BIOCHEMICAL STUDIES ON SOME MICROORGANISMS

Abstract

This study aimed to prepare yeast autolysates and evaluate their effects as plant promoters in different models including field applications. Also, an attempt was carried out to find a new source of plant promoter from microorganisms. In this study, two yeast (Saccharomyces cerevisae) samples were used: active dry yeast residue and fresh baker's yeast. The following categories were concerned: chemical composition of active dry yeast residue and baker's yeast (moisture, ash, total lipid, total nitrogen, crude protein, true protein, RNA, total carbohydrate, total hydrolysable carbohydrate, total soluble sugars, reducing sugars, non-reducing sugars, free amino acids, vitamin B1, B2 , niacin and B6), chemical composition of yeast autolysate (free amino acids, vitamin B, 2, niacin and B6, and minerals), paper chromatography of nucleobases and its derivatives in yeast autolysate, cytokinin activity of yeast autolysate, it was clearly showed that baker's yeast autolysate contain high amount of cytokinin precursors more than that of the autolysate of active dry yeast residue. The results revealed that the yeast autolysates had no effect on germination percentage of wheat. While in soybean seeds, the obtained data clearly showed that both yeast autolysates possessed promoting effect on seed germination. It was clearly noticed that both yeast autolysates promoted the development and growth of plumules and rootlets for both seedlings. it could be concluded that it was the first time that yeast autolysate applied in plant tissue culture medium and we can be successfully used it, in suitable concentration, instead of cytokinin. In addition, we can be also used yeast autolysate in field as a cheap source of plant growth promoter (cytokinin). Finally baker's yeast autolysate led to significant increase of vegetative growth, flowering and yield of tomato plant.