Biomass removal

False. Batch cultures can convert high proportions of substrates, as growth can be allowed to proceed until substrates are exhausted. In continuous cultures substrates are never fully converted, as medium is continuously removed. In fact, residual substrate concentration increases as the dilution rate increases, until virtually all of the medium remains unused. Continuous cultures usually recycle the medium after biomass removal to increase the efficiency of substrate conversion. 

The culture broth was recovered after 72 h of fermentation, the biomass removed and the total protein content measured. Broth aliquots with a protein content of 1 mg were collected and their pH regulated at different values ranging from 3.5 to 8.0. To each broth fraction, 50 mg of the microspheres sample, previously equilibrated at the corresponding pH, was added and the suspension left under stirring overnight. Then, the microspheres were removed by centrifugation and the protein content and the PG activity were assayed on the resulting supernatant. 

Trace elements can be transported out of arid soils through plant biomass removal and erosion/leaching. Plant biomass removal is through production of food, feedstuff, and fiber plants. Wind erosion is a serious loss of surface soils and trace element outputs from arid and semi-arid soils as discussed in the first chapter. 

Mirex may be removed from Lake Ontario by several mechanisms, including the transport of contaminated suspended particulate material via water outflow into the St. Lawrence River), biomass removal through fishing and migration (e.g. migrating eels contaminated with mirex), volatilization, and photolysis (Comba et al. 1993 Lum et al. 1987). Transport of mirex accumulated in body tissues by eels has been estimated to be 2,270 grams annually or twice the amount of mirex removed by transport of suspended particulates (1,370 grams annually) (Lum et al. 1987). 

After biomass removal has been achieved if appropriate, the main objective of the primary recovery stages is to isolate the product from significant impurities which will generally be in the same phase. At this stage of bioseparation, it is necessary to exploit some difference between the product and impurities such as solubility (in water or an organic solvent), particle size, surface affinity, charge and so on. 

Figure 14. Biomass removal. Effect of media aperture and broth treatment at...

E) Plant phosphorus uptake is dependent on [Psoil- Sorption and desorption of P occur in response to changes in [Pjoi] and [Chum] (Eq. (8)). Increases in microbial biomass remove phosphorus from the soil solution. 

ACTIVATED SLUDGE - An aerobic bioiogical process for conversion of soiubie organic matter to soiid biomass, removable by gravity or filtration. 

Most filtration processes used in large-scale biotechnology should not have the potential to generate microbial aerosols. Filtration columns normally use gravitational forces to separate products from impurities and so are low energy processes. The only potential problem can come in either rotary vacuum filtration or with filter presses if a violent method of biomass removal from the filter is used. Wickramanayake has reported that it is often the practice with filter presses to knock the cell mat of the filter with hammers. This practice has been shown to generate microbial aerosols. 

Changes in alkaloid profile have been detected for L. albus and L. angustifolius cultivars as a response to mechanical damage, such as biomass removal mimicking large herbivore action on aerial parts of the plants [38]. Both sweet and bitter varieties showed an increase in total alkaloids content, but sweet varieties increase is greater than bitter varieties one from 58.8 % to 67.9 % versus from 22 % to 32.8 %, respectively. 

The product may be biomass itself, an organic molecule which is an excreted secondary metabolite or a complex protein which is accumulated within parts of the microbial cells. Consequently there are many ways by which products are extracted and purified. However, water removal, biomass removal and further separations based on chemical and ionic properties are usually employed to produce a crude product which may be further refined and subjected to chemical conditioning before the final product is realized. 

Ares, A., Terry, T, Harrington, C., et al., 2007. Biomass removal, soil compaction, and vegetation control effects on five-year growth of Douglas-fir in coastal Washington. Forest Science 53,600-610. 

The most important application of MFCs is to recover electricity from aqueous organic matter (either S5mthetic or natural wastewaters). A large variety of fuel cell configurations, electrode materials, catholytes and operating modes were developed for a high electricity production and biomass removal. In this section, we will introduce some typical MFCs primarily based on the catholytes used and the operational modes. 

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