Decolorization of synthetic melanoidins-containing wastewater by a bacterial consortium

Abstract

The presence of melanoidins in molasses wastewater leads to water pollution both due to its dark brown color and its COD contents. In this study, a bacterial consortium isolated from waterfall sediment was tested for its decolorization. The identification of culturable bacteria by 16S rDNA based approach showed that the consortium composed of Klebsiella oxytoca, Serratia mercescens, Citrobacter sp. and unknown bacterium. In the context of academic study, prevention on the difficulties of providing effluent as well as its variations in compositions, several synthetic media prepared with respect to color and COD contents based on analysis of molasses wastewater, i.e., Viandox sauce (13.5% v/v), caramel (30% w/v), beet molasses wastewater (41.5% v/v) and sugarcane molasses wastewater (20% v/v) were used for decolorization using consortium with color removal 9.5, 1.13, 8.02 and 17.5%, respectively, within 2 days. However, Viandox sauce was retained for further study. The effect of initial pH and Viandox concentration on decolorization and growth of bacterial consortium were further determined. The highest decolorization of 18.3% was achieved at pH 4 after 2 day of incubation. Experiments on fresh or used medium and used or fresh bacterial cells, led to conclusion that the limitation of decolorization was due to nutritional deficiency. The effect of aeration on decolorization was also carried out in 2 L laboratory-scale suspended cell bioreactor. The maximum decolorization was 19.3% with aeration at KLa = 2.5836 h -1 (0.1 vvm).

Physicochemical Properties of Sugar Industry and Molasses Based Distillery Effluent and its Effect on Water Quality of River Musamya in Uganda

“…The pH values in this study were in line with the work of other authors [13][14][15] who found the pH of distillery wastewater relatively acidic (3.3 -3.9 and 3.8 -4.5, respectively). The low pH of the distillery effluent is due to the presence of higher concentration of organic acids such as CH3COOH formed during biochemical conversion of highly biodegradable organic matter [16,17] resulting from high BOD and COD loading (Table 3).…”

Microbiological Colourants Removal from Sugar Beet Molasses Vinasse – The Effects of Process Parameters and Vinasse Dilution

“…The exception is the study of Jiranuntipon et al (2008), who attempted to decolourize cane molasses vinasse, sugar beet molasses vinasse, caramel and Viandox sauce. These substances, depending on the variant, accounted for 20%; 41.5%; 30% and 13.5% v/v of culture medium for bacteria consortium obtained from waterfall sediments (pH0=4.0, T=30°C).…”

“…In the work presented in this study the reduction of caramel -coloured component of BMV was also at the lowest level of 6% and, in the case of using a mixed culture of lactic acid bacteria there was even an increase of these compounds in the medium (data not shown). This phenomenon can be explained by the high process temperature, high acidity, high osmotic pressure and high specific gravity caramel (Belitz et al, 2004;Chung et al, 1999;Jiranuntipon al., 2008).…”

“…Jiranuntipon et al (2008) found that the initial pH value is determined by the ability of removing coloured compounds by the bacteria, and they observed the highest decolourization with an initial medium pH of 4.0. Similar conclusions were reached by Ohmomo et al (1988) Sirianuntapiboon et al (2004) observed the highest decolourization of coloured compounds obtained from sugarcane molasses vinasse by acetogenic bacteria under a pH of 6.0.…”

Applications of submerged fermentation for biodegradation and decolourisation of melanoidins by an isolate Alcaligenes denitrificans SAG5

“…(Bharagava et al, 2009); Klebsiella oxytoca, Serratia mercescens and Citrobacter sp. (Jirianuntipon et al, 2008); Pseudomonas aeruginosa PAO1, Stenotrophomonas maltophila, and Proteus mirabilis (Mohana et al, 2007); Bacillus thuringiensis (MTCC 4714), Bacillus brevis (MTCC 4716) and Bacillus sp. (MTCC 6506) (Kumar and Chandra, 2006); Pseudomonas putida, Aeromonas sp.…”