Effect of Final Molasses Wastewater Treated with Purple Nonsulfur Bacteria (Rhodobacter sphaeroides) on the Growth and Quality of Spinach

Abstract

This study was conducted to investigate the effect of final molasses wastewater treated with purple nonsulfur bacteria (Rhodobacter sphaeroides) (PTB) on the growth and quality of spinach. More than 1:100 dilution of PTB did not inhibit the germination of spinach seeds. The application of the 1:100 dilution of PTB significantly improved both growth and quality of spinach compared to application of dilution of final molasses wastewater (Pre-PTB) or distilled water. This result showed that the application of PTB was more effective than the application of Pre-PTB. Moreover, the application of PTB tended to increase sugar and ascorbic acid contents of spinach in unsterilized sandy soil rather than in sterilized sandy soil. This suggests that the effect of application of PTB may be influenced by microorganisms in the sandy soil.