Mesophile

Table 12. Comparison of Methane Fermentation Performance Under High Rate Mesophillic Conditions ...

Desiting on pad roUs is a continuous process with regard to the passage of the fabric, but a hoi ding time of 2—16 h at 20—60°C is required. A mesophilic a-amylase is used before the size is removed in a wash chamber. 

Summation of mesophilic bacteria, fungi, and thermophilic bacteria. CPU = colony-forming units. 

Most waste treatment systems operate in the mesophilic region. The expense of altering the temperature of wastes encountered in abnormally cold or warm environments indicates the desirability of developing organisms which are suited to extremes of ambient waste temperatures. 

Mesophilic bacteria A group of bacteria that grow and thrive in a moderate temperature range between 68 F (20 C) and 113 F (45 C). 

There is an apparent anomaly in that it also states that the preferred combination of temperature and time is a minimum of 121 °C maintained for 15 minutes, which, by definition, equates to an Fq value of 15. The latter, however, is applicable where the material to be sterilized may contain relatively large numbers of thermophilic bacterial spores, and an Fq of 8 is appropriate for a microbiologically validated process where the bioburden is low and the spores likely to be present are those of (the generally more heat sensitive) mesophilic species. 

Childers SE, DR Lovley (2001) Differences in Ee(lll) rednction in the hyperthermophilic archaeon Pyrobacu-lum islandicum, versns mesophilic Fe(Ill)-redncing bacteria. FEMS Microbiol Lett 195 253-258. 

Simon HM, CE Jahn, LT Bergerud, MK Sliwinski, PJ Weimer, DK Willis, RM Goodman (2005) Cultivation of mesophilic soil crenarchaeotes in enrichment cultures from plant roots. Appl Environ Microbiol 71 4751-4760. 

Einster K, E Bak (1993) Complete oxidation of propionate, valerate, succinate, and other organic compounds by newly isolated types of marine, anaerobic, mesophilic. Gram-negative sulfur-reducing eubacteria. Appl Environ Microbiol 59 1452-1460. 

Samain E, HC Dubourguier, G Albagnac (1984) Isolation and characterization of Desulfobulbus elongatus sp. nov. from a mesophilic industrial digester. Syst Appl Microbiol 5 391-401. 

The treatment of sludge contaminated with NPl,2EO and NP by mesophilic and thermophilic aerobic processes has also been studied. Experiments carried out in batch cultures (60°C) and in continuous reactors (55°C) showed that, respectively, only 66% and 40% of the initial NP and NPl,2EO amounts were removed [58, 59]. In contrast, experiments done in continuous reactors under mesophilic temperatures (35°C) showed that these compounds were completely removed [56]. These results are in accordance with previous observations showing that NPEO are more easily transformed in aerobic environments [38]. 

In order to determine more precisely the fate of pharmaceuticals during sludge treatment, different experiments have been conducted in controlled conditions. In continuous anaerobic reactors treating sludge spiked with pharmaceuticals, Carballa et al. [114] observed removals higher than 80% for naproxen, sulfamethoxazole, and roxithromycin, while 40% and 23% of ibuprofen and iopromide, respectively, were eliminated at both mesophilic (37°C) and thermophilic (55°C) temperatures. For diclofenac and diazepam, elimination of about 60% was observed in mesophilic conditions while in thermophilic conditions, 38% and 73% of these two compounds, respectively, were eliminated. In these experiments, the sludge retention time (15 or 30 days) did not seem to influence pharmaceutical removal... 

During the aerobic thermophilic treatment of sludge, ibuprofen and galaxolide were removed, respectively, 95% and more than 75% of initial concentrations after 20 days of incubation. However, even after 45 days incubation no complete elimination was observed [61]. Observations in composted sludge, which is considered to be an aerobic treatment, showed that several pharmaceuticals, including carbamazepine, diphenhydramine, fluoxetine, and triclosan, were not significantly removed by composting at mesophilic or thermophilic temperatures [148]. 

The first-order and fractional power kinetics were also used to describe the behavior of DEHP biodegradation in the thermophilic phase, including the initial mesophilic phases (phase I) and the phase thereafter (phase II), respectively [62]. The fractional power kinetic model parameters, i.e., K and N. were calculated by (l)-(3) and derived from a plot of log (C/Co) versus log(f). The half time (f0.s) of DEHP degradation in phases I and II was calculated using first-order and fractional power kinetic equations (3), respectively. 

The DBT sulfone monooxygenase (TdsA) from Paenibacillus sp. strain All-2 has been isolated and characterized by Konishi et al [162], This enzyme was compared with the mesophilic enzyme dszA from R. erythropolis and found to have very little sequence homology however, had similar properties. The molecular mass of the enzyme TdsA was calculated by gel filtration and found to be 120 KDa, whereas with a subunit molecular mass calculated by SDS-PAGE to be 48 KDa. 

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