Abstract

INFLUENCE OF VARIOUS LIGHTS ON GROWTH OF PURPLE PHOTOTROPHIC BACTERIA

K. D. Kamble*

ABSTRACT

The purple phototrophic bacteria represent the group of phototrophic bacteria that converts light energy into chemical energy. The pigment responsible for this process is rhodopsin. Environmentally the bacteria play range of roles, few important to mention are nitrification and detoxification. The pigment rhodopsin is being used in artificial retina preparation and in many light sensing computer devices. In order to grow these bacteria in abundant quantities it is essential to optimize their major growth affecting factor i.e. light which too has various wavelengths. Keeping this aspect in view, the effect of major lights like red, blue and yellow was undertaken in this study. Whole cell spectra of the bacteria in these lights were studied. Also the bacterial photosynthetic pigment i.e. rhodopsin was extracted after growing the cells under these lights. It was observed that red light considerably enhanced the growth of phototrophs under study. Moderate growth was observed under yellow light yield whereas, lesser growth was observed in blue light. The phototrophic bacterium characterized through the study belonged to the genera Rhodobacter. The study suggests when abundant cells of purple phototrophic bacteria are required red light gives better growth compared to other lights.

Keywords: Purple phototrophs, influence, light, rhodopsin.