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The aim of the current work was to study the influence of stress on pigment production in Monascus purpureus under solid-state fermentation. Thermal stress was induced by incubating the culture at various high temperatures. For giving osmotic stress, different concentration of NaCl and glycerol were added to the solid substrate prior to autoclaving. Morphological studies were done by light microscopy and scanning electron microscopy. When the cells were exposed to high temperature, high glycerol and salt concentration, significant changes in pigment production and growth were observed. High temperature (>45 degrees C) induced the production of more yellow pigments. High concentration of NaCl induced conidiation and caused a decrease in fungal biomass (up to 50%) but red pigment production increased from 11.86 OD/gds to 20.14 OD/gds. When subjected to glycerol stress, a significant increase in aerial mycelia was observed when compared with the control conditions. The results attain significance for exploiting the fungal culture of Monascus purpureus LPB 97 for producing colors of choice--red, or yellow, or increasing the yield of red pigments considerably. Thus, these results could well impact the commercial aspect of Monascus pigments for industrial application.

The capacity to sense and respond to light is widespread in animals, plants, fungi and bacteria. The effect of light quality on growth and pigment yield of Monascus purpureus was investigated. Incubation in total darkness increased red pigment production from 14. 5 OD/ g dry substrate to 22 OD/g dry substrate. In contrast, growth of the fungus in direct illumination resulted in total suppression of pigment production. It was found that both red and blue light influenced pigment yield as well as culture morphology. The authors propose the existence of a light-perception system in Monascus purpureus.

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In vitiligo, the active melanocytes in the epidermis are totally missing, whereas melanoblast cells in the outer root sheath of hair follicles are not affected. In an attempt to find potent repigmenting agents for vitiligo therapy, pod extracts of Cassia occidentalis was found to be effective in inducing differentiation and migration of mouse melanoblast cell line. Methanolic extract redissolved in DMSO at 12.5 μg/ml was found to cause 3.5- to 3.8-fold melanin induction in melb-a melanoblast cells after 4 days in treatment medium. In addition it induced the tyrosinase activity and altered melb-a cell morphology. Transwell migration assay showed the potential of this herbal candidate to induce direct migration of treated cells. To the best of our knowledge, this is the first report investigating the effect of Cassia occidentalis on the differentiation and migration of melanoblast cells. The findings of present study are significant in designing preclinical and clinical studies on the efficacy of C. occidentalis as a stimulant for skin repigmentation in vitiligo.

The aim of this study was to investigate the antimicrobial activity of Bacillus subtilis LS 1-2 grown on citrus juice waste (CJW). Citrus-juice waste (CJW) was obtained from the residue of squeezed citrus fruits. To use CJW as a raw material for the growth of B. sutilitis, a citrus-juice medium (CJM) was prepared by treating CJW with Ca(OH) 2 . No antimicrobial activity was observed either in the culture broth of Luria Broth medium or in CJM itself. The maximum antimicrobial activity was obtained after 24 hr of cultivation (culture) of Bacillus sutilitis LS 1-2 in CJM. The culture supernatant exhibited inhibitory activity against E. coli O-157 (140 AU/mL), Staphylococcus aureus (180 AU/mL), and Candida albicans (260 AU/mL), respectively. Bacillus subtilus LS 1-2 also produced protease (3,600 U/ ml) and amylase (290 U/ml) in CJM. Antimicrobial activity of the culture broth was stable for 1 hr at 100 o C, pH 2-10, and bile acid (concentration needs, 1 mM TDOC and 0.27 mM DOCmM), respectively. These results indicate the potential of CJW as a novel bioresource and the scope of probiotic applications of Bacillus subtilis LS 1-2 in various industrial applications.