Red pigmented marine bacteria, Pseudoalteromonas rubra strains PS1 and SB14, were isolated from two sampling locations in different ecosystems on Alor Island, Indonesia, and cultured in the laboratory. We analyzed the 16S rRNA gene sequences and examined the pigment composition and found that both strains produced cycloprodigiosin (3), prodigiosin (4), and 2-methyl-3-hexyl-prodiginine (5) as major compounds. In addition, we detected three minor compounds: prodigiosin derivatives 2-methyl-3-propyl prodiginine (1), 2-methyl-3-butyl prodiginine (2), and 2-methyl-3-heptyl-prodiginine (6). To our knowledge, this is the first report that P. rubra synthesizes not only prodigiosin and cycloprodigiosin but also four prodigiosin derivatives that differ in the length of the alkyl chain. The antimicrobial activity of cycloprodigiosin, prodigiosin, and 2-methyl-3-hexyl-prodiginine was examined by a disk-diffusion test against Escherichia coli, Staphylococcus aureus, Salmonella typhi, and Candida albicans. We found that, at a concentration of 20 μg/mL, cycloprodigiosin showed the greatest inhibition (25.1 ± 0.55 mm) against S. aureus.

Health consciousness and the need to maintain immune system have increased the demand for fresh fruit and vegetable juices due to the presence of nutritional benefits including colorful pigments such as chlorophylls, carotenoids, and anthocyanins. Besides providing green, yellow, and red color in fruits and vegetables, these phytochemical compounds play an important role in health maintenance through their antioxidant activity. However, natural pigments have been known to be susceptible to adverse conditions including pH and temperature. Heat treatment is commonly applied in the processing of fresh juices in order to extend shelf-life. Nevertheless, thermal treatments have been reported to cause detrimental impacts on the quality of juices. Thus, non-thermal treatments such as high pressure processing (HPP) and ultraviolet (UV) light have become alternative methods to preserve the juices without high impact on nutritional and sensory characteristics. This review underlines the chlorophyll, carotenoid, and anthocyanin pigments in green, yellow, and red fresh juices obtained from several fruits and vegetables, with the influence of pH and non-thermal treatments (HPP and UV) on the color and stability of pigments in the fresh juices.

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Banana cultivars that are rich in provitamin A carotenoids and other nutrients may offer a potential food source to help alleviate vitamin A deficiencies, particularly in developing countries. The local plantain type banana, Agung Semeru (Musa paradisiaca L.), was investigated, in order to analyse the changes in the compositions of the provitamin A carotenoids and metabolite compounds, including the amino acids, organic acids, and sugars, during the ripening stage as this banana is widely processed for food products in either the unripe, ripe, or overripe stages. The bananas that had reached the desired ripening stages were subjected to high-performance liquid chromatography (HPLC) analysis, and the results indicated that the total provitamin A carotenoid concentrations ranged between 4748.83 μg/100 g dry weight (dw) and 7330.40 μg/100 g dw, with the highest level of vitamin A activity at 457.33±5.18 μg retinol activity equivalents (RAE)/100 g dw. Compared to the Cavendish variety, which is consumed worldwide, the Agung Semeru banana had vitamin A activity that was 40 to 90 times higher, dependent on the stage of ripening. The breakdown of the starch during the ripening stages resulted in an increase of its sugar compounds, such as sucrose, fructose, and glucose, as well as its dominant organic acids, such as malic acid, oxalic acid, and citric acid, which were observed using gas chromatography-mass spectrometry (GC-MS) during the ripening stages. The findings of this study show that the Agung Semeru banana is a promising fruit that could be widely produced as a nutritional and energy food resource, due to its high levels of vitamin A activity and sugars.

Photosynthetic purple bacteria have developed sophisticated processes to adapt their photosynthetic unit towards changes in light illumination in which the cells grow. Some purple bacteria show pronounced modification of their PSU from changing the composition and content of photosynthetic pigments, i.e. carotenoids, to replacing different composition of polypeptides that alter the Q y absorption bands of bacteriochlorophyll. Adjusting the spectrum by shifting spectral band position or tuning absorption intensity of spectral band are keys to collect light energy at specific ecological niches they inhabit. Furthermore photoprotection system will ensure the complex from damage.