33 research outputs found
Evaluation of enzymatic extract with lipase activity of yarrowia lipolytica. an application of data mining for the food industry wastewater treatment
The object of this research was to obtain the Crude Enzymatic Extract (CEE) of Yarrowia lipolytica ATCC 9773, in the medium of 30% Water of Sales (SW) applying a biologically treatment to three different concentrations yeast inoculum food wastewater, collected from cheese and whey production. It was evaluated the behavior of the inoculum in a suitable medium that stimulates lipids biodegradation. The standard liquid-liquid partition method SM 5520 B was used to quantify fat and oil removal for each concentration of yeast, before treatment and post treatment. The Industrial Fat effluent was characterized by physical chemical patterns, and two treatments were evaluated; Treatment 1 consisted of pH 5.0 and treatment 2 with a pH of 6.5, both with the following characteristics; Concentration of inoculum 8% 12% and 16% at 27Â °C temperature and evaluation time 32Â h. The best results (2.702Â mg/L fat and 83% degradation oil) were found to be pH 5.0, 16% concentration and 27Â °C, BOD5, and COD decreased by 43.07% and 44.35%, respectively during the 32Â h; For pH 6.5, 8% concentration at 32Â h and at room temperature, degraded 2.177Â mg/L fat and oil (67% degradation); The BOD5, and COD decreased by 37.93% and 39.19%, in the same time span. The treatment at pH 5.0 inoculum concentration of 16% was effective in removing 83% of the volume of fats and oil in the effluent, representing a useful tool for the wastewater treatment
Hydrolysis and microbial community analyses in two-stage anaerobic digestion of energy crops
Aims: The roles of the diverse populations of micro-organisms responsible for biodegradation of organic matter to form methane and carbon dioxide are rudimentarily understood. To expand the knowledge on links between microbial communities and the rate limiting, hydrolytic stage of two-stage biogas production from energy crops, this study was performed. Methods and Results: The process performance. and microbial communities (as determined by fluorescence in situ hybridization) in two separate two-stage batch digestions of sugar beets and grass/clover were studied. The microbial populations developed in the hydrolytic stage of anaerobic digestion of beets and grass/clover showed very few similarities, despite that the hydrolysis dynamics were similar. In both substrates, the solubilization of organic material was rapid for the first 10 days and accompanied by a build-up of volatile fatty acids (VFAs) and lactate. Between days 10 and 15, VFA and lactate concentrations decreased, as did the solubilization rates. For both substrates, Archaea started to appear in the hydrolytic stage between days 10 and 15, and the fraction of Bacteria decreased. The major bacterial group detected in the leachate fraction for beets was Alphaproteobacteria, whereas for grass/clover it was Firmicutes. The number of cells that bound to probes specifically targeting bacteria with cellulolytic activity was higher in the digestion of grass than in the digestion of beet. Conclusions: This study allowed the identification of the general bacterial groups involved, and the identification of a clear shift in the microbial population when hydrolysis rate became limiting for each of the substrates investigated. Significance and Impact of the Study: The findings from this study could be considered as a first step towards the development of strategies to stimulate hydrolysis further and ultimately increasing the methane production rates and yields from reactor-based digestion of these substrates