temperature 25–30 °C and under dark conditions. The violet pigment has a good antimicrobial activity against selected microorganisms. Of interest, the pigment was active against Staphylococcus aureus ATCC 29213 and methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300 with a MIC value of 7.8 and 15.6 μg mL⁻¹, respectively. However, the pigment is toxic to the V79-4 Chinese hamster lung cells with low selectivity index. The purified compounds were determined as violacein and deoxyviolacein respectively using FT-IR, LC-MS and NMR. The results confirmed the feasibility of using liquid pineapple waste as a potential low cost growth medium for the large-scale cultivation of violet pigment using C. violaceum UTM5.

A bacterial strain, designated UTM-3^T, isolated from the rhizosphere soil of Artocarpus integer (cempedak) in Malaysia was studied to determine its taxonomic position. Cells were Gram-stain-negative, non-spore-forming rods, devoid of flagella and gliding motility, that formed yellow-pigmented colonies on nutrient agar and contained MK-6 as the predominant menaquinone. Comparative analysis of the 16S rRNA gene sequence of strain UTM-3^T with those of the most closely related species showed that the strain constituted a distinct phyletic line within the genus Chryseobacterium with the highest sequence similarities to Chryseobacterium lactis NCTC 11390^T, Chryseobacterium viscerum 687B-08^T, Chryseobacterium tructae 1084-08^T, Chryseobacterium arthrosphaerae CC-VM-7^T, Chryseobacterium oncorhynchi 701B-08^T, Chryseobacterium vietnamense GIMN1.005^T, Chryseobacterium bernardetii NCTC 13530^T, Chryseobacterium nakagawai NCTC 13529^T, Chryseobacterium gallinarum LMG 27808^T, Chryseobacterium culicis R4-1A^T, Chryseobacterium flavum CW-E2^T, Chryseobacterium aquifrigidense CW9^T, Chryseobacterium ureilyticum CCUG 52546^T, Chryseobacterium indologenes NBRC 14944^T, Chryseobacterium gleum CCUG 14555^T, Chryseobacterium jejuense JS17-8^T, Chryseobacterium oranimense H8^T and Chryseobacterium joostei LMG 18212^T. The major whole-cell fatty acids were iso-C_15 : 0 and iso-C_17 : 1ω9c, followed by summed feature 4 (iso-C_15 : 0 2-OH and/or C_16 : 1ω7t) and iso-C_17 : 0 3-OH, and the polar lipid profile consisted of phosphatidylethanolamine and several unknown lipids. The DNA G+C content strain UTM-3^T was 34.8 mol%. On the basis of the phenotypic and phylogenetic evidence, it is concluded that the isolate represents a novel species of the genus Chryseobacterium , for which the name Chryseobacterium artocarpi sp. nov. is proposed. The type strain is UTM-3^T ( = CECT 8497^T = KCTC 32509^T).