Correlation of microbial mass with ATP and DNA concentrations in acidogenesis of whey permeate

Abstract

In this paper, we examine variations in the contents of ATP and DNA per unit microbial mass in an acidogenesis of whey permeate. We also introduce a novel approach to estimate microbial mass by measuring ATP and DNA when the ratios of ATP and DNA to microbial mass vary. Acidogenic experiments were performed at 35 degrees C and pH 6.0 in batch mode. The amounts of ATP and DNA per unit microbial mass were not consistent during the incubation except during the post-decay phase. Especially within the exponential phase, each showed a 10-fold difference between maximal and minimal values. In this case, the conventional method which converts ATP or DNA concentration into microbial mass using a fixed conversion factor can give inaccurate results. While the constant ratios of 0.74 mg ATP/g VSS and 1.96 mg DNA/g VSS were determined for the post-decay phase, the ATP and DNA concentrations showed strong linear relationships with the microbial mass (r2=0.99) within the ranges of 0.039-1.078 mg ATP/l and 0.075-2.080 mg DNA/l, respectively. The linear regression equations are as follows: (1) microbial mass concentration (mg/l)=478.5xATP concentration (mg/l)+293.5, (2) microbial mass concentration (mg/l)=257.2xDNA concentration (mg/l)+250.4. Therefore, changes in the mass of the acidogenic population should be monitored by the combined use of the regression equations obtained in the exponential phase and the constant ratios determined in the post-decay phase. This procedure should be widely applicable to the acidogenesis of dairy processing wastewaters, especially of a highly suspended organic wastewater such as whey.

Kinetics of Microbial Production of 2, 3-Butanediol from Cheese Whey Using Klebsiella pneumonia

“…Cheese whey has been treated by means of a coagulation-flocculation process by the application of coagulants FeSO 4 , Al 2 (SO 4 ) 3 , and FeCl 3 depending upon operating conditions on the basis of experimental results of sedimentation tank design for the treatment of COD and BOD respectively [8]. However, effluents coming from the coagulation-flocculation pre-stage necessitate half of the time required by the non-pretreated raw [3], [8]- [10].…”

“…In order to reduce the BOD level and acquire useful compounds, the cheese whey can be used as a cheap source of food and energy for the valuable products by microbes [3], [10]- [14]. Biological systems, either aerobic or anaerobic can be used in the treatment of whey based on the microbes used, availability and product formation [2], [3], [12].…”

“…Biological systems, either aerobic or anaerobic can be used in the treatment of whey based on the microbes used, availability and product formation [2], [3], [12]. However, anaerobic digestion offers advantages over aerobic process, especially in the production of toxic products from cheese whey [8]- [10]. Though, aerobic biodegradation of cheese whey achieves a higher degree of the reduction of the main contaminant indicators of COD and BOD compared with anaerobic biodegradation [8], [10].…”

“…However, anaerobic digestion offers advantages over aerobic process, especially in the production of toxic products from cheese whey [8]- [10]. Though, aerobic biodegradation of cheese whey achieves a higher degree of the reduction of the main contaminant indicators of COD and BOD compared with anaerobic biodegradation [8], [10]. A number of options have been proposed to convert permeate to value added products and other more profitable alternatives [1]- [3], [10]- [12], [14], one of which is production of potentially value added chemical 2,3-BD having diverse applications in chemical industries.…”

“…Though, aerobic biodegradation of cheese whey achieves a higher degree of the reduction of the main contaminant indicators of COD and BOD compared with anaerobic biodegradation [8], [10]. A number of options have been proposed to convert permeate to value added products and other more profitable alternatives [1]- [3], [10]- [12], [14], one of which is production of potentially value added chemical 2,3-BD having diverse applications in chemical industries. Many researchers work on the production of 2,3-BD and its immediate precursor has centered around the microorganisms such as Klebsiella oxytoca, Klebsiella pneumonia, Bacillus polymyxa, Enterobacter aerogenes etc.…”